فهرست مطالب

  • سال یازدهم شماره 4 (زمستان 1398)
  • تاریخ انتشار: 1398/12/10
  • تعداد عناوین: 22
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  • مجیدرضا کیانی، علیرضا کوچکی*، مهدی نصیری محلاتی، احمد زارع فیض آبادی صفحات 1183-1203

    به منظور بررسی وضعیت فشرده سازی و روند تغییرات آن در کشاورزی ایران 63 متغیر در قالب شش گروه کاربری اراضی، تولید، کارآیی مصرف، ورودی‏ها (نهاده، ماشین آلات)، انرژی و جمعیت برای دوره 50 ساله 1341 تا 1390 مورد بررسی قرار گرفت. تغییرات کاربری اراضی، افزایش مصرف نهاده‏ها و افزایش جمعیت به عنوان عوامل موثر در افزایش فشرده سازی تعیین شدند. برای تعیین ثبات سطح زیر کشت، تولید و عملکرد، ضریب تغییرات این متغیر‏ها در پنج دهه برای محصولات مهم زراعی و باغی به طور مجزا محاسبه شد و روند تغییرات این ضرایب به عنوان شاخصی برای ثبات تعیین شد. برای تعیین میزان حساسیت به تغییرات محیطی نسبت عملکرد هر محصول در هر سال به میانگین عملکرد محصول در بازه‏های 10 ساله به طور مجزا برای هر گیاه و برای همه محصولات به عنوان ظرفیت عملکرد محاسبه شد، شیب خط رگرسیون بین ظرفیت عملکرد هر محصول با میانگین ظرفیت عملکرد همه محصولات بیانگر میزان حساسیت آن محصول به تغییرات محیطی است. نتایج نشان داد که در طی مدت 50 سال سطح زیر کشت از حدود 6/6 به 3/13 میلیون هکتار و تولید محصولات کشاورزی از 11 به 94 میلیون تن افزایش یافته و در همین حال ضریب تغییرات سطح زیر کشت و تولید کاسته شد همبستگی منفی و معنی دار 47/0- و 89/0- به ترتیب بین ضرایب تغییرات سطح زیر کشت و تولید در دهه های مختلف نشان دهنده افزایش ثبات تولید بود. شاخص حساسیت به تغییرات محیطی مربوط به ذرت (Zea mays L.)، گندم (.Triticum aestivum L(و جو (.Hordeum vulgare L (به ترتیب برابر با 59/1، 99/0 و 93/0 بود که نشان دهنده پایین تر بودن ثبات عملکرد در محصولات اصلی است. تجزیه به مولفه‏های اصلی 63 متغیر، دو الگوی اصلی در تغییرات گروه‏ها را نشان داد. دسته اول با توصیف 51 درصد نشان‏دهنده افزایش فشرده‏سازی در قالب تغییر کاربری اراضی زراعی، تغییرات تولید و عملکرد و افزایش مصرف نهاده‏ها در طی 50 سال گذشته بود و مولفه دوم با توصیف 20 درصد از تغییرات بیانگر تغییرات مهمی در کشاورزی ایران شامل تغییر کارآیی مصرف نهاده و رشد جمعیت بود. در طی 50 سال گذشته شاخص های مرتبط با فشرده سازی نظیر سطح زیر کشت با دو برابر شدن از 6/6 به 13 میلیون هکتار، مصرف کود های شیمیایی با 35 برابر شدن از هفت به 250 کیلوگرم در هکتار، و تعداد تراکتور با 700 برابر شدن از 800 به 565 هزار عدد افزایش یافته است و کارآیی مصرف نهاده ها 300 درصد کاهش یافته و در مجموع نشان می دهد که کشاورزی ایران در طی دهه های گذشته فشرده تر شده و در عین حال ثبات عملکرد کاهش یافته است.

    کلیدواژگان: شاخص محیطی، ظرفیت عملکرد، مدل سازی
  • فرزاد مندنی*، کیانوش خانی، سعید جلالی هنرمند، محسن سعیدی صفحات 1205-1224

    این تحقیق با هدف بررسی نقش باکتری های تقویت کننده رشد بر برخی از مهم ترین ویژگی های بوم شناختی فیزیولوژیک سویا (Glycine max L.) تحت رژیم های مختلف رطوبتی به صورت کرت های خرد شده فاکتوریل در قالب طرح بلوک های کامل تصادفی در مزرعه تحقیقاتی پردیس کشاورزی و منابع طبیعی دانشگاه رازی با سه تکرار در سال 1396 اجرا شد. تیمارهای آزمایش شامل رژیم های مختلف رطوبتی (I1: قطع آبیاری از مرحله پرشدن دانه ها تا انتهای دوره رشد، I2: قطع آبیاری از مرحله پایان تشکیل غلاف تا انتهای دوره رشد و I3: آبیاری کامل در تمام طول فصل رشد) بدون تنش آبیاری در حدود 50 درصد تخلیه رطوبت) به عنوان عامل اصلی و سویه های باکتری تقویت کننده (B1: بدون باکتری، B2: Bacillus subtilis، B3: Bacillus licheniformis) و ارقام سویای کوثر، M9 وTMS به عنوان دیگر فاکتورها در نظر گرفته شد. صفات مورد ارزیابی شامل شاخص سطح برگ، روند جذب تشعشع، سرعت رشد محصول، سرعت رشد نسبی، وزن خشک کل، کارایی مصرف تشعشع و عملکرد دانه بود. نتایج نشان داد که با افزایش تنش خشکی ویژگی های مورد ارزیابی ارقام مختلف سویا به شدت کاهش یافت. کاربرد سویه های مختلف باکتری به شدت منجر به بهبود ویژگی های مورد ارزیابی شد. بالاترین شاخص سطح برگ (7/6)، روند جذب تشعشع (2/18 مگاژول در مترمربع)، سرعت رشد محصول (6/20 گرم در در مترمربع در روز)، وزن خشک کل (7/1104 گرم در مترمربع) و کارایی مصرف تشعشع (165/1 گرم در مگاژول) مربوط به رقم TMS و در شرایط آبیاری کامل + تلقیح باکتری لیکنی فورمیس وکم ترین میزان صفات مذکور مربوط به رقم کوثر و در شرایط قطع آبیاری از اواسط تشکیل غلاف + بدون تلقیح باکتری بود. عملکرد دانه سویا به طور معنی داری تحت تاثیر تیمارهای آزمایش قرار گرفت، به طوری که بیش ترین عملکرد دانه به میزان 9/380 گرم در مترمربع مربوط به رقم TMS در تیمار آبیاری کامل + تلقیح باکتری سوبتیلیس بود و کم ترین آن به میزان 2/134 گرم در مترمربع مربوط به رقم کوثر بود که در تیمار قطع آبیاری از اواسط تشکیل غلاف + بدون باکتری مشاهده شد. به نظر می رسد در صورت کاهش مقدار آب قابل دسترس، تلقیح با باکتری های تقویت کننده رشد گیاه منجر به افزایش تحمل به تنش کمبود آب به ویژه در شرایط تنش ملایم می گردد.

    کلیدواژگان: تنش کمبود رطوبت، جذب تشعشع، شاخص های رشد، عملکرد دانه، کارایی مصرف تشعشع
  • المیرا محمدوند، علیرضا کوچکی*، مهدی نصیری محلاتی، بیژن یعقوبی صفحات 1225-1239

    زمان رویش و تراکم علف های هرز اهمیت بسیاری در اثرات متقابل رقابتی آن ها با گیاه زراعی دارد. لذا برای علف هرز سوروف آبی (Echinochloa oryzoides (Ard.) Fritsch)، به عنوان یک گونه نسبتا تازه وارد، بررسی نقش زمان رویش در خزانه برنج (Oryza sativa L.) و در نتیجه سن گیاهچه علف هرز در هنگام انتقال از خزانه به زمین اصلی و نیز بررسی میزان این انتقال و در نتیجه تراکم نسبی علف هرز در زمین اصلی ضرورت دارد. نقش سن گیاهچه سوروف آبی هنگام نشاکاری (10، 20 و 30 روز) و نسبت تراکم سوروف آبی: برنج در هرکپه (4:0، 3:1، 2:2، 1:3 و 0:4 علف هرز: برنج) بر صفات سوروف آبی و برنج در هنگام رسیدگی گیاه زراعی (90 روز پس از نشاکاری)، طی دو سال مطالعه مزرعه ای در قالب طرح بلوک های کامل تصادفی با سه تکرار مورد بررسی قرار گرفت. افزایش تعداد گیاهچه در نسبت های مختلف کاشت سبب افزایش عملکرد بیولوژیک، عملکرد دانه، عملکرد نسبی هر دو گونه و شاخص غالبیت برنج شد؛ اگرچه شاخص برداشت کاهش یافت. به جز عملکرد دانه برنج در تک کشتی و در نسبت 3:1 (علف هرز: برنج) سال دوم که تفاوت معنی داری با سوروف آبی نداشت؛ در سایر نسبت ها عملکرد بیولوژیک و عملکرد دانه علف هرز بیش تر از برنج متناظر بود. شاخص برداشت برنج در همه نسبت های کاشت بیش تر از علف هرز بود. در سال اول آزمایش، تیمار گیاهچه های 30 روزه سوروف آبی دارای بیش ترین عملکرد بیولوژیک، دانه و نسبی علف هرز، کم ترین عملکرد دانه و نسبی برنج، و کم ترین شاخص برداشت هر دو گونه بودند. در همه سنین گیاهچه علف هرز عملکرد سوروف آبی بیش تر از برنج متناظر بود. بررسی صفات ارزیابی شده و نمودارهای سری های جانشینی حاکی از قابلیت رقابت بالای علف هرز نسبت به گیاه زراعی بود که بر ضرورت توجه به گسترش این علف هرز در منطقه تاکید دارد.

    کلیدواژگان: الگوهای رویش، تراکم نسبی، رقابت، نسبت کاشت
  • فروتن بهادری بیرگانی*، جهانفر دانشیان، سیدعلیرضا ولد آبادی، سعید سیف زاده، اسماعیل حدیدی ماسوله صفحات 1241-1259

    به منظور ارزیابی روند تغییرات میزان کربن و ماده آلی، نیتروژن، فسفر و پتاسیم در خاک و عملکرد نیشکر (Saccharum officinarum L.) در شرایط تناوب های زراعی مختلف، آزمایشی در قالب طرح بلوک های کامل تصادفی با سه تکرار به مدت سه سال متوالی در مزرعه تحقیقاتی کشت وصنعت نیشکر امیرکبیر اهواز طی سال های 95-1393 اجرا شد. ده تناوب رایج زراعی شامل 1) گندم- شبدر- نیشکر، 2) کلزا- شبدر- نیشکر، 3) جو- شبدر- نیشکر، 4) سورگوم- شبدر- نیشکر، 5) شبدر- ماش- نیشکر، 6) شبدر- شبدر- نیشکر، 7) شبدر- شبدر چین سوم- نیشکر، 8) شبدر- سویا- نیشکر، 9) شبدر- ذرت- نیشکر و 10) شاهد- شاهد- نیشکر به عنوان تیمار مدنظر قرار گرفتند. نیتروژن خاک، فسفر قابل جذب، پتاسیم قابل جذب و کربن آلی مورد مطالعه قرار گرفتند. نتایج نشان داد اگرچه روند تغییرات فسفر در سه سال اجرای آزمایش در هر دو عمق خاک تفاوت معنی داری نداشت، اما میزان پتاسیم و کربن آلی خاک در سال سوم آزمایش کاهش یافت. نتایج تجزیه واریانس نشان داد که میزان فسفر، نیتروژن و کربن آلی در هر دو عمق خاک 30-0 سانتی متر در تناوب های زراعی تفاوت معنی داری با هم داشتند. هم چنین پتاسیم در عمق صفر تا 30 سانتی متر و نسبت کربن به نیتروژن در عمق30 تا 60 سانتی متر در تناوب زراعی متفاوت بود. بیش ترین میزان باقی مانده نیتروژن، فسفر و نسبت کربن به نیتروژن به ترتیب در تناوب های زراعی شبدر- شبدر- نیشکر، آیش- آیش- نیشکر و سورگوم- شبدر - نیشکر به ترتیب با 124 و 121 تن در هکتار بوده است. بیش ترین عملکرد نیشکر مربوط به تناوب زراعی شبدر- ماش- نیشکر و کم ترین آن در تناوب آیش- آیش- نیشکر به دست آمد. به طور کلی، نتایج عملکرد نشان داد که انتخاب بقولات در تناوب با نیشکر، مقدار نیتروژن خاک و عملکرد نیشکر را افزایش می دهد.

    کلیدواژگان: بقولات، شبدر، فسفر، ماده آلی، نیتروژن
  • افتخار رحمتی، شیوا خالص رو*، غلامرضا حیدری صفحات 1261-1273

    کشت مخلوط یکی از پایداراترین نظام های زراعی می باشد، گیاهان دارویی نیز نقش مهمی در تامین نیازهای انسان دارند، بنابراین، به منظور ارزیابی عملکرد و کیفیت گیاه دارویی سیاهدانه  (Nigella sativa L.)در کشت مخلوط با شنبلیله (Trigonella foenum-graecum L.) آزمایشی در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه کردستان طی سال زراعی 1394 انجام شد. آزمایش در قالب طرح بلوک های کامل تصادفی با سه تکرار اجرا شد. تیمار های آزمایشی شامل کشت خالص سیاهدانه، کشت خالص شنبلیله، 50% سیاهدانه + 50% شنبلیله، 25% سیاهدانه + 75% شنبلیله، 75% سیاهدانه + 25% شنبلیله، 100% سیاهدانه + 5/12% شنبلیله، 100% سیاهدانه + 25% شنبلیله، 100% سیاهدانه + 5/37% شنبلیله، 100% سیاهدانه + 50% شنبلیله بر اساس سری های جایگزینی و افزایشی بودند. در این پژوهش صفات مختلف از قبیل تعداد شاخه جانبی در بوته، تعداد کپسول در بوته، تعداد دانه در کپسول، وزن هزار دانه، عملکرد وزن خشک کل، عملکرد دانه، درصد اسانس و عملکرد اسانس سیاهدانه، تعداد شاخه جانبی در بوته، تعداد غلاف در بوته، تعداد دانه در غلاف، وزن هزار دانه، عملکرد وزن خشک کل و عملکرد دانه شنبلیله و هم چنین شاخص های کشت مخلوط مانند LER و ATER مورد ارزیابی قرار گرفتند. نتایج نشان داد نسبت های مختلف کاشت، اثر معنی داری بر صفات نام برده هر دو گیاه داشت. بیش ترین مقادیر عملکرد دانه (15/972 کیلوگرم در هکتار) و عملکرد وزن خشک کل (1/2757 کیلوگرم در هکتار) سیاهدانه از نسبت 100% سیاهدانه + 5/12% شنبلیله حاصل شد؛ اما نتایج در مورد شنبلیله نشان داد بیش ترین عملکرد دانه و عملکرد وزن خشک کل به ترتیب با مقادیر 4/784 و 7/3266 کیلوگرم در هکتار از کشت خالص آن حاصل گردید. بر اساس نتایج این آزمایش، بیش ترین ATER (30/1) از تیمار افزایشی 100% سیاهدانه + 5/12% شنبلیله به دست آمد. لذا چنین می توان استنباط کرد که در پژوهش حاضر، این نسبت کشت مخلوط افزایشی در مقایسه با سایر نسبت ها، ویژگی های مثبت بیش تری داشت.

    کلیدواژگان: اسانس، سری های افزایشی، کشاورزی پایدار، گیاه دارویی، نسبت برابری زمین
  • سمیه سهیلی موحد، سعید خماری*، پریسا شیخ زاده، بهرام علیزاده صفحات 1275-1291

    به منظور بررسی اثر محلول پاشی عناصر کم مصرف بور و روی بر عملکرد و برخی صفات مورفولوژیک و زراعی گلرنگ بهاره (Carthamus tinctorius L.) (رقم محلی اصفهان) تحت تنش خشکی انتهای فصل، دو آزمایش جداگانه طی سال های زراعی 93- 1392 و 94- 1393 در مزرعه تحقیقاتی دانشگاه محقق اردبیلی به صورت اسپیلیت فاکتوریل در قالب طرح پایه بلوک های کامل تصادفی با سه تکرار انجام گرفت. کرت اصلی شامل سه سطح محدودیت آب (=S1 آبیاری کامل تا انتهای فصل، =S2 قطع آبیاری از مرحله گل دهی و =S3 قطع آبیاری از مرحله دانه بندی) و کرت فرعی شامل ترکیب فاکتوریل عناصر ریزمغذی بور (0B1= ، 350  B2=و 700B3=  پی پی ام) و روی (0Zn1= ، 1000Zn2=  و 2000Zn3=  پی پی ام) بود. نتایج نشان داد که در سال اول آزمایش کلیه صفات مورد بررسی تحت اثرات منفی محدودیت آب قرار گرفتند. تنش خشکی در مرحله گل دهی (S2) و دانه بندی (S3)، به صورت معنی داری عملکرد دانه را نسبت به شاهد (S1) کاهش داد (به ترتیب 62/15 درصد و 77/12 درصد). در سال دوم به علت بارش های فراوان در طی دوره تنش اختلاف معنی داری بین تیمارهای آبیاری در کلیه صفات مشاهده نشد. در هر دو سال آزمایش تیمارهای B3Zn2 و B2Zn2 در صفات عملکرد و درصد مغز دانه حداکثر افزایش معنی دار و در صفات درصد پوسته دانه و نسبت پوسته به مغز بیش ترین کاهش معنی دار را نسبت به شاهد نشان دادند. هم چنین این تیمارها بالاترین قطر طبق (به ترتیب 83/42 و 31/42 میلی متر)، طول (به ترتیب 84/8 و 63/8 میلی متر) و عرض دانه (به ترتیب 89/4 و 77/4 میلی متر) را دارا بودند. در هر دو سال آزمایش بیش ترین طول دانه در کلیه سطوح آبیاری در تیمار B3 مشاهده شد. محلول پاشی عناصر بور و روی در شرایط تنش در مرحله گل دهی و دانه بندی، اکثر صفات مورد بررسی را به طور معنی داری بهبود بخشید. وجود همبستگی مثبت و معنی دار بین عملکرد و سایر صفات مورد مطالعه نشان داد که عناصر ریزمغذی اگر در زمان مناسب و به مقدار بهینه مصرف گردد، در مقاومت به خشکی گیاه اثر مثبت خواهند گذاشت. به طور کلی، محلول پاشی برگی عناصر بور و روی نسبت به شاهد توانست تا حدودی خسارات ناشی از محدودیت آب را در گلرنگ جبران نماید.

    کلیدواژگان: آهن، روی، فسفر، کودهای آلی، نیتروژن
  • جلال قادری*، عادل نعمتی، محمود شریعتمداری صفحات 1293-1307

    با توجه به کمبود مواد آلی در خاک ها و با هدف استفاده بهینه از کودهای آلی و شیمیایی برای دست یابی به کشاورزی پایدار، آزمایشی به منظور بررسی تاثیر کودهای شیمیایی و کود آلی کمپوست زباله شهری بر عملکرد کمی وکیفی گندم (Triticum astivum L.) رقم بهار، با چهار سطح کودهای شیمیایی (بدون مصرف، سیستم رایج، بر اساس آنالیز خاک و 25 درصد کم تر از آنالیز خاک) و کمپوست زباله شهری در چهار سطح (0، 10 ، 20 و 30 تن بر هکتار) به صورت فاکتوریل و در قالب طرح بلوک های کامل تصادفی در سه تکرار، در سال زراعی 93-1392 در کرمانشاه اجرا شد. نتایج حاصل از تجزیه واریانس نشان داد که اثر اصلی مصرف کمپوست، کودهای شیمیایی و اثر برهم کنش آن ها روی صفات آزمایشی معنی دار شد. در این تحقیق کاربرد کودهای شیمیایی و کمپوست سبب افزایش معنی دار عملکرد دانه، وزن هزار دانه، تعداد دانه در سنبله، ارتفاع گیاه، تعداد پنجه در بوته، درصد پروتیین و غلظت عناصر غذایی در دانه گندم گردید. مقایسه میانگین اثر برهم کنش کودهای شیمیایی و کمپوست زباله شهری نشان داد با کاربرد تیمار 10 تن بر هکتار کمپوست و کودهای شیمیایی 25 درصد کم تر از آنالیز خاک، بیش ترین عملکرد دانه (5900 کیلوگرم بر هکتار)، وزن هزار دانه (39 گرم)، تعداد دانه در سنبله (71)، درصد پروتیین (6/12) و غلظت عناصر غذایی در دانه به دست آمد و کم ترین میزان صفات مورد بررسی در شاهد مشاهده گردید. با توجه به نتایج به دست آمده و در نظر گرفتن مسایل زیست محیطی، کاربرد توام 10 تن بر هکتار کمپوست و کودهای شیمیایی 25 درصد کم تر از آنالیز خاک پیشنهاد می شود.

    کلیدواژگان: آهن، روی، فسفر، کودهای آلی، نیتروژن
  • عبدالقادر عنایتی، مرتضی برمکی*، رئوف سیدشریفی، عبداللطیف قلی زاده صفحات 1309-1326

    کمبود آب در مراحل انتهایی رشد گندم (Triticum aestivum L.) منجر به تولید بذر بی کیفیت می شود. کاربرد بی رویه کودهای شیمیایی آسیب های جدی به محیط زیست وارد می کند. به منظور بررسی اثر باکتری ازتوباکتر کروکوکوم (Azotobacter chroococcum) و قارچ میکوریزا گلوموس اینترارادیسز(Glomus intraradices) بر عملکرد، اجزای عملکرد ارقام گندم و جوانه زنی بذرهای حاصل تحت شرایط آبیاری تکمیلی، آزمایشی با سه تکرار به صورت فاکتوریل در قالب طرح پایه بلوک های کامل تصادفی در ایستگاه تحقیقات کشاورزی گرگان (عراقی محله) در سال زراعی 1395-1394 اجرا گردید. عوامل آزمایش شامل دو رقم گندم آبی (20-80-N و گنبد)، شش سطح تلقیح شامل (1) عدم تلقیح به عنوان شاهد، (2) تلقیح بذر با قارچ میکوریزا گلوموس اینترارادیسز، (3) تلقیح بذر با باکتری سویه ازتوباکتر کروکوکوم (پودری)، (4) تلقیح با فرم مایع ازتوباکتر کروکوکوم، (5) تلقیح با سویه ازتوباکتر کروکوکوم (پودری) + گلوموس اینترارادیسز، (6) تلقیح با فرم مایع ازتوباکتر کروکوکوم + گلوموس اینترارادیسز) و سه سطح آبیاری تکمیلی (عدم آبیاری، آبیاری در مرحله آبستنی و آبیاری در مرحله گل دهی کامل) بود. در این بررسی صفات عملکرد، اجزای عملکرد و جوانه زنی بذرهای گندم حاصل مورد مطالعه قرار گرفتند. نتایج نشان داد که تلقیح بذر ارقام گندم با ترکیب توام ازتوباکتر و میکوریزا اثر معنی داری روی عملکرد، اجزای عملکرد و هم چنین بهبود مولفه های جوانه زنی بذرهای تولیدی گندم داشت. بیش ترین عملکرد دانه (33/5987 کیلوگرم در هکتار) در بوته های حاصل از بذرهای تلقیح شده با گلوموس اینترارادیسز + فرم مایع ازتوباکتر کروکوکوم تحت آبیاری تکمیلی در مرحله گل دهی کامل به دست آمد. رقم 20-80-N و تلقیح بذر با گلوموس اینترارادیسز + فرم مایع ازتوباکتر کروکوکوم با افزایش 10 درصدی نسبت به شاهد، بالاترین عملکرد دانه را به خود اختصاص داد. درصد و سرعت جوانه زنی بذور ارقام گندم تحت تاثیر آبیاری تکمیلی به طور قابل ملاحظه ای افزایش یافت. هم چنین تلقیح بذر گندم با کودهای بیولوژیک سبب افزایش درصد جوانه زنی بذور حاصل شد. به طوری که بالاترین درصد جوانه زنی در تیمار تلقیح بذر با گلوموس اینترارادیسز + فرم مایع ازتوباکتر کروکوکوم (75/95) حاصل شد. رقم 20-80-N در مقایسه با رقم گنبد نسبت به تلقیح بذر و آبیاری تکمیلی از نظر صفات مورد مطالعه پاسخ بهتری را از خود نشان داد.

    کلیدواژگان: کود بیولوژیک، تلقیح، شاخص برداشت، کیفیت بذر
  • ایمان حقیان، محسن شرافتمندراد* صفحات 1327-1341

    شناسایی نیازهای اکولوژیک گونه های گیاهی مختلف و عوامل محیطی موثر در استقرار آن ها را می توان نخستین گام در راستای شناخت مناطق مستعد رشد و توسعه آن ها جهت اصلاح و احیای مراتع از طریق مرتع کاری دانست. از این رو، در مطالعه حاضر، نقش متغیرهای فیزیکی و شیمیایی خاک در پراکنش و استقرار گیاهان دارویی در منطقه دراسله استان مازندران مورد مطالعه قرار گرفته است. برای اندازه گیری پوشش گیاهی از پلات های یک متر مربعی در امتداد ترانسکت های 50 متری با استقرار تصادفی- سیستماتیک استفاده شد. در کنار هر ترانسکت یک نمونه خاک نیز برداشت و جهت تعیین ویژگی های فیزیکی و شیمیایی خاک به آزمایشگاه منتقل شد. سپس با تکنیک رسته بندی و انجام تجزیه و تحلیل های تطبیق قوس گیری شده (DCA)3 و تطبیق متعارفی (CCA)4 اثر این متغیرها بر پراکنش گیاهان دارویی تعیین شد. تعداد 29 گیاه دارویی در منطقه شناسایی شد. نتایج آنالیزهای چندمتغیره نیز نشان داد که اثر متغیرهای خاکی بر پراکنش گیاهان دارویی معنی دار است و اکثر گونه ها تحت تاثیر این متغیرها قرار گرفتند. در این بین، اسیدیته و میزان رس تعداد بیش تری از گیاهان را تحت تاثیر قرار دادند. بنابراین، پراکنش گیاهان دارویی در منطقه دراسله تا حد زیادی متاثر از متغیرهای خاکی است و با شناسایی این عوامل می توان گام موثری در معرفی و کاشت این گیاهان در مناطق مستعد و مناسب برداشت.

    کلیدواژگان: آنالیز چند متغیره، پوشش گیاهی، رسته بندی، عوامل محیطی، مرتع
  • سیدعطاالله سیادت*، ابوالفضل درخشان صفحات 1343-1356

    بهبود رشد گیاه زراعی با کاربرد کود نیتروژن می تواند به میزان قابل توجهی عملکرد محصول را افزایش و بازده اقتصادی را بهبود بخشد. با این حال، استفاده بیش از حد از کود نیتروژن در نظام های کشت فشرده منجر به کاهش کارایی زراعی مصرف نیتروژن، افزایش انتشار گاز های گلخانه ای و آلودگی آب و خاک شده است. غلظت نیتروژن بحرانی (Nc) حداقل نیتروژن مورد نیاز برای حداکثر رشد گیاه است و می تواند به عنوان ابزاری برای مدیریت دقیق نیتروژن در طی فصل رشد استفاده شود. مطالعه فعلی با هدف تعیین منحنی رقیق شدن غلظت نیتروژن بحرانی بر مبنای ماده خشک برگ (LDM) در کلزای بهاره (Brassica napus L.) انجام شد. برای این منظور، یک آزمایش مزرعه ای با هفت سطح مصرف صفر، 50، 100، 150، 200، 250 و 300 کیلوگرم نیتروژن خالص در هکتار انجام گرفت و ماده خشک و غلظت نیتروژن برگ دو رقم کلزای بهاره در طی فصل رشد اندازه گیری شد. منحنی رقیق شدن غلظت نیتروژن بحرانی برگ کلزای بهاره با رابطه Nc=5.08LDM-0.06 توصیف شد. شاخص تغذیه نیتروژنی (NNI) بسته به میزان مصرف نیتروژن در رقم دلگان از 72/0 تا 14/1 و در رقم هایولا 401 از 53/0 تا 15/1 متغیر بود. کمبود نیتروژن تجمعی (Nand) در رقم دلگان بین 61/11- و 09/107 کیلوگرم نیتروژن در هکتار و در رقم هایولا 401 بین 22/24- و 64/129 کیلوگرم نیتروژن در هکتار تعیین شد. همبستگی مثبت معنی داری بین اختلاف میزان مصرف نیتروژن (ΔN) با تغییرات شاخص تغذیه نیتروژنی (ΔNNI) و کمبود نیتروژن تجمعی (ΔNand) وجود داشت. به طور کلی، منحنی رقیق شدن غلظت نیتروژن بحرانی و شاخص تغذیه نیتروژنی و کمبود نیتروژن تجمعی مشتق از آن به خوبی وضعیت محدودیت و عدم محدودیت تغذیه نیتروژنی را در دو رقم کلزای بهاره مشخص کرد و می تواند به عنوان شاخص قابل اطمینانی از وضعیت نیتروژن گیاه زراعی در طی فصل رشد استفاده شود.

    کلیدواژگان: بهینه سازی مصرف نیتروژن، شاخص تغذیه نیتروژنی، کمبود نیتروژن، مدل سازی، مدیریت دقیق نیتروژن
  • فرزانه ریگی، مهدی دهمرده*، عیسی خمری، رضا باقری صفحات 1357-1374

    به منظور ارزیابی تاثیر جهت کشت و تقسیط نیتروژن بر صفات اکومورفولوژیکی، عملکرد و اجزای عملکرد گیاه دارویی چای ترش ((Hibiscus sabdariffa L. آزمایشی به صورت اسپلیت پلات در قالب طرح بلوک های کامل تصادفی در سه تکرار در پژوهشکده تحقیقاتی دانشگاه زابل در سال زراعی 1396-1395 اجرا شد. تیمارهای آزمایش شامل جهت کشت در دو سطح (شمالی- جنوبی، شرقی- غربی) به عنوان عامل اصلی و تقسیط نیتروژن از منبع اوره چهار سطح (یک سوم قبل از کاشت، یک سوم مرحله چهار برگی، یک سوم مرحله ساقه رفتن؛ یک دوم قبل ازکاشت یک دوم مرحله چهار برگی؛ یک دوم مرحله چهار برگی یک دوم مرحله ساقه رفتن؛ یک سوم مرحله چهار برگی، یک سوم مرحله ساقه رفتن، یک سوم مرحله گل دهی) به عنوان عامل فرعی بودند. نتایج تجزیه واریانس نشان داد که جهت کشت و تقسیط نیتروژن بر صفات ارتفاع بوته، قطر ساقه، تعداد شاخه جانبی، تعداد غوزه در بوته، وزن تر کاسبرگ، وزن خشک کاسبرگ و شاخص برداشت معنی دار بود. اما تعداد شاخه جانبی و قطر ساقه تنها تحت تاثیر جهت کشت قرار گرفتند. عملکرد بیولوژیک تنها تحت تاثیر تقسیط نیتروژن قرار گرفت. اثر متقابل جهت کشت و تقسیط نیتروژن برای صفت شاخص برداشت معنی دار (پنج درصد) و برای سایر صفات مورفولوژیک بسیار معنی دار (یک درصد) شد. بر اساس نتایج مقایسه میانگین تیمارها مشخص گردید که به جز تعداد شاخه جانبی تمامی صفات مورفولوژیکی اندازه گیری شده در جهت کشت شمالی- جنوبی دارای بیش ترین مقدار بودند. در این مطالعه تقسیط نیتروژن به صورت مصرف در مرحله چهاربرگی، مرحله ساقه رفتن و گل دهی نسبت به سایر تیمارها بر ویژگی های اندازه گیری شده تاثیر معنی داری داشت. زمان بندی صحیح مصرف کود، مهم تر از کل مقدار کود به کار رفته می باشد، به طوری که تقسیط زمانی مصرف کود نیتروژن به سه مرحله، باعث افزایش ویژگی های عملکردی چای ترش شد که در نتیجه می تواند کاهش هزینه های کودی و آلودگی محیط زیست را در پی داشته باشد.

    کلیدواژگان: آلودگی محیط زیست، دمای خاک، عملکرد کاسبرگ
  • محبوبه عسگریان، محمدحسین امینی فرد*، مهدی خیاط، مهدی جهانی صفحات 1375-1388

    به منظور بررسی تاثیر سطوح کود کامل NPK و اسید فولویک بر برخی صفات رویشی و زایشی گیاه ریحان (Ocimum basilicum L.)، آزمایشی به صورت فاکتوریل در قالب طرح پایه بلوک های کامل تصادفی، در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه بیرجند در سال زراعی 96- 1395 اجرا شد. فاکتورهای آزمایش شامل محلول پاشی کود کاملNPK  (20-20-20) در سه سطح (صفر، سه و شش در هزار) و مصرف خاکی اسید فولویک در سه سطح (0 و 5 و 10 کیلوگرم در هکتار) با سه تکرار بودند. نتایج نشان داد، کود کاملNPK  تاثیر معنی داری بر ارتفاع، تعداد برگ، وزن هزار دانه و عملکرد بیولوژیک داشت، به طوری که بیش ترین میزان ارتفاع (4/48 سانتی متر) و عملکرد بیولوژیک (1/2 کیلوگرم در مترمربع) از کاربرد سطح شش در هزار کود کامل و کم ترین آن (5/36 سانتی متر و 6/1 کیلوگرم در مترمربع) از شاهد (عدم کاربرد کود) به دست آمد. هم چنین بیش ترین میزان تعداد برگ بوته (5/129) و وزن هزار دانه (5/1 گرم) با کاربرد 10 کیلوگرم در هکتار اسید فولویک و کم ترین میزان این صفات (120 و 4/1 گرم) در شاهد مشاهده شد. اما فاصله میان گره و تعداد بذر بوته تحت تاثیر تیمارهای کودی قرار نگرفت. هم چنین اثرات متقابل نیز نشان داد،که بیش ترین میزان عملکرد بیولوژیک (2/2 کیلوگرم در مترمربع) و وزن خشک بوته (8/483 گرم در مترمربع)، در تیمار مصرف هم زمان شش در هزار کود کامل و10 کیلوگرم در هکتار اسید فولویک و کم ترین میزان آن ها (4/1کیلوگرم در مترمربع و 5/259 گرم در مترمربع)، در شاهد (عدم کودهی) مشاهده شد. به طور کلی، نتایج بیانگر تاثیر مثبت و افزایشی کاربرد تلفیقی کودهای شیمیایی و آلی بر میزان عملکرد گیاه ریحان بود و بر این اساس پیشنهاد می شود، می توان تیمار شش در هزار کود کامل و 10 کیلوگرم در هکتار اسیدفولویک را به عنوان راهکاری اکولوژیک برای افزایش عملکرد کمی گیاه دارویی ریحان توصیه نمود.

    کلیدواژگان: ارتفاع بوته، تعداد بذر، شاخص برداشت، عملکرد بیولوژیکی
  • محمود محمدی، سیدعلی محمد مدرس ثانوی*، همت الله پیردشتی، زین العابدین طهماسبی سروستانی، بهنام زند صفحات 1389-1407

    تغییرات شرایط محیطی طی دوره ی رشد گیاه غیرقابل پیش بینی است و از این رو ایجاد تنش در هنگام رشد گیاه امری اجتناب ناپذیر می باشد؛ یکی از مهم ترین این تنش ها، تنش کم آبی می باشد. بنابراین، برای بهبود بهره وری رشد و تولید گیاه در شرایط تنش، علاوه بر اعمال نهاده های کشاورزی مناسب (کاربرد کودهای شیمیایی و بیولوژیکی)، نیاز به شناخت و درک فرآیندهای مورفوفیزیولوژیکی گیاه می باشد. در همین زمینه آزمایشی با هدف بررسی اثر برهم کنش انواع کود و تنش خشکی بر خصوصیات مورفوفیزیولوژیکی و عملکرد گل مغربی (Oenothera biennis L.) به صورت مزرعه ای در دو شهرستان تهران و ورامین در سال 94-1393 انجام شد. آزمایش به صورت اسپلیت فاکتوریل در قالب طرح بلوک های کامل تصادفی در سه تکرار اجرا شد. عامل اصلی شامل سه تیمار بدون تنش آبی (50% از ظرفیت زراعی)، تنش متوسط (40% از ظرفیت زراعی) و تنش شدید (30% از ظرفیت زراعی) بود و عوامل فرعی شامل کاربرد کود شیمیایی در سه سطح (بدون مصرف کود، مصرف 50 و 100% نیتروژن + فسفر مورد نیاز)، قارچ میکوریزا و باکتری آزوسپیریلوم (کاربرد و عدم کاربرد) در نظر گرفته شد. اعمال تنش کم آبی (متوسط و شدید) باعث کاهش ارتفاع بوته، وزن خشک ساقه، شاخص سطح برگ، عملکرد دانه و محتوای نسبی آب شد. بالاترین میزان کارایی مصرف آب در تنش کم آبی متوسط و بیش ترین میزان وزن خشک ریشه، نسبت وزن خشک ریشه به اندام هوایی و آنزیم کاتالاز در تنش کم آبی شدید مشاهده شد. هم چنین نتایج نشان داد کاربرد کودهای شیمیایی (نیتروژن و فسفر) و بیولوژیکی (میکوریزا و آزوسپیریلوم) می تواند اثرات منفی تنش کم آبی را بر عملکرد گل مغربی کاهش داده و سبب بهبود رشد آن شود.

    کلیدواژگان: آزوسپیریلوم، کم آبی، کود بیولوژیکی، میکوریزا
  • جواد حمزه ئی*، جواد صدیقی کامل صفحات 1409-1422

    یکی از راهکارهای حرکت به سمت کشاورزی پایدار، ایجاد تنوع و به کارگیری کشت مخلوطی از گیاهان، ارقام و یا ایزولاین های مختلف در زراعت است. هم چنین جهت افزایش بهره وری در نظام کشاورزی، مدیریت منابع و نهاده ها نیز نقش اساسی دارند. به همین دلیل در این آزمایش واکنش سیب زمینی (Solanum tuberosum L.) به الگوهای مختلف کشت (کشت خالص سیب زمینی و کشت های مخلوط افزایشی لوبیا سبز (Phaseolus vulgaris L.) در بین ردیف های سیب زمینی، روی ردیف های سیب زمینی و بین و روی ردیف های سیب زمینی) و سطوح نیتروژن (صفر، 80 و 160 کیلوگرم نیتروژن در هکتار) بررسی شد. آزمایش به صورت فاکتوریل بر پایه بلوک های کامل تصادفی در سه تکرار در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه بوعلی سینا و در سال زراعی 1395 اجرا شد. ویژگی های زراعی، اجزای عملکرد و عملکرد سیب زمینی، عملکرد معادل سیب زمینی، عملکرد غلاف لوبیا سبز، نسبت برابری زمین و مجموع ارزش نسبی اندازه گیری و مورد تجزیه و تحلیل قرار گرفت. بیش ترین عملکرد غده سیب زمینی (50/42 تن در هکتار) از تیمار کشت مخلوط بین ردیفی لوبیا سبز با دریافت 160 کیلوگرم نیتروژن به دست آمد که با تیمار کشت مخلوط بین ردیفی لوبیا سبز با دریافت 80 کیلوگرم نیتروژن (با عملکرد معادل 51/41 تن در هکتار)، اختلاف معنی داری نداشت. هم چنین، بالاترین عملکرد غلاف لوبیا سبز (515 گرم در مترمربع)، نسبت برابری زمین (53/1)، مجموع ارزش نسبی (45/1) و بالاترین عملکرد معادل سیب زمینی (38/54 تن در هکتار) از تیمار کشت مخلوط بین ردیفی لوبیا سبز با دریافت 80 کیلوگرم نیتروژن به دست آمد. بنابراین، تیمار کشت مخلوط بین ردیفی لوبیا سبز با دریافت 80 کیلوگرم نیتروژن از نظر رشد، عملکرد غده، بهبود کارایی استفاده از زمین و کارایی مصرف نیتروژن مناسب ترین تیمار بود. در کل، کشت لوبیا سبز در بین ردیف های سیب زمینی به دلیل تعلق آن ها به دو تیره مختلف و تفاوت های اکولوژیکی، مورفولوژیکی و تغذیه ای، جنبه های هم یاری و مکملی مناسبی در کشت مخلوط دارند. این امر موجب افزایش بهره وری بهتر از زمین، نور و مواد غذایی موجود در واحد سطح و نیز افزایش تنوع در اکوسیستم های کشاورزی می گردد.

    کلیدواژگان: چند کشتی، کارایی مصرف منابع، لگوم، مجموع ارزش نسبی، نسبت برابری زمین
  • افسانه یوسفی، رضا میرزایی تالارپشتی، جعفر نباتی*، سعید صوفی زاده صفحات 1423-1436

    به منظور بررسی اثر باکتری های حل کننده فسفر، پتاسیم و تثبیت کننده آزادزی نیتروژن بر شاخص های رشدی ماش (Vigna radiata L.)، آزمایشی در سال زراعی 1396 در مزرعه پژوهشی دانشکده کشاورزی دانشگاه فردوسی مشهد به صورت فاکتوریل در قالب طرح بلوک های کامل تصادفی، با دو توده ماش (دزفولی و هندی)، شش تیمار کودی شامل: 1- باکتری های آزادزی تثبیت کننده نیتروژن، 2- باکتری های حل کننده فسفر، 3- باکتری های حل کننده پتاسیم، 4- باکتری های آزادزی تثبیت کننده نیتروژن + باکتری های حل کننده پتاسیم و فسفر، 5- کود شیمیایی نیتروژن و 6- شاهد (بدون کود زیستی و شیمیایی) در سه تکرار اجرا شد. مقدار واحد کلونی ریز موجود در هر گرم کود زیستی 107 واحد بود. صفات مورد مطالعه شامل شاخص سطح برگ، ماده خشک تجمعی، سرعت رشد محصول، سرعت آسیمیلاسیون خالص، سرعت رشد نسبی و عملکرد دانه بود. نتایج نشان داد که بیش ترین شاخص سطح برگ (80/3)، تجمع ماده خشک (835 گرم بر مترمربع) و عملکرد دانه (1558 کیلوگرم در هکتار) ماش در توده هندی به دست آمد و توده دزفولی بیش ترین سرعت رشد محصول (25 گرم در مترمربع در روز)، سرعت رشد نسبی (056/0 گرم در مترمربع در روز) و سرعت آسیمیلاسیون خالص (95/18 گرم دی اکسید کربن در مترمربع در روز) را نشان داد. کم ترین شاخص های رشد در شاهد در هر دو توده دزفولی و هندی به دست آمد. بر این اساس می توان چنین نتیجه گرفت که کاربرد هم زمان کودهای زیستی در بهبود شرایط رشدی گیاه اثر قابل توجهی داشته است و از طریق افزایش رشد و توسعه ریشه و در نتیجه جذب بهتر آب و مواد غذایی از خاک توانسته است، سبب افزایش عملکرد و بهبود صفات کمی گیاه گردد.

    کلیدواژگان: سرعت آسیمیلاسیون خالص، سرعت رشد محصول، شاخص سطح برگ، کودهای زیستی
  • سید محمد سیدی، پرویز رضوانی مقدم*، محمد خواجه حسینی، حمید شاهنده صفحات 1437-1448

    به منظور تاثیر گوگرد و باکتری های اکسید کننده گوگردی بر میزان مصرف فسفر و تاثیر آن بر عملکرد کمی و کیفی سیاهدانه (Nigella sativa L.) در خاک آهکی، آزمایشی در سال زراعی 92-1391 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد به اجرا در آمد. این مطالعه به صورت فاکتوریل در قالب طرح بلوک های کامل تصادفی با 12 تیمار و سه تکرار طراحی شد. چهار اصلاح کننده خاک آهکی (شاهد، ورمی کمپوست + باکتری تیوباسیلوس، گوگرد + باکتری تیوباسیلوس و ورمی کمپوست + گوگرد + باکتری تیوباسیلوس) و سه سطح کاربرد فسفر (صفر، 30 و 60 کیلوگرم در هکتار) به ترتیب به عنوان عامل اول و دوم آزمایش انتخاب شدند. بر اساس نتایج تجزیه واریانس، ارتفاع بوته، شاخص سطح برگ و وزن خشک بوته سیاهدانه در مرحله گل دهی به طور معنی دار تحت تاثیر اثر متقابل مقدار فسفر و اصلاح کننده های خاک قرار گرفتند. هم چنین اثر متقابل ذکر شده بر عملکرد دانه و عملکرد بیولوژیک سیاهدانه معنی دار بود. در شرایط عدم کاربرد فسفر، نقش تیمار گوگرد + باکتری تیوباسیلوس در افزایش معنی دار عملکرد دانه و عملکرد بیولوژیک سیاهدانه بیش از کاربرد 30 و 60 کیلوگرم در هکتار فسفر به تنهایی بود. کاربرد ورمی کمپوست + باکتری تیوباسیلوس به تنهایی و یا همراه با گوگرد بیش ترین تاثیر معنی دار را در افزایش عملکرد دانه و بیولوژیک سیاهدانه داشت. به طوری که در نتیجه کاربرد تیمار ورمی کمپوست + باکتری تیوباسیلوس و نیز تیمار ورمی کمپوست + گوگرد + باکتری تیوباسیلوس، عملکرد دانه نسبت به تیمار شاهد به ترتیب تا 3/63 و 4/84 درصد افزایش یافت. در خاک های آهکی، اکسیداسیون بیولوژیکی گوگرد به تنهایی و یا همراه با کود ورمی کمپوست می تواند به راهکاری مناسب جهت فراهمی بیش تر فسفر در خاک و افزایش عملکرد کمی و کیفی سیاهدانه مطرح باشد.

    کلیدواژگان: باکتری تیوباسیلوس، درصد اسانس، درصد روغن، گوگرد، ورمی کمپوست
  • سعید جاهدی پور، علیرضا کوچکی*، مهدی نصیری محلاتی، پرویز رضوانی مقدم صفحات 1449-1465

    به منظور دستیابی به توسعه پایدار و هم چنین حفاظت از اکوسیستم های طبیعی و تنوع زیستی آن ها، لازم است نقش عوامل بوم شناختی و تاثیر آن ها بر تنوع گونه های گیاهی مورد ارزیابی قرار گیرد. در این راستا، در پژوهش حاضر تاثیر عوامل بوم شناختی بر تنوع زیستی گونه های گیاهی در بوم نظام طبیعی بهارکیش قوچان در بهار سال 1393 بررسی شد. ابتدا با روی هم اندازی چهار نقشه شیب، جهت جغرافیایی، طبقات ارتفاعی و سازندهای زمین شناسی نقشه واحدهای کاری تهیه شد، سپس بر اساس ساختار، نحوه توزیع و حضور گونه های غالب، چهار تیپ همگن مشخص شده و 35 پلات در هر تیپ گیاهی به روش سیستماتیک- تصادفی مسقر گردید و پلات های با سطح نمونه دو مترمربعی (بر اساس روش تعیین حداقل سطح) جهت برآورد پوشش گیاهی به کار گرفته شد. نمونه برداری از پوشش گیاهی در کلیه پلات ها و نمونه برداری از خاک به صورت نمونه مرکب از هر واحد کاری به وسیله اوگر از عمق صفر تا 30 سانتی متری انجام شد. در هر پلات گیاهان موجود فهرست و درصد تاج پوشش ثبت و کلیه ویژگی های خاک شامل: درصد رس، سیلت، شن، ماده آلی، رطوبت اشباع، کربن آلی و میزان اسیدیته و هدایت الکتریکی و هم چنین ویژگی های توپوگرافیک از جمله: شیب، جهت جغرافیایی و ارتفاع از سطح دریا اندازه گیری شد. از طرفی، تغییرات تنوع در سازند های مختلف زمین شناسی نیز مشخص شد. مطالعه تنوع زیستی گونه های گیاهی با استفاده از شاخص های تنوع شانون- وینر و سیپمپسون، شاخص غنای مارگالف و شاخص یکنواختی اسمیت- ویلسون انجام شد. هم چنین به منظور تعیین مهم ترین عوامل تاثیرگذار بر تغییرات تنوع گونه ای از آنالیز تجزیه به مولفه های اصلی و در محیط PCA استفاده شد. نتایج پژوهش نشان داد که ارتفاع از سطح دریا بر تنوع، غنا و یکنواختی گونه های گیاهی منطقه تاثیر معنی داری داشته و در دامنه ارتفاعی میانی2200-1900 متر، شاخص های تنوع سیمپسون و شانون- وینر، غنای مارگالف و یکنواختی اسمیت- ویلسون بیش ترین مقدار را داشتند. هم چنین جهت دامنه شمالی و شیب دامنه، تنوع و غنای گونه ای را به طور معنی داری تحت تاثیر قرار داده و در شیب های تا 15 درصد، تنوع شانون- وینر و غنای گونه ای مارگالف بالاترین مقدار را داشته و شاخص یکنواختی اسمیت- ویلسون در شیب 15 تا 45 درصد، بیش ترین مقدار را داشت. نتایج حاصل از تجزیه به مولفه های اصلی نشان داد که با توجه به قدر مطلق ضرایب، مولفه اول شامل: درصد کربن آلی خاک، درصد ماده آلی و درصد رس و مولفه دوم شامل: هدایت الکتریکی و ارتفاع و درصد رطوبت اشباع، درصد سیلت، درصد شن و درصد شیب، بیش ترین تاثیر را بر تنوع گونه ای منطقه مورد مطالعه داشتند.

    کلیدواژگان: تجزیه به مولفه های اصلی، عوامل توپوگرافیک، عوامل خاکی، مرتع
  • شاهین حسنی، محمود رمرودی*، محمدرضا اصغری پور، ابراهیم احمدی صفحات 1467-1481

    این بررسی با هدف مقایسه آلاینده‏های جو (Hordeum vulrare L.) آبی و دیم در منطقه خرم‏آباد با استفاده از روش ارزیابی چرخه حیات انجام شد. واحد کارکردی در این پژوهش معادل تولید یک تن محصول جو در نظر گرفته شد. از اثرات زیست محیطی مهم می‏توان به گرمایش جهانی، تخریب لایه اوزون، پدیده اختناق دریاچه، پتانسیل اسیدی شدن و پتانسیل سمیت انسانی اشاره کرد. اندازه‏گیری پتانسیل هرکدام از اثرات زیست محیطی فوق الذکر با توجه به معادل تولید واحد در نظر گرفته شده توسط پایگاه داده جهانی محاسبه شد. نتایج نشان داد که میزان انتشار گازهای گلخانه‏ای در اثر زیست محیطی گرمایش جهانی در تولید یک تن جو آبی و دیم به ترتیب برابر 06/1112 و 96/699 واحد معادل کیلوگرم تولید CO2 است. در اثر زیست محیطی تخریب لایه اوزون این مقدار برای تولید یک تن جو آبی و جو دیم به ترتیب برابر 000228/0 و 000206/0 واحد معادل کیلوگرم تولید CEC11 محاسبه شد. پتانسیل اختناق دریاچه در تولید یک تن جو آبی و دیم به ترتیب برابر 66/2 و 71/2 واحد معادل تولید کیلوگرم PO4 محاسبه شد. در طراحی یک سناریو بلندمدت برای ادامه روند تولید به صورت کنونی، افزایش آلاینده‏های زیست محیطی با توجه به انباشت آلاینده‏های سال‏های قبل افزایش پتانسیل تخریب‏های زیست محیطی را نشان داد. بیش ترین میزان شاخص نهایی زیست محیطی (Eco-X) به ترتیب مربوط به دو اثر زیست محیطی گرمایش جهانی 0163/0 در جو آبی، 0108/0 در جو دیم و اثر زیست محیطی سمیت آب‏های شیرین که در هر دو محصول 0144/0 به دست آمد.

    کلیدواژگان: اختناق دریاچه، تخریب‏های زیست محیطی، طراحی سناریو بلندمدت اثرات زیست محیطی، گرمایش جهانی
  • علیرضا کوچکی*، فرنوش فلاح پور، افسانه امین غفوری صفحات 1483-1496

    به منظور تعیین بهترین عرض نوار در کشت مخلوط ردیفی کنجد (Sesamum indicum L.) و کتان (Linum usitatissimum L.) آزمایشی در قالب طرح بلوک های کامل تصادفی با سه تکرار در مزرعه تحقیقاتی دانشگاه فردوسی مشهد در دو سال زراعی 89- 1388 و 90- 1389 اجرا شد. تیمارهای آزمایش شامل چهار الگوی مخلوط ردیفی (یک ردیف کنجد+ یک ردیف کتان (1:1)، دو ردیف کنجد+ دو ردیف کتان (2:2)، سه ردیف کنجد+ سه ردیف کتان (3:3) و چهار ردیف کنجد+ چهار ردیف کتان (4:4)) و کشت خالص کنجد و کتان بود. صفات مورد مطالعه شامل تراکم و وزن خشک علف های هرز و عملکرد و اجزای عملکرد دو گیاه بود. نتایج نشان دادند که اثر الگوهای مختلف کشت مخلوط بر وزن خشک و تراکم علف های هرز معنی دار بود. بیش ترین و کم ترین وزن خشک علف های هرز به ترتیب در تیمار کشت خالص کتان (1/832 گرم در مترمربع) و کشت مخلوط دو ردیفی (66/41 گرم در مترمربع) مشاهده شد. بالاترین عملکرد بیولوژیکی کنجد در کشت خالص (با 7/9508 کیلوگرم در هکتار) و در کتان در کشت خالص و الگوی مخلوط دو ردیفی (به ترتیب با 3/3987 و 7/3521 کیلوگرم در هکتار) به دست آمد. حداکثر عملکرد دانه نیز در هر دو گیاه (به ترتیب در کنجد و کتان 3/4876 و 12/2122 کیلوگرم در هکتار) در کشت خالص حاصل شد. نسبت برابری زمین در الگوهای مختلف بین 34/1- 68/0 متغیر بود و بیش ترین مقدار در الگوی دو ردیفی مشاهده شد. به علاوه کشت مخلوط با افزایش تنوع، باعث کاهش تعداد و وزن خشک علف های هرز گردید و به طور کلی بهترین نتایج در الگوی دو ردیف کنجد+ دو ردیف کتان مشاهده شد.

    کلیدواژگان: عملکرد بیولوژیک، عملکرد دانه، فراوانی نسبی، نسبت برابری زمین
  • جلیل شفق کلوانق*، عادل دلایی میلان، سعید زهتاب سلماسی، یعقوب راعی، سهیلا دست برهان صفحات 1497-1510

    چندکشتی به دلیل شباهت ساختاری به اکوسیستم های طبیعی از نظر تنوع گونه ای و پایداری زیستی، مورد توجه اکولوژیست ها قرار گرفته و موجب افزایش تولید، حفظ حاصلخیزی و کنترل فرسایش خاک و بهره برداری بهینه از منابع محیطی موجود می شود. از این رو، به منظور ارزیابی اثر کشت مخلوط بالنگوی شهری (Lallemantia iberica Fischer & C.A. Meyer) و زیره سبز (Cuminum cyminum L.)  بر کنترل علف های هرز و عملکرد بالنگوی شهری، آزمایشی در سال زراعی 93-1392 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه تبریز به صورت فاکتوریل بر پایه طرح بلوک های کامل تصادفی با سه تکرار انجام شد. کنترل کامل (a1) و عدم کنترل علف های هرز (a2) به عنوان فاکتور اول و سیستم های مختلف کشت شامل کشت خالص بالنگوی شهری (b1)، کشت خالص زیره سبز (b2) و کشت مخلوط افزایشی با نسبت های 20% بالنگوی شهری و 100% زیره سبز (b3)، 40% بالنگوی شهری و 100% زیره سبز (b4) و 60% بالنگوی شهری و 100% زیره سبز (b5) به عنوان فاکتور دوم در نظر گرفته شد. نتایج نشان داد که زیست توده علف های هرز در الگوی کشت 100 به 20 زیره سبز- بالنگوی شهری کم تر از کشت خالص بالنگوی شهری بود. بیش ترین عملکرد بیولوژیکی، عملکرد دانه و شاخص برداشت بالنگوی شهری به کنترل کامل علف های هرز در کشت خالص اختصاص داشت. عدم کنترل علف های هرز در کشت مخلوط 100 به 20 زیره سبز- بالنگوی شهری به تولید کم ترین زیست توده و عملکرد دانه بالنگوی شهری منجر شد و کم ترین شاخص برداشت بالنگوی شهری با کشت مخلوط 100 به 40 زیره سبز- بالنگوی شهری در شرایط عدم کنترل علف های هرز به دست آمد. نسبت برابری زمین در الگوهای کشت مخلوط بیش تر از یک بود. بالاترین نسبت برابری زمین (به میزان 4/1) و مجموع ارزش نسبی (به میزان 94/0) به کشت مخلوط 100 به 60 زیره سبز- بالنگوی شهری در شرایط عدم کنترل علف های هرز مربوط بود. کم ترین LER و RVT نیز در شرایط عدم کنترل علف های هرز و در الگوی کشت 100 به 20 زیره سبز- بالنگوی شهری به دست آمد. پس می توان گفت که کشت مخلوط افزایشی زیره سبز- بالنگوی شهری، به ویژه در شرایط عدم کنترل علف های هرز، نسبت به تک کشتی هر یک از دو گیاه برتری داشته و ضمن ایجاد تنوع و پایداری تولید و مهار علف های هرز مزرعه، کارایی استفاده از زمین را نیز افزایش می دهد.

    کلیدواژگان: پایداری زیستی، تداخل، تنوع گونه ای، نسبت برابری زمین
  • زهرا خمر، مهدی دهمرده*، عیسی خمری، سیدمحسن موسوی نیک صفحات 1511-1525

    به منظور بررسی اثر فواصل بین ردیف ، وجین علف های هرز و نسبت های کشت مخلوط ارزن مرواریدی (Pennisetum americanum L) و بادام زمینی رقم گلی (Arachis hypogea L.)، آزمایشی به صورت فاکتوریل در قالب طرح بلوک های کامل تصادفی در سه تکرار در سال 1391 در پژوهشکده کشاورزی دانشگاه زابل اجرا شد. فاکتورهای آزمایشی شامل چهار نسبت کاشت سری جایگزینی و افزایشی (ارزن خالص، 50 درصد ارزن + 50 درصد بادام زمینی، 100 درصد ارزن + 100 درصد بادام زمینی و بادام زمینی خالص)، سه سطح وجین علف های هرز (عدم وجین، یک بار وجین و دوبار وجین علف های هرز) و فواصل بین ردیف ها با دو سطح (40 و 50 سانتی متر) در نظر گرفته شد. صفات مورد ارزیابی منابع محیطی شامل (تشعشعات فعال فتوسنتزی، دما و رطوبت)، عناصر غذایی خاک شامل (نیتروژن (N)، منیزیم (Mg)، کلسیم (Ca) و کربن (C)) و جهت ارزیابی کشت مخلوط نسبت به خالص از شاخص نسبت برابری زمین استفاده گردید. تمامی صفات مورد بررسی تحت تاثیر سیستم کاشت قرار گرفتند. اثر متقابل معنی داری بین سیستم کاشت، وجین علف های هرز و فواصل بین ردیف ها در میزان جذب نور، دما و رطوبت وجود داشت. نتایج نشان داد که میزان تابش فعال فتوسنتزی جذب شده در کشت مخلوط بالاتر از کشت خالص هر دو گیاه بود. نتایج تغییرات عناصر غذایی خاک نشان داد که مقدار عناصر دو ظرفیتی (کلسیم و منیزیم) در مخلوط افزایشی و تک کشتی ارزن بیش تر از مخلوط جایگزینی و تک کشتی بادام زمینی بود. تیمار مخلوط افزایشی بالاترین نسبت برابری زمین (65/1) را به خود اختصاص داد. در مجموع، کشت مخلوط همراه با افزایش فواصل بین ردیف ها و وجین علف های هرز موجب افزایش میزان عناصر خاک پس از برداشت محصول و افزایش حاصلخیزی خاک شد و تیمار 100 درصد ارزن + 100 درصد بادام زمینی به دلیل بهره برداری بهتر از منابع، افزایش حاصلخیزی خاک و افزایش عملکرد نسبت به کشت های خالص برترین تیمار آزمایش بود.

    کلیدواژگان: تشعشع فعال فتوسنتزی، دمای خاک، رطوبت حجمی خاک، نسبت برابری زمین
  • عبدالنور مصدقی، ناصر اکبری*، عبدالمهدی بخشنده، فریدون سرمدیان، بهروز نصیری، سعید صوفی زاده صفحات 1527-1543

    استفاده درست و بهینه از اراضی کشاورزی مستلزم ارزیابی دقیق منابع آگرواکولوژیکی بوم نظام تولید یک منطقه است، و یکی از ساز و کارهای موثر برای درک این توانمندی پهنه بندی اگرواکولوژیکی می باشد. در این مطالعه، به منظور پهنه بندی اگرواکولوژیکی نظام‏های تولید گندم آبی (Triticum aestivum L.) دشت کشاورزی خیز شاوور خوزستان از تصاویر ماهواره ای و سیستم اطلاعات جغرافیایی استفاده شد. پس از پهنه بندی در نهایت، هشت پهنه اگرواکولوژیکی به دست آمد. سپس مشخصات اقلیم، خاک و توپوگرافی هر پهنه با نیازهای رویشی گندم مقایسه و کلاس های تناسب اراضی با استفاده از روش پارامتریک (ریشه دوم) و استوری تعیین شدند. نتایج نشان داد که کلاس تناسب اقلیم برای محصول گندم بسیار مناسب (S1) می باشد. بر اساس این روش ها به ترتیب تقریبا 42 و 58 درصد اراضی در کلاس های نسبتا مناسب (S2) و تناسب بحرانی (S3) قرار گرفتند. علاوه براین، از محدودیت های عمده در منطقه شامل حاصلخیزی ضعیف خاک، کمبود ماده آلی، پایین بودن ظرفیت تبادل کاتیونی (C.E.C) و هم چنین شور و سدیمی بودن اراضی می باشد. پتانسیل تولید گندم نیز با استفاده از روش فایو محاسبه، و مقدار آن 6823 کیلوگرم در هکتار به دست آمد. هم چنین پتانسیل تولید اراضی در هر یک از پهنه ها، نیز برآورد شد، که به دلیل اثرات عوامل محدودکننده فوق الذکر پتانسیل تولید اراضی گندم در پهنه های موسوم به اراضی خلف عزیز (A)، بام دژ (B)، الهایی (C)، علی چعب (D)، کرخه (E)، عبدالخان (F)، سید عباس (G) و بیت حاتم (H) به ترتیب 28، 60، 60، 60، 55، 52، 40 و 51 درصد کاهش نشان داد که با اصلاح این محدودیت ها مثل اعمال مدیریت صحیح از قبیل افزایش ماده آلی به خاک و آب شویی اراضی می توان تولید محصول را در این بوم نظام ها افزایش داد.

    کلیدواژگان: پتانسیل تولید، تناسب اراضی، ماده آلی
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  • Majid Reza kiani, Alireza Koocheki*, Mahdi Nasiri Mahallati, Ahamd Zareh Feiz Abadi Pages 1183-1203
    Introduction

    In the next 20 years, food production for the growing population is one of the most important issues. As increasing planting area is limited, improving productivity and yield is the only solution which could be reached through crop breeding and improving pest, disease and weeds control methods and increasing use efficeincy of fertilizers and water. Most of the time, increasing production in agricltulre is alongside with more intensification in agriculture. There is now specific definition for this term but in a general definition it means increasing the number of crops planted in unit of area (one hectare) through a year, as well as increasing using of inputs including fertilizers, chemicals and machinery in unit of area. Macleod and Moller (2006) evaluated the trend of intensification in Newzland agriculture by examining changes in 35 agricultural variables (e.g planting area, yield, inputs in unit of area and population related to agricultural production). Their results showed that intesnification is increased through 40 years (1961-200) which can threat sustainability of Newzeland farming in future.Agriculture intensification in Iran started since 1921 by using agricultural machinery and chemical fertilizers and increased rapidly after approval of land reform law in 1961s. Increasing the application of inputs in Iran agriculture has resulted to decrease sustainability of agricltural production and aslo destruction of forest and rangelands.  Therefore, in this research time trend of intensification of cropping systems of Iran is studied using different indicators.

    Materials and Methods

    In order to evaluate the status and the trend of agriculture intensification in Iran, 63 variables in 5 groups including land use (cultivated area of each crop), production of each crop, yield, inputs (fertilizers, machinery and energy) and urban and ural population are examained for a 50-year period (1962 to 2011). Poduction stability was evaluated by calculating coeficeint of variance (CV) of planting area, production and yield in main agriculltural crops and fruits seperatly in each decades. For evaluating the sensivity of crops and fruit production to environmental changes the ratio of yield in a individual year to overal mean of yield for each ten years calculated for each crop seperately and for all crops as a yield capacity. The slope of the regression between yield capacity of each crop to yield capacity of all crops is an index for sensivity to environmental changes. All analysis and drwaing graphs were conducted using Xlstat 2014 and Excel 2103.

    Results

    Results showed that land use changes, increasing use of inputs and population growth are the main factors affecting intensification in Iran agriculture. From 1961 to 2011 the planting area has extended 2 times related to 6.6 million hectare at the beginning of this period and the agricultural productions increased to 94 million tons which was 7 times higher related to 13.3 million tons in 1961. During this period the main driving factor before 1980 is approving land reform law and increasing use of inputs which resulted to increase cultivated area and productions. In the following years increasing the application  of fertilizers, agricultural machinery and new varieties were the main factors affecting agricultural productions and intensifciation. Our research showed that through the evaluation period, variance of cultivated area and production decreased but the variance of yield increased and hence yield stability decreased. Principal component analysis (PCA) classified 63 variables in two main compontents which first one described 51 percent of total variation including land use, production, yield trend and also uses of inputs. The second component described 20 percent of variation including input use efficiency and use of maschinery.Based on the changes in agicultural variables, PCA divided years into to 6 periods including 1962-1965, 1966-1980, 1981-1990, 1991-1998, 1999-2007and 2008-2011. During the first 3 periods agricultural area, production and yield were increased but during the next 3 periods the rate of increasing decreased. However, our research showed that Iran agriculture has been going through intensification in the last 50 years and approaching to food security is most likely possible through increasing efficient use of inputs by improving varieties and managmement of agricultural systems.

    Keywords: Agriculture, Intensification, Iran, Stability, Yield capacity
  • Farzad Mondani*, Kianoosh Khani, Saeid Jalali Honarmand, Mohsen Saeedi Pages 1205-1224
    Introduction

    Water scarcity and frequent droughts are becoming a serious problem particularly in the context of alarming predictions of climate change in the world. Within the arid and semi-arid regions, water availability is a major limitation for crop production. Thus, it is necessary to improve yield and the efficient utilization of limited available water in the irrigated agroecosystems. One possibility to enhance crop yield under water limitation is using soil microorganisms that increase the radiation and water efficiency and uptake capacity. Among these potential soil microorganisms, plant growth-promoting rhizobacteria (PGPR) are the most promising, including all bacteria inhabiting the rhizosphere and the rhizoplane able to simulate plant growth and yield. Therefore, the objective of the present study was to evaluate the effects of the PGPR on the ecophysiological characteristics of soybean under different moisture regimes.

    Material and Methods

    The field experiment was conducted during 2016 at the research farm of Campus of Agriculture and Natural Research, Razi University, Kermanshah, Iran (34°, 19´ N, 47°, 50´ E with 1320 m altitude). A split plot factorial experiment was conducted based on randomized complete block design. Main plots had three irrigation regimes in which irrigation was cut based on the soybean stages (I1: water deficit stress from mid pod development stage to maturity stage; I2: water deficit stress from grain filling development stage to maturity stage; and I3: optimum irrigation in all development stages) and sub-plots were composed of plant growth-promoting rhizobacteria (PGPR) (B1: no bacteria; B2: Bacillus subtilis; and B: Bacillus licheniformis) and soybean cultivar (TMS, M9 and Kosar). The experimental plots were irrigated based on furrow method. I3 treatment were irrigated every 7 days until the end of the growing period while in the I1 and I2 treatments, the plots were irrigated every 7 days until the start of the water deficit stress. In order to inoculate with the PGPR, the soybean seeds were plunged in a 1:10 (v:v) solution of liquid culture and distilled water, respectively for 10 minutes. All seeds including inoculated and no inoculated seeds oven-dried at 30 ℃ for 5 h. Finally, the soybean inoculated seeds by PGPR were inoculated by Rhizobium japonicum before sowing and cultivated immediately at 4 to 5 cm soil depth. The evaluated traits were the leaf area index (LAI), radiation absorption (RA), crop growth rate (CGR), relative growth ratio (RGR), total dry weight (TDW), radiation use efficiency (RUE) and Grain yield (GY).

    Results and Discussion

    The results indicated that the water deficit stress reduced the LAI, RA, CGR, RGR, TDW, RUE and GY of soybean. The PGPR application improved all measured traits of soybean in all irrigation regime treatments. The highest LAI (6.7), RA (18.2 MJ.m-2), CGR (20.6 g.m-2.d-1), TDW (1104.7 g.m-2) and RUE (1.165 g.MJ-1) were related to TMS cultivar in the optimum irrigation and B. licheniformis treatment and the lowest them were related to Kosar cultivar under water deficit stress from mid pod development stage to maturity stage and no bacteria treatment. The greatest GY (380.9 g.m-2) was related to TMS cultivar which was observed in the optimum irrigation and B. licheniformis treatment and the lowest GY (134.2 g.m-2) was related to Kosar cultivar which was observed in the water deficit stress from mid pod development stage to maturity stage and no bacteria treatment. In this study, B. licheniformis compared to B. subtilis presented a more effective improvement in soybean LAI, RA, CGR, RGR, TDW, RUE and GY.

    Conclusion

    It seems that the PGPR could promote the soybean growth and yield via increasing the root system and more uptake of water in the rhizosphere. Nevertheless, as the results showed, the more effects of the PGPR were observed in the I2 treatment compared to other treatments. The PGPR actually could promote the soybean growth and yield in the mid water deficit stress.

    Keywords: Grain yield, Growth indices, Radiation absorption, Radiation use efficiency, Water deficit stress
  • elmira mohammadvand, Alireza Koocheki*, Mahdi Nassiri Mahallati, bijan Yaghoubi Pages 1225-1239
    Introduction

    Weed–crop competition as one of the main reasons for crop loss is often influenced by many factors including emergence time and density of competing species. Patterns of weed seedling emergence affect the outcome of weed–crop interference interactions. Information on weed seedling emergence in relation to crop seeding will assist in developing an optimum weed control program.Weeds emerge simultaneously with a crop, have the greatest potential impact on crop production. Results from Chauhan & Johnson (2010) showed the advantage for weeds over rice in situations where these species emerge earlier in the growing season because of significantly greater biomass production comparing to those emerging later in the season. Minimal shading and competition for nutrients and soil moisture are associated with early emergence.The importance of density in competition studies is because of the relationship among plant yield, number of individuals, and resources present. Increasing the density may enhance the plant’s share of the total resource pool and reduce resource availability for adjacent plant. Thus, to analyze competition between the crop and weeds, the variation in density should be considered. Season-long competition with watergrass at densities of 86 and 36 plants/m2 reduced rice yields by 59% and 46%, respectively.Understanding relative aggressiveness of component species is required for the integrated weed management and it would improve weed management strategies. For watergrass as a relatively new-introduced weed species in paddy rice fields of Guilan province, it is essential to investigate the effects of the emergence time in nursery, to determine weed seedling ages at the time of transplanting, as well the amount of weed seedling translocation characterizing weed density in the field.

    Materials and Methods

    Factorial arrangements of watergrass seedlings ages at the time of transplanting (10, 20 and 30 days), and plant proportions of weed:rice (0:4, 1:3, 2:2, 3:1, and 4:0) were designed as a randomized complete block with three replications to study yield characteristics and competitive ability of watergrass and rice over two years of a field experiment. Individual plants of each hill constituted as a single experimental unit. The area between individual hills was hand-weeded to avoid competition from other species. At rice maturity stage, plants were harvested, and rice and watergrass panicles were separated from stems by hand. Panicles were dried to a constant weight at 75 ℃, and weights were determined. Grain weights standardized to 12% moisture content. Biological yields of rice and watergrass were also measured after sampling their above-ground parts from an area of 1 m2 and drying at 75 ℃ until constant weight. Data were subjected to ANOVA, and means were separated using Fisher’s Protected LSD at P < 0.05. Competitiveness of the species was assessed based on the relative yield (the ratio between the production of the species in the mixture and in monoculture), relative yield total (total relative yield of the two associated species), aggressivity index and replacement series diagrams (models describing the possible outcomes of the interaction of two species when grown in a replacement series).

    Results and Discussion

    For each species, the greater ratio at the planting proportion, the higher biological yield, grain yield, relative yield, and aggressivity index, but the lower harvest index. When grown in monocultures, and 1 weed: 3 rice of the second year, the two species produced similar grain yield; however in the other mixtures watergrass produced more biological and grain yield compared to the rice. Harvest index of rice was greater than watergrass in all planting proportions. In the first year, trials of 30-day watergrass seedling ages represented the highest values of biological-, grain-, and relative yield, and the lowest values of grain and relative yield of rice and harvest indices of both species. Also, for all watergrass seedling ages in both years, weed production was more than rice.

    Conclusion

    Investigating grain and biological yield, and relative yield of both species, and aggressivity index of rice, beside replacement series diagrams exhibited higher competitiveness for watergrass comparing to rice. Therefore, it is important to maintain watergrass control in order to insure the sustainability of transplanted rice production.

    Keywords: Competition, Emergence patterns, Planting proportion, Relative density
  • Forotan Bahadori Birgani*, Jahanfar Daneshiyan, SeyedAliReza Valad Abadi, Saeed Seyfzadeh, Esmaeel Hadidi Masoleh Pages 1241-1259
    Introduction

    Khuzestan province is one of the important regions for sugarcane production with more than 100,000 hectares under sugarcane cultivation. Sugarcane monoculture is common all over the world and continuing this system gradually reduces the yield and soil fertility. Monoculture systems, by creating unfavorable biological and physicochemical conditions in the soil, reduce the amount of organic carbon and nutrients in the soil. However, in an agricultural system, suitable agronomic selection, proper management of agronomic operation specially plowing, proper use of chemical and organic fertilizers, preservation of vegetation and proper management of plant residue have a decisive role in the amount and dynamics of mineral and organic elements. Various studies showed that rotation, particularly with green fertilizers, have led to breaking the pathogenic cycle and improving the physical and chemical properties of soil, including soil organic matter.

    Materials and Methods

    In order to evaluate the changes in the amount of carbon and organic matter, nitrogen, phosphorus and potassium residue in soil under different crop rotation conditions, this study was performed in a randomized complete block design with three replications during 2014-2016 for three consecutive years in the field of Amirkabir sugarcane Agro-Industry. The experiment treatments consisted of ten alternatives: 1) wheat-clover-sugarcane; 2) rapeseed-clover-sugarcane; 3) barley-clover-sugarcane; 4) sorghum-clover-sugarcane; 5) clover-vetch-sugarcane; 6) clover- clover- sugarcane, 7) clover- clover (third aftermath)- sugarcane, 8) clover- soybean- sugarcane, 9) clover- corn - sugarcane, and 10) fallow- fallow- sugarcane. The results showed that there was no significant difference between the changes in phosphorus in three years of experiment at both soil depths, but the amount of potassium and organic carbon was decreased during the third year of experiment. Analysis of variance showed that the amount of P, N and organic carbon content were significantly different in both soil depths under crop rotations. Also, under crop rotation, potassium and C/N ratio were different in 0-30 cm and 30-60 cm soil depths, respectively. The highest amount of nitrogen, phosphorus and carbon to nitrogen ratio were observed in clover-clover- sugarcane, fallow-fallow-sugarcane and sorghum-clover-sugarcane.

    Results and Discussion

    The results showed that the changes in the phosphorus content during three years of implementation of the project based on variance analysis even at 0-30 C depth, or at a depth of 60 to 30 cm, did not have a significant difference and the amount of phosphorus was remained almost constant.NitrogenThe results showed that the process of nitrogen changes during three years of experiment was based on analysis of variance at 0-30 and 30-60 cm of soil depths has significant difference and the amount of nitrogen has changed.Organic matter, Organic carbon and C:NOrganic matters of the soil is as the most effective factor in the sustainability of pasture and forest ecosystems, soil protection layer against erosion, temperature regulator, habitat and food supply for soil organisms and the main place of mineral nutrition.Potassium Potassium plays an important role in soil fertility. The statistical analysis of soil potassium showed that the amount of potassium had significant differences in two studied soil layers during three years of project implementation.Sugarcane yieldThe results showed that the highest yields were related to the crop rotation of clover-mung bean-sugarcane and clover- clover (third aftermath)-sugarcane rotations with 124 and 121 t.ha-1, respectively. Also, the lowest yield was related to the varieties of fallow-fallow-sugarcane and clover-corn-Sugarcane, with 95 and 98 t.ha-1, respectively.

    Conclusion

    The results showed that phosphorus in the soil did not change significantly during the experiment, but the amount of potassium, organic carbon and soil organic matter during the first and the second years remained constant but it decreased during the third year. Also, the implementation of different crop rotation affected soil nutrient elements. The highest amount of nitrogen, phosphorus and carbon to nitrogen ratios were observed in clover-clover- sugarcane, fallow-fallow-sugarcane and sorghum-clover-sugarcane. The impact of crop rotation on sugarcane yield also showed that cultivating legumes of clover and mung bean before sugarcane has a great influence on sugarcane yield.

    Keywords: Clover, Fabaceae, Organic matter, Phosphorus
  • Eftekhar rahmati, shiva khalesro*, Gholamreza Heidari Pages 1261-1273
    Introduction

    Intercropping system is one of the most important strategies for achieving sustainable agriculture goals. Intercropping increases biodiversity in agroecosystems and enhances yield on a given piece of land by making more efficient use of the available resources. In these systems, legumes are a key functional group, and are highly valued for the agroecological services they provide. Adding legumes in fields is justified by their natural ability to exploit atmospheric nitrogen. This additional source of N is expected to avoid inter-specific competition between plants and legumes for N acquisition. Medicinal plants play pivotal role in human health. The use of sustainable agriculture is the foundation for safe and healthy Medicinal plants. Therefore, the purpose of this research was evaluation of quantitative and qualitative traits of black cumin (Nigella sativa L.) and fenugreek (Trigonella foenum-greacum L.) in additive and replacement series of intercropping.

    Materials and Methods

    Field experiment was conducted at the Agricultural Research station, University of Kurdistan, during 2015 growing season. In this research, qualitative and quantitative traits of black cumin and fenugreek were investigated. Experimental design was randomized complete block with three replications. Experimental factors were 50% fenugreek + 50% black cumin, 25% black cumin + 75% fenugreek, 75% black cumin + 25% fenugreek, 100% black cumin + 12.5% fenugreek, 100% black cumin + 25% fenugreek, 100% black cumin + 37.5% fenugreek, 100% black cumin + 50% fenugreek based on replacement and additive series and their monocultures. The seeds were sown directly on 4th of May for both plants. In this study, morphological characteristics consisted of branch number per plant, follicle number per plant, seed number per follicle, 1000 seed weight, essential oil content, essential oil yield of black cumin and branch number per plant, pod number per plant, seed number per pod, 1000 seed weight of fenugreek and biological and seed yield were measured in both plants. Intercropping indexes included of LER and ATER were also evaluated. The obtained data were subjected to analysis of variance (ANOVA) using SAS statistical software and means were compared using the least significant difference test (L.S.D) at level of 0.05.

    Results and Discussion

    The results revealed that different intercropping ratios had significant effect on morphological traits, biological and seed yield of both plants. The usage of 100% black cumin + 12.5% fenugreek gave the highest values of branch number per plant (18.87), follicle Number per plant (29.73), Seed number per follicle (52.6), 1000-seed weight (2.67 g), seed yield (972.1 kg.ha-1), biological yield (2757.1 kg.ha-1) and essential oil yield (11.19 kg.ha-1) of black cumin. It seems that black cumin was more efficient for uptake nutrient resources in comparison with fenugreek. With increasing fenugreek density different traits of black cumin decreased in the other additive treatments. This decrement maybe related to the effect of density which increases competition. Statistical analysis revealed that all traits of fenugreek such as branch number per plant, pod number per plant, Seed number per pod, 1000-seed weight, biological yield and seed yield were 12.27, 16.80, 11.63, 15.77g, 3266.7 kg.ha-1 and 874.4 kg.ha-1, respectively. These values belonged to monoculture of fenugreek. Intercropping indexes included of LER (1.36) and ATER (1.30) showed higher values in 100% black cumin + 12.5% fenugreek treatment.

    Conclusion

    The highest values of most characteristics of black cumin were obtained from 100% black cumin + 12.5% fenugreek. Furthermore, it could be concluded that the mentioned additive series was the best treatment of intercropping and gave the highest LER and ATER due to improved growth condition.

    Keywords: Additive series, Essential oil, Land equivalent ratio, Medicinal plants, Sustainable agriculture
  • somayeh soheili movahhed, saeid khomari*, parisa sheikhzadeh, bahram alizadeh Pages 1275-1291
    Introduction

    Plants under natural and agronomic conditions are constantly exposed to different stresses. In this regard, drought stress is the most important limiting factor to crop yields in many parts of the world and Iran, particularly, if the water stress occurs during the flowering stage, it will affect the crop production. Drought stress disrupts the nutritional balance of plant. Proper nutrition under stress conditions can partly help plant against various stresses. Plants growth under stress can be improved by micro nutrients foliar application. Boron is important in the plant growth and its deficiency is one of the major constraints to crop production. Zinc plays a key role in the various biochemical processes of plant cells. Its deficiency will be apparent in various forms such as growth retardation, yield and concentration of the element in different parts of a plant such as seeds. The aim of this study was to investigate the effect of boron and zinc foliar application on yield and some agronomic and morphological traits of spring safflower (cv. Mahalli-e Esfahan) under late-season water deficit in Ardabil province.

    Materials and Methods

    The field experiment was conducted at the Research Farm of the University of Mohaghegh Ardabili, Ardabil, Iran during 2013-14 and 2014-15 growing seasons. The experimental design was a split factorial in a randomized complete block with three replications. Three irrigation treatments (S1: full irrigation until the end of season (control), S2: irrigation with holding from flowering and S3: irrigation with holding from seed filling) were randomized to the main plots and the sub-plot included factorial combination of B (B1: 0, B2: 350, B3: 700 ppm) and Zn (Zn1: 0, Zn2: 1000, Zn3: 2000 ppm). B was added as boric acid (H3BO3) and Zn as zinc sulfate (ZnSO4). The treatments were applied during flowering (when 50% of the plants were at anthesis) as foliar applications. All other agricultural practices (weeds control and irrigation), were performed when they were required and as recommended for safflower production. The measured traits included seed coat percentage, seed kernel percentage, seed coat to kernel ratio, leaf number, capitol diameter, seed length, seed width and seed yield. Analyses of variance and comparison of means at P≤0.05 were carried out, using SAS 9.1 software. The means were compared using LSD test.

    Results and Discussion

    Combined analysis of variance of the data showed that year, irrigation and year × irrigation interaction were significant for all the traits. Also, all traits (except leaf number) were significantly affected by B, Zn and B × Zn interaction. Seed coat percentage, seed kernel percentage and seed coat to kernel ratio were significantly affected by year×B, year × Zn and year×B×Zn interactions. Seed length and seed yield were significantly affected by year×irrigation×B and year×B×Zn interactions, respectively. During the first year, all the investigated traits influenced from deterrent impacts of drought stress. Water deficit stress at the flowering and seed filling stages significantly decreased seed yield compared to full irrigation (15.62% at flowering and 12.77% at seed filling). During the second year, there was no significant difference among all the treatments due to heavy rainfall. The results showed that B and Zn foliar application had a positive and significant effect on seed coat percentage, seed kernel percentage, seed coat to kernel ratio, capitol diameter, seed length, seed width and seed yield. The treatments of B3Zn2 and B2Zn2 had the greatest increase of these parameters in comparison with B1Zn1 (control) in both years. Boron and zinc foliar application significantly improved most traits under water stress levels.Acknowledgments We would like to thank from the Faculty of Agriculture, Mohaghegh Ardabili University, for supporting this study.

    Keywords: Drought stress, Micronutrients, Seed coat, kernel
  • jalal ghaderi*, Adel Nemati, Mohmoud Shariatmadari Pages 1293-1307
    Introduction

    Use of chemical fertilizers is an essential component of modern farming and about 50% of the world’s crop production can be attributed to fertilizer use. Sustainable production of crops cannot be maintained by using only chemical fertilizers and similarly it is not possible to obtain higher crop yield using organic manure alone. A balanced fertilization is needed to obtain optimum potential yield. The continuous imbalanced use of chemical fertilizers is creating complexity in our soils and the soil health is deteriorating. Application of municipal solid waste compost (MSW) is commonly applied to the soils to improve their physical, chemical and biological properties. Soil amendment with MSW is very useful for agricultural crop production. Wheat (Triticum aestivum L.) is the world’s leading cereal crop both in area and production and about two-third of people of our planet live on it. It plays an important role in diet of human being as well as in industrial uses. The present study was conducted to better understand the effect of MSW and chemical fertilizers on quantitative and qualitative yield of irrigated wheat in kermanshah condition.

    Materials and Methods

    In order to study the effects of municipal solid waste compost (MSW) and chemical fertilizers on quantitative and qualitative yield of Bahar wheat cultivar, a field experiment was conducted with chemical fertilizers at four levels (0, conventional farmers, based on soil test and 25% lower than the soil test), and MSW at four levels (0, 10, 20 and 30 ton.ha-1) in a factorial experiment based on randomized complete blocks design (RCBD) with three replications in Kermanshah region during 2014-2015.Prior to sowing, MSW and chemical fertilizers was applied and mixed thoroughly with the soil. Before planting, combined soil sample from a depth of 0–30 cm was collected to determine some soil chemical properties.Plots were designed with 4 ×4 m, 1 m apart from each other., 1.5 m alley was kept between blocks. Wheat seeds (var. Bahar) were planted 2.5 cm apart from each other. During the growth and development stages, plots were irrigated based on the crop water requirement. Irrigation method was sprinkler. Grain yield were determined after the harvest and seed samples (harvesting stage) were taken and rinsed with distilled water, oven dried at 70°C, ground, digested and analyzed for determining the N, P, K, Fe, Zn, Mn, Cu, Pb and Cd concentration. Analysis of variance was performed using MSTAT-C and mean comparisons done by Duncan’s multiple range test (P ≤ 0.05).

    Results and Discussion

    Results showed that MWS and chemical fertilizers and their interaction effects had significant effects on experimental traits. Using of MWS with chemical fertilizers led to increase plant height, 1000 grain weight, seed number per spike, grain yield, protein percent and nutrients concentration in grain. The results of means comparison showed that the highest grain yield (5900 kg.ha-1), 1000 seed weight (39 g), grain number per spike (71), protein percent (12.6) and nutrients concentration in grain was obtained under the co-application of 10 ton.ha-1 MWS and chemical fertilizers (25 percent less than the soil test) and the lowest amounts of experimental traits were shown in control treatment. Our results are in agreement with some experiments which use of compost and chemical fertilizers on irrigated wheat.

    Conclusion

    The result of this experiment revealed that using of compost and chemical fertilizers in integrated form instead of individual application has a beneficial effect on improving the quantitative and qualitative yield of irrigated wheat. Based on the obtained results, co-application of 10 ton.ha-1 compost and chemical fertilizers (25 percent less than the soil test) at kermanshah condition can be recommended.

    Keywords: Iron, Nitrogen, Organic manure, Phosphorus, Zinc
  • Abdolghader Enayati, morteza barmaki*, Raouf SeyedSharifi, Abdollatif Gholizadeh Pages 1309-1326
    Introduction

    Water shortage in terminal phases of wheat growth causes low-quality seeds in wheat. Extra use of chemical fertilizer has an adverse effect on the environment. Wheat (Triticum aestivum L.) is very important in Iran grown on 7 million ha of the total national cultivated; irrigated wheat farms accounting for 35% of the total wheat lands. It grows mainly during dry seasons, where irrigation is necessary because precipitation in the growing season is far less than the crop water requirement. Within the arid and semi-arid regions, water available is a major limitation for crop production. Wheat needs sufficient available water and nutrient to achieve optimum yields, quality, and adequate grain-protein content. In recent years, the water shortage has gradually increased in most of the countries mainly due to the annual increasing irrigation and dry climate. Therefore, the present study was undertaken to evaluate the effects of azotobacter and mycorrhiza fungus on yield and yield components of wheat varieties and quality of derived seeds under supplementary irrigation. The present study experiment was conducted as a factorial arranged in a randomized complete block design with three replications in the Research station of Gorgan (Iraqi Mahalle).

    Materials and Methods

    To evaluate the effect of azotobacter and mycorrihza application on yield, yield components and seed quality of wheat cultivars an experiment was carried out in the Research Station of Gorgan (Iraqi Mahalle). Experimental factors including two irrigated wheat varieties namely N-80-20 and Gonbad Cv., six levels of inoculations (1) non inoculated as control, (2) application of mycorrihza  (G. intraradices), (3) inoculation with powdery A.chroococcum, (4) inoculation with liquid A.chroococcum, (5) inoculation with powdery A.chroococcum+G. intraradices, (6) inoculation with liquid A.chroococcum+G. intraradices, and three levels of supplementary irrigation (non-irrigated, irrigation at booting and irrigation at the full flowering stage). The studied traits were plant height, spike length, number of spikes, number of seed per spike, 1000-seed weight, seed yield, biologic yield, harvest index, seed germination percentage, seed germination rate, seedling length, seedling dry weight and length vigor index. For statistical analysis, analysis of variance (ANOVA) and Duncan’s multiple range test (DMRT) were performed using SPSS and STATISTICA software. The graphs were drawn by excel software.

    Results and Discussion

    Results revealed that inoculation of wheat varieties with a combination of azotobacter and mycorrihza induced seed yield and yield components increment as well as quality improvement of derived seeds. Supplementary irrigation at full flowering phase had more positive effects on traits of wheat varieties. Considering the investigated characteristics, N-80-20 had a better response to seed inoculation and supplementary irrigation comparing to Gonbad cultivar. The maximum seed yield (5987.33 kg.ha-1) was achieved with the application of mycorrihza + liquid azotobacter under supplementary irrigation at full flowering phase of wheat growth.It seems that application of biological fertilizers and supplementary irrigation is an appropriate and low-cost method for increasing of yield and improvement of seed quality of wheat. Seed inoculation of N-80-20 cultivar with mycorrihza + liquied azotobacter was increased the seed yield 10 percentage compared to control condition. Seed germination percentage and rate of wheat cultivars under supplementary irrigation was significantly increased. The maximum seed germination percentage (95.7%) was observed with the application of mycorrihza + liquied azotobacter. N-80-20 in compared to Gonbad cultivar was demonstrated better response regarding studied traits.

    Conclusion

    According to the results, in order to increase seed yield and improving seed quality, inoculation of seeds with a joint combination of azotobacter and mycorrihza along with supplementary irrigation at the full flowering stage of wheat could be recommended.

    Keywords: Biologic fertilizer, Seed quality, Seed yield, Supplementary irrigation, Wheat cultivars
  • Iman Haghian, Mohsen Sharafatmandrad* Pages 1327-1341
    Introduction

    Plants distribution in nature is not by chance, but it is a function of various factors such as topographical, edaphic, climatic, anthropogenic factors, etc. Environmental factors along with management factors play an important role on the species composition and richness. In fact, there is a high correlation between the establishment of plants and environmental conditions, so that the composition and structure of plant communities largely influenced by environmental factors. In particular, soil and its numerous properties play a significant role in the establishment of plant species. These facts show the importance of medicinal plants and their influential environmental factors and state that such studies are necessary in all fields of natural resources. Therefore, this study was aimed to determine the region plant communities and their medicinal plant species, and to identify factors affecting the establishment of these communities using ordination method. Considering the region conditions, its pristine nature, the high population of exploiters, and lack of basic information about vegetation, this study can also be effective in improving economic and social conditions of the region residents.

    Materials and Methods

    The study area basin is mountain rangelands of Deraseleh that is located in one of sub basins of Talar River (one of the major Caspian Sea sub basin) in Mazandaran Province. For random-systematic sampling, the 50-meter transects were randomly laid out in the region and 5 plots were systematically established along each transect with 10 meters interval. Therefore, a total of 60 transects and 300 plots were sampled. Soil samples were taken in the middle of transects from 0–30 cm depth. Soil samples was transferred to the laboratory to measure soil properties including soil texture, electrical conductivity (EC), acidity (pH), nitrogen (N), phosphorus (P), calcium carbonate (CaCO3) and potassium (K) and organic carbon (OC).After data normalization, DCA that is an indirect ordination method was used to identify changes in plant composition and to determine gradient length. As gradient length was more than three, CCA that is a direct ordination method was selected for assessing the vegetation and environmental variables relationships.

    Results and Discussion

    The region flora consists of 94 plant species belonging to 79 genera and 29 plant families. Considering medicinal plants, 29 species were dominant in the region and Lamiaceae family with 13 species had the frequency in the region.DCA analysis showed that the importance of axes decline to the forth axis on the basis of Eigen values. Based on the gradient length and Eigen values, CCA was used to determine the effect of soil factors on medicinal plants. Different soil factors had significant effects on species distribution. Each of soil properties controls the distribution of the species to a certain extent. CCA analysis showed that the effect of environmental factors on vegetation is meaningful (P=0.001; F=1.68). Generally, some species were affected by a variable but some by several variables. Some species did not show significant correlation with soil properties.

    Conclusion

    Knowing about environmental factors controlling vegetation can optimize management of rangeland ecosystems that helps farmers to utilize their land sustainably. Identifying medicinal plants and understanding their controlling factors can be effective in determining management practices. In this study, ordination techniques showed that plant species belonged to the same family or genus are not necessarily influenced by the same environmental factor. For example, two species of Ferula were influenced by different factors. Soil texture and pH had somewhat more effects than other variables on vegetation. Soil properties had negligible effect on some species such as Senecio vulgaris and Vaccaria liniflora. It can be suggested that other factors such as topography and management may be effective on this species. In conclusion it must be said that, the ecological needs must be identified for optimal utilization of forage and medicinal species and species with use in industry. Then, proceed to the cultivation and exploitation of plant species according to controlling environmental factors.

    Keywords: Environmental factors, Multivariate analysis, Ordination, Rangeland, Vegetation
  • SeyedAta Siadat*, Abolfazl Derakhshan Pages 1343-1356
    Introduction

    Supplementing crop growth with nitrogen (N) can significantly increase yields. However, the excessive use of N in intensive cropping systems has led to lower N use efficiency, an increase in greenhouse gas emissions as well as water pollution. The critical N concentration (Nc) is the minimum N required for maximal growth and can be used as a tool for accurate N management during the growing season. Leaf dry matter (LDM) is an important indicator of crop growth potential and a measure of light-energy utilization, and yield formation in rapeseed. LDM increases as more N fertilizer is applied, although differences in LDM are small under high fertilization levels. Therefore, construction of a Nc curve based on LDM during the vegetative growth of spring rapeseed would be a worthwhile objective. Our aims in the present study were (i) to construct a leaf Nc curve, (ii) to compare this curve with published data, and (iii) to explore its potential for estimating spring rapeseed leaf N status.

    Materials and Methods

    A field experiment with seven levels of N fertilizer including 0, 50, 100, 150, 200, 250 and 300 kg.ha-1 was performed, and LDM and leaf N concentration (LNC) of two spring rapeseed cultivars were measured during the growing season. The procedure used for constructing the leaf Nc curve was first proposed by Justes et al. (1994). The N nutrition index (NNI) on each sampling date was calculated by dividing LNC by leaf Nc concentration. The accumulated N deficit (Nand) in leaves for each sampling date was determined by subtracting the N accumulation in leaves under the Nc condition from actual N accumulation in leaves under different N rates.

    Results and Discussion

    N application rate exhibited a significant effect on LDM during the vegetative growth of rapeseed. The LDM increased gradually with increasing N utilization. LDM ranged from 0.06-3.83 ton.ha-1 for Hyola 401 cv. and from 0.06-3.56 ton.ha-1 for Dalgan cv. LNC generally increased with increasing N application. LNC remained relatively stable during the early growth but decreased gradually as cultivars reached the flowering stage. LNC values ranged from 2.44-6.2% for Hyola 401 cv. and from 3.14-6.1% for Dalgan cv. The leaf Nc concentrations in Hyola 401 and Dalgan cultivars declined with increasing LDM and the curve for these cultivars was fitted according to the equation Nc=5.08LDM-0.06. The similar trends of decline in leaf N dilution have been previously reported in winter wheat, maize and rice, when N dilution was estimated on the whole plant or specific plant organs basis. NNI values began to decrease with the decrease in the quantity of applied N. NNI values varied from 0.72-1.14 in the Dalgan cv. and from 0.53-1.15 in the Hyola 401 cv. The NNI values were greater than one for non-N limiting treatments and less than one for N-limiting treatments. These results confirm that NNI can provide accurate and quantitative insight into the N nutrition status of rapeseed. The Nand values ranged between -11.61-107.09 kg N ha-1 in the Dalgan cv. and between -24.22-129.64 for the Hyola 401 cv. depending on the N dosage. Nand decreased with increased N rates, while intensified gradually over growth progress of rapeseed and reached its peak at flowering stage for N-limiting treatments. These results confirmed the usefulness of Nand for assessing N nutrition in spring rapeseed. There was a significant positive correlation between the changes in N application rates (ΔN) and the changes in NNI (ΔNNI), and between ΔN and the changes in Nand (ΔNand). Generally, the Nc dilution curve, NNI, and Nand derived from it well recognized nutrition status of two cultivars under N-limiting and non-N limiting conditions, and can be used to as a reliable indicator of the crop N status during the growing season.

    Conclusion

    The N concentration in the canopy leaves decreased with advancing maturity, while a higher N application rate generally exhibited a higher leaf N concentration. The present Nc dilution curve based on LDM provides an insight into N nutrition status in spring rapeseed plant and can serve as a novel tool to improve N fertilization management in rapeseed.

    Keywords: Critical nitrogen, Nitrogen deficiency, Nitrogen nutrition index, Nitrogen use optimization, Precise nitrogen management
  • FARZANEH rigi, Mehdi dahmardeh*, issa khammari, reza bagheri Pages 1357-1374
    Introduction

    Roselle (Hibiscus sabdariffa L.) is a medicinal plant and belongs to the family Malvaceae, short day plant, self-pollination, one year old or a few years old in the warm and indigenous climate of Africa. The main objective in crop management is to maximize light gain by crop canopy. Nitrogen is the first element that has a shortage in arid and semi-arid regions. Considering that agriculture in the Sistan region is associated with unfavorable environmental factors such as water shortages and nutrients in the soil, and severe 120-day winds. The aim of this research was to investigate the planting direction for determining the most suitable planting direction, optimal use of chemical fertilizers and determining their best application time for the medicinal plant of Roselle under Sistan climate conditions.

    Materials and Methods

    A split plot experiment was conducted in a randomized complete block design with three replications at the Research Institute of Zabol University during growing season of 2016-2017. Treatments experiment included two levels of planting directions two levels (North-South, East-West) As the main plot and the split of nitrogen fertilizer from the source of urea in four levels (1/3 per planting, 1/3 four leaf stage, 1/3 stem elongation; 1/2 post planting, 1/2 four leaf stage; 1/2 four leaf stage, 1/2 stem elongation; 1/3 four leaf stage, 1/3 stem elongation, 1/3 Flowering stage) as a subsidiary agent. Ecological parameters such as light, temperature and soil moisture at the end of flowering stage and organic matter, nitrogen and soil carbon were measured after plant harvest. The morphological characteristics were measured at the end of the growth season at the end of the complete inspection of the Sepals. Data were averaged for each sample (measured for 5 samples), with variance and mean computation. The mean test was performed using a 5% mean field test and a knowledge Duncan multiple test. Statistical data analysis was performed using SAS software version 9.1.

    Results and Discussion

    The results showed that the effect of planting directions and split of nitrogen fertilizer on traits stem height, stem diameter, number of lateral branch, number of boll, economical yield, sepals dry weight, harvest  index was significant. Except for the number of lateral branches, all morphological traits measured for north-south planting directions were the highest. The highest economical yield was 644 kg.ha-1 the biological yield of 9352 kg.ha-1and the harvest index of 6.39 kg.ha-1were obtained from treatment (1/3 four leaf stage, 1/3 stem elongation, 1/3 flowering stage) The results of correlation coefficients between morphological and ecological traits showed that the highest correlation (0.96) (0.91) was found between the number of flower bowls with economic performance and between stem diameter and economic performance, which was positive and very significant. Thereafter, there was the highest correlation (-0.85) between biological yield and soil organic matter (after plant harvest), which was negative and very significant.

    Conclusion

    The results showed that planting directions north-south enjoying the better of ecological agents increase the yield and sepals been in medicinal plant Roselle, Also with nitrogen fertilizer management in such a way that soil nitrogen availability is more adapted to the sensitive times of the need for Roselle, It can be used with a nitrogen split application in order to increase the yield of Roselle, Application of treatment (1/3 four leaf stage, 1/3 stem elongation, 1/3 Flowering stage), which is simultaneously with the plant's sensitive vegetative and reproductive stages is recommended. Therefore, the use of chemical fertilizers as a split, while lead to reducing consumption and increasing the efficiency of chemical fertilizers in order to achieve sustainable agriculture and environmental protection is recommended.

    Keywords: Sepals yield, Soil matter organic, Soil nitrogen, Soil temperature
  • Mahboobeh askarian, mohammadhossein aminifard*, Mehdi Khayyat, Mehdi jahani Pages 1375-1388
    Introduction

    Basil (Ocimum basilicum) is an herbaceous medicinal plant from the Lamiaceae family with a wide range of applications in culinary, cosmetic, food, perfumery and medical industries. The presence of more than 200 chemicals includes flavonoids, monoterpenes, sesquiterpenes, triterpenes and aromatic compounds in basil oil have been identified. The main components of its oil are eugenol, methyleugenol, linalool, estragole and anethole, varying by chemotype. Basil is one of the most important medicinal plants in Iran, which is widely used in various industries including pharmaceuticals, cosmetics, sanitary and food industries, and it is considered as an anti-fluff and appetizer in traditional medicine. Therefore, in order to maximize yield and increase the length of the basil production period, the appropriate management of this product is necessary. Among which the use of suitable nutritional elements is one of the useful ways to improve the performance of this plant. Therefore, the purpose of this study was to evaluate the effects of different levels of NPK fertilizer and fulvic acid, and their interaction on vegetative, reproductive growth and yield of Basil's medicinal plant.

    Materials and Methods

    In this study, the effects of applications of fulvic acid and NPK fertilizer on yield and growth characteristics of basil were evaluated under field conditions. Treatments were three levels of NPK fertilizer (0, 3 and 6 per thousand) and three levels of fulvic acid (0, 5 and 10 kg.ha-1). The experiment was designed as factorial arrangement based on randomized complete block design with three replications at the research station of Faculty of Agriculture University of Birjand during growing season of 2017. The measured indices including vegetative characteristics (plant height, laterals number.plant-1, plant weight (g.m-2), leaf weight(g), leaves No.plant-1) and reproductive characteristics (grain yield, 1000-seed weight, seed number, biological yield and harvest index). Finally, the experimental data were statistically analyzed using SAS program ver. 9.2 and means were separated Duncan multiple test at 5% probability level of probability.

    Results and Discussion

    The results showed that NPK fertilizer had a significant effect on vegetative characteristics (plant height, fresh and dry weight of plant (g.m-2), lateral number per plant and leaves No.plant-1), so that the highest plant height and biological yield (48.4 cm and 2.16 kg.m-2, respectively) were obtained with application of six per thousand of NPK fertilizer. The results showed that NPK fertilizer had significant effect on 1000-seed weight. The highest 1000-seed weight (1.6 g) was obtained at six per thousand of NPK fertilizer, and the lowest of 1000- seed weight, (1.4 g) was observed in the control. Fulvic acid affected vegetative characteristics (plant height and laterals number per plant), so that the highest plant height and laterals number.plant-1 (46.0 cm and 15.88 per plant) was obtained with the application of 10 kg.ha-1 fulvic acid treatment. Also, the results showed a significant effect of fulvic acid on reproductive characteristics (plant weight (g.m-2), 1000- seed weight (g)). The highest leaves No.plant-1 (129.5) and 1000- seed weight (1.5g) were obtained at 10 kg .ha-1 fulvic acid, and the lowest of plant weight, 1000-seed weight were observed in the control. The interactions showed that the highest biological yield (2.29 kg.m-2) and plant  dry weight (483.83 g.m-2) were obtained from treatment at six per thousand of  NPK fertilizer and 10 kg.ha-1 fulvic acid and the lowest amounts (1.44 kg.m-2 and 259.5 g.m-2) was obtained from control.

    Conclusion

    The results of this study showed that fulvic acid and NPK fertilizer had significant effect on yield and growth characteristics of basil. Thus, results showed that fulvic acid (10 kg.ha-1) and NPK fertilizer (six per thousand) had strong impact on yield and growth characteristics of basil under field conditions.  Acknowledgements Authors are grateful to Ebrahim Ebrahimabadi for their help with the field experiments.

    Keywords: Biological yield, Harvest index, Plant height, Seed number
  • Mahmood Mohammadi, SeyedAli Mohammad Modarres Sanavy*, Hemmatolah Pirdashti, Zeinolabedin Tahmasebi Sarvestani, Behnam Zand Pages 1389-1407
    Introduction

    To improve crops productivity under drought stress conditions, not only proper management of inputs in time, amount and form, but also the understanding of important physiological processes and defense mechanisms are required to avoid drought stress. Most plant species have the ability to form a symbiosis relationship with the Arbuscular mycorrhizal fungi. AMF could increase growth and yield of plants under water stress, and it is one of the most important biological fertilizers which can be used in mycorrhizal and Azospirillum fields. Research results have shown that mycorrhizal and Azospirillum fungi can moderate the adverse effects of drought stress in plants. One of the most important effects in terms of drought stress is changing the levels of some hormones in plant such as acetic acid and indole acetic acid. Other effects are direct absorption of water by fungal hyphae in soil and its transfer to the host plant, increasing leaf gas exchange, photosynthesis rate as well as enhance the activity of antioxidant enzymes in corn, excellent nitrate and phosphorus assimilation. In addition, extend the water absorption by increasing the leaf water hydration, leaf photosynthesis activity, osmotic regulation and changes in cell membrane flexibility. Hence, the current study was aimed to evaluate chemical fertilizers (nitrogen + phosphorus) and biological fertilizers (Azospirillum and mycorrhizal fungi) effects on water deficit stress on morpho-physiological traits and yield of evening primrose at different experimental stations (Tehran and Varamin regions).

    Material and Methods

    Two experiments were conducted at two experimental stations in Tehran and Varamin in 2014 and 2015. Experiments were conducted in a split factorial layout within a randomized complete block design with three replications. Three irrigation regime treatments (IR 50 % FC, IR 40 % FC and IR 30 % FC; 50, 40 and 30 percent of field capacity) were randomized to the main plots. Subplots were consisted of factorial combinations of three chemical fertilizers (CF 0, CF 50 % and CF 100 %: no-application, 50 and 100 percent of nitrogen + phosphorus needed by plant) as well as four biological fertilizers (“-M and –Az” and “+M and +Az”: non-inoculated and inoculated with mycorrhizal and Azospirillum).

    Results and Discussion

    Water stress (moderate and severe) reduced plant height, shoot dry weight, leaf area index, seed yield, phosphorus content and relative water content. However, the highest water use efficiency was obtained at moderate water deficit stress. In addition, the highest root dry weight, root ratio shoot dry weight and catalase were obtained at severe water deficit stress. The application of chemical fertilizers and biological fertilizers in all cases mitigated the negative effects of water deficit stress on plant height, shoot dry weight, root dry weight, root ratio shoot dry weight, leaf area index, seed yield, phosphorus content, catalase, relative water content and water use efficiency traits. Water use efficiency of evening primrose increased with moderate water deficit, application of chemical (Nitrogen + Phosphorus) and biological (mycorrhizal fungi and Azospirillum) fertilizers.

    Conclusion

     The compelling results of this study revealed that the inoculation mycorrhizal and Azospirillum could improve evening primrose growth under water deficit stress. Results showed that the application of biological fertilizers can improve evening primrose growth under drought stress. Moreover, mycorrhiza symbioses can increase absorption of moisture and nutrients, reduced irrigation requirements, enhancement drought resistance, more access to food in new places, production of thinner roots, increase root length and nitrogen fixation, which lead to reduction of drought detrimental effects.

    Keywords: Azospirillum, Biological fertilizer, Mycorrhizal, Water Deficit Stress, Yield
  • Javad Hamzei*, Javad Sedighi Kamel Pages 1409-1422
    Introduction

    One of the ways to move towards sustainable agriculture is to create diversity and using intercropping of crops, cultivars and / or different isolines in agriculture. In order to increase productivity in the agricultural system, resource management and inputs also play a key role. In addition, to preserve ecological balance and stability of the system, the main goals in the intercropping systems are maximum exploitation of environmental resources such as water, soil, food, the quantitative as well as qualitative increase of yield, and reduction of damage from pests, diseases, and weeds. In addition, improvement social conditions, such as greater economic stability and adequate nutrition for humans are pursued. Therefore, the present study aimed to exploit the agro-ecological benefits of additive intercropping of green bean in reduction of nitrogen consumption in potato cultivation and improving the land use efficiency and potato equivalent yield.

    Materials and Methods

    In order to evaluate the effects of additive intercropping of green bean on potato growth, tuber yield, nitrogen use efficiency, land use efficiency, and potato equivalent yield as well as green bean yield, an experiment was conducted at the Farm Research of Faculty Agriculture (latitude 35◦1'N, longitude 48◦31'E and 1690 m altitude), Bu-Ali Sina University, Hamedan, Iran, in the growing season of 2016. Experiment was laid out as a factorial based on randomized complete block design with three replications. Four planting patterns including sole cropping of potato (M1), green bean intercrops between potato rows (M2), green bean intercrops within potato rows (M3) and green bean intercrops between and within potato rows (M4) were applied in combination with three levels of nitrogen fertilizer (N0, N80 and N160: 0, 80 and 160 kg N ha-1, respectively). Intercropping system was done using additive design. So that, the potato density was kept constant and in all cropping patterns, 50% sole green bean planting density was added to potato plots. Traits of plant height (PH), tuber yield (TY), number of tuber per plant (NTP), tuber dry matter (TDW), harvest index (HI), and potato equivalent yield (PEY) for potato, and green bean pod yield (GPY), number of pods per plant (NPP), and biological yield (BY) for  green bean were evaluated. Land equivalent ratio (LER), relative value total (RVT) indices were also studied.

    Results and Discussion

    Results demonstrate that planting pattern and N had the strongest influence on tuber equivalent yield as well as tuber yield of winter wheat followed by interactions between these treatment factors. Accordingly, when normal and high N levels were applied, potato equivalent yield values were comparable to, or higher than, those obtained without consumption of N. The highest potato tuber yield (42.50 t.ha-1) was revealed at the treatment of green bean intercrops between potato rows with consumption of 160 kg N ha-1. This treatment did not show significant difference with the treatment of green bean intercrops between potato rows with consumption of 80 kg N ha-1, which had a yield of 41.51 t.ha-1. Also, the highest values for yield of green beans (515 g.m-2), the land equivalent ratio (1.50), total relative value (1.45) and the highest potato equivalent yield (54.38 t.ha-1) were obtained at M2 × N80 (green bean cultivation between potato rows with consumption of 80 kg N ha-1) treatment. Legumes have the ability to nitrogen fixation and using of them in intercropped systems can be suitable for reduce nitrogen use as well as environmental problems. Therefore, in terms of growth, tuber yield, land use efficiency and nitrogen utilization efficiency, treatment of green bean intercrops between potato rows with consumption of 80 kg N ha-1 was the best treatment for potato production.

    Conclusion

    In general, the cultivation of green beans between potato rows due to ecological, morphological and nutritional differences has cooperation aspects in intercropping. This will increase the productivity of the land, the light and food in the unit area and the diversity in agricultural ecosystems.

    Keywords: Land equivalent ratio, Legume, Multiple cropping, Relative value total, Resource use efficiency, Tuber
  • Afsaneh Yousefi, Reza Mirzaeitalarposhti, jafar nabati*, Saeed Soufizadeh Pages 1423-1436
    Introduction

    Economic problems as well as environmental concerns related to irregular and excessive application of agricultural chemicals have shifted the attentions toward application of biological fertilizers in many agro-ecosystems. In order to reduce environmental pollution and ecological damage caused by usage of chemical fertilizers, there is a need to use resources and inputs, which not only meet crop nutrient requirements, but also guarantee the long-term sustainability of agricultural systems. Beans are used as human food sources and to improve soil fertility through bio-stabilization of nitrogen. The purpose of this study was to investigate the effect of biofertilizer including (free-living nitrogen-fixating bacteria, and potassium and phosphorus solubilizing bacteria) on growth Indicators of two mung bean landrace.

    Materials and Methods

    In order to investigate the effect of free-living nitrogen fixating, phosphorus and potassium solubilizing bacteria on growth indices of mung bean (Vigna radiata L.), a field experiment was carried out based on a randomized complete block design as factorial arrangement. Two mung bean landrace (Dezfouli and Indian) were planted under six fertilization systems at the Agricultural Research Station of Ferdowsi University of Mashhad, Iran in 2017. Six fertilization treatments include: 1-free-living nitrogen fixating 2- phosphorus solubilizing bacteria 3- potassium solubilizing bacteria 4- free-living nitrogen fixating +phosphorus solubilizing bacteria + potassium solubilizing bacteria 5- nitrogen fertilizer 6- Control (without biological and chemical fertilizers) were applied. Before planting, a soil depth of 0-30 cm was obtained from soil samples and the soil physico-chemical properties were measured. Sampling was started 20 days after planting by taking 6 destructive samples. Plant were sampled two weekly intervals to determine the growth parameters of mung bean including leaf area index (LAI), dry matter accumulation (DM), crop growth rate (CGR), relative growth rate (RGR), and net assimilation rate (NAR).

    Results and Discussion

    The results showed that the highest leaf area index (3.80) and dry matter accumulation (835 g. m-2) were observed in Indian mung bean, also the highest Crop growth rate (25 g.m-2.day-1), net assimilation rate (18.95 g CO2.m-2.day-1) and relative growth rate (0.056 g.g-1.day-1) were obtained in Dezfuli Landrace. The lowest growth indices in control treatment were obtained in both Dezfuli and Indian Landrace. Also, the highest yield (1558 kg. ha-1) at application time of bifertilizers was obtained for Indian mung bean under (free-living nitrogen fixating + phosphorus solubilizing bacteria + potassium solubilizing bacteria) treatment. The use of bio-fertilizers through synergistic effects by creating a suitable substrate and favorable for nutrients improves the growth and increase of yield. Also, increasing leaf area can increase the plant's photosynthetic potential and increase dry matter, at finally to increased plant yield. Mung bean plant despite its ability to stabilize nitrogen due to its poor root yield is low. Inoculation with free-living nitrogen fixating, phosphorus solubilizing and potassium solubilizing bacteria, due to increased access to nutrients, which is an effective factor in stimulating the growth and photosynthesis of plants. It improves the growth conditions, develops vegetative growth, extends and prolongs the leaf area, produces photosynthetic materials and as a result increases yield. The application of the mentioned bio fertilizers has increased the number of elements and the development of photosynthetic surfaces and the plant produced the produced material to the reproductive organs and finally growth indices have increased compared to the control treatment.

    Conclusion

    It was revealed that symbiosis of various biofertilizers not only improve mung bean Growth Indicators but also can reduce negative aspects of chemical fertilizer application in crop production systems. Giving attention to more frequent application of biological fertilizers could be considered as an important agro-ecological approach, which results in healthier soil and water resources.

    Keywords: Biological Fertilizers, Crop growth rate, Leaf area index, Net assimilation rate, Sustainable agriculture
  • S.M Seyyedi, Parviz Rezvani Moghaddam*, M. Khajeh Hossieni, H. Shahandeh Pages 1437-1448
    Introduction

    Phosphorus deficiency due to the chemical function of calcareous compounds is considered as one of the most important problems in the sustainable nutrition of black seed (Nigella sativa L.), especially in arid and semi-arid regions of Iran. Furthermore, low soil organic matter content in these areas can adversely affect phosphorus availability and thus challenge the sustainable production of black seed. Accordingly, biochemical modification of calcareous soils based on ecological approaches including biological sulfur oxidation or increased phosphorus solubility by organic fertilizers, such as vermicompost, may alleviate these problems.

    Materials and Methods

    In order to some approaches for increasing the soil soluble phosphorus and its effects on quantitative and qualitative yields of black seed in a calcareous soil, a field experiment was conducted at Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in the growing years of 2010-2011. A complete randomized block design based on the factorial arrangement with three replications and 12 treatments were used. The resources of soil amendment (1- ‍Control, 2- Vermicompost + Thiobacillus, 3- Sulfur + Thiobacillus and 4- Vermicompost + sulfur + Thiobacillus) and three levels of phosphorus (0, 30 and 60 kg.ha-1) were the first and second experimental factors, respectively. In order to evaluate the experimental treatments, plots were designed with 3 m long and 2 m width, 0.5 m apart from each other. To eliminate all influence of lateral effects, 1 m alley was kept between blocks. Vermicompost (pH: 7.59, organic carbon: 34.76%, total nitrogen: 2.31%, and total phosphorus: 1.78%), sulfur (along with Thiobacillus) and diammonium phosphate were incorporated into the soil before seed sowing. The analysis of variance and the least significant difference test (LSD: 0.05) were performed using SAS 9.3 software (SAS, 2011).

    Results and Discussion

    According to the results, the interaction effect of soil amendment × phosphorus rate on plant height, leaf area index and plant dry weight of black seed was significant. Biological and grain yields of black seed notably affected by the interaction between soil amendment × phosphorus rate. Based on our results, plant height significantly increased with increasing levels of phosphorus fertilizer. In addition, phosphorus solubility due to sulfur + Thiobacillus application considerably improved this index compared to control. From the results, grain and biological yields of black seed by applying the sulfur + Thiobacillus treatment were considerably higher than phosphorus 30 or 60 kg.ha-1 treatments. The highest biological and grain yields of black seed were observed in vermicompost + Thiobacillus or vermicompost + sulfur + Thiobacillus treatments. With applying the mentioned treatments, grain yield of black seed were significantly increased (by 63.3 and 84.4%, respectively) compared to control treatment. In general, optimal growth and yield of crops are dependent on balanced nutrient uptake. Given the positive correlation between sulfur and nitrogen, as well as between phosphorus and nitrogen, the specific role of biological sulfur oxidation combined with vermicompost can be due to increased phosphorus solubility in the soil and ultimately facilitated uptake nitrogen.

    Conclusion

    In alkali soils, biological sulfur oxidation individually or in combination with vermicompost treatment can be a suitable approach to increase the soil soluble phosphorus and quantitative and qualitative yields of black seed. The results also suggested that the application of phosphorus fertilizers in soils dominated by calcareous compounds might have limited efficacy. As a result, the biochemical reactivity of Nigella plant to phosphorus uptake is improved only in conditions where the rhizosphere can be balanced in terms of soil pH and phosphorus solubility. Acknowledgements The authors acknowledge the financial support of the project by Vice President for Research and Technology, Ferdowsi University of Mashhad, Iran.

    Keywords: Essential oil percentage, Thiobacillus bacteria, Oil percentage, Sulfur, Vermicompost
  • Saeed Jahedi pour, Alireza Koocheki*, Mehdi Nassiri Mahallati, Parviz Rezvani Moghaddam Pages 1449-1465
    Introduction

    Biodiversity as a key factor of sustainability of natural ecosystems have been largely used in studies on natural vegetations (e.g. rangelands) at different spatial scales. Baharkish pasture with area of 1035 hectare is situated in 60 km distance southern of the city Quchan in Khorasan Razavi province. The lowest and the highest altitudes of the pasture are 1740 and 2440 meters a.s.l., respectively. Long-term (25-year) mean annual precipitation and temperature of the region is 337 mm and 9.4°C with 998.2 mm evaporation. In this study, about 200 hectares of Baharkish pasture with moderate grazing pressure was chosen by the clipping and weighing method to study the effects of environmental factors of plant species richness and diversity.

    Materials and Methods

    In order to evaluate the effect of ecological factors on the biodiversity of plant species in Quchan Baharkish pasture, at first all topographic maps (1:25,000), geological maps (1:100,000), aerial photos (1:20000) and satellite images of Quchan Baharkish were collected. Then, maps of altitude classes, slope, aspect and geological formations were prepared and merged by overlapping in ArcGIS 10.2. The generated maps were coded and 13 homogenous working units and their maps were prepared for further studies, field visits and pasture vegetation measurements. Finally,  four homogeneous vegetation types were determined for sampling based on the structure, distribution, and presence of dominant species. Hence, in each vegetation type 35 plots (2m2 each) were systematic-randomly selected and used for composite soil sampling (0-30 cm depth) and estimation of  vegetation indices. The species number and percentage of canopy cover were estimated in each plot and the plot locations were recorded with GPS devices in U.T.M system.Plant species diversity per plot was estimated using Shannon-Wiener and Simpson diversity indices, richness index of Margalef and evenness index of Smith-Wilson in Ecological Methodology software. One-way ANOVA was used to examine the components of biodiversity and Tukey test was performed for multiple mean comparisons. Principal component analysis (PCA) was conducted to classify vegetation types and to determine the contribution of ecological factors on biodiversity of the studies pasture.

    Results and Discussion

    The results indicated that altitude had significant effect on species diversity, richness and evenness and the highest values of Simpson and Shannon indices were obtained at 1900-2200 m a.s.l. Indirect effect of soil formation and direct influence of temperature were led to variation in distribution of plant species and rangeland community structure. Amount and type of precipitation and consequently vegetation type was changed with altitude. Species richness and diversity was significantly affected by slope, and lower slopes (<15%) showed the highest values of richness and diversity index. However, evenness was higher in 15- 45% slopes. Overall, northern slopes had significantly higher species diversity, suggesting that plant available water is drastically influenced by slope through infiltration rate and land index. Results of PCA indicated that the first PC containing soil organic carbon, sand content and slope had the highest effect on species diversity.

    Conclusion

    In general, it can be concluded that plant biodiversity in natural ecosystems was affected by topographic and edaphic factors particularly in high altitudes. The results of PCA showed that the PC1 including percentage of soil organic carbon, organic matter and clay and PC2 including electrical conductivity and elevation, percentage of soil moisture, silt, sand and slope had the greatest impact on species diversity. In addition, getting insight in to the relationship between diversity and ecological, topographic and edaphic factors can be proposed as an ecological approach for sustainable rangeland management.

    Keywords: Edaphic factors, Principal components analysis, Rangeland, Topographic factors
  • Shahin Hassani, Mahmood ramroudi*, MohammadReza Asgharipour, Ebrahim Asghripour Pages 1467-1481
    Introduction

    Expanding the global population and their requirement for water, food, and energy is a challenge that is compounded by increased pressure on natural resources. The decision on how and to what extent humans need to consume resources, requires precise and sophisticated scientific research and analysis. In this study, Life Cycle Assessment (LCA) methodology has been used. According to this method, it is possible to measure any performance of any given farm on the basis of the number of inputs that the farmer will provide to the plant and the outputs of it. To evaluate the effects of a production process, a goal and scope of the study should be explained, then it can be used to assess a life cycle inventory and to carry out an impact assessment. The goal of this study was to compare the environmental effects of irrigated and rainfed barley in Khorramabad.

    Materials and Methods

    The LCA includes the definition of the goal and scope, the analysis of the inventory, the impact assessment, and the interpretation of the results. The data was collected from farmers through questionnaires. The selection of impact assessments should reflect the comprehensive set of environmental issues associated with the product system under study, taking into account the goal and scope. The designed functional unit for the present study is to produce one ton of grain yield. SimaPro and ecoinvent-3 are used for LCA.
    For investigating uncertainty and measuring random data, the Monte Carlo statistical method is used to prevent the exponential growth of data. To access the Monte Carlo method, the square or second power of geometric standard deviation must be estimated and it is indicated by the GSD2 method.

    Results and Discussion

    The great difference between irrigated and rainfed barley was due to inputs of electricity and irrigation. More energy consumption in irrigated crops resulted in higher yield at this condition. The amount of greenhouse gases (GHGs) emissions in producing one ton of irrigated and rainfed barley was equivalent to 1112.069 and 699.96 units per kg CO2 production, respectively. The potential for greenhouse gas emissions has been reported by researchers in irrigated and rainfed barley equivalent was to 898.24 and 604.66 units per kg CO2 production, respectively.Nitrate and phosphate are essential for plant life, but increasing their concentration in the water body causes excessive growth of algae in freshwater. Further, this will reduce the amount of oxygen in the water and ultimately lead to the deterioration of the ecosystem. The potential of eutrophication in the current study in Khorramabad for one ton of irrigated and rainfed barley was equivalent to 2.66 and 2.71 units per kg po4 production, respectively. The highest emission associated with eutrophication has been reported in wheat farms using agricultural machinery.Increasing mechanization and the use of fossil fuels contribute to increasing GHGs emissions. This problem will not affect impact assessment and in addition to increasing the potential of global warming. Therefore, any operation affects all environmental impacts and should be considered as a management solution to reduce them. The ozone destruction potential is represented by the reference of CFC-11 unit per kg production. A large number of emission factors associated with this environmental impact from the use of pesticides and herbicides during the agricultural process. CFCs are the most important substances that have the property of destroying the ozone layer (Guinee, 2002). In the present research, the difference in the potential for destruction of the ozone layer is evident in the production of irrigated barley and rainfall barley.

    Conclusion

    The environmental impact assessment for the production of one ton of barley has been calculated, but production is important. In the present study, considering that environmental production and release of pollutants in rainfall barley is far less compared to rainfed. Therefore, according to the research findings, corrective management for the production of barley should be applied to both irrigated and rainfed barley. Managing the use of pesticides and fertilizers is important. Properly integrated management such as rotation can be successful in reducing the application of pesticides and fertilizer.

    Keywords: Design of long-term environmental, Environmental degradation, Eutrification, Global warming
  • alireza koocheki*, Farnoush Fallahpour, afsane aminghafouri Pages 1483-1496
    Introduction

    Providing food for the rising world population is one of the first human needs. In recent years, there has been increased interest in agricultural production systems in order to achieve high productivity and promote sustainability over time. Intercropping is one of the methods that simultaneously can increase the agricultural system productivity and also reduce their side effects on the environment.  Intercropping can provide numerous benefits to cropping systems through increasing the total yield and land-use efficiency by enhancing the use of light, water, and nutrient, as well as improving soil conservation and declining the economic damage of agricultural pests, diseases, and weeds.Several factors can influence the growth and yield of the species used in the intercropping, including the kind of selected crops, sowing ratio, and competition between the mixture components. Therefore, the present study, to compare the different intercropping patterns of sesame and flax and their effects on the yield and the weed density.

    Materials and Methods

    In order to determine the best width of strip in row intercropping of sesame (Sesamum indicum L.) and flax (Linum usitatissimum L.) a two-year field study based on a randomized complete block design with three replications was conducted during the growing seasons of 2009-2010 and 2010-2011 in the Agriculture Research Station of Ferdowsi University of Mashhad. Treatments were four patterns of sesame-flax row intercropping including one row of sesame + one row of flax (1:1), two rows of sesame + two rows of flax (2:2), three rows of sesame + three rows of flax (3:3), four rows of sesame + four rows of flax (4:4) and monoculture of sesame and monoculture of flax. The crops were sown simultaneously on 1 and 5 May in 2009 and 2010, respectively. The crops were irrigated after sowing and thinned out in the 4-6 leaf stage. In the first month after sowing, all plots were weeded by hand and after that, we did not use any method for controlling of weeds and the density and dry weight of weeds were evaluated in four sampling dates. At the end of the experiment, the yield and yield components of both crops were measured and the land equivalent ratio (LER) was calculated based on the yield of each crop in monoculture and in intercropping patterns.

    Results and Discussion

    The results showed a significant difference among different intercropping patterns based on the density and dry weight of weeds. The highest and lowest dry weight of weeds were observed in flax monoculture (832.1 g.m-2) and 2:2 pattern (41.66 g.m-2), respectively. On the other hand, improving diversity by using intercropping had a negative effect on the density and dry weight of weeds. The maximum amount of biological yield of sesame was recorded in monoculture (9508.7 kg.ha-1) and for flax was recorded in monoculture and the pattern of 2:2 (3987.3 and 3521.7 kg.ha-1, respectively). Besides, the highest seed yield of the two crops was gained in monoculture (4876.3 and 2122.12 kg.ha-1 for sesame and flax, respectively). The land equivalent ratio (LER) for different patterns ranged from 0.68-1.34 and the maximum LER belonged to the pattern of 2:2. In general, the best result was obtained in the pattern of two rows of sesame+ two rows of flax (2:2). 

    Conclusion

    Overall, our results indicated that in intercropping, planting pattern with two or three rows of flax among the sesame rows had the best planting composition to achieve the highest yields for the two crops. In addition, the land equivalent ratio in these patterns was calculated more than one. One of the other effects of intercropping in our study was reducing the density and biomass of weeds. As a result, choosing the right pattern in the intercropping not only can be effective on the crop yield, but also by reducing the density of weeds can decrease the environmental impact of agricultural production systems by diminishing the use of chemical herbicides.

    Keywords: Biological yield, land equivalent ration, relative density, Seed yield
  • Jalil Shafagh, Kolvanagh*, Adel Dalayi Milan, Saeid Zehtab Salmasi, Yaegoob Raei, Soheila Dastborhan Pages 1497-1510
    Introduction

    Intercropping is one of the most common practices used in sustainable agricultural systems which have an important role in increasing the productivity and stability of yield in order to improve resource utilization and environmental factors. Intercropping is an option for reducing weed problems through non-chemical methods. Dragon’s head (Lallemantia iberica Fish. et Mey.) is an annual herb from the Lamiaceae family. This plant mainly cultivated for its grains that contain about 30% (even 35-38%) siccative oil with iodine value between 163 and 203, which is used in foods, but especially in dye and varnish industry. Despite the positive effects of intercropping on weed control and the increment in crop yield and the very important role of dragon’s head in sustainable agriculture in arid and semi-arid regions of Iran, information on the effects of these factors on this medicinal plant is scarce. Therefore, in this research, the effect of cumin-dragon’s head additive intercropping in the improvement of the dragon’s head yield and weed control was investigated.

    Materials and Methods

    To evaluate the effect of cumin and dragon’s head additive intercropping on weed control and yield of dragon’s head, a factorial experiment based on a randomized complete block design with three replications was carried out at the Research Farm of the Faculty of Agriculture, University of Tabriz, Iran in 2014. Treatments were two levels of weed control (complete control and no weed control) and sole cropping of two crops as well as three additive intercropping ratios including of 100% cumin + 20% dragon’s head, 100% cumin + 40% dragon’s head, 100% cumin + 60% dragon’s head. At the maturity time, plants of 1 m2 in the middle part of each plot were harvested and biological yield, grain yield per unit area as well as harvest index of dragon’s head were determined. Land equivalent ratio (LER) and relative value total (RVT) were used to quantify the efficiency of the intercropping treatments.Data were analyzed by MSTAT-C requires and SPSS 16 softwares and the means were compared using Duncan multiple range tests at p ≤ 0.05. Excel software was used to draw figures.

    Results and Discussion

    The effect of planting pattern was significant on the dry weight of weeds. Intercropping of 100% cumin + 20% dragon’s head had the lowest weed biomass. The highest biological and grain yields of dragon’s head under weedy and weed-free conditions were obtained from the monoculture of the dragon’s head. However, among different intercropping treatments, the highest biological and grain yields of dragon’s head were related to 100% cumin + 60% dragon’s head in both conditions of weed treatment. The maximum harvest index was also recorded for monoculture of dragon’s head under weed-free conditions. The land equivalent ratio was more than 1 in intercropping patterns (LER>1) that shows the positive effect of intercropping on yield. Although weed biomass in 100% cumin + 60% dragon’s was higher than that other planting patterns, the maximum LER (1.42) based on seed yield were observed in this planting system under weedy condition. In weed-free conditions, increasing of dragon’s head density reduced LER, while in the weedy conditions, the increment in dragon’s head density was associated with improved LER, indicating the higher efficiency of intercropping of these two plants under no weed control conditions.

    Conclusion

    The results of this research showed that the combination of 100% cumin + 60% dragon’s head, especially under weedy condition, was the superior treatment, because of the highest land equivalent ratio (1.42). In general, intercropping of cumin and dragon’s head, especially 100% cumin + 60% dragon’s head, is recommended for the creation of variety and production stability and increasing land-use efficiency under weedy condition.

    Keywords: Intercropping, Interference, Lallemantia iberica, Land equivalent ratio, Yield
  • z. Khamar, m. dahmardeh*, E. khammari, S.M moosavi nik Pages 1511-1525
    Introduction

    Increase agricultural production to match the increasing demand for food sources is inevitable. It causes too much pressure on the agricultural resource base and threatens the sustainability of these systems. Intercropping is an important method of high production in agriculture. This technic can affect soil environmental condition. Sustainable Agriculture defines the proper management of agricultural resources which in addition to changing human needs, maintaining environmental quality and capacity of soil and water resources. The aim of this study was to investigate the competition between two types of millet and peanuts and determine the best planting ratio of mixed cropping.

    Materials and Methods

    In order to investigate the effect of density, weeding and different ratios of millet (Panucum miliaceum L. var Common) and peanuts (Arachis hypogaea L. var Goli), an experiment as factorial has been conducted in a randomized complete block design with three replications at the Agricultural Research Farm of Zabol University during 2012. The experimental treatment consisted of 4 planting ratio at (sole millet, 50% millet + 50% peanut, 100% millet + 100% peanut and sole peanut),  3 weeding levels (non-weeding, once weeding and twice weeding) and 2 levels of intervals between rows (40 and 50 centimeters). Traits evaluated by environmental resources including (Photosynthetically Active Radiation and temperature and humidity of soil), soil nutrient elements (Ca, Mg, Na, and C), and land equivalent ratio (LER) for evaluation of intercropping compared to the monoculture.

    Results and Discussion

    The results showed that all studied traits were affected by the planting system. There was a significant interaction between planting system, weeding and density in light absorption, temperature and humidity. The results showed that the absorbed Photosynthetically Active Radiation in the intercropping (75.5%) was higher than the monoculture of both plants. Weed control increased the adsorption of Photosynthetically Active Radiation by 70.75%, and in the twice weeding treatments and low density, the highest amount of adsorbed Photosynthetically Active Radiation was obtained. The highest volumetric soil moisture was obtained in sole peanut (31.1%) and the highest soil temperature was obtained in sole millet (29.66 °C), respectively. Comparison of volumetric soil moisture and temperature in weed and density treatments indicated an increase in moisture content and a decrease in temperature by increasing weeding and density. The reduction of soil temperature in intercropping systems compared to sole millet can be attributed to the greater absorption of light by the intercropping canopy and the increase of shadow by plant canopy. Since the soil temperature under the canopy of intercropping systems was less than the soil temperature in sole millet, so the moisture content in the intercropping systems was higher than sole millet. The results of the changes in soil nutrient elements showed that the number of bivalent elements (calcium and magnesium contents) in additive intercropping series and monoculture of millet (0.033 and 1.907 ppm) was higher than the replacement intercropping and monoculture of peanut. The study of weeding showed that with increasing weeding, the amount of calcium and magnesium of the soil increased after weed harvesting. The cation exchange capacity of the root of the legumes is about twice as much as the root of the cereals. A plant with a higher cation exchange capacity can absorb more bivalent elements. For this reason, the power of peanut competition in absorbing bivalent elements of calcium and magnesium was higher than that of millet. The additive intercropping had the highest land equivalent ratio (1.65). The effect of weed control and density on the land equivalent ratio was significant, and twice weeding treatment with higher density had the maximum land equivalent ratio.

    Conclusions

    In total, intercropping systems with increasing weeding and density increased the number of soil elements after weeding and increased soil fertility, and treatment of 100% millet + 100% peanuts due to better utilization of resources and increased soil fertility and increase yield compared to monocultures, it was the best treatment in this study.

    Keywords: Land equivalent ratio, Photosynthetically active radiation, Soil temperature, Volumetric soil moisture
  • Abdolnoor Mosadeghi, Naser Akbari*, Abdolmehdi Bakhshandeh, Fereydoon Sarmadian, Behroz Nasiri, Saeid Soufizadeh Pages 1527-1543
    Introduction

    Growing demand for food in the coming decades will require a significant increase in crop production. Indeed, the variability of weather, soil and topography result in different agro-ecological conditions which may be suitable or unsuitable for some crops. To determine land suitability in an ecosystem, agro-ecological zonation is one of the effective tools for recognizing the capabilities of land and allocating them to the best and most profitable types of crop utilization. Currently, it is one of the most commonly used methods for determining the agro-ecological characteristics of large geographical areas for the production of crops. This research was performed to perform the agro-ecological zoning Shavoor area for the production of wheat. Therefore, this research was conducted with the aim of agro-ecological zoning and evaluate the land suitability in a part of Shavoor lands of Khouzestan, with using the parametric method (square root). Also, wheat potential production and potential land production were calculated.

    Material and Methods

    Study area: The present study conducted in Shavoor area, Khouzestan Province, Iran, is located in 31° 47' 39" to 31° 53' 19" N latitude and 48° 27' 32" to 48° 22' 12" E longitude. The study area is 5000 ha. The length of the "growing season" or "growing period" (LGS or LGP), as defined by the Agro-Ecological Zones project, is the period (in days) during a year when precipitation exceeds half the potential evapotranspiration. A period required to evapotranspiration an assumed 100mm of water from excess precipitation stored in the soil profile is sometimes added. No provision made for stored soil moisture. To obtain a length of the growth period, the rain, and potential evapotranspiration during the growth period estimated from the data weather of Safiabad station. For soil mapping, it was used for precise semi-detail studies irrigation and drain networks of Shavoor plain. Finally, the soil map prepared. Landsat 8 and IRS satellite images in 2016 were used to provide a land-use map. The agro-ecological zoning map of the study area was obtained by the combination of agro-climatic and agro-edaphic data and apply the function in the GIS environment. To evaluate the Land suitability in Agro-ecological zoning, conformity of the land characteristics in each defined zone with wheat growing requirements performance, and the final class of land was measured. To estimate the Potential yield in the region, the FAO model, was used.

    Results and Discussion

    After overlapping desired maps in the GIS, the study area defined and separated into 8 Agro-ecological zones. Land suitability evaluation

    results

    Based on square root and Storie methods 42% and 58% of the land were located in the classes including moderately suitable land (S2) and marginally suitable (S3). The potential yield of wheat was obtained 6823 kg ha-1 by using the FAO method. The land production potential in each of the zones was also estimated. Because of the effects of the aforementioned limitation factors, the land potential production for wheat decreased in lands the Khalaf Aziz (A), Bam Dej (B), Elhaee (C), Ali Chaab (D), Karkheh (E), Abdul Khan (F), Sayed Abbass (G) and Bait Hatam (H) by 28, 60, 60, 60, 55, 52, 40 and 51%, respectively. By improving these constraints, such as proper management practices such as increasing organic matter to the soil and land leaching, it is possible to increase the production of wheat in these ecosystems.

    Conclusion

    This evaluation conducted to agroecological zoning of the Shavoor plain for agro-ecosystem planning. Land suitability and land production potential estimated in each zone for wheat-based on parametric (square root) and Storie method. The results showed that climatic properties did not create significant limitations for wheat cultivation in an ecosystem. Limitations related to soil properties results showed that the A and F zones of the study area were the moderately suitable class (S2). Also, the deficit of organic matter, salinity, and alkalinity in the other parts are the major limiting factors.

    Keywords: Land suitability, Land potential yield, Organic matter