alfalfa

This study was conducted to investigate the effect of potassium and phosphorus biofertilizers on growth characteristics and yield of alfalfa (cv. ‘Nikshahri’) at different ages.

This combined experiment was conducted as factorial based on a randomized complete block design with three replications during two consecutive years under the climatic conditions of Jiroft, Kerman, Iran. The studied factors included alfalfa age (one, three and five-years old) and bio-fertilizers (Control, Pota-Barvar, Phosphate Barvar II, Pota-Barvar + Phosphate Barvar II). The biofertilizers were used along with irrigation water.

The results of the combined variance analysis showed that there was a significant difference between different ages of alfalfa in terms of some growth characteristics and yield. The highest yield and growth characteristics were related to three-year-old plants and the yield significantly decreased by increasing the age to 5-years old. Based on the results, the highest growth characteristics (except internode length) and yield were related to Pota-Barvar + Phosphate Barvar II treatment, which was not significantly different with Pota-Barvar treatment in term of leaf area index and leaf: stem weight ratio. The interaction effect of age and biofertilizer showed that the combined application of biofertilizers improved the growth characteristics and yield of the older alfalfa plants and the highest yield was found in 3-years old plants treated by combination of both biofertilizers.

The combined application of both biofertilizers (PotaBarvar + Phosphate Barvar II) can be an effective way to prevent alfalfa yield decline in old farms.

This research was conducted to evaluate the effect of weed interference and non-interference in different densities of alfalfa on yield, nutritional value and some morphological traits of alfalfa as a forage crop. 

The experiment was performed as factorial and based on a randomized complete block design with three replications in two cuttings during 2018-2019 crop years. The experimental treatments were weed interference and non-interference in two levels (hand weeding and non-hand weeding) and plant density in four levels (20, 40, 60 and 80 stems per square meter). 

Weeds identified in this Alfalfa field included: Carthamus tinctorius, Centaurea cyanus, Ceratocephalus falcatus, Convolvulus arvensis, Cuscuta sp., Cynodon dactylon, Descurainia sophia, Euphorbia maculate, Poa bulbous, Hordeum morinim, Lactuca scariola, Rumex acetosella, Salvia sclarea, Sisymbrium irio, Sorghum halepense, Taraxacum officinalis, Tragopogon graminifolius, Vaccaria hispanica. The results of each harvest in the third year of established alfalfa showed that the presence of weeds caused a decrease in the quantity and quality of alfalfa forage plant. 

The results obtained in two cuttings in the third year of established alfalfa showed that the weeds caused quantitative and qualitative reduction in alfalfa. Alfalfa in the second cutting had better growth compared to the first cutting, so that the plant produced the highest fresh and dry yield in the second cutting. Weed non-interference increased the levels of superior morphological traits of alfalfa, such as fresh and dry yield, plant height, and number of leaves per plant, number of main-stem nodes, leaf area and percentage of vegetation cover as well as increased the nutritional value of alfalfa in terms of nutrient elements, proteins and factors such as ADF, Ash, CF, NDF.

The goal of study was to evaluate promising alfalfa cultivars for drought stress and identify the most tolerant and superior cultivars for drought stress.  

The experiment was conducted as split plot based on randomized complete blocks design with three replications in the East Azarbaijan Agriculture and Natural Resources Research and Education Center during three cropping seasons (2016-19). In the main plots, the irrigation factor was applied at three levels - at the first irrigation level only to the end of the first harvest, at the second level irrigation until the end of the second harvest, and at the third level irrigation until the end of the third harvest (complete irrigation). The second factor was six cultivars and alfalfa ecotypes.  

The effect of irrigation levels was significant for all measured traits. The fresh and dry matter yields of the studied genotypes were affected by irrigation levels and decreased significantly. Water stress significantly reduced plant height at first and second levels of irrigation 23% and 17%, respectively. Water stress, also significantly reduced the number of stems at the first and second levels of irrigation 34% and 30%, respectively.  

The responses of genotypes for dry matter yield were similar as fresh forage yield. In conclusion, synthetic and Azar cultivars and Varzghan ecotype were the most suitable cultivars for deficit irrigation conditions and are suitable for cultivation in low irrigation conditions in Tabriz plain.

Corn has been regarded as one of the important crops from the view point of both human and animal feeding resource. Intercropping defined as cultivation of two or more species together. The advantages of intercropping can be included: efficient use of water and sunlight, exchange of nutrients, weed competition reduction, reduction of pathogens and the increase of soil fertility. Research shows that intercropping combinations of legume–grass will increase forage quality. Because, grasses Grains have a lot of carbohydrates and legumes are rich in protein and vitamins. This study was conducted to evaluate the effect of inoculation with azotobacter and nitrogen levels on grain and corn yield components at simultaneous cropping system with legumes under the weather conditions of Markazi province.
This study was carried out at agricultural research field of Payame Noor University, Arak Branch during 2011. A factorial arrangement of treatment in a randomized complete block design with three replications was used. Methods of plant nutrition (M0= inoculation with azotobacter, M1= inoculation with azotobacter 37/5 Kg ha-1 of rare nitrogen with foliar application method, M2= inoculation with azotobacter 150 Kg ha-1 of rare nitrogen mix with soil) and simultaneous cropping treatment of legumes, [S1= corn alfalfa (Medicago sativa L.), S2= corn bitter vetch (Lathyrus sativus L.), S3= corn mung bean (Vigna radiata L.), S4= corn chickpea (Cicer arientinum L.), S5= corn vetch (Vicia ervillia L.) ] were assigned in plots. Each sub plot consisted of 4 rows, 6 m long with 60 cm between rows space and 20 cm between plants on the rows and S.C Apex hybrid was used. In this study characteristics such as: plant height, earing height, the number of grains per m-2, the number of rows per ear, the number of grains per row, surface of ear leaf, grain yield of corn, 1000 grain weight, harvest index of corn, nitrogen use efficiency, dry weight of legumes were assessed. After analyzing the data, the means by Duncan multiple range test were compared to five percent. All of the correlation coefficients were calculated and their significance was determined by Mstat-c software.
Results indicated that the effect of nutrition methods on corn characteristics such as: plant height, the number of grains per m-2, the number of grains per row, surface of ear leaf, grain yield of corn, 1000 grain weight, nitrogen use efficiency and dry weight of legumes was significant. The impact of simultaneous cropping treatment on the characteristics such as: plant height, the number of grains per m-2, the number of grains per row, corn grain yield, 1000 grain weight, corn harvest index, nitrogen use efficiency, dry weight of legumes was significant, too. Maximum and minimum grain yield (4237 and 1973 kg ha-1) were obtained with the (inoculation with azotobacter 150 Kg ha-1 nitrogen fertilizer Simultaneous cropping system of vetch and corn) and (inoculation with azotobacter Simultaneous cropping system of corn and alfalfa) treatments, respectively. Inoculation with azotobacter 37.5 Kg ha-1 nitrogen fertilizer simultaneous cropping system of vetch and corn with 51.7 kg kg-1 and inoculation with azotobacter 150 Kg ha-1 nitrogen fertilizer simultaneous cropping system of corn and chickpea with 10.1 kg kg-1 were the highest and lowest amount of nitrogen use efficiency.
Over the past few decades, global approach to modern agriculture, as in other human activities has been causing damage to natural resources, polluting and destroying the environment and causing ecological imbalance. Inorganic fertilizers used in agriculture cause the destruction of natural ecosystems. Therefore, combined use of bio-fertilizers, chemicals manures and nitrogen fixation by the legume will increase the quantity and quality of agricultural products. It can also be one of the most effective ways to achieve sustainable agriculture. But, application of chemical fertilizers causes soil degradation and increase the production cost.

Water deficit is one of the most important environmental stresses that adversely affect crop growth and production. Mycorrhizal fungi and symbiotic bacteria have important role in resistance to drought stress. A factorial experiment based on randomized complete block design was conducted with three replications in greenhouse, University of Mohaghegh Ardabil in 2013. Treatments were water stress at three levels ( 35%, 55% and 75% field capacity) and four seed inoculation as mycorrhiza (Glomus mosseae), Rhizobium (Sinorhizobium meliloti), mixed Inoculation (Glomus mosseae Sinorhizobium meliloti) and non-inoculated as control. The results showed that in severe stress, amount of proline, soluble sugars and water use efficiency increased (2.65 µmol/g FW, 2.21 mg/g FW, 1.1 g/kg, respectively) as compared to control. While the concentration of nitrogen, quantum yield, protein, osmotic potential and relative water content (0.57 %, 0.16, 0.8 mg/g.fwt, 27.81 % and - 0.6 bar) decreased, respectively. In between treatments including maximum and minimum amounts averages , soluble protein (5.17, 2.56 mg/g FW), soluble sugars (4.61, 3.55 mg/g FW) proline (5.8, 2.83 µmol/g FW), relative water content (81.61, 70.12(%, concentration of nitrogen (3.81, 2.66(% water use efficiency (0.86, 0.25 g/kg), respectively, were belonged to mixed inoculation and control. While the lowest amount of osmotic potential (-1.41 bar) related to mixed inoculation, and the most amount (-1.06 bar) to control. Quantum yield did not show significant difference in between the Inoculated treatments.

Alfalfa (Medicago sativa L.) is the most important forage crap in the world and is widely cultivated especially, in arid and semi-arid regions. Because of it’s widely distribution, alfalfa has developed different morphological, physiological, and biochemical mechanisms across environmental stresses, especially drought. Thus, this experiment was conducted to determine catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POX) activities, hydrogenperoxide, and malondialdehyde (MDA) contentsof roots and shoots of ten alfalfa cultivars (Qomi, Isfahani, Hamedani, Bami, Ordobadi, Gharayonje, Nikshahri, Yazdi, Baghdadi and Cody) under sixwater potential (0, -0.2, -0.4, -0.6, -0.8 and -1MP) during germination.Drought stress increased CAT, APX and POX activities, hydrogen peroxide, and MDA contents, in both root and shoot, however such alterations were cultivar-drought level-specific.According to the correlation between measured traits at drought condition, antioxidant enzymes activity in roots and shoots had negative and significant correlation with hydrogen peroxide and MDA contents of both root and shoot. Cultivars with higher enzyme activities had lower hydrogen peroxide and MDA contents (Qomi, Baghdadi, Nikshahri and Bami), while cultivars with lower enzyme activities and higher hydrogen peroxide and MDA content (Isfahani, Ordobadi and Hamedani), suggesting that tolerant cultivars may have retained sufficient water and had active enzymatic defense systems against oxidative injury, moreover, antioxidant enzymes activity can be used as biochemical indicator for drought tolerance in alfalfa cultivars.

In order to evaluate the effect of simultaneous cropping with legumes and application of chemical and biological fertilizers on nitrogen agronomic efficiency of corn، this study was carried out in field of agricultural research of Arak Payame Noor University in 2011. A factorial arrangement of treatments in a randomized complete block design with three replications was used. Methods of plant nutrition (M0= inoculation with azotobacter، M1= inoculation with azotobacter + 37. 5 Kg. ha-1 of rare nitrogen with foliar application method، M2= inoculation with azotobacter+150 Kg. ha-1 of rare nitrogen mix with soil) and simultaneous cropping treatment of legumes، (S1= corn + alfalfa، S2= corn + bitter vetch، S3= corn + mung bean، S4= corn + chickpea، S5= corn + vetch) were assigned in plots. Each sub plot consisted of 4 rows، 6 m long with 60 cm between rows space and 20 cm between plants on the rows and S. C Apex hybrid was used. Results showed that the methods of nutrition effect on the characteristics such as stem height، number of grain per ear، wet weight of ear، harvest index of legumes، biological yield of corn، productivity index، grain yield of legumes، nitrogen agronomic efficiency and yield of wet forage was significant. Effect of simultaneous cropping treatment on the number of green leaf، number of grain per ear، wet weight of ear، harvest index of legumes، biological yield of corn، productivity index، harvest index of ear، grain yield of legumes، nitrogen agronomic efficiency and yield of wet forage was significant. The maximum and minimum of yield of wet forage (52. 2 and 32. 2 ton. ha-1) were obtained with the inoculation with azotobacter + 150 Kg. ha-1 nitrigen + Simultaneous cropping of bitter vetch and corn and inoculation with azotobacter + non application of nitrogen + Simultaneous cropping of corn and alfalfa treatments، respectively.

In order to investigate the effects of summer cover crops, their residues as well as mechanical and chemical methods on weed density and biomass in citrus orchards, an experiment was conducted based on randomized complete block (RCB) design with 7 treatments and 3 replications in Rudan, Bandar_Abas, Iran. The treatments includes soybean (Glycine max L.), alfalfa (Medicago rigidula L.), and berseem clover (Trifolium alexandrinum L.), cultivation, barley straw mulch, glyphosate herbicide and weedy check. cover crops were planted on 3rd February, 2009. Barley straw mulch was used simultaneously. During the experiment, cultivation was retreated monthly. Herbicide was applied on 19th April, 2009 as cutting the cover crops. The results showed that soybean and alfalfa cover crops produced the highest and the lowest weed biomass, respectively. Barley straw mulch and berseem clover cover crop were the best controls of decreasing weed density, while alfalfa cover crop resulted in the least efficacy. In short, soybean cover crop and tillage were the most efficacious and alfalfa cover crop was the most inefficacious treatment for weed management in citrus orchard.