جستجوی مقالات مرتبط با کلیدواژه « محصولات کشاورزی » در نشریات گروه « آب و خاک »

The purpose of this study was to survey the spatial quantities of 22 crop in seven major agricultural crops in 13 major cities of Golestan province and to study its 9-year mean virtual water flow from 2007 to 2015. The priority of crop cultivation was also ranked based on its virtual water values. The results of this study showed that the virtual water of different crops in the cities of the province is different according to the performance. The results of this study showed that rice with virtual water content of 1740 m3 / ton in Ali Abad and Gorgan up to 2840 m3 / ton in Maraveh-Tapeh area had the highest amount of virtual water. Cereals with an average virtual water of 1500 m3 / ton also have high levels of virtual water and Cucurbits and vegetable products with the average virtual water of 100 and 350 m3 / ton have the lowest amounts of virtual water. The results also showed that exports and imports of agricultural products are currently incorrect and Golestan province, despite having a shortage of water, is an average 396 MM3 of virtual water exporter annually, largely driven by exports of cereal and rice products. Ranking the pattern of crop cultivation from the perspective of virtual water also showed that in this province, cucurbits and vegetable crops in all cities are in the top priority and crops such as cereals and rice are last priority.

In the process of conducting this research, 110 studies on monitoring nitrate content in agricultural products produced in Iran were gathered. These studies were published until March 20, 2023. The collected studies underwent evaluation for methodology, quality control, and quality assurance of results and were then assessed based on standard research criteria. The evaluation of the study's methodology revealed that only 27.3% of the studies adhered to standard methods for sampling, storage, and sample transfer. In 15.5% of the studies, the method of preparation and extraction followed standard procedures. Additionally, in 30% of the studies, the nitrate measurement method was conducted according to established standard procedures. The evaluation of quality control in the studies showed that only 20.9% reported some indicators of quality control and assurance. The assessment of nitrate concentration in agricultural products revealed the weighted mean concentrations of nitrate (mg kg-1 fresh weight) as follows: potato 98.7, cucumber 120.9, tomato 40.7, onion 39.6, watermelon 19.9, melon 62.9, carrot 151.1, eggplant 235.2, peppers 329, other root and tuber vegetables 542.4, lettuce 907.7, spinach 995.4, celery 1093.4, fresh edible legumes 37.7, parsley 596.5, cabbages 414.7, other leafy vegetables 635.6, apple 32.4, and orange 37.2. The findings of the present research reveal that the mean nitrate concentrations in Iran’s agricultural products fall below the maximum permissible levels outlined by both the Iranian national standard and international standards. As a result, it can be generally concluded that there is no significant cause for concern regarding residual nitrate concentration in Iran’s agricultural products.

Frequent droughts in the Sistan region have caused a severe crisis in the agricultural sector of this region. Meanwhile, the agricultural sector plays a significant role in the economy of this region. Therefore, determining the crop program and cultivation pattern, taking into account water constraints, is especially necessary to maximize the profits of the agricultural sector in this region. For this purpose, in this study, to determine the crop program, shade price and final value with emphasis on optimizing water consumption in the three main agricultural sectors in Sistan region (Zabol, Zahak and Miangangi) and on five strategic crops (wheat, barley). , Potatoes, onions and tomatoes). The analysis was performed based on 3 scenarios: 1) current cultivation, 2) maximizing profits by considering the water and land requirements, and 3) maximizing profits according to the constraints including land and area consumption constraints. The results showed that due to the application of water and land restrictions (Scenario 2) in the mentioned areas, wheat and barley crops are removed from the cultivation pattern, but other crops increase their area under cultivation and by applying all restrictions (Scenario 3) Barley crop will be removed from the cultivation pattern, but other crops for the mentioned areas will change their cultivated area. Therefore, considering that Sistan region is facing a shortage of water resources, therefore, it is suggested that optimization models and the results of this study can be used as a suitable tool to reduce water consumption and increase production in water resources management community plans.

Today, due to limited resources, increasing the productivity of inputs, especially water inputs in the agricultural sector to achieve food security in the country is a fundamental strategy. In this regard, the objectives of the present study were to determine the physical and economic irrigation water productivity in the production of crop production under research conditions in Seed and Plant Improvement Institute (SPII) research farm in Alborz province based on 2016-2019 dates in 2020. In this study, in order to estimate irrigation water productivity used physical and economic productivity. According to the results, during 2016-2019 years, The mean of sale return percent of irrigated wheat, barley, canola and forage were estimated 13.4, 39.3, 38.9 and 19.5 percent and means of investment return percent of irrigated wheat, barley, canola and forage were estimated 15.5, 64.6, 63.6 and 24.8 percent. The means of physical productivity of irrigation water for wheat, barley, canola and forage were estimated 0.56, 0.51, 0.33 and 2.8 kg/m3 and means of economic productivity of irrigation water based on gross income for wheat, barley, canola and forage were estimated 8996.8, 10431.8, 18750 and 5915.9 rials/m3 and means of economic productivity of irrigation water based on profit for wheat, barley, canola and forage were estimated 1191.1, 10750, 7291.7 and 1312.2 rials/m3.

In this study, the trend of agricultural water consumption was investigated for 22 years (1989-2011) in Iran, considering crop and livestock requirements per capita. Crop and livestock products were categorized into nine groups so that, each group has its particular subgroups. The results of this study showed that the trend of water consumption per capita was ascending over the proposed period with regard to the diet variations. Wheat in cereal crops and meat in livestock products had the largest water consumption values. The average capita water consumption was estimated about 1420 m3 during 1989-2011 which the maximum and minimum amount of water consumption corresponded to the year of 1389 and 2007, respectively. The volume of virtual water consumed by crops and livestock has been increased from 61 billion m3 in 1368 up to 120 billion m3 in 1390. The portion of imported virtual water through agricultural and livestocks products has been 11-27 billion m3 with an average of 17.6 billion m3 in the proposed period. Rainfed productions with average consumption of 17.3 billion m3 of water by rainfall provide a part of annual water consumption. Therefore, the portion of renewable water resources in agriculture was estimated to be varied from 63 (2008) to 81 (2011) billion m3. According to the water resources assessment indices, Iran was faced to water crisis during the proposed period in which population growth and diet changes may be effective.  Regulation of Proper diet such as reducing creal and meat consumption, establishing a dynamic market for selling agricultural products, recycling waste products, importing particular food products and increasing water productive could be effective in prevention of water management crises.

The agricultural sector plays a vital role in the national economy and food production in Iran. In the meantime, due to the country's particular climate and the disproportionate distribution of time and place of precipitation, water cultivation is the main driver of food production. In arid areas such as Khuzestan province, nearly one hundred percent of agricultural production comes from water cultivation. According to the Research Center of the Iran Parliament, in order to meet the food needs until 2030, based on approximate 2600 kcal/day more than 150 billion cubic meters of annual water will be required that is not available in water cart of Iran. In at globalizing world, where problems increase with the effect of warming and climate changes, it seems that decrease in usable freshwater bodies will pose a serious problem. This study intends to investigate climate change impacts on evapotranspiration (ET) of agricultural crop in Khouzestan province in future periods. The importance and urgency of the subject and the limited research done in this regard, the local and regional effects of climate fluctuations on the evapotranspiration of agricultural products are of particular importance. These changes are of great importance, especially in fertile and agricultural areas such as Khuzestan. In this research, climate change impact on precipitation and evapotranspiration of agricultural products in future periods was investigated. In order to investigate climate change impact on ET, the CanESM2 atmospheric general circulation model (GCM) data under two RCP scenarios (IPCC-AR5) were used. In order to downscale CanESM2 model data, SDSM analysis software was used. The data used in this study include precipitation, minimum and maximum temperature and daily average temperature. To determine the feasibility of future periods meteorological data production of SDSM model, calibration and verification was performed for the base periods (1990-2005). Minimum and maximum temperature and precipitation estimated by SDSM method by CanESM2 data in three future periods: 2030s, 2060s and 2090s and compared with historical data. The strategic agricultural products such as wheat, barley, rice, corn and sugar cane were selected for this study. Potential evapotranspiration of these products were used during the cultivation period. According to the fifth report of the Intergovernmental Panel on Climate Change (IPCC) using CanESM2 model under RCP scenarios, meteorological data in the upcoming periods were simulated, the average periods potential evapotranspiration were calculated with information generated in the upcoming periods. Results showed that temperature on average increases about 4°C in all selected scenarios, this increase is higher in case of RCP8.5 compared to RCP4.5, and precipitation reduce in 2060s and 2090s. Studied Crops ET under RCP4.5 compared to baseline is always less than RCP8.5 scenario. For rice and corn, the average ET increase in 2060s and 2090s is higher than the others. It can be concluded that studied crop ET will increase in future periods, therefore we should consider that there will be lack of water and less crop production in Khouzestan province. We should change our cultivation periods and cultivate more effective crops in order to increase water efficiency and decrease potential evapotranspiration in some area of Khouzestan province.

In this article, the role of imports and exports of major agricultural products on amount of virtual water trade, net virtual water import (NVWI), and country water indices included water footprint (WF), water scarcity (WS), water dependency (WD), and water self-sufficiency (WSS) in agricultural sector was studied for a five-year period (1388- 1384). The results show that the volume of imported virtual water to Iran during the mentioned period for 16 major crops was three times more than the volume of exported virtual water for 16 major crops (about 125.8 and 37.9 billion cubic meters, respectively). This means that the NVWI in this period was positive. It is noted that sever increasing in positive NVWI in the two last years of this period has been accrued due to population increasing and drought events in most provinces of the country. Also, Annual meanly country water footprint in agricultural sector is 104.8 billion cubic meters in this period and with average annual 17.6 billion cubic meters through NVWI, Iran has been saved the same amount of its internal water resourecs. Calculated indices of WS, WD and WSS in Iran showed that the average annual intensity of water use in agricultural sector in the mentioned period has been 67.1% which is high (WS index close to 100). Average annual country's agricultural dependency on imports of virtual water (WD) has been 16.8%. This percentage indicates that if the country instead of importing agricultural products, produce those amount into country, an average of about 16.8% should be added to the water consumption in the agricultural sector. Also, average annual Iran's selfsufficiency to water (WSS) has been estimated about 83.2%.

Heavy metals are types of elements naturally present in soil or enter into soil as a result of human activities. The most important route of exposure to heavy metals is daily intake of food. Crops grown in contaminated soil (due to mining activities, industrial operations and agriculture) may contain high concentrations of heavy metals. Also closeness to cities and industrial centers can have a great influence on the accumulation of heavy metals to agricultural products grown in the region. The study aimed to determine the concentration of heavy metals in soil and agricultural products around urban and industrial areas of Zanjan province (North West of Iran) and consumption hazard probability. Soil (75 samples of soil from a depth of 0 to 10 cm) and plant 101 samples) samples, in the summer 2011, were randomly taken from industrial areas as follow: tomatoes (Lycopersicum esculentum M), wheat seed (Triticum vulgare), barley seeds (Hordeum vulgare), alfalfa shoots (Medicago sativa L.), potato tubers (Solanumtuberosum L.), apple fruit, vegetables and fruits such as Dill (Aniethum graveolens L.), leek (Allium porrum L.), Gardencress (Barbara verna L.) and basil (Ocimum basilicum L.). Plant samples were then washed with distilled water, oven dried for48 hours at a temperature of 70 ´C until constant weight was attained and then they digested using 2 M hydrochloric acid (HCl) and nitric acid digestion in 5 M. Concentrations of heavy metals in the soil and crops were determined by atomic absorption spectrometry. DTPA extraction of metals by Lindsay and Norvell (1978) method and sequential extraction method by Tessier et al. (1979) were performed. Statistical analysis was accomplished using the software SPSS 16.0 and the comparison of mean values was done using the Duncan test at the 5% level of significance. The magnitude of variations for total copper was from 11.5 to 352.5 (average 52.4), zinc was from 96.3 to 1353.8 (average 264.8), lead was between 40.0 and 470.0 (average 105.7), nickel ranged from 12.8 to 77.0 (average 46.7) and chromium varied from 10.0 to 49.5 (average 21.7) mg kg-1. DTPA extracted heavy metals for copper varied from 1.50 to 21.23, averaging 4.47, zinc from 0.57 to 76.50 averaging 23.15, lead from 2.43 to 63.38 averaging 16.81 and nickel from 0.28 to 2.32 averaging 1.20 mg kg-1. Chemical changes in the different fractions were as follows: Cu (residual > bounded to organic matter > bounded to Fe-Mn oxides > bounded to carbonate > exchangeable fraction), Zn and Ni (residual > bounded to Fe-Mn oxides > bounded to carbonate > bounded to organic matter > exchangeable fraction,) and Pb (residual > bounded to Fe- Mn oxides > bounded to organic matter > bounded to carbonate > exchangeable fraction). The concentration of heavy metals in plant parts were high with respect to studied location. The highest amounts of Zn (Gardencress), Pb (Dill), Cu (Leek), Ni (Basil) and Cr (Basil), respectively were found to be 150.25, 41.2, 23.13, 6.46 and 3.47 mg kg-1 and the minimum amounts of the metals studied were found in fruits, wheat and barley grains. The total amount of metals in plants were as follow (Zn >> Pb > Cu > Ni > Cr). Bioaccumulation factor (BAF) of metals in plants were as Zn=Cu > Pb >> Cr > Ni. Hazard probability (HQ) in cancerous diseases for each element (except Pb) in both children and adults was less than unit. HQ content of Pb was much higher than the unit and for children and adults 9.07 and 6.94, respectively showing high contribution of Pb contamination of crops that threatens the consumer health in that location. The total amount of risk (THQ) in children was higher than that in adults. The results obtained in this study indicate that an urgent attention is required for consumer products related to public health, especially vegetables grown in the studied regions. Toxic effects of heavy metals have many deleterious effects which are more pronounced over time. With conventional monitoring of food quality produced in farms and presented in markets, excessive accumulation of heavy metals entering in to the human food chain can be prevented. Also, we can change the risk potential of heavy metals in the region by growing vegetables which accumulate heavy metals.

Greenhouse whitefly, Trialeurodes vaporariorum West. is one of the most important pests of the field crops and ornamental plants in greenhouses. Pest control is based on using chemical insecticides and biological control agents. In this study, the efficiency of the green lacewing, Chrysoperla carnea ( Steph.) with release ratios of 1:1, 1:5, 1:10, 1:15, and 1:20 (predator:prey) using eggs in chrysobag and the effect of three insecticides including Confidor (35% Sc), Permethrin (25% Ec) and Dimilin (25% Wp) at concentrations of 0.3 ml/l, 0.3 ml/l and 0.15 g/l in water, respectively, were investigated. In one experiment, the eggs of the green lacewing were released on tomato plants that were infested with 150 different nymphal instars of the pest. Control treatment included chrysobag whithout any egg. After 11 days, nymphal mortality was calculated. In insecticidal experiments, in control treatment, only water was sprayed. Both experiments were conducted in a randomized complete block design with four replications in a greenhouse with 25±5 °C, 50-60% RH and 14:10 LD period light conditions. The means of data were compared using Duncan Multiple Range Test. The results showed that the maximum nymphal mortality of 52.42% was due to the release ratio of 1:1 (predator:prey) however, this was not sufficient and did not control the pest population. The results of the chemical control also revealed that one application of Confidor caused the highest mortality about 88% that was more effective in reducing pest population compared with the release of predator eggs. Neither method had absolute control. In general, results indicated that to be more effective the two methods need to be applied more than once, and they must be combined into one or with other control methods.