Fateme Aghamir; Saeid Soufizadeh; Ahmad Soheili
Abstract
Introduction: Climate change is one of the most important human challenges in food security in the agricultural sector, especially in arid and semi-arid regions. The most important climatic variables affecting crop yield, rainfall and temperature, carbon dioxide, especially in rainfed areas are of great ...
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Introduction: Climate change is one of the most important human challenges in food security in the agricultural sector, especially in arid and semi-arid regions. The most important climatic variables affecting crop yield, rainfall and temperature, carbon dioxide, especially in rainfed areas are of great importance. The results of researchers in Iran indicate the effect of obvious and undeniable climate change on crop yields in Iran. By using modeling knowledge in selecting the appropriate plant and cultivar for a region, determining the optimal plant characteristics, determining the best crop management, predicting the effect of diversity and climate change on crop growth and yield, and estimating potential yield in a low cost, fast and accurate way can be Adverse climate change on agriculture with negative mitigation options. Material and methods: In the present study, the effect of temperature increase, increase and decrease of 20% in precipitation and increase of carbon dioxide concentration on phenology and yield of dryland wheat in four cities of Dehgolan, Divandere, Saqez and Sanandaj in Kurdistan province with long-term climatic data of Kurdistan province in it was studied from 1370 to 1393. In this study, in order to simulate the daily growth and development of wheat in the conditions of climate change and to evaluate the potential effects of the simulation under the APSIM wheat model, 24 climate change scenarios and 1 baseline scenario, based on the product of temperature increase multiplied by +1, +2 , +3 and +4 ° C, change in precipitation of 2020% and three concentrations of carbon dioxide were considered 462.5, 527.5 and 725 ppm, respectively. Model inputs include climate (temperature, rainfall and radiation), soil (soil water and soil nitrogen), genetic coefficients and crop management information and its outputs including flowering date, physiological maturity date, maximum leaf area index date, leaf area index, Grain yield and biological yield were analyzed in future and past climatic conditions. Results and discussion: In scenarios with increasing rainfall compared to the base period, flowering uniformity, physiological maturity will increase in all cities but will decrease in Dehgolan. The uniformity of the maximum range of the leaf area index will increase in all cities and in Dehgolan the percentage of increase in uniformity is the lowest. Also, the uniformity of the leaf area index of Dehgolan and Sanandaj will increase, and Saqez and Divan Darreh will decrease. With decreasing rainfall, flowering uniformity, physiological maturity, the maximum range of leaf area index decreases in all cities and the percentage of uniformity reduction in Dehgolan is the lowest. With increasing rainfall, biological and grain yield fluctuations were highest in Dehgolan and lowest in Sanandaj, and with decreasing rainfall, all cities had biological fluctuations, Sanandaj had the least fluctuations and Divan Darreh had the most fluctuations. Conclusion: The effect of climate change factors including temperature, precipitation and carbon dioxide on different regions of Kurdistan province is different; In rainfed cultivation, in the basic period, wheat phenology and yield are affected by the initial water moisture in the soil, while by changing the climate, wheat phenology can be justified by increasing the temperature with the optimal crop temperature and by increasing rainfall with the wheat leaf area index.
Afsaneh Yousefi; Reza Mirzaeitalarposhti; Fatemeh-Sadat Aghamir; Jafar Nabati
Abstract
Introduction: Economic problems caused by increased consumption of fertilizers from one hand and environmental issues related to non-scientific consumption of such fertilizers (e.g., pollution of water and soil, loss of soil fertility, and crop quality) on the other hand, have shifted attentions towards ...
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Introduction: Economic problems caused by increased consumption of fertilizers from one hand and environmental issues related to non-scientific consumption of such fertilizers (e.g., pollution of water and soil, loss of soil fertility, and crop quality) on the other hand, have shifted attentions towards application of biological fertilizers. In order to reduce environmental pollution and ecological damage caused by the use 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. The purpose of this study was to reduce the harmful effects of chemical fertilizers on the agroecosystem and to reduce the cost associated with crop production through application of biofertilizers (free-living nitrogen-fixating bacteria, and potassium and phosphate solubilizing bacteria) on mung bean. Material and methods: A field experiment was carried out as a randomized complete block design with factorial arrangement of treatments. Two mung bean genotypes (Dezfouli and Indian) were planted under six fertilization systems at the Agricultural Research Station of Ferdowsi University of Mashhad, Iran in 2017. Fertilization treatments were Nitro Bacteria (NB), Phosphate Power Bacteria (PhPB), Potassium Power Bacteria (PPB), NB+PhPB+PPB, chemical nitrogen fertilizer (N), and no fertilizer as control (C). Prior to planting, the soil was sampled at a depth of 0-30 cm for measurement of common physico-chemical characteristics. At the end of the growing season, an area of 1 m2 from the middle of each plot was harvested for crop traits. Plant height, the number of branches per plant, grain yield, biological yield, and yield components including the number of pods per plant, the number of seeds per pod, and 100-seed weight were measured accordingly. Results and discussion: The results showed a significant difference between mung bean genotypes and also fertilization treatments regarding yield and yield components (p < 0.05). The highest biological yield (6555 kg ha-1 ) and grain yield (1558 kg ha-1 ) were obtained from Dezfouli genotype under NPB+PhPB+PPB treatment. The lowest biomass and grain yield were observed for Indian genotype under control treatment with 3518 and 1393 kg ha-1 , respectively. The results showed that the combined application of nitrogen stabilizing bacteria and potassium and phosphate release bacteria, due to increased access to nutrients that is an effective factor in stimulating the growth and photosynthesis of plants, improved conditions for growth and production of photosynthetic materials, and also increased the yield of mung bean plants. Conclusion: It was revealed that the combined application of various biofertilizers not only improves the mung bean yield, but also can reduce negative aspects of chemical fertilizer application in crop production systems. Paying attention to more frequent use of biological fertilizers could be considered as an important agroecological approach, which results in healthier soil and water resources.
Fateme Aghamir; Hosseinali Bahrami
Volume 16, Issue 2 , July 2018, , Pages 217-232
Abstract
Introduction: A growing population demands more food and water; with the reduction of conventional water resources, it will be essential to increase the efficiency of nutrient use in conventional systems. Iran is located in the mid-latitude belt of arid and semi-arid regions of the Earth and such arid ...
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Introduction: A growing population demands more food and water; with the reduction of conventional water resources, it will be essential to increase the efficiency of nutrient use in conventional systems. Iran is located in the mid-latitude belt of arid and semi-arid regions of the Earth and such arid and semi-arid regions cover more than 60% of the country. As a result, water is the most important limiting factor for biological and agricultural activities and the use of unconventional water in agriculture is inevitable and important under our country's conditions. Unconventional waters are not directly usable and must be adapted for use, including the removal of biological contamination, heavy metals, salinity and pH amendment. The aim of this study was to evaluate the effect of magnetic water on the essential nutrients uptake by maize (Zea mays) in saline conditions. Materials and methods: Magnetic water was supplied by a magnetic device with an electromagnetic field intensity varying from 8 to 10 mT. The experimental design was two factors factorial (2x3) arranged in a randomized complete block design. The combinations of the treatments were at two levels of water - non-magnetic (normal) and magnetic - and three levels of salinity (800, 1300 and 2100 ppm NaCl) with three replications. Soil physicochemical properties including texture, organic carbon, cation exchange capacity, electrical conductivity, pH, nitrate, sulfate, chlorine, phosphorous, iron, zinc, manganese, copper, and soluble and exchangeable calcium, magnesium, sodium and potassium, as well as elements present in the plant, including total nitrogen, phosphorus, potassium, sodium, calcium, magnesium, iron, zinc, manganese and copper, were all measured using standard methods. Results and discussion: The results of chemical water analysis showed that the electromagnetic field had no significant effect on its chemical properties. Regarding soil properties before and after harvest, magnetic water had a significant effect on soluble and exchangeable sodium, chlorine, calcium and magnesium. The results, also showed that with increasing salinity, macronutrients uptake and protein percentage were reduced, while micronutrient uptake and sodium levels increased; moreover, comparisons of treatment means showed that magnetic treatment increased uptake of all the nutrients and the protein percentage in leaves and seeds of maize plants, but no significant changes were observed in their roots and shoots. The results showed that magnetic water reduces sodium accumulation and its destructive effects on the reproductive organs of maize plant. Due to the accumulation of sodium in roots and stems, the plant's resistance to salt stress increased. Conclusion: Due to the poor water quality in the agricultural section, it appears that utilization of magnetic water in arid and semi-arid regions of Iran can lead to improved yield and water productivity; therefore, it is recommended that further research be undertaken in this areas.
