hadi khorsandi

Conservation agriculture is one of the successful strategies of sustainable agriculture in the context of climate change. Conservation agriculture with residues mantanance systems, could decrese soil temperature and this may affect crop growth in cold regions. For this purpose, an experiment was conducted during 2018-2019 and 2019-2020 in two controlled and field conditions in Dryland Agricultural Research Institute of Maragheh. Under controlled conditions, wheat genotypes (Baran, Saradri, Rizhav, Saji, Rascon, Gerdish) were exposed to different cold and frost temperatures (+4, -5, -10 and -15 ° C) and under field conditions, those genotypes were planted inthree different dates (late shahrivar, late mehr and late aban) in chickpea rotation under conservation tillage (no till) and conventional tillage conditions. Results of controlled conditions showed that Sardari and Baran cultivars are cold tolerant cultivars due to having the highest amount of chlorophyll and Superoxide dismutase (SOD) and the lowest content of malondialdehyde (MDA). In contrast, H2O2 content in Rizhav and Saji genotypes at -15 ° C was higher than other genotypes. In conservation tillage conditions, all of the genotypes had the highest antioxidant enzymes activity and the lowest content of H2O2 and MDA. However, Sardari and Baran were more effective genotypes under cold stress conditions, compared toother genotypes. According to the results, in cold drylands regions, planting date can affect phenological stages of the plants in dealing with cold stress in winter and spring, and selection of cold-tolerant genotypes can improve physiological characteristics of plants especially in conservation agriculture system under cold stress conditions.

To evaluate rainfall productivity and grain yield of dryland wheat genotypes under different rotation and tillage managements, a split-split plot experiment based on RCBD with three replications was conducted in Dryland Agricultural Research Institute for 4 years (2016-20). Three crop rotations (chickpea-wheat, safflower-wheat, and vetch-wheat) were located in main plots and three different tillage methods (conventional, minimum, and zero tillage) were considered in subplots and two Baran and Azar 2 wheat genotypes were considered in sub-sub plots. Results indicated tillage and crop rotation treatments significantly affect precipitation efficiency. Maximum rainfall productivity was recorded for Baran in zero and minimum tillage systems with forage (vetch) rotation by 0.71 and 0.7 kg/m3. Rainfall productivity under zero tillage treatment during three years of the experiments increased from 0.45 up to 0.67 (approximately 32 %). The highest relative water content, stomatal conductance and harvest index were recorded from Baran in vetch rotation under zero tillage treatment. The highest grain yield was belonged to the vetch, chickpea and safflower rotations by 2231, 2105 and 1991 kg/ha, respectively. With increasing soil water content and improving rainfall productivity in the conservation agriculture system, grain yield was increased by 5% and 8 % under minimum and zero tillage treatments than that of a conventional system. Therefore, in cold rainfed climates, in order to develop in wheat conservation, it is recommended to the application of autumn forage and chickpeas rotation in zero tillage conditions.

In this study, the effects of different levels of tillage and nitrogen fertilizer on wheat yield in rotation with chickpea were studied.

An experiment with 8 treatments in a split plot design based on randomized complete block design with two factors of tillage type including T0= low tillage and T1= no tillage and quantities of different nitrogen fertilizer application at four levels including N0= without nitrogen application, N30= 30, N45= 45 and N60= 60 kg.ha-1 pure nitrogen for 4 years in 3 replicates from 2015 to 2019 in moderate-cold region of Kermanshah was conducted.

Finally evaluated treatments technically and economically were. The highest amount of organic carbon (0.703%) belonged to T0N45 treatment. The results of soil analysis showed that the effects of tillage and nitrogen fertilizer application. The results showed that the highest yield occurred in the second crop year in T1N45 treatment. The results of economic evaluation showed that each treatment alone was economically profitable and among the treatments, T1N0 treatment had the highest benefit-to-expenditure ratio.

In both no tillage and low tillage systems, it was observed that the ratio of present value to interest expense decreased with increasing nitrogen use. Finally, considering the ratio of present benefit - cost ratio difference showed that T1N45 treatment, namely rainfed wheat cultivar with low tillage and 45 kg/ ha nitrogen fertilizer, be known as the best economically treatment in Sararood region of Kermanshah.

Potassium as a key element in environmental stress conditions, had fundamental role in plants growth and development. Under water deficit stress conditions, absorption of this element decreases. For this purpose, to evaluate changes in physiological parameters and grain yield of dryland wheat (Baran, Homa, Hashtrood) with application of different levels of potassium sulfate (control, 75 and 150 kg/ha), a factorial experiment based on randomized complete block design (RCBD) with 3 replications was conducted during 2017-18 and 2018-19 growing sessions. Accumulation of potassium (K) increased in varieties by application of potassium sulfate so that, maximum K content was recorded in Hashtrood than other varieties. Also, relative water content, chlorophyll content and NDVI of Hashtrood was more than others. Relative water content and chlorophyll content index of all varieties was increased by application of 75 kg/ha potassium sulfate. Stomatal conductance of Hashtroud by application of 75 kg/ha potassium sulfate was more than Baran and Homa. Photochemical efficiency of PSII and photosynthesis efficiency of studied varieties by application of 75 kg/ha potassium sulfate was higher than other treatments and as a result, grain number, weight and yield was improved. Based on the results, application of the 75 kg/ha potassium sulfate by improving plant tolerance to the water stress, could increase grain yields under dryland areas.

This research conducted to investigate on effects of foliar spraying and soil split application of nitrogen on differences of dryland bread wheat varieties and genotype for nitrogen uptake, grain and straw yield. In order to do this study, experiment was conducted with factorial arrangement completely randomized block design with factor A: total, split and foliar spray applications and factor B: wheat varieties Azar2, Sardari and, Turkey 3702 genotype with three replications for three years from 2007 to 2010 in Maragheh. The results indicated that effects of urea foliar spraying, split and total nitrogen fertilizer application methods were significantly different for grain and straw yields, nitrogen uptake grain and straw of wheat varieties and genotype. Urea spraying and split method of nitrogen had highest grain and straw yields and nitrogen uptake. In addition, main effects of wheat varieties and genotype were found significantly different. Azar2 and Turkey 3702 genotype at same level increased grain yield compared to Sardari variety. Turkey 3702, Azar2 and Sardari at different methods of nitrogen application were significantly different for nitrogen content of grain. Turkey 3702 compared to other wheat varieties had heights grain nitrogen content at nitrogen split application. It can be concluded that spray and split applications of nitrogen compared to total nitrogen application can increase nitrogen content of grain and grain and straw yields. In addition, wheat genotype and varieties at nitrogen application methods can increase differently nitrogen uptake, grain and straw yields.

In order to study the effects of manganese sulfate in increasing seed yield of four safflower genotypes (Carthamus tinctorius) under rainfed conditions، this experiment carried out in Maragheh agricultural research station. The experiment was arranged with four Mn fertilizer levels (0،10،20،30 kg ha-1) as soil application together with two foliar spray levels (1% and 2%) of 1. 5 kg ha-1 manganese sulphate with four Safflower genotypes (V1=19829 V2=333،،V3=335 and V4= Sina)، as factorial based on RCBD design with four replications. At maturity، plots were harvested and biomass and grain yield were measured. The results of combined (two-year) analysis showed that manganese application increased 100 kg ha-1 grain yield and 500 kg ha-1 biomass. It can be concluded that manganese sulfate fertilizer application (at a rate of 10 kg ha-1 in the soil) or foliar spray (1. 5 kg ha-1) would increased crop yield in safflower under rainfed condition.