In order to determine the critical nitrogen concentration of canola leaf and studying the correlation of yield and yield components of this plant with leaf nitrogen concentration, 35 farms were managed in the same way of Varamin plain and in the dominant soil serie (Varamin), were selected during 2016. Leaf samples were pick up from these farms at flowering stage and were prepared for analysis. In harvest season, all 35 fields were harvested and the mean grain yield was determined. The critical nitrogen concentration in dry leaves was determined at 3% by using Kate and Nelson's graphical method, for 90% relative yield. There was a significant correlation between the content of canola leaf nitrogen as independent variable (X) with other traits, including grain yield and yield components as dependent variables (Y) at the 35 studied farms. The results of the studies showed that canola seed yield was affected by leaf nitrogen content. The content of nitrogen in canola leaves was significantly correlated with grain yield. This correlation was followed by a quadratic function with a coefficient of explanation of 0.97. Relative yield of canola seed increased only to 4.36% nitrogen concentration of leaves, and since then, the increase in leaf nitrogen did not affect grain yield.

In order to investigate the effect of irrigation regime and biofertilizers on yield and yield components of irrigated wheat, an experiment was conducted in a split-plot layout based on randomized complete block design with three replications at Sarab Changai research station, Khoramabad, during 2014-2015 crop year. Irrigation intervals were in two levels including 75 and 150 mm evaporation from A class evaporation pan were allocated to main plots and biological fertilizers were in four levels including Azotobacter, Micorhiza, Azotobacter + Micorhiza and blank (No fertilizer use) were allocated to sub plots. The results showed that the effect of Irrigation intervals, biological fertilizer and their interaction effects on determined characteristics are significant. 75 mm evaporation from A class evaporation pan was superior than the 150 mm evaporation in all traits. In 75 mm evaporation spike length (7%), spike weight (7.7%), grain number in spike(6.7%), Weight of one thousand grains (7.3%), grain yield(7.1%), biological yield(7.4%) were higher than 150 mm evaporation. Azotobacter + Micorhiza fertilizer treatment was superior to other fertilizer treatments. So that In this treatment the spike length was 28.6%, spike weight 48.3%, number of seeds per spike 56.9%, 1000 grain weight 39.8%, grain yield 54.4%, biological yield 51.3% and water use efficiency 55.7% were increased than blank.

In order to study the effect of nitrogen and irrigation interval on quantity traits and protein of mung bean (Vigna radiata L.), a factorial experiment based on randomized complete block design was conducted with three replications at research farm of Gonbad Kavous University during 2016. Interval irrigation factor was at three levels including irrigation each 10, 20 and 30-day, nitrogen fertilizer in three levels of non-application and application of 50 and 100 kg per hectare and mung bean genotypes in two levels of VC-1973A and Partov. The results showed that the highest grain yield was obtained from 30-day irrigation interval with 100 and 50 kg per hectare nitrogen and the lowest grain yield was obtained from 10–day irrigation interval and 100 kg nitrogen/ha and non-application treatment and also 20–day irrigation interval and non-application of nitrogen/ha. Grain yield in VC-1973A was 72.52% higher than partov gernotype. The highest protein percentage was obtained from irrigation interval of 30-day and the lowest was obtained from 10-day irrigation interval. With increasing of nitrogen consumption, protein percentage increased but proline decreased. Increasing of irrigation intervals from 10 to 30-day increased the amount of proline in mung bean genotypes. Protein percentage and amount of proline in Partov was 9.49% and 29.66% more than VC-1973A. In addition, although in some traits Partov was superior but in more traits especially grain yield VC-1973A was better than Partov and increasing of interval irrigation and nitrogen consumption created better conditions for mung bean production.

Elements such as nitrogen (N), molybdenum (Mo), and cobalt (Co) are needed to improve the quantity and quality of beans. In order to study the effects of these elements on pod yield and concentration of nutrients in bean, a factorial pot experiment was conducted in 2016 in greenhouse conditions at University of Zanjan, using a CRD with three replications. The experimental factors consisted of four levels of N (50, 100, 150, and 200 mg/l), three levels of Mo (0.067, 0.2, and 0.6 mg/l), and Co (0.006, 0.06, and 0.3 mg/l). The results showed that the highest dry weight of pods was obtained from treatment of N100Mo0.2Co0.06 which was 34.05 g/pot and had no significant difference with N150Mo0.6Co0.06 treatment. The application of different levels of factors increased the concentrations of N, P, and Mg in bean leaves in treatments of N200Mo0.6Co0.3, N200Mo0.6Co0.006, and N150Mo0.6Co0.3 and the highest increase in concentrations of mentioned elements were 6.94, 0.91, and 0.41% respectively. However, the concentrations of K and Ca decreased as a result of the application of the factors. The highest concentrations of Fe, Mn, Cu, Mo, and Co bean were measured in treatments of N200Mo0.6Co0.006, N150Mo0.2Co0.006, N200Mo0.6Co0.3, N150Mo0.6Co0.3, and N150Mo0.067Co0.006 which were 490, 185.4, 8.26, 284.5, and 54.9 mg/kg, respectively. Overall, according to the results, N100Mo0.2Co0.06 is recommended for bean.

Evaluation the effect of drought stress and foliar nutrition of iron nano-chelate and fulvic acid on grain yield and fatty acids composition in seed oil of two sesame cultivars was conducted during a factorial split-plot experiment based on randomized complete block design with three replicates in 2017 in the Research Farm Shahed University of Tehran. The experimental factors included drought stress in three levels: full irrigation as control, irrigation up to 50% seed ripping, and flowering, as well as four treatments of foliar nutrition by iron nano-chelate and fulvic acid in Dashtestan and Halil cultivars. The results showed that the drought stress reduced grain yield and also, seed oil content. The highest grain yield was observed in full irrigation (2303.3 kg/ha) and the co-application of iron nano-chelate and fulvic acid (2246.4 kg/ha). Halil cultivar had the highest mean of the total number of capsules (81.19), number of seeds per plant (4786.1), 1000-grain weight (3.21 g), grain yield (2172.7 kg/ha), and biological yield (13534.6 kg/ha) in compared with Dashtestan. The highest oil and protein yield were observed in full irrigation and irrigation up to 50% seed ripping. Irrigation cut off at 50% flowering and seed ripping had the highest oleic and linoleic fatty acids compared to the control treatment, but the highest palmitic and stearic fatty acids were obtained in full irrigation treatment (10.86 and 10.73%, respectively). Halil and Dashtestan cultivars had the highest unsaturated and saturated fatty acids, respectively.

A field experiment was conducted to evaluate and compare the effects of N and P chemical fertilizers with biological N and P fertilizers on competition between cotton and weeds with split plot arrangement in a randomized complete block design with three replications during the years 2014 and 2015. The main plots consisted of two levels of weed management practices including weed free and weedy check. Sub plots had five treatments included integrated application of biological and chemical fertilizers:1-Control (Without fertilizer) 2-Urea+Triplesuperphosphate (TSP) 3-Nitroxin+50% urea+100% TSP 4-100% urea+Barvar2 +50% TSP 5-Nitroxin+Barvar2+50% urea+50% TSP. In the first year, control of weeds increased LAI and number of boll per plant to 34 and 22 percent, respectively and cotton yield increased by 67 percent in the first year and 50 percent in the second year. Fertilizer treatments had a significant effect on stem length, LAI, number of sympodial branches and boll per plant, and yield of cotton. Under weed interference condition, use chemical fertilizers alone reduced cotton growth and yield due to increasing competitive ability of weeds. But reducing urea consumption by half and replace it with nitroxin, increased cotton yield by 61% compared to the chemical fertilizer treatment due to increasing number of boll per plant. This result indicates that the use of biological fertilizers reduce the negative effects of chemical fertilizers and increase crop competitiveness against weeds

In order to investigate the effect of different levels of nitrogen on some grain storage compounds and quantitative and qualitative yield of three sunflower cultivars, an experiment was carried out as split plots based on randomized complete block design with four replications in Dezful region during 2017-2018. In this research, four levels of nitrogen fertilizer (0, 60, 120 and 180 kg ha-1 N) were considered as the main factor and three sunflower cultivars (Ghasem, Record and Progress) as a sub factor. The results showed that increasing nitrogen consumption reduced the percentage of oil, percentage of stearic acid and linoleic acid percentage but, protein percentage, oleic acid and palmitic acid percentage increased significantly. There were significant differences between different cultivars in grain yield and oil content where Qasem cultivar had the highest grain yield (3920 kg ha-1) and oil (1860 kg ha-1) with the consumption of 180 kg ha-1 N. Also, the results indicated that the highest correlation of grain yield with the studied traits belonged to oil yield (r=0.97**) followed by protein content (r=0.85**) and the lowest to linoleic acid (r=-0.58*). In general, it can be stated that more nitrogen consumption has been effective in increasing the quality and quantity of sunflower and Qasim cultivar had a higher ability to absorb nitrogen in order to increase yield per unit area.

In order to study the effect of 0.05 g.L-1 Uniconazole and biofertilizers application on yield, chlorophyll content and grain filling components of wheat using segmented model under soil salinity conditions, an experiment was carried out as factorial based on randomized complete block design with three replications. Factors were included soil salinity in four levels (non-application of salinity as control and 40, 80 and 120 mM salinity in soil), by NaCl and single and combination application of Uniconazole and bio fertilizers (1) control or without bio fertilizers and Uniconazole, (2) mycorrhiza fungi, (3) Uniconazole, (4) Pseudomonas putida, (5) mycorrhiza with Pseudomonas putida, (6) mycorrhiza with Uniconazole, (7) both application of mycorrhiza with Uniconazole and Pseudomonas). A segmented model was used to quantifying the grain filling parameters. The results showed that both application of mycorrhiza with Uniconazole and Pseudomonas under no salinity condition increased the content of chlorophyll a, total chlorophyll, carotenoid, root weight and volume (39.8, 51.6, 47.2, 97.9 and 54.7% respectively) and also maximum of grain weight, grain filling period, effective grain filling period and grain weight (78.4, 21.8, 32.2 and 108.8% respectively) in comparison with no application of bio fertilizers and Uniconazole under the highest soil salinity level. Based on the results, bio fertilizers and Uniconazole application can be suggested as a proper approach for increasing of yield and grain filling period of wheat under soil salinity condition.

Biological fertilizers are natural inputs that can be used as complementary or alternative fertilizers in sustainable agriculture. A split plot experiment has been conducted in a randomized complete block design with three replications in Khuzestan province during 2018-19. Three different planting methods (spraying), linear and atmospheric and stack plots in main plots and three levels of application of 100% urea, 70% urea plus 100 g Azotobacter, 50% urea plus 100 g Azotobacter in plots. Sub-comparisons. The results of analysis of variance showed that the main effects application of urea fertilizer plus azotobacter and planting pattern had a significant effect on number of pods per plant, number of seeds per pod, grain yield, protein percentage, parietin yield. The use of 70% urea plus Azotobacter significantly increased the yield of rapeseed oil but was in a class with 100% urea treatment. The use of 70% urea plus Azotobacter significantly increased the yield of rapeseed oil but was in a class with 100% urea treatment. Interaction between sowing pattern and the combination of urea and aztobacter had a significant effect on grain yield and biological yield. The most appropriate yield of method planting furrow and 70% of urea with azotobacter application. In this study, considering the 25% savings in nitrogen fertilizer consumption, in addition to 33% increase in canola quality, it reduced the costs by 30%, which is economically viable and recommended.

The evaluation of different forage crops (clover, barley, chickpea, vetch, and fenugreek) and planting method's effect on the quality and quantity of forage yield was the main goal of this study. This study was conducted as a split-plot based on a randomized complete blocks design with three replications on the experimental research field of agriculture faculty, the Shahid Chamran University of Ahvaz during 2017-2018. Main plot included three planting methods (row intercropping with 10 cm and 20 cm interval and mixed intercropping) and sub-plot was seven forage crops with dominance of barley (50% barley+50% clover as control, 50% barley+25% clover+25% chickpea, 50% barley+25% clover+25% vetch, 50% barley+25% clover+25% fenugreek and 50% barley+25% vetch+25% fenugreek). Total forage yield and yield components and also, some quality parameters of forage (ADF, NDF, WSC, DMD, raw fiber and ash were measured. The results showed that the highest total forage yield (1268.9 g.m-2) was belonged to crop diversity of 50% barley + 25% chickpea + 25% fenugreek with 10 cm - row intercropping. It can be due to the highest of all forage yield components including stem, leaves and reproductive dry weight.

In order to study the effect of pendimethalin (Prowl) on weed control of onion (Allium cepa L.) fields, an experiment was carried out in randomized complete block design with four replications, during 2017 in Agricultural Research Center of South Kerman. Treatments included application of pendimethalin (Prowl) at 3.5, 3, 2.5, 2 L ha-1 (pre-emergence), oxyfluorfen (Goal) at 750 ml ha-1, and repeat 18 day later (post-emergence), oxadiazon (Ronestar) at 3 L ha-1 (per-emergence), oxadiazon at 2 L ha-1 (post-emergence), ioxynil (Totril) at 3 L ha-1 (post-emergence) plus removing narrow leaves weeds by hand, and weed free as control. The highest relative abundance of weed species was Bromus tectorum L., Malva parviflor L., Chenopodium murale L., Anagallis arvensis L, Rumex crispus L. at 39, 17. 12, 9, 8% respectively. The results showed that herbicide treatments had significant effect on weed density and biomass. Applications of pendimethalin at 3.5 L ha-1 reduced biomass of A. arvensis, R. crispus, M. parviflor, B. tectorum, C. murale, and total weed by 100, 92, 91, 82, 77, 79 respectively. Onion yield was 59.95 ton ha-1 and increased by 138% when pendimethalin was applied at 3.5 L ha-1. Therefore, Applications of pendimethalin at 3.5 L ha-1 is recommended in onion fields because of optimum weed control efficiency and increasing yield.

In order to study the effect of organic amendment application on the growth and biochemical characteristics of French marigold (Tagetes patula) in soil contaminated with different levels of gas condensate, a factorial experiment was conducted based on a completely randomized design with three replications. The experimental factors consisted of gas condensate at five levels of 0, 7,500, 15,000, 30,000 and 60,000 μL per kg of soil, and soil amendment including vermicompost (5%), biochar (2%), Activated carbon (1%), vermicompost+ activated carbon+ biochar and non-amendment treatments. The results of the analysis of variance showed that the main and interactive effects of gas condensate and soil amendments were significant on traits of fresh and dry weight of root and shoot, chlorophyll a and b and proline content (P < 0.01). At the highest level of contaminant, the application of activated carbon and vermicompost+ activated carbon+ biochar respectively caused 3.82 and 4.45-fold increase in shoot fresh weight, 3.76 and 4.4-fold increase in root fresh weight, 2.52 and 2.56-fold increase in chlorophyll a, and also decreased 30.66 and 39.5 percent of proline content compared to the non-amendment treatment at this level of contaminant. The results of this research indicated the effective and useful role of organic soil amendment, especially activated carbon and vermicompost+ activated carbon+ biochar in reducing the toxicity of gas condensate on French marigold.