Relationship of nitrogen (N) supply to nitrogen remobilization and leaf and grain P, K, and N status of wheat lacks clarity. The present pot experiment was conducted to evaluate nitrogen remobilization and leaf and grain P, K, and N status of ancient wheats of different ploidy levels in response to nitrogen. The experiment was carried out in Fall 2017-Spring 2018 at the Isfahan University of Technology, Isfahan, Iran. The experiment was designed as a 3-replicate factorial completely random design with N fertilization treatment (at four levels of 0, 18. 66, 37. 33, and 56 mg N kg-1 soil) and genotype (consisting of 12 genotypes) as experimental factors. Nitrogen remobilization of the ancient and hulled wheats were increased when exposed to the low and medium N supplies. However, the Nitrogen remobilization of the standard durum and bread wheats were increased with increases in the N supply. Leaf and grain P, leaf N, and grain K concentrations responded positively to the N supply and ancient and hulled wheats equaled or exceeded those of the improved wheats particularly when grown in the absence of high N supplies. The presented data indicates that in conditions of nitrogen deficiency, the ancient wheats outperform improved wheats in terms of absorption and utilization of macronutrients.

One of the adverse effects to plants in the presence of salinity is the reduction in nitrogen uptake. The objective of this experiment was to determine response of wheat cultivars (cvs) CR11(Iranian salttolerant), Ghods(Iranian salt-sensitive) and Kharchia - 65 (as standard salt-tolerant) to the rate of shoot and root nitrogen accumulation at anthesis and harvest maturity when exposed to different concentrations: 0, 100, 200 and 300 mol m-3 of mixture of NaCl and CaCl2 in 5:1 molar ratio and three levels of amonium nitrate (0, 2 and 4 mol. m-3) in semi-controlled environment and sand culture medium. The results showed that, although nitrogen accumulation was decreased with increasing level of salinity specially before anthesis, but the nitrogen concentration in different organs (roots, leaf, stem and grain) was not changed necessarily, and depend on plant ability to nitrogen absorption and biomass production, the cultivars responded differently to salinity. N application at 100 and 200 mol.m-3 of salinity caused better nitrogen uptake efficiency and nitrogen utilization efficiency and consequently better nitrogen use efficiency and rise in N content, but at 300 mol.m-3 of salinity, nitrogen not only did not adverse effects of salinity but also caused a reduction in nitrogen content of plant. Although, nitrogen reduced the adverse effects of salinity, however the form of nitrogen is important and it needs to be studied in detail.

Dissolved Organic nitrogen (DON) is an important constituent of Dissolved Organic Matter (DOM). It has a considerable effect on total dissolved soil nitrogen and it is very important as a nitrogen source of many aquatic and terrestrial ecosystems. Dissolved inorganic nitrogen, which is another form of total soil dissolved nitrogen, includes NO3, NO2 and NH4, which is very important for plant nutrient. Soil managements such as fertilizer application affects the flux and concentration of DON and DIN in soils. The purpose of this study was to evaluate the effects of different N-fertilizers application on DON and DIN content of two Alfisols located in near the Caspian Sea in the north of Iran. An experiment carried out using complete randomized design with factorial arrangements. Four level of N-fertilizers (Urea, Ammonium nitrate, Ammonium sulfate with Control)) and six different times (0, 7, 14, 28, 42, 60 day) with three replications in two different soils. Changes in DON, DIN, pH and soil respiration were monitored during the period of 60 days. The results showed that dissolved organic nitrogen decreased significantly by N- fertilizer application in both soil samples however, NO3, NO2 and NH4 increased. Ammonium sulfate showed the maximum effect on DON reduction and it can be due to the pH reduction. Changes in DON during the experiment varied from 11 to 75 % in both soil. At the end of experiment, NO3 + NO2 formed a major part of total Dissolved nitrogen in soils.

The objective of this study was to investigate the effect of exogenous nitric oxide on cellular response and production ofsecondary metabolites in Catharanthus roseus callus. The cell suspension and callus of C. roseus were treated with sodiumnitroprusside, and then cell viability, morphology, the amount of H2O2, proline, lipid peroxidation, the activity of superoxidedismutase, catalase and peroxidase were evaluated. Also production of total antioxidant, alkaloid, flavonoid and phenoliccompounds were estimated. A Significant (p<0.05) reduction was observed in viability according to the dose of treatment.Also, the amounts fo H2O2, proline, total antioxidant, alkaloid, flavonoid, total phenolic compounds and the activity of theinvestigated enzymes increased significantly. Malondialdehyde level as a lipid peroxidation indicator was increase dsignificantly in response to treatment. In conclusion, we may announce that the sodium nitroprusside caused cellular membrane damage due to oxidative stress, but an increase in the production of secondary metabolites was observed too.Exogenous NO treatment might be a useful way to increase production of alkaloids at cellular level.

Effects of nitrogen fertilizer levels on Agronomic Efficiency (Ea), Physiological Efficiency (Ep), and Recovery Efficiency (Er), in rice (Oryza sativa L.) Cv. Khazar was investigated in a RCBD of three replications in a sandy soil in Guilan province, Iran in 2003. This study compared the effects of six N rates, namely: control (no N fertilizer), 40 (Basal), 40+40 (Basal + Midtillering), 40+20+20 (Basal + Midtillering + Panicle initiation), 60+60 (Basal + Midtillering) and 60+30+30 (Basal + Midtillering + Panicle initiation) Kg/ha in the form of urea. Nitrogen contents in shoot and in rice grain were determined at the end of plant growth and physiological maturity. Results indicated that grain yield in triple split application treatments sixth and fourth (4832, 4668 kg/ha) were significantly higher than those in the rest of the treatments. The highest N uptake was observed in sixth treatment (146.9 kg/ha), which was significantly higher than in the others. The highest Ea, Ep and Er were observed in the fourth treatment (20.1, 30.1 and 66.9% respectively). Ea and Er were significantly higher in the fourth treatment than in the others, but Ep significantly differed only in the second treatment. There were no significant differences observed among treatments in Nitrogen Harvest Index (NHI), the highest NHI being related to the forth treatment (0.44). Grain yield was not significant in the fourth treatment in comparison with that in the sixth one, but the higher Ea, Ep and Er may lead to an economization of N fertilizer application and as well to its less leaching in the sandy soil. The fourth treatment was finally decided as the best treatment for rice, Cv. Khazar throughout the whole experiment.

Introduction Nitrogen (N), an essential nutrient for growth and development of plants, is added to agricultural fields to boost crop yields. Major concern in modern agriculture to account for maximum nutrient use efficiency, improve the soil fertility and prevent groundwater pollution. Environmental and economic challenges due to nitrogen application in agricultural have increased regard to nitrogen use efficiency (NUE). Improving the nitrogen use efficiency, which is the fraction of the applied fertilizer nitrogen taken up by a plant for its physiological and growth purposes, is one of the strategies for reducing N loss in agriculture. With the continued escalating costs of inorganic fertilizers, NUE in field crops should be enhanced to reduce production costs. Therefore, it is essential that appropriate N fertilizer management practices are adopted to optimize the use of applied N in cropping systems. NUE and better plant growth are related to soil’s physico-chemical traits. In this context, the application of soil amendments, such as zeolie, has great importance for the reclamation of soil properties and improve plant growth. Natural zeolites are naturally occurring, hydrated aluminosilicates with and being considered as good soil amendment for minimizes N losses and increase NUE. Therefore the objective of this study was investigating the effect of different levels of clinoptilolite zeolite and nitrogen fertilizer on the efficiency of nitrogen use, growth and yield of maize (Zea mays L.) in field conditions. Materials and methods This study carried out in field condition as a split-plot arrangement based on randomized complete blocks and in three replications, at the University of Kurdistan research farm in Dehgolan. The experimental treatments include the application of clinoptilolite zeolite at four levels (0, 5, 10 and 15 ton ha-1) as the main plot and the application of nitrogen at five levels (0, 50, 100, 150 and 200 kg N ha-1) as the sub-plot. Urea fertilizer was used to supply the required nitrogen.Maize cultivation (KSC 260 cultivar) was done in 2021. At the end of cultivation season, harvest was done from each plot, and some plant growth traits (leaf area, cob length and cob diameter), leaf N concentration, yield components (grain number in cob, raw number in cob and grain weight in cob), and grain yield were measured. In addition, the NUE was calculated. In order to investigate the effect of zeolite on soil nitrogen status, soil samples were collected from plots after harvest, and cation exchange capacity (CEC), and total soil nitrogen (TN) were measured. Analysis of variance (ANOVA) was performed using SAS program version 9.4 (SAS Institute, Cary, NC). Significant differences of the mean values (P <0 .05 for F-test) were determined by Duncans’s Multiple Range test. Results and Discussion The results showed that as a result of the application of 10 and 15 ton zeolite ha-1, the soil cation exchange capacity the soil total nitrogen concentration, leaf nitrogen concentration, leaf area index ,cob length, grain yield and nitrogen use efficiency increased significantly. The results showed that the highest leaf N concentration, plant growth indices, grain yield and yield omponents was observed in the treatments of co-application of 150 and 200 kg N ha-1 with 10 and 15 ton ha-1 of zeolite. There was no significant difference between the grain yields in these treatments. The results also indicated that Moreover, nitrogen use efficiency decreased with increasing nitrogen application levels. The nitrogen use efficiency (NUE) in the 150 kg N ha-1 treatment was significantly higher than 200 kg N ha-1 treatment. The results demonstrated that there was no significant difference between two nitrogen fertilizer levels (150 and 200 kg N ha-1) positive effects on grain yield. The improved maize growth and enhanced grain yield induced by zeolite amendment were related to the increase in soil CEC, soil N status, N uptake in plant, as well as probably improved soil nutrient availability and physicochemical propertis. Leaf N concentration (56.6), leaf area index (56.5%), cob length (21.5%), leaf nitrogen concentration (56.6%), grain weight in cob (61.8%), grain number in cob (41.6%) and grain yield (38.6%) in the plant were significantly higher than control treatment. Conclusion It could be concluded that application of potassium sulfate fertilizer results In general, it can be concluded that the combined use of zeolite (at the level of 10 ton ha-1) and nitrogen (150 kg ha-1) can be a suitable solution for improving corn yield and increasing the nitrogen use efficiency (NUE).

In order to evaluate the effect of nitrogen (N) rate on the grain protein content and Nitrogen Use Efficiency (NUE) of wheat (Triticum aestivum L.), a greenhouse experiment was conducted using a factorial in completely randomized design, in three replications. In this study, two cultivars (Pishtaz: C1 and Sepahan: C2) and six nitrogen rates (N1: 0, N2: 30, N3: 60, N4: 90, N5: 120 and N6: 150 mg N/Kg) were studied. Results showed that the grain yield, grain protein content and protein yield increased significantly with increasing N fertilizer. However, there were significant reduction in NUE, N Agronomic Efficiency (NAE) and N Physiologic Efficiency (NPE) by increasing amount of N fertilizer. Pishtaz showed a higher grain yield compared to Sepahan but the protein content of Sepahan was more than Pishtaz cultivar.Also, the highest level of grain protein content that was produce in this study was in N6C2 with 10.65 protein percentage.