In order to study effects of biofertilizer and nitrogen on nitrogen use efficiency and harvest index of wheat (Triticum aestivum L.) an experiment was conducted with nitrogen rate (0, 33, 67, 100 kg/ha urea), seed biofertilization with nitragin and wheat cultivars (Alvand and MV17 ). Results showed that with increasing of urea application fertile tillers number per plant improved. When biofertilized seeds were planted, grain yield increased from 6017 kg/ha in control to 6591 kg/ha in application of 33 kg/ha urea and 6954 kg/ha in 67 kg/ha urea in Alvand, and from 3547 kg/ha in control to 4428 kg/ha in application of 33 kg/ha urea and 4724 kg/ha in 67 kg/ha urea in MV17. Seed biofertilization with nitragin increased harvest index of crop up to 2.3%. In biofertilized treatments, when wheat plants were fertilized with lower dose of urea, grain yield improved in both cultivars. With increasing of urea rate from 67 to 100 kg/ha the yield reduced. In non-biofertilized plants grain yield in those plots fertilized with full dose of urea was the highest. In experiment environmental condition with wheat seed biofertilization before planting we can improve grain yield and reduce urea application up to 33% of recommended dose.

Due to the increasing environmental and economic costs associated with nitrogen (N) consumption, improving N use efficiency in rice cultivation systems is of great importance. In this regard, the combined effect of different surface and subsurface drainage systems and water management on the nitrogen harvest index (NHI) of rice was investigated. During three rice growing seasons (2014 to 2016), two rice varieties of Tarom Hashemi and Tarom Daylmani were cultivated under alternate wetting and drying in paddy fields with surface and subsurface drainage systems. At harvest, grain yield and biomass and plant and seed nitrogen were measured. The NHI was determined as the ratio of grain nitrogen to nitrogen absorbed by aboveground part of plant. The amount of NHI was directly related to the amount of urea fertilizer used, varying between 58.31 and 68.45 in different seasons. The average nitrogen absorbed by the Hashemi and Daylmani plants in the subsurface drainage systems was 161.7 and 155.7 kg ha-1, respectively, and in the control was 144.7 and 193.7 kg ha-1, respectively. Also, the average grain yield, grain nitrogen, harvest index and NHI in the subsurface drainage systems were 5329.3 kg ha-1, 105.9 kg ha-1, 37.8% and 67.2%, respectively, and in the control treatment was 4667.7 kg ha-1, 88.6 kg ha-1, 32.4% and 56.3%, respectively. Based on the results, drainage through subsurface drainage systems under intermittent irrigation and drainage management can improve the N use efficiency in rice cropping system

nitrogen and phosphorus are essential nutrients in crop production. In order to investigate the effects of different nitrogen and phosphorus levels on biomass and harvest index of mungbean, Partow variety a field experiment was conducted at the Research Farm of the Islamic Azad University of Shahre-rey in Tehran, Iran in 2009. The Experiment was laid out with factorial arrangement in a Randomized Complete Block Design with three replications. Five levels of nitrogen (0, 30, 60, 90 and 120 kg N ha-1) and six levels of phosphorus (0, 30, 60, 90, 120 and 150 kg P2O5 ha-1) were the treatment variables. Results showed that application of N and P fertilizers significantly increased the biomass and harvest index. Interaction effect of nitrogen and phosphorus was significant. With the increase of phosphorus application, nitrogen had positive effect on increase of biomass and harvest index. The maximum biomass (793.8 g m-2) was obtained when 120 kg N ha-1 and 150 kg P2O5 ha-1 were applied. The highest harvest index (28.62%) was recorded when 90 kg N ha-1 and 120 kg P2o5 ha-1 were applied.

The competition for nitrogen is an effective factor can be affected crop- weed interactions. In order to determine of black seed nitrogen use efficiency and harvest index at different weed competition durations, a field experiment was conducted at Agricultural Research Station, Ferdowsi University of Mashhad, Iran, during 2009- 2010. The experiment was Randomized Complete Block Design (RCBD) with 12 treatments and 3 replications. Two sets of treatments consist of weed-infested and weed-free periods were used. At the first set of treatments, weeds compete with black seed up to 0, 14, 28, 42, 56 and 70 day after emergence (weed-infested periods). At weed free treatments, plots were kept free of weeds up to the mentioned stages. Results indicated that different weed interference durations had significant effects on nitrogen contents of seed, stubble and biomass of black seed. nitrogen harvest index was significantly affected by different weed competition durations. In this experiment, uptake (recovery), physiological (internal) and use (agronomic) efficiency of nitrogen in black seed decreased with decreasing weed free and increasing weed-infested periods. However, these competition periods had more effect on nitrogen uptake efficiency than physiological efficiency of nitrogen.

In order to evaluate the effect of increasing soil soluble phosphorus (P) and its effect on nitrogen (N) and P uptake, P uptake efficiency and P harvest index of black seed (Nigella sativa L.) in a calcareous soil; a field experiment was conducted as factorial layout based on a randomized complete block design with three replications at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in year 2013. The experimental treatments were all combination of soil amendment in four levels (vermicimpost (V) + Tiobacilus (T), Sulfur (S) + T, V+S+T and control) and three levels of phosphorus (0, 30 and 60 kg.ha-1). Results showed that S+T and V+S+T had significant effects on reducing soil pH (by 0.94 and 0.61 units, respectively). The resources of soil amendment (V+T, S+T and S+V+T) significantly increased the P uptake by plant and P harvest index of black seed. A significant positive correlation was observed between P and N concentration of plant. However, there was a significant negative correlation between grain yield and P uptake efficiency of black seed.

In order to investigate the possibility of quinoa producing in Garmsar, Iran, a factorial experiment conducted in randomized complete block design with three replications in 2018-2019 growing season at Garmsar Agricultural Research Station. The factors were planting date at three levels (March 6th, April 1st and April 6th) and the three genotypes of quinoa (Q26, Q29 and Titicaca). Results showed that the effect of planting date was significant for all studied traits except the harvest index. Also, all studied traits were significantly different in all genotypes. Titicaca planted on March 6th had the highest yield (2276 kg.ha-1).The grain yield and yield components decreased with the delaying the planting date. Compared to early plantings, Latest date, April 6th, led to reduction of all traits, especially grain yield (about 50%). The results of simple phenotypic correlation between the studied traits showed that grain yield per hectare had the highest correlation with plant yield (0.877) and then with leaf area index (0.832), panicle weight (0.815) and number of branches per plant (0.745) that was significant at the 1% probability level.

harvest index (HI), ratio of seed yield to aboveground dry matter, is a very important parameter for estimating seed yield in several crop models. In this study, the importance, definition, variability and estimation methods of HI in crop models were discussed. HI estimation methods are categorized into two groups including: (i) complex methods that estimate HI from the beginning of seed growth to crop maturity, dynamically and (ii) simple methods that estimate the final HI at crop maturity. HI is a trait that is affected by many environmental parameters and the genotype of a crop. Soil water content or soil water suction during growing season, soil nutrient, groundwater depth, high air temperature, plant population and irrigation water salinity are some environmental factors affecting the HI. Therefore, in all models that used HI to estimate crop yield, either complex (e. g., AquaCrop model) or simple method, the harvest index estimating equations should be calibrated by changing the genotypes or cultivars, environmental and non-environmental parameters.

IntroductionOne of the major factors restricting the crop production is nitrogen. nitrogen has an important role in achieving maximum yield and it improves the yield and quality of all crops (Ullah et al., 2010). In the arid and semi-arid regions of Iran, the deficiency of organic matter in the soil as the natural resource required by the plant and the moisture tension, are the major factors of absorbing nitrogen and after moisture tension, nitrogen tension is the major limiting factor of crop production (Sadri, 2017). Nitroxin fertilizer contains nitrogen fixing bacteria that fix the air nitrogen, balance the high-consumption and micronutrient elements, synthesis and secretion of plant growth stimulants and as a result, protection of plant against pathogens, biological and non-biological stresses.One way to examine the efficiency of the fertilizers, especially nitrogen, is studying nitrogen use efficiency. This indicator shows the increase in yield by each unit increase in the input (Delbert and Ulter, 1989). One way to manage different nutritional resources is to evaluate the nitrogen use efficiency. This study aims to evaluate the function and indicators of nitrogen efficiency in manure treatments and different resources of nitrogen in safflower. Material and MethodsThis experiment was conducted as randomized complete block design with three replications in the research farm of faculty of agriculture university of Jiroft in 2018-2019 year. The first factor included different sources of nitrogen fertilizer in six levels of urea fertilizer, urea with sulfur coating, ammonium nitrate, nitroxin, nano nitrogen and control, the second factor included animal manure in two levels of consumption and non-consumption was considered. The intra row and inter row distance was 30 and 10 cm respectively with 2×3 m2 plot size. Drip irrigation was used and during the different plant growth stages, no chemical pesticide and herbicide was used nitrogen of seed, leaf and shoot was carried out using Kjeldhal method. Data were analyzed by SAS software version 9.4. Mean values were compared according to Duncan test at P < 0.05. Results and DiscussionThe results showed that manure and difference resource of nitrogen has significant effect on the seed yield, seed nitrogen percentage, biomass, plant nitrogen content, the efficiency of use, physiological, absorption, productivity and nitrogen harvest index in safflower. The highest nitrogen in seed (3.46%), biomass (1.05%), seed yield (284 g.m-2), seed nitrogen content (1138.8 g.m-2), and biomass nitrogen content (752.5 g.m-2) obtained in manure + nitroxin treatment. the results indicated the positive and significant effect of manure and biological fertilizer on the improvement of yield and nitrogen efficiency. The interaction of manure and different nitrogen fertilizers on seed yield was significant. The highest and lowest seed yield obtained by manure + nitroxin treatment (284 g.m-2) and not using manure and control treatment (68.3 g.m-2) respectively.In safflower, using nitrogen fertilizers can increase seed yield by affecting the branches of the plant (Weiss, 2000). The researchers reported that the use of nitrogen, compared to control (not using nitrogen) increased safflower seed yield.According to the results, manure treatment compared to not using manure treatment showed 24.3% increase in seed nitrogen. Nitroxin and nano nitrogen fertilizers have the highest seed nitrogen percentage (3.46 and 3.21, respectively) and the lowest nitrogen was in control treatment (1.9%). Manure + nitroxin treatment had the highest nitrogen in biomass and plant. In safflower, the use of manure increased the absorbed nitrogen percentage compared to control treatment (Ghanbari et al., 2016). In this regard, the researchers observed the increase in absorption efficiency and use of nitrogen in saffron through using organic fertilizers compared to chemical fertilizers. The results of this research showed that using biological fertilizers, especially nitroxin, has positive effect in increasing seed number in plant, seed yield, days to maturing, nitrogen percent, absorbed phosphorous by plant and nitrogen physiological efficiency (Arab-Niasar et al., 2019). Conclusion The results of this experiment showed that using manure and biological fertilizer improves nitrogen efficiency compared to not using manure condition. It seems that the combined use of manure with chemical fertilizers reduces the loss and washing nutritional elements, especially nitrogen. The use of organic fertilizers to improve soil structure, maintain water and access to required elements by plants should be considered as a priority. Regarding the highest yield in manure + nitroxin treatment, it is suggested to use nitrogen fertilizers with biological origin.

harvest index is one of the important parameters in estimation of modules of seed yield prediction. Since, this parameter undergoes changes under various conditions. Therefore, this research was aimed to prepare relations to estimate it. for this purpuse, a compound analysis experiment with randomized complete block design with four replications was conducted at the Gorgan University of Agricultural Sciences and Natural Resources Univercity Research Farm in 2005. The treatments were four wheat varieties (Koohdasht, Shirudi, Tajan, Zagros) and six different sowing dates (14 December, 20 Jan, 20 Feb, 20 March, 16 Apr, 17 May). The results indicated that a significant difference was obvious in different sawing dates in respect to the slope of harvest index line (dHI/dt). These changes were attributed to mean temperature, pre-Grain filling accumulated biomass, and fraction of post-anthesis (fG) producted dry matter. Therefore, based on obtained results and evaluated models, fG was the best optian for simulation of dHI/dt and harvest index, in this respect, RMSE of dHI/dt for all varities by fG was 0.25 percentage per day which was the lowest one. Therefore, these relations can be used to evaluate the slope of harvest index line, or to model grain yield in crop simulation models.