An experiment was carried out to assess the effect of four NITROGEN levels viz. T1 (full doze of urea i.e. 215 kg urea ha-1 at 15 DAT), T2 (full doze of urea at two equal SPLITs, ½ at 15 DAT + ½ at 30 DAT), T3 (full doze of urea at two equal SPLITs, ½ at 15 DAT + ½ at 55 DAT) and T4 (full doze of urea at three equal SPLITs, 1/3 at 15 DAT + 1/3 at 30 DAT + 1/3 at 55 DAT) on morpho-physiological attributes of Boro rice genotypes viz. V1 (BINAdhan 5), V2 (Tainan 3) and V3 (BINAdhan 6). Plant height, number of tillers hill-1, number of leaves hill-1, leaf area hill-1 (cm2), DM (dry matter) of root, stem and leaves hill-1, TDM (total dry matter) hill-1 and chlorophyll content in leaves (at 74 DAT), were increased with the SPLIT APPLICATION of N. Among the treatments, T4 showed the best performance and grain yield (45.25 g hill-1) compared to control (30.61 g hill-1). Among the genotypes, BINAdhan 5 and BINAdhan 6 showed similar performance in respect of most of the parameters but BINA dhan 6 produced the highest grain yield (40.26 g hill-1) compared to BINA dhan 5 (35.54 g hill-1) and Tainan 3 (33.90 g hill-1). Full dose of urea (215 kg urea ha-1) applied at three equal SPLIT at 15, 30 and 55 DAT was found to be the most beneficial one for the all the rice genotypes. Leaf chlorophyll content had a strong contribution to grain yield of rice.

A field study was conducted to determine the integration of SPLIT N fertilization and herbicide APPLICATION on weed management and wheat (Triticum aestivum L.) yield in Shiraz, Iran, in 2005/2006 and 2006/2007 growing seasons. The experimental design was SPLIT plot with four replications. Main factors consisted of N timing and SPLITting, and sub plots included iodosulfuron-methyl-sodium plus mesosulfuron-methyl-sodium, solfosulfuron and two weedy and weed free controls. Compared with the weedy check, iodosulfuron-methyl-sodium plus mesosulfuron-methyl-sodium and solfosulfuron reduced weed biomass by 66% in 2005/06 and 55% in 2006/07, 37% in 2005/06 and 45% in 2006/07, respectively. In all herbicide treatments applied in both years, the highest (353.6 kg h-1 in 2005/06 and 224.1 kg h-1 in 2006/07) and the lowest (65.6 kg h-1 in 2005/06, and 24.0 kg h-1 in 2006/07) weed biomass were obtained from the full N (304 kg urea ha-1) APPLICATION at tillering stage and zero N APPLICATION at sowing and stem elongation stages T1N0, T2N1, T3N0 and no N fertilization at sowing, tillering and stem elongation stages T1N0, T2N0 and T3N0. NITROGEN use efficiency of the crop increased when N was SPLIT. Consequently, wheat LAI and grain yield increased. However, in the presence of weeds, both LAI and grain yield increases were lower. The results of the present study showed that integration of N and herbicide treatments caused even a higher increase in wheat LAI and grain yield, but resulted in a higher reduction in weed biomass when compared with either treatment alone. N SPLITting of T1N½, T2N½ and T3N0 increased wheat grain yield (61% in 2005/06 and 75% in 2006/07), biological yield (76% in 2005/06, 94% in 2006/07), and LAI (62% in 2005/06 and 2006/07). In conclusion, weed control was essential for efficient use of N fertilizer by the crop. Therefore, in order to increase wheat grain yield, integration of SPLIT N and herbicide is recommended for the region. The results of this study showed that N SPLITting treatments of T1N½, T2N½, T3N0 and iodosulfuron-methyl-sodium plus mesosulfuron-methyl-sodium had the best efficiency in terms of weed control in wheat.

Due to the importance of sesame as an oil crop, in order to investigate the effects of different levels and APPLICATION time of NITROGEN (N) on quantitative and qualitative yield of this crop, an experiment was conducted in two successive years from July 2009, on JL-13 variety in Jiroft. Experimental design was factorial with Completely Randomized Block Design (CRBD) with three replications. Treatments were 5 levels of NITROGEN (0, 25, 50, 75, 100 kg N ha-1) as urea and SPLIT APPLICATION of N (two SPLITs: before planting and before flowering; and 3 SPLITs: before planting+before flowering+before seed pods).Every plot contained four planting rows (five meters length). Spacing between two rows and plants were 50 and 10 cm, respectively. Two central rows were cut for yield and yield components determination. N absorption and NITROGEN agronomic efficiency were also measured. Results showed that the effect of N SPLITting on yield, yield components, and oil content of sesame was not significant. NITROGEN APPLICATION increased seed yield, yield component, and N agronomic efficiency significantly. APPLICATION of 75 kg N ha-1 resulted in the highest seed and oil yield, i.e.1137 and 602 kg ha-1, respectively. Thus, under the condition of this experiment, APPLICATION of 75 kg N ha-1 in two SPLITs is recommendable.

To evaluate the effect of NITROGEN rate and its SPLIT APPLICATION on seed yield and nitrogrn use efficiency (NUE) of quinoa cultivars, experiments were performed during 2018-2019 and 2019-2020 growing seasons as factor SPLIT plot based on randomized complete block design with three repetitions at Khuzestan Agricultural and Natural Resources Research and Training Center Station. Experiment treatments were NITROGEN fertilizer (0, 100, 200 and 300 kg. ha-1) as the main factor and four levels of SPLIT NITROGEN fertilizer APPLICATIONs (50% basic + 50% six-leaf, 50% basic + 25% Six-leaf percentage + 25% mid-flowering, 25% basic + 50% six-leaf + 25% mid-flowering and 25% basic + 25% six-leaf + 50% mid-flowering) and three cultivars of quinoa (Gizat, Q26, Titicaca) as sub-plot. The results showed, SPAD, height plant, number of plant branches, number of panicules per area unit and seeds per panicule as influenced by NITROGEN content × SPLIT × cultivare, interaction. The years× NITROGEN rate×SPLIT APPLICATION× cultivar intractions were significant on plant height, 1000 seed weight, seed yield, biological yields, harvest index and NUE. The highest seed yield under all different levels of NITROGEN was related to cultivar Q26, in both years by the use of 200 kg of NITROGEN, the highest seed yield in the first year belonged to at 25% base APPLICATION + 50% at six-leaf stage+ 25% at mid-flowering stage and in the second year, to at 50% as base APPLICATION+ 25% at six-leaf stage+ 25% mid-flowering stage. Highest NUE belonged to Gizal (52. 8 g. kg-1) and Q26 (51. 8 g. kg-1) cultvars from 200 kg. ha-1 NITROGEN by SPLIT APPLICATIONs of 25% base + 25% at six-leaf stage+ 50% at midflowering stage, while in second year from 100 kg. ha-1 NITROGEN. In general, climatic conditions and SPLIT APPLICATION of fertilizer were effective roles in increasing the efficiency of NITROGEN consumption. Thus by the use of proper management seed yield can be increased and the risk of its production decreased.

To evaluate the effect of NITROGEN and water withholding in vegetative growth stage of corn on efficacy of nicosulfuron and 2,4-D+ MCPA an experiment was conducted as a factorial arrangement in a randomized complete block design with three replications at Tarbiat Modares University in 2017. The first factor contained four treatments including APPLICATION of nicosulfuron, 2,4-D+ MCPA, weed free and weed infested as control. The second factor consisted of normal irrigation and water withholding from 4 to 8 leaf stage. Third factor contained either urea APPLICATION or no fertilizer APPLICATION. Normal irrigation and NITROGEN fertilizer APPLICATION significantly increased nicosulfuron and 2,4-D+ MCPA efficacy in weed control and total weed dry weight decreased to 341 and 361 g.m-2 respectively compared 1370 g.m-2 as weed infested. Nicosulfuron and 2,4-D+ MCPA reduced weed total dry weight significantly under irrigation withholding. Grain yield increased with APPLICATION of NITROGEN and nicosulfuron. Grain yield was higher with APPLICATION of 2,4-D+ MCPA than nicosulfuron without NITROGEN APPLICATION under irrigation withholding. APPLICATION of nicosulfuron with NITROGEN APPLICATION provided satisfactory weed control and increased grain yield.

Due to market price, rice production in Isfahan province has expanded to many locations, where there is enough fresh water for a cropping season, with no considerations on negative aspects of this practice. Organic fertilizers have been recommended as an amendment to reduce the negative impact of puddling on soil physical and chemical properties. This experiment was conducted to study the effects of cow manure on sustainability of rice yield under soil submergence and puddling practice. According to a randomized complete block design with three replications, rice were planted under six fertilizer treatments for three years. Treatments included three methods of urea APPLICATIONs, two levels of cow manure and a no fertilizer APPLICATION as a check. Analysis of variance revealed a significant yield difference among fertilizer treatments for the first year of the experiment. Mean yield comparisons showed that highest yield was obtained when 104 kg/ha NITROGEN was applied at different rice growth stages. In the second year, except for 1000-grain weight, other measured traits were significantly different among fertilizer treatments. In this year, significantly higher yield were obtained from the plots that received the highest organic manure each year (32 ton/ha). Lowest yield belonged to the check treatment. Analysis of variance for the third year,s data also indicated a significant difference among fertilizer treatments for plant dry weight, number of plants per hill, plant height and seed yield. Similar to the second year, highest value on these traits belonged to treatment with highest organic fertilizer, and the lowest to the check treatment. It may be concluded that organic manure APPLICATION in rice culture could sustain a higher yield compared to chemical fertilizers, which is a common practice in Isfahan province.

In this research, the effects of SPLIT APPLICATION of NITROGEN fertilizer on yield and yield component of three varieties of corn have been investigated. For this purpose, a SPLIT plot experiment on the base of randomized complete blocks in four replications was used. The main plots were three varieties of corn (370, 447 and 499), and sub plots were six SPLIT APPLICATION of urea fertilizer treatments. In each treatment 180 Kg/ha pure NITROGEN (392 Kg/ha urea) was used. The results show that there is significant difference in bush height, grain yield, harvest index and number of kernel in ear between varieties and there is no significant difference in weight of 100 grains and bush diameter. Variety of 499 was the best one view point of mentioned characteristics. Also fertilizer treatments show significant difference. In all characteristics, except of weight of 100, the forth treatment (N4: 98Kg urea/ha in planting time, 147Kg urea/ha three weeks before flowering, 147Kg urea/ha three weeks later flowering) was identified as a best treatment. Interaction of variety-fertilizer treatment only has significant effect on grain yield, harvest index and number of kernel in ear. According to obtained results of this research, variety of 499 is preferred for planting because in this variety the highest yield has been achieved. Also, the forth fertilizer treatment is suggested among the all treatments.

In order to investigation of NITROGEN fertilizer SPLIT APPLICATION effect on quantity yield and grain quality of rice varieties, an experiment was carried out based on RCBD design as SPLIT plot experiment in three replications in Langroud in 2006. Main and sub factor were variety (Hashemi and Bahar 1) and five NITROGEN fertilizer SPLIT APPLICATION (SPLIT of 150 kg.ha-1 N at transplanting, stemming, heading and flowering stages). Quantity traits (yield and its components, straw yield, harvest index, plant height, main and sub panicle length) and three cooking quality index include: grain amylose content, gel consistence and gel temperature were measured. Results showed that the effect of SPLIT APPLICATION was significant on grain yield, stuble yield, 1000 grains weight and plant height. N1 SPLIT (50% in transplanting and 50% in stemming) was the best treatment with 6619 Kg.h-1 mean yield. This SPLIT in Hashemi has more harvest index and amylose content (45.75% and 22.21%, respectively). Bahar 1 with more mean grain yield (6977 Kg.h-1) and harvest index (49.87%) than Hashemi (3933 Kg.h-1 and 40.35%) have significant difference. Also Bahar 1 has significant difference with Hashemi in mean of the number of grain in main and sub panicul (192.08 and 124.83, repectively). Hashemi and Bahar 1 were set in moderate and low amylose content groups, with 21.45% and 19.21%, respectively. The interaction effect between SPLIT and variety was significant on straw yield, harvest index, 1000 grains yield, percent of unfilled grain and plant height.