جستجوی مقالات مرتبط با کلیدواژه « بهره وری نیتروژن » در نشریات گروه « زراعت »

To investigate the effect of tillage systems and nitrogen fertilizer on corn characteristics, in 2016 and 2017, a research field was conducted in the research farm of Islamic Azad University Chalous Branch during two cropping years.The experiment was performed as a split-plot in a randomized complete block design with three replications. Experimental factors include tillage at three levels (no-tillage, conservation tillage and conventional tillage) in the main plot and nitrogen fertilizer sources at four levels, including non-application of zero, 33, 66,and 100% of the recommended amount of nitrogen fertilizer based on the test. The soil was on a subplot.Comparing the average effect of tillage showed that the highest grain yield was obtained in conservation tillage treatment at the rate of 10247 kg/ha-1. Comparison of tillage's average effect showed that the highest biological product was received in conservation tillage at the rate of 15754 kg/ha-1. Comparison of the average interaction of the year in tillage also showed that the highest NUPE was observed in the conservation tillage treatment in the second year at the rate of 0.90 kg.kg-1, which showed an increase of 47% compared to the treatment no tillage in the first year. NUPE in tillage treatments increased in the second year compared to the first year, which was higher in conservation and non-tillage tillage treatments. Comparison of the average treatment of nitrogen fertilizer showed that the highest grain nitrogen was obtained in the treatment of 100% nitrogen fertilizer at the rate of 1.98%, which showed an increase of 25.7% compared to the control treatment.In general, the results of this study showed that by applying conservation tillage methods, the least damage can be done to the soil structure, and through this, maximum yield and efficiency can be achieved in the corn plant. Therefore, according to grain yield, the most appropriate treatment for the study area is the use of conservation tillage in the case of fertilizer application of 66% nitrogen.

Nitrogen (N) is one of the main limiting factors in agroecosystems all around the world. However, high application rates of N fertilizers would lead to negative environmental consequences. Reduction of N fertilizers consumption decreases production costs and environmental pollution. Therefore, N efficiency to be enhanced due to the high N fertilizer cost and required measures to prevent the waste of N. Cultivation of diverse crop cultivars with higher resources absorption and utilization efficiency is one of the major approaches in sustainable agriculture that would result in the effective use of natural and chemical inputs and reduce significantly the environmental risks. Quchan City is one of the potato production poles in Khorasan Razavi province. In this region, large amounts of N fertilizers annually are consumed in the potato agroecosystem. Therefore, the potato of the present study was evaluating N uptake and utilization efficiency, and finally, N uses efficiency in the potato agroecosystem of Quchan.

This experiment was performed in the cropping year of 2020-21 in Quchan located in Khorasan Razavi province. A split plots arrangement based on a randomized complete block design with three replications was conducted. Different nitrogen application rates (0, 50, 100, and 150 kg of pure nitrogen per hectare) were assigned to the main plot and the sub-plot factor consisted of two potato cultivars, Agria and Arinda. To calculate the efficiency of nitrogen application, the amount of nitrogen in the soil was also considered. Equations (1 to 3) were used to calculate nitrogen efficiencies:                                                                                                       Eq. 1
                                                                                                        Eq. 2
                                                                                                    Eq. 3

The results of the analysis of variance showed that the effect of nitrogen fertilizer and cultivar on yield was significant. At the same levels of nitrogen, the Arinda cultivar had a higher yield and with increasing nitrogen application, an increase in yield was observed in both Agria and Arinda cultivars. The effect of nitrogen application and cultivar on nitrogen uptake, utilization, and use efficiency was significant (p≤0.01). Comparing the interaction of nitrogen and cultivar on nitrogen utilization efficiency, showed that the Arinda cultivar had higher efficiency than the Agria cultivar.

By increasing the amount of nitrogen fertilizer application, improvement was achieved in most of the evaluated characteristics of potato cultivars, including yield. Arinda cultivar had better conditions in terms of tuber yield and nitrogen uptake, utilization, and use efficiency compared to Agria.

Environmental and economic challenges resulting from the application of nitrogen fertilizers have increased concerns about its productivity in the agricultural systems. This study was conducted to evaluate SSM-Wheat model to simulate nitrogen budgeting with various nitrogen application scenarios (Dry land-without nitrogen, Dry land-low nitrogen, Irrigated-without nitrogen, Irrigated-conventional, Irrigated-high nitrogen and Irrigated-very high nitrogen) in rainfed and irrigated conditions in the wheat-based cropping systems of Gorgan region in Iran in a 21-years period (1990-2010). Results indicated that the average total losses of nitrogen were significantly different among different scenarios. In all scenarios, the proportion of nitrogen loss (81%), as gaseous was more than that of leaching (19%). Nitrogen loss by nitrification ranged between 5.9 and 59.2 kg.ha-1 with average 23.2 kg.ha-1 while nitrogen volatilization ranged between 0 and 14.9 kg.ha-1 with an average 5.8 kg.ha-1. Also, the maximum nitrogen leached was associated with irrigated wheat-high nitrogen scenario that had significant difference with other scenarios. However, the lowest amount observed in the rainfed wheat-without nitrogen scenario that had no significant difference with irrigated wheat-without nitrogen scenario. The highest productivity was observed in irrigated wheat-conventional scenarios (26 kg.kg-1) and irrigated wheat high nitrogen (25.9 kg.kg-1) which was significantly different than the other scenarios. Therefore, irrigated wheat- conventional scenario was identified as suitable scenario in wheat production in Gorgan, Iran, due to cost saving, low leaching, less environmental pollution, adequate irrigation and less fertilizer use.