Quantitative Evaluation And Control Of Environmental Impact On Winter Wheat Yield In Dry Land Under Different Precipitation Years

The study is to quantitatively evaluate the environmental impact and resource consumption of different dry years of dry land winter wheat planting processes,and to control the environmental impact of the life cycle through irrigation,and to reduce the environmental impact of crops on the premise of ensuring food security.This paper takes the winter wheat production system in Wenxi County of Shanxi Province as the research object,and divides different precipitation year types according to the annual precpitation of the birth;The DNDC model was used to simulate the emission of carbon,nitrogen and other pollutants in the wheat production process,and establish spatial distribution of yield and pollutant emissions through ArcGIS.Its pollutant emission coefficient was derived from relevant literature at home and abroad;A functional unit for the production of 1 t wheat kernel was used as a functional unit to evaluate the energy consumption and pollutant discharge in the production process of winter wheat of different precipitation years.Based on this,the quantitative evaluation of environmental impact was conducted.Irrigation was used to change the soil moisture limits of farmland and the environmental impact of winter wheat production was evaluated.The results show:(1)DNDC simulation results show that:the precipitation will affect winter wheat yield and pollutant emissions.With the increase of precipitation,winter wheat yield and CO2 emission are increasing trend,and NH3 volatilization is decreasing trend.Due to the short study time span,nitrate The relationship between nitrogen leaching and precipitation is not obvious.The results of CK experiment approached the multi-year average of the study group.When the soil properties and farmland management measures of the same survey site were the same,the relative spatial distribution of wheat yield and carbon and nitrogen pollutant emissions in different precipitation years did not change significantly in the study area.(2)From the perspective of the whole life cycle of winter wheat production,its environmental impact potential is eutrophication,environmental acidification,land use,greenhouse effect and energy consumption.The main reason for the environmental impact is excessive and unreasonable application of fertilizers during wheat cultivation.(3)The environmental impact of winter wheat planting process is closely related to precipitation.There is a linear negative correlation between the five environmental factors and precipitation.The comprehensive index of environmental impact of winter wheat planted on dry lands of different precipitation types is 0.3715,0.2884,and 0.2504,and the order is dry year>flat water year>flood year.Irrigation was improved to improve the overall index of environmental impact in the dry year,flat water year,and wet year dropped to 0.2836,0.217,and 0.193,respectively.Reasonable irrigation can significantly increase the winter wheat grain yield,reduce the life cycle of resource consumption and ecological environment.(4)In different precipitation types,the shortage of water-saving irrigation for winter wheat planted in dry land to supplement the precipitation,and the rational use of chemical fertilizers to effectively improve the efficiency of the use of water and fertilizer resources,can ensure the ecological environment and food production safety.