Distribution Characteristics And Control Countermeasures Of Livestock And Poultry Breeding Pollution In Northern Liaoning

In recent years,animal husbandry in the world has been rapid development,has brought serious threats to the ecological environment of the world.It is reported that animal manure produced by animal farming in Canada has far exceeded crop demand.In the United States,60%of the rivers are seriously polluted by agricultural production,while more than 1,000 major rivers in China have been polluted to varying degrees by animal farming.Especially along with the continuous industrialization,regionalization and intensification of animal husbandry industry in China,large-scale animal husbandry enterprises are also increasing year by year.Liaoning Province is a major province for livestock and poultry breeding,especially in the northern region.It is a key area for traditional livestock and poultry breeding for many years.The pollution of livestock and poultry has become one of the key factors for pollution in the northern part of Liaoning.Based on this,17 counties and cities in Liaoning Province,which is the concentrated distribution area of livestock and poultry breeding,are selected as the typical research objects.The data obtained from environmental statistics and pollution sources census of some large-scale livestock and poultry farms are selected to discuss the spatial analysis function of Geodatabase based on Arc GIS software.And analyzed the development status and pollution distribution characteristics of livestock and poultry in this area.At the same time,on the basis of nitrogen balance theory,carrying capacity of livestock and poultry breeding environment and early warning analysis were carried out in this region.Finally,the relevant countermeasures for preventing and controlling livestock and poultry breeding pollution were put forward,which provided scientific basis for rural pollution control in northern Liaoning.Based on the spatialization of the large-scale breeding farms in northern Liaoning and the related data of some large-scale farm households,the present situation of animal breeding was analyzed and discussed from the aspects of breeding structure,quantity and density.The results show that the density difference of livestock and poultry breeding in northern Liaoning is relatively obvious.The areas with high stocking density are concentrated in the western region.According to the basic data such as the quantity of livestock and poultry farming in the northern Liaoning region,the discharge coefficient method is used to calculate the emissions of various pollutants in livestock and poultry farming,and the emission intensity is calculated.According to the research data,the areas with the largest COD emissions in the northern part of Liaoning in 2017 are Kaiyhan County and Faku County,which are 2873t and 2642t respectively.The COD,TP,TN,and NH₃-N emissions are spatially different,and the places with higher emissions are mainly concentrated in Shenyang and Fuxin,such as Faku County and Zhangwu County.The spatial difference of TN and COD intensity is obvious,and the strong area is Shenyang.The areas where NH3-N and TP are less intense are concentrated in the Tieling area.Nitrogen balance theory was used to quantitatively calculate the nitrogen supply and nitrogen demand of crops under the current planting patterns in various cities and counties in northern Liaoning,and then calculate the environmental carrying capacity of livestock and poultry in cities and counties in northern Liaoning.Finally,through the analysis of the environmental carrying capacity of livestock and poultry farming in northern Liaoning,combined with the regional characteristics of northern Liaoning,the paper puts forward the suggestions and Countermeasures for the prevention and control of livestock and poultry farming pollution in northern Liaoning from three different aspects,namely,national policy,Feeding technology and engineering measures,and preliminarily estimates the impact of these measures on the environment.The benefit of the environment provides scientific basis for the animal husbandry enterprises in northern Liaoning and relevant state departments to prevent and control pollution.