湖南省畜禽养殖粪污的耕地负荷与土地承载力评价OA北大核心CSTPCD

[Objective]The purposes of this study were to provide a scientific foundation for the prevention and control of agricultural non-point source pollution,and to promote coordinated development between agriculture and animal husbandry by calculating and analyzing livestock manure load of farmland and land carrying capacity.[Methods]We considered the comprehensive utilization rate of livestock and poultry waste,and employed the method of the pollution generation and discharge coefficient and the method of the nutrient-balance to separately calculate livestock manure load of farmland and land carrying capacity in different regions of Hunan Province in 2020.The spatial layout of livestock and poultry breeding and the distribution of manure pollution were analyzed by utilizing data regarding livestock manure and crop yield in Hunan Province.[Results]A total of 4.27×107 pigs were bred in Hunan Province in 2020,with significant variation across regions.The loads of livestock and poultry manure,TN,and TP on farmland in Hunan Province were 19.04 t/hm2,94.85 kg/hm2,and 24.99 kg/hm2,respectively,and the cultivated land load alert levels all exceeded level Ⅱ,posing a slight threat to the farmland environment.At least two farmland load warning levels in Yongzhou,Loudi,Huaihua,and Chenzhou City reached level Ⅲ or above,indicating a heightened environmental risk.The maximum land carrying capacity of livestock and poultry breeding land was 1.23 × 108 pig equivalents,but the currently raised pig equivalents only accounted for 37.18％of this value.This result indicated that there was significant potential for increasing the livestock breeding capacity in various cities,with seven cities(Changde,Yiyang,Yueyang,Shaoyang,Changsha,Yongzhou,and Hengyang City)capable of breeding more than 5.00 × 106 pig equivalents.Given the absence of breeding overload within these regions,crop managers in woodland and orchards in Yongzhou,Loudi,Huaihua,and Chenzhou City were encouraged to increase their application of organic fertilizers and manure absorption to lower the risk of farmland pollution.[Conclusion]Overall,the risk posed by livestock and poultry breeding to the farmland environment in Hunan Province remains relatively low,suggesting substantial potential for future industry expansion.However,certain regions are facing farmland pollution risks,thus necessitating a redirection in manure disposal to lessen the pressure of manure absorption on farmland,thereby promoting sustainable agricultural development.