Spatial-temporal evolution of agricultural non-point source pollution in Guangxi and its prevention and control countermeasures

【Objective】To analyze the spatial-temporal evolution law of agricultural non-point source pollution in Guangxi，and to put forward the prevention and control countermeasures to control agricultural non-point source pollution，so as to provide theoretical basis for the prevention and control of agricultural non-point source pollution in Guangxi and the implementation of rural revitalization policy.【Method】The Xijiang Economic Belt，resource-rich area in western Guangxi and Beibu Gulf Economic Zone were taken as research units. A list of farmland chemical fertilizers and livestock and poultry manure pollution was made，and the unit survey method was used to calculate the amount and intensity of agricultural non-point source pollutant emission in Guangxi from 2008 to 2019.【Result】The agricultural non-point source polluted areas and the pollutant regional distribution had not changed，and the Xijiang Economic Belt was the main area where the total amount and intensity of pollutant emission increased. The changes in pollutant emission structure and intensity structure of different regions were quite different. Seem from the structure of pollutant emission，the Xijiang Economic Belt had expanded from chemical oxygen demand（COD）to total nitrogen（TN），and the Beibu Gulf Economic Zone had expanded from TN to COD. The resource-rich area in western Guangxi had not changed significantly and was still TN. Seem from the structure of pollutant emission intensity，in the Xijiang Economic Belt，COD changed to COD and TN，and the resource-rich area in western Guangxi changed from TN to COD and TN，and the Beibu Gulf Economic Zone changed from TN to COD. The expansion of the scale of commercial crops and the growth of pig breeding were the main reasons for the structural changes in the structure and intensity of pollutant emissions in various regions.【Suggestion】The level of agricultural science and technology level should be improved. Large-scale breeding should be developed. Agricultural education and training should be strengthened，and investment in rural pollution control should be increased.