Analysis of the Land Carrying Capacity of Livestock and Poultry Manure and the Theoretical Substitution Potential of Nitrogen and Phosphorus Fertilizers in the Upper Reaches of the Ganjiang River
This study provides relevant theoretical foundations and data support for the development model of balanced crop-livestock production in agriculture and animal husbandry.Based on agricultural data from the upper regions of the Gan River from 2009 to 2019,the supply and demand of nitrogen and phosphorus nutrients from livestock and poultry manure,the land carrying capacity index for livestock and poultry waste,and the theoretical substitution potential for nitrogen and phosphorus fertilizers were calcu-lated and analyzed according to the"Technical Guidelines for Calculating the Land Carrying Capacity of Livestock and Poultry Manure."The results indicate that:(1)Temporally,the supply and demand of ni-trogen and phosphorus nutrients from livestock and poultry manure,as well as the land carrying capacity index for livestock and poultry waste in the upper Gan River region,are generally low,with an overall trend of first increasing and then decreasing.The theoretical substitution potential has increased in most areas,with some exceptions.(2)Spatially,the overall nutrient supply is low,with the central region be-ing greater than the surrounding areas;the nutrient demand shows significant regional disparities,being higher in the central and northern regions and lower in the southwestern region.The land carrying capacity index is relatively high in certain areas of the south,while the theoretical substitution potential is generally high.Overall,the pressure from livestock and poultry waste in the upper Gan River region is relatively low,but there are still certain risks that require enhanced management.The theoretical substitution poten-tial is significant,indicating a need to strengthen efforts in promoting the concept of balanced crop-live-stock production and supporting the development of integrated crop-livestock agriculture.
livestock manureland carrying capacitybalanced planting and breedingnitrogen and phosphorus fertilizer