Does the agricultural co-agglomeration help reduce livestock and poultry pollution? From the perspective of planting and breeding combination in China

Given the problem of considerable livestock and poultry pollution and the differentiation of the regional agricultural layout in China, the combination of planting and breeding (CPB) forms an agricultural co-agglomeration to recycle manure waste into croplands to reduce livestock and poultry pollution. This study aims to evaluate CPB co-agglomeration and empirically examine its effects on livestock and poultry pollution. Based on provincial data from 1997 to 2020 in China, this study constructed three indicators to evaluate CPB co-agglomeration, summarized its temporal and spatial characteristics, and conducted a spatial analysis using the Spatial Lag Model (SLM) to empirically investigate its effect on livestock and poultry pollution. The results showed that: first, from 1997 to 2020, the overall level of CPB co-agglomeration in China declined and the region with higher CPB co-agglomeration level transferred from the central provinces to the west provinces. Second, livestock and poultry pollution in most provinces had significantly positive spatial correlations with adjacent regions. The co-agglomeration of CPB had a significantly positive effect on reducing livestock and poultry pollution; however, the effect had no significant spatial spillover. Third, the breeding industry agglomeration and the moderate expansion of breeding industry scale significantly reduced pollution. These findings provide a reference for reducing livestock and poultry pollution by promoting CPB co-agglomeration to establish a waste recycling system. Optimizing the layout of the planting and breeding industry helps achieve the goal of long-term sustainable development of the breeding industry.