How Farmland Fragmentation Affects Crop Yields Through Irrigation and Labor Input: An Empirical Study Based on Maize Production in China

Against the backdrop of increasingly emphasized sustainable development goals and the pursuit of high-quality agricultural growth, farmland fragmentation not only undermines agricultural production efficiency and crop yield levels but also poses challenges to achieving food security, ecological conservation, and rural revitalization. Drawing on data from the China Rural Revitalization Survey Database, this study employs econometric models—including ordinary least squares estimation, moderation effects, and mediation effects—to investigate the mechanisms and impacts of farmland fragmentation on maize yield per unit area. It also conducts heterogeneity analysis across farm sizes and land transfer situations. The key findings are as follows: (1) Farmland fragmentation significantly reduces maize yield, constrains mechanized operations, increases production costs, and decreases field management efficiency. (2) The negative impact of fragmentation is exacerbated under conditions of straw return practices and exposure to natural disasters. (3) Irrigation capacity and labor input function as mediating variables; fragmentation reduces the effective irrigated area while increasing farmers’ fieldwork time and physical exertion, thereby influencing maize yield. (4) The impact of fragmentation is heterogeneous across different types of farmers. Large-scale farmers, who depend more heavily on land consolidation and mechanization, are more adversely affected. Although land transfer partially mitigates the negative effects, farmers who rent in land still face limitations due to scattered plots. The study recommends optimizing land consolidation and transfer mechanisms, increasing agricultural investment, improving infrastructure, and strengthening agricultural socialized services to enhance agricultural productivity and alleviate the adverse effects of farmland fragmentation.