Farmland size is a key factor in debates over agricultural land use, food security, agrochemical pollution, and the future of smallholder systems. This paper examines relationships between farmland size, chemical fertilizers and irrigation management, and maize and wheat yield in Mexico. We used agricultural census data to estimate the mean farmland areas and crop yields of 5.5 million farms and nine million agricultural plots in 2,455 Mexican municipalities. We also derived indices of socio-environmental and management factors to examine relationships with yield. Using multiple regression models, we found that although mean farmland area positively relates to maize and wheat yield, the relationships depend critically on the management contexts of chemical fertilizers and irrigation, which vary widely across farm size gradients. Smallholder yield gaps were associated with deficits in irrigation, rather than chemical inputs. Findings highlight the growing need for expanded irrigation access and/or water management assistance for smaller farms.

农田面积是有关农业土地使用，粮食安全，农药化学污染以及小农户制度未来的辩论的关键因素。本文研究了墨西哥农田面积，化肥和灌溉管理与玉米和小麦产量之间的关系。我们使用农业普查数据估算了墨西哥2455个自治市的550万个农场和900万个农业用地的平均农田面积和农作物产量。我们还得出了社会环境和管理因素的指数，以检验与产量的关系。使用多元回归模型，我们发现尽管平均耕地面积与玉米和小麦的产量成正比，但这种关系在很大程度上取决于化肥和灌溉的管理环境，在整个农场规模梯度之间变化很大。小农的产量缺口与灌溉不足而不是化学投入有关。调查结果突显了对小型农场扩大灌溉渠道和/或水管理援助的需求不断增长。