Reducing China’s fertilizer use by increasing farm size

• Increase in farm size should be integrated into the actions to reduce fertilizer use.
• Large-scale farms are more sensitive to fertilizer use if fertilizer subsidies are withdrawn.
• Increasing farm size can also increase food production on a per-area basis.
• Achieving a zero increase of fertilizer use should consider the socioeconomic aspects.

The excessive use of fertilizer has resulted in serious environmental degradation and a high health cost in China. Much research has focused on the technological innovation to improve fertilizer use efficiency in crop production, but the socioeconomic constraints are at present poorly understood. Here, we find that fertilizer use on a per-area basis sharply decreased with the increase of farm size; surprisingly, the crop yield is higher in large-scale farms compared to that in smallholder farms in China. High labor cost suggests a low machinery level in smallholder farms, which inhibit the application of precise fertilization technologies and management based on scientific knowledge. Meanwhile, the dependence of income from cropland is lower for smallholder farmers who have part-time jobs in urban areas compared to the professional farmers in large-scale farms. Therefore, compared to smallholder farms, large-scale farms are generally more sensitive to the increase of fertilizer price and would reduce their fertilizer use if withdrawing fertilizer subsidies that used to be considered as the key driver of fertilizer overuse. Considering the dominance of smallholder farms in China, increasing farm size should be integrated into the actions such as improving technological innovation and providing better information transfer to achieve the goal of no increase in Chinese fertilizer use.