Reducing the application of chemical fertilizers can improve the quality and promote the sustainable use of cultivated land, which is part of the green and sustainable development of agriculture. Based on the 2019 China Rural Household Panel Survey data, this article evaluated the impact of cultivated-land-management scale on fertilizer reduction via the OLS regression method. The results showed that, after controlling for other factors, the scale of cultivated land management is a strong factor affecting the intensity of fertilizer application by Chinese farmers. According to the results of quantitative analysis, the amount of fertilizer applied per hectare decreased by 20.6% for every 1 ha increase in the average grain sown area per household. The study also found that employing workers in agricultural production and operation can help achieve the aim of fertilizer reduction, but the fact that the head of the household is male, the increase in total household income and the increase in the proportion of household agricultural labor are not conducive to fertilizer reduction. A mechanism-of-action test showed that the expansion of the scale of cultivated land management can drive the reduction of chemical-fertilizer use by urging farmers to adopt agricultural technology and mechanized fertilization. Extensive research found that the fragmentation of cultivated land increased the amount of fertilizer applied per hectare by farmers. Therefore, the fragmentation of cultivated fields is a barrier to decreasing fertilizer application.