Surplus use of agricultural inputs such as fertilizers and pesticides that cause land and water pollution have been a serious problem in China. This study investigated surplus fertilizer use for corn, rice, vegetable, and tomato farming in terms of farm management by the smoothed bootstrap levels. Higher surplus fertilizer use was observed for farmers using manure, although their chemical fertilizer use levels were similar or lower. It was also confirmed that the input value of both purchased and self-made manures was more unstable than that of chemical fertilizers.