In order to provide reference for rational fertilization and safe production of eggplant, the maximum profit of nitrogen, phosphorus and potassium on eggplant in greenhouse was studied. In the greenhouse of Dangzhai town, Ganzhou district, Zhangye city, Gansu province, a field plot experiment was carried out to study the maximum application amount of nitrogen, phosphorus and potassium on eggplant in greenhouse. The results showed that the yield of eggplant increased gradually with the increase of nitrogen, phosphorus and potassium application gradient, and the marginal product, marginal output value and marginal profit all showed a decreasing trend, and the marginal profit finally appeared negative value. According to the formula of maximum profit application amount, the maximum profit application amount of nitrogen, phosphorus and potassium on eggplant was 0.62, 0.41 and 0.29 t/hm2, respectively, and the theoretical yield of maximum profit application amount was 95.58, 96.04, 95.35 t/hm2, respectively. |