Study on the response and fertilization model of cucumber for nitrogen, phosphorus and manure application in greenhouse under drip irrigation

The response and fertilization model of cucumber for nitrogen, phosphorus and manure application were studied under greenhouse in a field experiment in northern Shaanxi of the Loess Plateau. The optimum design of nitrogen, phosphorus and manure with 5 levels was applied in the field experiment. The result shows that the order of the effects of nitrogen, phosphorus and manure on yield improvement is manure nitrogen phosphorus. To improve cucumber yield under the greenhouse environment, the main measure should be the application of organic manure. With the phosphorus application amount less than 750 kg/ha and nitrogen application amount less than 1150 kg/ha, there are remarkable yield increase effects, while the N and P fertilizer efficiencies are decreased when the application amounts are increased. When the target yield of cucumber is from 83000 to 88000 kg/ha, and confidence interval is 95%, the optimum fertilizer application amounts are 807.5–1309.3 kg/ha, 576.6–991.6 kg/ha, and 41.3–148.9 t/ha for N, P2O5, and manure, respectively. The ratio of N∶P2O5 is 1∶0.714–0.757. During cultivation process of cucumber, it should pay attention to the application of organic manure fertilizer and as well as the combined application of nitrogen and phosphorus.