“Three Four One Four”Test of Plastic Film Corn

“Three four one four”test of plastic film corn in Longshan county of Hunan province was carried out.Regression equations between maize yield and N，P and K were built.Optimum fertilization scheme was obtained that pure nitrogen was 165 kg/hm2，pure phosphorus was 87 kg/hm2 and pure potassium was 88.5 kg/hm2.