氮肥减施及玉米间作绿肥对饲草产量、土壤化学性质的影响OA

To investigate the effects of nitrogen reduction on forage yield and soil nutrients under the intercropping pattern of silage corn(Zea mays)and leguminous(Leguminosae)green manure in the Loess Plateau region of Shanxi province,four treatments were set up for silage corn intercropped with leguminous green manure(Y1:corn+corn;Y2:corn+Mulu No.9 soybean;Y3:corn+Mulu No.2 soybean;Y4:corn+lablab bean),with two nitrogen fertilizer gradients(Z1:100%N application;Z2:90%N application).In the first year,nitrogen fertilizer was applied normally,and nitrogen reduction began in the second year.During the silage corn harvest period,indicators such as fresh forage yield,soil nutrient content,and enzyme activity were measured.The results showed that under the same nitrogen application rate,intercropping green manure increased mixed forage yield by 2.58%-13.03%,and improved soil total nitrogen by 4.09%-17.60%,nitrate nitrogen by 8.45%-14.61%,ammonium nitrogen by 0.88%-8.00%,organic matter by 9.82%-12.29%,and urease activity by 9.34%-15.82%.Reducing nitrogen fertilizer by 10%decreased forage yield by 4.46%,soil total nitrogen by 9.46%,nitrate nitrogen by 7.51%,ammonium nitrogen by 4.47%,organic matter by 2.13%,urease activity by 5.39%,nitrate reductase activity by 3.63%,and nitrite reductase activity by 5.87%.Intercropping green manure could enhance soil nutrient content and enzyme activity while compensating for the yield loss caused by a 10%nitrogen reduction,with the treatment of intercropping lablab bean and applying 90%nitrogen fertilizer showing the best performance.