Effect of combined application of green manure and chemical fertilizer on wheat yield and soil fertility

An experiment was carried out in Gansu Hexi oasis irrigation area to investigate,under the condition of total amount of N application remaining unchanged,the effect of green manure replacing chemical fertilizer with the same content of N on wheat yield and chief characteristics,soil fertility and soil microbial quantity.The results showed that,in the first year,the wheat yield decreased with the increase of green manure,but the content of soil available N,P,K and organic matter increased after green manure harvest;In the second year,the increase of green manure increased wheat yield,and 70% green manure N + 30% chemical fertilizer N achieved the highest yield of 8 562 kg/hm2,24.7% more than that by FFP.Green manure replacing N fertilizer by 30%~45% improved soil fertility and wheat yield,and had good economic and ecological benefits.