１、土壤内地膜残留 :八十年代未 ,由于地膜玉米以其增温、保墒、提高出苗率等特点 ,迅速地推广普及。但另一方面 ,地膜玉米这一特点 ,又造成了玉米早期生产过旺 ,若中期揭膜等田间管理措施方法不当 ,将造成肥料利用率低 ,导致中后期生产衰竭。２、玉米抽穗至乳熟期是玉米生长 1, the soil within the membrane residue: the eighties, due to the plastic film corn with its warming, preserving soil, raising the emergence rate and other characteristics, the rapid popularization. However, on the other hand, the characteristic of mulching corn has also resulted in the overproduction of corn in the early stage. If improper methods of field management measures such as medium mulching are used, the utilization rate of fertilizers will be low, leading to the failure of production in the middle and later stages. 2, corn heading to milky maturity is corn growth