关键词: 氮沉降, 土壤酶活性, 光皮桦, 华西雨屏区

Abstract: Under the condition of continental semi-arid climate in Shanxi province,whole stalk mulching on non-tillaged corn farmlands has a favourable effect on the rhizospheric N-fixation and yield increasing.with annual mulching,the N-fixation intensity of corn root system and its rhizosphere at the early vegetative growing stage is respectively 310 and 38.2% higher than that without mulching, and 85.8 and 25.3% higher than that with traditional tillage. Whole stalk mulching can increase the soil moisture content of cultivatedlayer by 2.1-3.0%,organic matter content by 0.1-0.28% and average yield by 57.7%。It also has astronger effect on the veriical distribution of N-fixation intensity in corn rhizosphere.

Key words: nitrogen deposition, soil enzyme activity, Betula luminifera,  Rainy Area of West China.