Abstract: Through an ecological function analysis for the planting subsystem in Xiaozhangzhuang village of Yingshang county, it is considered that because of the continued improvement of farmland environment and readjustment of planting structures, the combination of communities, environment and technological regulation in the subsystem is rationalized. The analyses are made from three aspects: level and efficieney of energy input, cyoling of mineral nutrients and reproducing efficieney of investment funds. The photo-utilization ratio of dominant crops has reached or suppassed that in the middle reaches of the Changjiang River. The system has a strong self-sustainability to field nutrient balances. The soil N and P are surplus, but K is a little deficit. The reproducing efficieney of investment funds is significantly promoted when it reaches to a definite level.

Key words: nitrogen removal, litter addition, soil respiration, soil organic carbon decomposition