The results show that shelternets has different influence on the photosynthesis of crops after observing the most index of physiological and ecological process characteristics of crop photosynthesis in shelternets. The strongest reaction occurs in the area of 0~2H around farmland margin. Furthermore

there is obvious difference of photosynthesis in different time

position and direction of belts

which is mainly due to the difference of density of photosynthetic active radiation received by crops in shelternets

and thus result in the difference of crop production. Consequently

shelternet is regarded as the primary reason that formed the environment heterogeneity in the interface of farmland ecosystem. The trees group in shleternets formed by different disposition caused the changes of environment factors tied to physiological activity of crops grew in shelternets

and this important changes influenced necessarily the physiological and ecological process of crop photosynthesis in shleternets.