Abstract: Farmland shelterbelt is a main component of oasis agro-ecosystem in the Hexi corridor of Gansu Province, which plays an important role in maintaining local agricultural production and ecological balance. This paper studied the photosynthetic characteristics of maize at its grain-filling stage and the grain yield of maize under the protection of the shelterbelt. The results showed that at the same distances east and west of the shelterbelt, maize plants at the east side always intercepted more photosynthetic active radiation (PAR) than those at the west side. Within 20 m from the west side of the shelterbelt, the net photosynthetic rate (Pn) of maize plants was lower because of the serious shading by trees; and within 15 m from the west side, the Pn was lower than that from the east side. The grain yield of maize was decreased within 10 m from the east and 15〖KG-*2〗-〖KG-*7〗20 m from the west side, but increased or not affected in other locations.

Key words: sloping farmland, hedgerow, soil infiltration, common empirical model, purple soil area.