林带两侧附近作物生产效能的研究

文中探讨了农林复合系统中林带两侧附近作物的生产效能。结果表明：其附近农田CO2浓度水平和垂直分布不均匀，光合强度于近林带的0．5H（距林带0．5倍树高）处数值明显低于2H（距林带2倍树高），尤以NO5H（指林带北侧0．5倍树高）处最低。光能利用率的分布也表现出类似的特点。水分利用效率分布与上述参数不同之处在于其最低值出现在SO5H（指林带南侧0．5倍树高处），而NO5H，由于林带遮荫，蒸腾量减少，仍表现出较高的水分利用效率。

Study on the crop production Efficiency on Both Sides of the Forest Belt

This article discussed the crop production efficiency on both sides of the forest belt in the composite system of agriculture and forestry. The result showed that the vertical and horizontal distribution of the air co2 concentration in the fields on both sides of the forest belt was not homogeneous. The amount of the photosynthetic intensity at 0. 5H near the forest belt (it meant 0. 5 times as much as the average height of the forest belt) was obviously lower than that at 2H (2 times as much as the average height of the forest belt),especially that at NO 5 H(0. 5 time as much as the average height of the forest belt,here N means on the northern side of the forest belt) was the lowest among all these treatments. The distribution of the efficiency of light energy application also appeared shows similar tendency. The distribution of the water-use-efficiency differed from the above-mentioned parameters on that its lowest amount appeared at SO5H (0. 5 times as much as the average height of forest belt,here S means on the southern side of the forest belt),but due to the screening of the forest belt with the reduction of the transpiration amount,the water-use-efficiency at NO5H showed to be still higher.