摘要： 模拟林木遮荫试验结果表明,遮荫程度每提高25％,小麦进入某个生长发育期就推迟2d左右;遮荫程度每提高10％,土壤水分(0～40cm)蒸发就减少0.58个百分点;并且遮荫程度与小麦叶绿素含量、光合速度和蒸腾速率呈正比关系,与光能利用率和蒸腾耗水指数呈反比关系。试验结果还说明,适当遮荫对小麦的叶面积和地上部分生物量积累有促进作用,遮荫程度25％时的小麦产量仅比全光下的低1.25％,而生物量却提高7.9％。综合试验结果说明,如果不考虑林木与农作物根系竞争,在农林间作系统中,林木的遮荫程度如果不高于20％,就不会对农作物的生长和产量造成比较严重的影响,可以把它作为农林间作林木上限遮荫的一个阈值。

关键词: 农林间作, 遮荫, 小麦, 生长发育, 产量, 模拟

Abstract: Simulating tree shading experiment show that wheat enter a developing stage will post-pone 2 days along with the shading degree adding to 25% ,and soil water (0~40 cm)evaporation will reduce 0.58 per cent point when shading add to 10 % as well. And it also demonstrate that suitable shading degree have direct proportion with wheat chlorophyll content, photosynthetic rate and transpiration rate and as well as has inverse ratio with light utilized rate and water consump-tion rate. The suitable shading degree can stimulate wheat leaf area growth and biomass accumula-tion , and the treatment of shading degree 25 % , for example, is only lower 1.25 % in wheat output but is higher 7.9%in biomass compared with sunshine treatment. To sum up,suitable tree shad-ing degree, less than 20% ,in tree-crop intercropping system will not led to decrease wheat output seriously if tree root effect is ignored, and the shading value can be the largest shading degree value in tree-crop intercropping system.

Key words: Tree-crop intercropping, Shading, Wheat development, Yield, Simulation

中图分类号: 

• S512.1