小麦/大豆间作中作物种间的竞争作用和促进作用

Interspecific competition and facilitation in wheat/soybean intercropping system.

春小麦／春大豆间作是西北一熟制灌区广泛采用的高产种植形式．本文采用田间小区和微区根系分隔试验研究了这种种植形式作物种间的竞争作用和促进作用．结果表明，小麦／大豆间作具有明显的间作优势．土地当量比为１．２３～１．２６．小麦为优势种，竞争力强于大豆，具有明显的间作边行优势．小麦边行优势的１／３贡献来自于地下部．小麦收获后，大豆生长具有恢复作用，认为这种恢复作用是间作优势的机制之一．间作相对于单作两种作物的收获指数均有显著提高．收获指数的种间促进作用是间作优势的另一机制．

Wheat and soybean intercropping is a high yield planting system widely distributed in one crop a year irrigation area of northwest China. Field plot and microplot root partition experiments show that under wheat/soybean intercropping, the land equivalent ratio was 1.23～1.26,and wheat was the dominant species with more competitive ability relative to soybean and possessing obvious edge row advantages, in which, 1/3 of the contribution came from its underground part. There was a recovery to soybean growth after wheat harvesting, which was considered as one of the mechanisms of interspecific facilitation. The harvesting index of intercropped species was significantly higher than that of sole species, indicating another mechanism of facilitation in the intercropping.