大豆根构型在玉米/大豆间作系统中的营养作用

Nutritional Effects of Soybean Root Architecture in a Maize/Soybean Intercropping System

运用根构型不同的大豆品种与玉米进行间作,比较大豆根构型在玉米/大豆间作系统中的营养作用。结果表明,玉米与大豆间作具有明显的间作优势,间作作物的生物量、氮磷含量都显著好于单作。玉米与浅根型大豆品种巴西10号间作,间作优势大于与深根型大豆品种本地2号。说明大豆根构型在玉米/大豆间作系统中具有十分重要的作用。间作系统的氮磷养分竞争比率表明,玉米/大豆这类豆科/禾本科间作组合的优势主要来自对氮的优势性吸收,而玉米与不同基因型大豆间作的优势差异则主要来源于对土壤磷吸收的差异。浅根型大豆品种不仅有利于两种间作作物对土壤磷的吸收,同时还有利于对氮的吸收。

In the present study, two soybean genotypes differing in root architecture were employed to evaluate the effects of soybean root architecture on N and P nutrient status and crop growth in a maize/soybean intercropping system. The results showed that land equivalent ratio (LER), biomass and N/P content of crops significantly increased in the maize/soybean intercropping system. LER was also higher in maize intercropped with Baxi10, the soybean genotype with a shallow root system, than that in maize intercropped with Bendi2, the soybean genotype with a deep root system, indicating that soybean root architecture may play an important role in the maize/soybean intercropping system. The greater LER in the legume-grass intercropping system (such as the maize/soybean intercropping system) could be mainly attributed to the greater N uptake as indicated by the competition ratio of maize to soybean (CRms), while the differences in LER between maize intercropped with different soybean genotypes might have resulted from different soil P uptake. Soybean genotype with a shallower root system was advantageous not only for soil P uptake but also for N uptake by both crops.