Dong Yan, Tang Li, Zheng Yi, Zhu You-Yong, Zhang Fu-Suo
College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China.
Ying Yong Sheng Tai Xue Bao. 2008 Jul;19(7):1559-66.
With field plot experiment, this paper studied the effects of different nitrogen application rate (0, 90, 180 and 270 kg x hm(-2)) on the rhizosphere microbial community and its diversity in wheat-faba bean intercropping ecosystem. The results indicated that the amount of rhizosphere microbes fluctuated with crop growth stages, being the highest at the flowering stage of test crops. Comparing with monocropping, intercropping significantly increased the total amount of microbes and the numbers of bacteria, fungi and actinomyces in the rhizosphere of both wheat and faba bean, but decreased the microbial diversity in the rhizosphere of faba bean at its flowering and maturing stages. Under no nitrogen and low nitrogen application rate, a larger difference was observed in the amount of rhizosphere microbes between intercropping and monocropping. The promotion effect of intercropping in increasing the amount of rhizosphere microbes was more apparent at tillering and flowering stages, but declined significantly at maturing stage. With increasing nitrogen application rate, the amount of microbes in wheat rhizosphere increased first and decreased then, with the peak appeared at 180 kg N x hm(-2), and the effect was more obvious on monocropped wheat than on intercropped one. Nitrogen application rate had no significant effects on the numbers of bacteria, fungi and actinomyces and the microbial diversity in faba bean rhizosphere, but decreased the total amount of microbes in the rhizosphere of intercropped faba bean. Rational nitrogen application could regulate rhizosphere microbial community effectively, and there was an obvious correlation between aboveground plant diversity and belowground microbial community.
通过田间小区试验，研究了不同施氮量（0、90、180和270 kg·hm⁻²）对小麦 - 蚕豆间作生态系统根际微生物群落及其多样性的影响。结果表明，根际微生物数量随作物生育期波动，在供试作物开花期最高。与单作相比，间作显著增加了小麦和蚕豆根际微生物总量以及细菌、真菌和放线菌数量，但在蚕豆开花期和成熟期降低了其根际微生物多样性。在不施氮和低施氮量条件下，间作与单作根际微生物数量差异较大。间作对增加根际微生物数量的促进作用在分蘖期和开花期更明显，但在成熟期显著下降。随着施氮量增加，小麦根际微生物数量先增加后减少，峰值出现在180 kg N·hm⁻²，且对单作小麦的影响比对间作小麦更明显。施氮量对蚕豆根际细菌、真菌和放线菌数量及微生物多样性无显著影响，但降低了间作蚕豆根际微生物总量。合理施氮能有效调控根际微生物群落，地上植物多样性与地下微生物群落之间存在明显相关性。
