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作 者 ：王群,尹飞,郝四平,李潮海*

期 刊 ：生态学报 2009年 29卷 6期 页码：3096~3104

关键词：下层土壤容重；玉米；根际微生物数量；微生物量C；微生物量N；

Keywords:subsoil bulk density, corn, population of rhizosphere microorganisms, soil microbial biomass carbon, soil microbial biomass nitrogen,

摘 要 ：采用微区池栽模拟试验，研究下层（20~40cm 、40~60cm）土壤容重改变后，玉米根际微生物数量、微生物量C（MBC）和微生物量N（MBN）的动态变化规律。结果表明，玉米根际微生物（细菌、放线菌、真菌）数量、MBC和MBN随土层加深和下层土壤容重增加而降低，且相同层次不同容重的处理间差异达显著水平；不同层次土壤根际微生物数量、MBC和MBN既受本土层容重大小影响，也随相邻土层容重增大其降幅增加，且20~40cm土层容重对土壤微生物数量、MBC和MBN的影响远大于40~60cm土层容重。玉米生育期间，三者受下层土壤容重变化和玉米生长发育的双重影响，且玉米的生长发育过程放大了容重对根际微生物数量、MBC和MBN的影响效果。

Abstract:A mini-plot experiment was conducted to study the impacts of subsoil bulk density on rhizospheric soil microbial population, SMBC, and SMBN in corn field on a sandy loam soil at the Experimental Farm of Henan Agricultural University in 2005 and 2006. The plot was 1 m by 1m in size and was planted with six corns. Five different soil bulk density were included and the experiment was arranged in a randomized complete block design with four blocks. The population of soil bacteria, fungi, and actinomycete decreased with increase in soil bulk density and soil depth. Soil microbial biomass C and N response the same as soil microbial populations to soil bulk density and soil depth. The higher the soil bulk density, the less of soil microorganisms, SMBC and SMBN in the rhizosphere. All selected soil properties were significant differences among soil bulk densities in the same soil layer, and they were also affected by soil bulk density in the adjacent layers. The effects of soil bulk density on selected soil properties were more evident in the 20-40 cm than in the 40-60 cm depth. Furthermore, corn growth had a significant effect on microbial populations, SMBC, SMBN, in soil rhizosphere. The effects of soil bulk density on soil biochemical properties were more apparent at the corn silking stage than other growing stages.

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