Responses of extracellular enzyme activities and microbial community in both the rhizosphere and bulk soil to long-term fertilization practices in a fluvo-aquic soil
Responses of extracellular enzyme activities and microbial community in both the rhizosphere and bulk soil to long-term fertilization practices in a fluvo-aquic soil
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DOI：
10.1016/j.geoderma.2011.07.020
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发表时间：
2012-03-01
期刊：
影响因子：
6.1
通讯作者：
Zhou, Wei
中科院分区：
文献类型：
--
作者：
Ai, Chao;Liang, Guoqing;Zhou, Wei
无机或有机施肥对土壤微生物生态的影响近来受到重视，但关于根际对胞外酶活性和微生物群落结构的影响却知之甚少。通过酶标荧光测定法和磷脂脂肪酸分析（PLFA），分别对来自一个长期（31年）施肥试验田小麦生殖期的根际和非根际土壤样品中参与碳、氮、磷和硫循环的11种胞外酶以及微生物群落结构进行了研究。这些样品取自6种处理：对照（CK，不施肥）、氮肥（N）、氮磷肥（NP）、氮磷钾肥（NPK）、有机肥（M）以及有机肥加氮磷钾肥（MNPK）。根际对无机或有机肥料的反应与非根际土壤显著不同。除了硝态氮外，根际的养分浓度通常高于非根际土壤。M和MNPK处理极大地增加了有机碳、全氮、铵态氮和全硫的含量。无机肥料（N、NP和NPK）通常维持或降低了根际的大多数酶活性，但显著增加了非根际土壤中的这些酶活性。然而，有机处理（M和MNPK）提高了根际和非根际土壤中大多数酶的活性。与非根际土壤相比，根际中总磷脂脂肪酸含量较高，细菌与真菌以及放线菌与真菌的比率较低。在非根际土壤中，细菌与真菌以及放线菌与真菌的比率在N处理中最高，在M处理中最低。然而，在根际中，无机和有机处理之间细菌、真菌和放线菌的丰度没有统计学上的显著差异。有机肥增加了根际和非根际土壤中的总磷脂脂肪酸以及革兰氏阳性菌与革兰氏阴性菌的比率。我们的研究结果表明，施肥制度的改变对非根际土壤微生物群落的影响大于对根际的影响。版权归英国皇家所有（C）2011，由爱思唯尔出版集团出版。保留所有权利。
The influence of inorganic or organic fertilization on soil microbial ecology has been emphasized recently, but less is known about rhizosphere effects on extracellular enzyme activities and microbial community structure. Eleven extracellular enzymes involved in C, N, P. and S cycling and microbial community structure in both the rhizosphere and bulk soil samples from a long-term (31-year) fertilizer experimental field at the wheat reproductive stage were investigated by microplate fluorometric assay and phospholipid fatty acid analysis (PLFA), respectively. The samples were taken from six treatments: control (CK, without fertilization), fertilizer N (N), fertilizer N and P (NP), fertilizer N, P and K (NPK), organic manure (M), and organic manure plus fertilizer N, P and K (MNPK). Responses to inorganic or organic fertilizers in the rhizosphere were significantly different from those in the bulk soil. Except for NO3--N, thus, nutrient concentrations were generally higher in the rhizosphere than in the bulk soil. M and MNPK treatments greatly increased organic C, total N, NH4+-N and total S. Inorganic fertilizers (N, NP, and NPK) generally maintained or reduced most enzyme activities in the rhizosphere, but markedly increased these enzyme activities in the bulk soil. However, organic treatments (M and MNPK) enhanced most enzyme activities in both the rhizosphere and bulk soil. Higher total PLFA and lower ratios of bacteria to fungi and of actinomycetes to fungi were observed in the rhizosphere compared with the bulk soil. In the bulk soil, the ratios of bacteria to fungi and of actinomycetes to fungi were highest in the N treatment and lowest in the M treatment. However, in the rhizosphere there were no statistically significant differences in the abundance of bacteria, fungi and actinomycetes between the inorganic and organic treatments. Organic fertilization increased total PLEA and Gram+ to Gram bacteria ratio in both the rhizosphere and bulk soil. Our results indicated that changes in fertilization regime had a greater impact on the bulk soil microbial community than in the rhizosphere. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.