The impacts of organic amendments: Do they confer stability against drought on the soil microbial community?
The impacts of organic amendments: Do they confer stability against drought on the soil microbial community?
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DOI：
10.1016/j.soilbio.2017.06.012
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发表时间：
2017-10-01
影响因子：
9.7
通讯作者：
Garcia, C.
中科院分区：
文献类型：
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作者：
Bastida, F.;Torres, I. F.;Garcia, C.
有机残留物的应用已被认为是防止半干旱环境中土壤退化的一种适当战略。然而，有机改良剂与干旱之间的相互作用还不完全清楚。在这里，我们评估半干旱地区的污泥和堆肥改良剂是否会影响土壤微生物群落的稳定性和微生物介导的抗旱过程。从西班牙东南部的一项长期恢复试验中收集了经过污泥修正、堆肥修正和对照(未修正)的土壤。以60%的最佳持水能力(WHC)对每个处理的土壤样品进行预培养，建立了干旱诱导模型。然后，一部分样品被部分干燥，随后保持在20%的WHC(诱导干旱样品)，而另一个子集保持在60%的WHC。在培养2、9和45d后，分析微生物生物量(通过磷脂脂肪酸分析，PLFA5)、与C、N和P循环有关的酶活性、微生物多样性和微生物种群(通过16S rRNA及其扩增片段测序)的响应。在平行样品中，通过跟踪添加富含碳13的植物组织(97原子%)后二氧化碳的同位素特征，评估了土壤有机质(SOM)和新鲜有机质(FOM)的矿化程度。总体而言，我们发现：i)土壤微生物生物量在培养45天后在20%WHC比60%WHC的相应土壤更大；ii)土壤微生物生物量的变化伴随着微生物种群相对丰度的变化；iii)20%WHC的土壤SOM和FOM释放的CO2比60%WHC的土壤减少，而β-葡萄糖苷酶和尿素酶的活性高于60%WHC的土壤；以及iv)细菌和真菌的多样性没有因为干旱而改变。对土壤微生物群落的多层次描述有助于更好地了解改良土壤对干旱的反应。(C)2017爱思唯尔有限公司。保留所有权利。
The application of organic residues has been presented as an adequate strategy against soil degradation in semiarid environments. However, the interactions between organic amendments and drought are not fully known. Here, we evaluate whether sludge and compost amendment in semiarid areas influences the stability of the soil microbial community and microbially-mediated processes against drought. Sludge-amended, compost-amended and control (without amendment) soils were collected from a longterm restoration trial in southeastern Spain. A drought-induction model was initiated by first pre incubating soil samples from each treatment at an optimum water-holding capacity (WHC) of 60%. One subset of samples was then partly dried and subsequently maintained at 20% of the WHC (induced drought samples) and another subset was maintained at 60% of the WHC. The responses of the microbial biomass (through the analysis of phospholipid fatty acids, PLFA5), enzyme activities related to the C, N and P cycles, microbial diversity and microbial populations (through 16S rRNA and ITS amplicon sequencing) were analysed after 2, 9, and 45 days of incubation. In parallel samples, the mineralisation of soil organic matter (SOM) and fresh-organic matter (FOM) were evaluated by tracking the isotope signature of CO2 after addition of C-13-enriched plant tissue (97 atom %). Overall, we found that: i) the soil microbial biomass was greater in amended soils at 20% WHC than in the corresponding soils at 60% WHC after 45 days of incubation; ii) changes in the soil microbial biomass were accompanied by changes in the relative abundances of microbial populations; iii) the release of CO2 from SOM and FOM was diminished in soils at 20% WHC, in comparison to soils at 60% WHC, while beta-glucosidase and urease activities were higher in amended soils at 20% WHC than in soils at 60% WHC; and iv) bacterial and fungal diversity did not change as a consequence of drought. A multi-level characterisation of the soil microbial community provided a better understanding of the responses of amended soils to drought. (C) 2017 Elsevier Ltd. All rights reserved.