Aggregational differentiation of ureolytic microbes in an Ultisol under long-term organic and chemical fertilizations.
Aggregational differentiation of ureolytic microbes in an Ultisol under long-term organic and chemical fertilizations.
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DOI：
10.1016/j.scitotenv.2020.137103
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发表时间：
2020-02
期刊：
影响因子：
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通讯作者：
Li Wang;Xiang Xiong;Xuesong Luo;Wenli Chen;S. Wen;Bo-ren Wang;Chengrong Chen;Qiaoyun Huang
中科院分区：
文献类型：
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作者：
Li Wang;Xiang Xiong;Xuesong Luo;Wenli Chen;S. Wen;Bo-ren Wang;Chengrong Chen;Qiaoyun Huang
尿素分解微生物在土壤氮素转化中起着重要作用。土壤团聚体和相关微生物被报道可以改变农业管理对土壤养分循环的影响。然而，在酸性土壤中，不同土壤团聚体中的尿素分解微生物群落对长期施肥制度的响应仍不清楚。在本研究中，我们在一个26年的施肥试验的Ultisol的3个团聚体组分（2-0.25，0.25-0.053，<0.053 mm）的尿素分解微生物区系和脲酶活性进行了表征。结果表明，长期施用化肥（NPK）导致土壤酸化，显著降低了土壤团聚体中尿素分解微生物群落的丰度、丰富度和活性（P< .05）。施用有机肥（M和MNPK）可缓解这些负面影响，显著（P<0.05）提高土壤尿素分解菌群的丰度、α多样性和活性。长期施肥制度也驱动了土壤团聚体中尿素分解微生物组成的分化（Adonis，F = 17.4，P = 0.001，R2= 33.6%），其中施用有机肥是最重要的驱动因素。这种变异对土壤脲酶活性的变异有一定的贡献（结构方程模型，通径系数：0.45，P = .008）。不同土壤团聚体间的尿素分解微生物群落差异不显著，这与土壤养分的分布规律相一致，表明资源有效性在微环境中起主导作用。不同土壤团聚体中的尿素分解微生物群落对长期施肥的反应一致。本研究表明，有机肥的施用是一种可持续的施肥制度，以减轻土壤尿素分解微生物多样性和活性的损失在酸性土壤。
Ureolytic microorganisms play a crucial role in soil nitrogen transformation. Soil aggregates and associated microbes are reported to modify the impact of agricultural management on soil nutrient cycling. However, the responses of ureolytic microbial communities in various soil aggregates to long-term fertilization regimes are still unclear in acid soils. In this study, we characterized the ureolytic microflora as well as urease activity in three soil aggregate fractions (2–0.25, 0.25–0.053, <0.053 mm) from an Ultisol with 26-year fertilization experiment. The results showed that long-term chemical fertilization (NPK) significantly decreased the abundance, richness and activity of ureolytic microbial community across soil aggregates (P< .05) due to strong soil acidification. While manure application (M and MNPK) could mitigate these negative impacts and markedly (P< .05) improved the abundance, α-diversity and activity of soil ureolytic microflora. Long-term fertilization regimes also drove the differentiation of ureolytic microbial compositions in soil aggregates (Adonis, F = 17.4,P= .001, R2= 33.6%), and manure application appeared to be the most important driver. This variation partly contributed to the aberrance of soil urease activity (structure equation model, path coefficient: 0.45,P= .008). No significant differences were found for ureolytic microbial community among soil aggregates, which was in accordance with the distribution patterns of soil nutrients, indicating the dominant role of resources availability in determining ureolytic microbiota in micro-environment. The ureolytic microbial community among different soil aggregates responded uniformly to long-term fertilizations. Our study revealed that manure application was a sustainable fertilization regime to alleviate the loss of soil ureolytic microbial diversity and activity in acid soils.