Response of soil microbes to a reduction in phosphorus fertilizer in rice-wheat rotation paddy soils with varying soil P levels
Response of soil microbes to a reduction in phosphorus fertilizer in rice-wheat rotation paddy soils with varying soil P levels
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DOI：
10.1016/j.still.2018.04.005
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发表时间：
2018-09
影响因子：
6.5
通讯作者：
Yu Wang;Xu Zhao;Zhiying Guo;Z. Jia;Shenqiang Wang;K. Ding
中科院分区：
文献类型：
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作者：
Yu Wang;Xu Zhao;Zhiying Guo;Z. Jia;Shenqiang Wang;K. Ding
在土壤磷素积累过多的农业生态系统中，减少化肥施用是最佳的管理措施之一。然而，很少有研究集中在土壤微生物的反应，减少磷输入的稻麦轮作。为了确定一个磷减少制度的可行性及其对土壤微生物的影响，我们修改了磷肥投入在一个为期四年的盆栽试验。试验设稻麦双季施磷（PR + W）、麦季单施磷（PW）、稻季单施磷（PR）和稻麦双季不施磷（Pzero）为对照。我们使用了10种不同磷水平的水稻土，包括富磷、中磷和低磷。稻麦轮作4年后，与常规耕作（PR + W）相比，PW处理保持了作物产量，但降低了土壤Olsen-P累积量20.8-88.7%（p< 0.05），而PR和Pzero处理显著降低了小麦产量（p< 0.05）。土壤Olsen-P对水稻和小麦产量的临界值分别为4.19-5.24和7.00-16.8 mg kg− 1。454焦磷酸测序数据的分析表明，施肥制度是影响土壤微生物组的主要因素，其次是土壤性质和有效磷。随后的逐步回归分析进一步表明，土壤pH值是细菌群落组成的主要驱动因素。此外，α-变形菌和γ-变形菌的相对丰度在施磷土壤中较高。宜兴市土壤中9个优势细菌门的分类组成在PW和PR + W处理之间没有显著变化，表明这种磷肥减量制度没有改变该地区土壤细菌群落的组成。研究结果有助于了解水稻-小麦轮作体系中磷肥减量对土壤微生物群落的影响。
Reducing chemical fertilization is one of the best management practices in agro-ecosystems where soil phosphorus (P) has accumulated to excessive levels. However, few studies have focused on the response of soil microbes to decreases in P input in a rice-wheat rotation. To determine the feasibility of a P reduction regime and its impacts on soil microbes, we modified P fertilizer inputs in a four-year pot experiment. Our treatments contained P fertilization during both rice and wheat seasons (PR + W), P fertilization during wheat-growing season only (PW), P fertilization during the rice season only (PR), and no P fertilization during either rice or wheat season (Pzero) as the control. We used ten paddy soils with varied P levels, including P-rich, P-moderate, and P-low. After four years of rice-wheat cropping, the PW treatment maintained crop yields but reduced soil Olsen-P accumulation by 20.8–88.7% (p< 0.05) compared to current farming practices (PR + W); however, the PR and Pzero treatments significantly decreased wheat yield (p< 0.05). The critical levels of soil Olsen-P were 4.19–5.24 and 7.00–16.8 mg kg−1for optimal rice and wheat yield, respectively. Analysis of 454 pyrosequencing data from fresh samples revealed that the fertilizer regime was the main factor impacting the soil microbiome, followed by soil properties and available P. Subsequent stepwise regression analysis further indicated that soil pH was a major driver of bacterial community composition. Furthermore, the relative abundances ofAlphaproteobacteriaandGammaproteobacteriawere higher in P-fertilized soils. There were no significant changes in the taxonomic composition of the nine dominant bacteria phyla between the PW and PR + W treatments in soils form Yixing city, suggesting that this P fertilization reduction regime did not alter the bacterial community composition in this region. The results could help to understand the effects of P fertilizer reduction on the soil microbial community in rice-wheat rotation paddy soils.