Xu Jing, Si Linlin, Zhang Xian, Cao Kai, Wang Jianhong
Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
Front Microbiol. 2023 Dec 14;14:1255056. doi: 10.3389/fmicb.2023.1255056. eCollection 2023.
Green manure application is a common practice to improve soil fertility in China. However, the impact of different green manure-fertilizer combinations on the soil microbial communities in the low-fertility immature red soil in southern China remains unclear. In this study, we conducted a pot experiment using two common green manure crops, ryegrass ( L.) and Chinese milk vetch ( L.), along with a fallow treatment. We also considered three combined fertilizer management strategies, including mineral, humic acid, and organic manure fertilizers. We evaluated the soil microbial biomass, activity, communities, functional prediction and their correlation with soil properties during green manure growth and incorporation periods, to assess the potential alterations caused by different green manure and fertilizer combinations. Our findings indicate that green manure application, particularly in combination with organic fertilizers, increased the alpha diversity of the soil bacterial community, while the opposite trend was observed in the fungal community. The application of green manure altered the soil microbial communities during both growth and incorporation periods, especially the taxa that participate in carbon, nitrogen and sulfur cycles. Notably, ryegrass significantly increased the relative abundance of bacterial phylum and fungal phylum , whereas Chinese milk vetch significantly stimulated the bacterial phylum and fungal phylum . Compared with fallow treatments, green manure application significantly increased the soil pH by 4.1%-12.4%, and microbial biomass carbon by 29.8%-72.9%, regardless of the types of combined fertilizer. Additionally, the application of green manure resulted in a 35.6%-142.6% increase in urease activity and a 65.9%-172.9% increase in -glucosidase activity compared to fallow treatments, while led to a 22.5%-55.6% decrease in catalase activity. Further analysis revealed that the changes in both bacterial and fungal communities positively correlated with soil pH, soil organic matter, total nitrogen and alkali hydrolyzed nitrogen contents. Moreover, the relationship between the soil microbial community and soil enzyme activities was regulated by the specific green manure species. In conclusion, our results provide insight into the effects of different green manure-fertilizer combinations on soil microorganisms and their underlying mechanisms in improving soil fertility in the low-fertility immature red soil.
在中国，施用绿肥是提高土壤肥力的常见做法。然而，不同绿肥与肥料组合对中国南方低肥力未成熟红壤土壤微生物群落的影响仍不清楚。在本研究中，我们使用两种常见绿肥作物黑麦草（Lolium perenne L.）和紫云英（Astragalus sinicus L.）进行了盆栽试验，并设置了休耕处理。我们还考虑了三种肥料综合管理策略，包括矿物肥料、腐殖酸肥料和有机肥。我们评估了绿肥生长和翻压期土壤微生物生物量、活性、群落、功能预测及其与土壤性质的相关性，以评估不同绿肥和肥料组合引起的潜在变化。我们的研究结果表明，施用绿肥，特别是与有机肥结合施用，增加了土壤细菌群落的α多样性，而真菌群落则呈现相反趋势。绿肥的施用在生长和翻压期均改变了土壤微生物群落，特别是参与碳、氮和硫循环的分类群。值得注意的是，黑麦草显著增加了细菌门 和真菌门 的相对丰度，而紫云英则显著促进了细菌门 和真菌门 的生长。与休耕处理相比，无论肥料组合类型如何，施用绿肥均使土壤pH值显著提高4.1%-12.4%，微生物生物量碳增加29.8%-72.9%。此外，与休耕处理相比，施用绿肥使脲酶活性提高35.6%-142.6%，β-葡萄糖苷酶活性提高65.9%-172.9%，而过氧化氢酶活性降低22.5%-55.6%。进一步分析表明，细菌和真菌群落的变化与土壤pH值、土壤有机质、全氮和碱解氮含量呈正相关。此外，土壤微生物群落与土壤酶活性之间的关系受特定绿肥种类的调控。总之，我们的研究结果为不同绿肥与肥料组合对土壤微生物的影响及其在低肥力未成熟红壤中提高土壤肥力的潜在机制提供了见解。
