不同土壤改良剂对红美人生长及土壤微生物群落的影响

Effects of soil amendments on plant growth of Hongmeiren and soil microbial community

我国南方地区土壤酸化现象较为普遍,同时土壤中富集高浓度的无机铝单体,严重影响了土壤肥力和植物生长。土壤改良剂的施用是一种改善土壤酸化、修复重金属污染、提高作物生产力的有效措施。该研究选用椰糠、石灰、生物质炭和草木灰这4种土壤改良剂,进行了为期180 d的微宇宙模拟试验,探究了土壤改良剂对南方酸性土壤理化性质、植物生长与生理,以及土壤微生物群落的影响特征。研究表明,4种改良剂明显改善了土壤酸化现象,降低了土壤铝含量,增加了土壤碳、氮含量。改良剂对植物根系活性没有显著影响,但提升了叶片中β-类胡萝卜素含量。改良剂对土壤细菌群落结构产生显著的影响,降低了变形菌门(Proteobacteria)和假单胞菌属(Pseudomonas)的相对丰度;零模型(null model)揭示了施用改良剂后,微生物装配过程为决定性过程(deterministic process),而非随机过程(stochastic process)。改良剂可以有效缓解土壤酸化现象,促进植物光合作用,提升能源物质储备,改变了土壤微生物群落的装配机制。

Soil acidification coupled with high contents of aluminum loads in red soils in the Southeast of China,posing a great threat to soil fertility and plant growth.The application of soil amendments is an effective way to improve acidified soil,remediate heavy metal pollution,and improve crop productivities.Here our study selected four soil amendments such as coconut,lime,biochar and plant ash,and conducted a 180-day greenhouse pot trial,to explore the effects of soil amendments on soil properties,plant growth and physiology of Hongmeiren,and soil microbial communities.The results showed that the four amendments significantly improved the soil acidification,reduced the aluminum contents,and increased soil carbon and nitrogen contents;the application of soil amendments had no significant effect on the root activity,but increasedβ-carotenoid contents of leaves of Hongmeiren;structure of soil bacterial community had significantly been changed,especially reducing the relative abundances of Proteobacteria and Pseudomonas;zero model(null model)revealed that the microbial assembly process was a deterministic process rather than stochastic process.These findings indicate that soil amendments could effectively alleviate the acidification of soil,promote plant photosynthesis,increase energy substances,and change the assembly mechanism of soil microbial community.