生物炭对连作设施黄瓜根际细菌丰度的影响

Effect of Biochar on Bacterial Abundance in Cucumber Rhizosphere under Continuous Cropping

连作障碍是土壤修复世界难题,中国设施栽培随着栽培年限延长普遍出现严重的连作障碍问题,土壤微生物区系和多样性的失调是设施连作障碍最根本的原因。生物炭能增加土壤有机物质含量,提高土壤保肥、持水能力,促进作物对营养物质吸收,针对设施连作蔬菜,开展生物炭对连作障碍的根际微生物内在作用机理研究将成为蔬菜科技攻关的重要方向,这对于设施黄瓜高效绿色生产和土壤环境提质增效具有非常大的应用意义和发展前景。本试验以设施黄瓜为研究对象,采用田间试验法,以正常定植土壤为对照,用日光温室黄瓜早春茬进行试验,开展土壤连作10年和20年不添加生物炭和正常定植、连作10年和20年分别统一施用生物炭2×10^(4)kg/hm^(2)5个处理,研究生物炭对设施连作栽培黄瓜根际细菌群落结构的变化规律,探明生物炭对连作黄瓜根际细菌菌群结构变化及其互作机制。试验结果表明:生物炭处理后均提高了连作黄瓜根际土壤细菌群落多样性和丰富度,共获得细菌OUT 3048个,对于在不同连作年份向土壤中添加生物炭不会改变优势细菌的种类,但是通过生物炭处理改变了不同连作年限土壤优势菌门的相对丰度,各处理均以变形菌门为第1大优势菌门,酸杆菌门为第2大优势菌门,生物炭处理显著提高连作10年和连作20年土壤中酸杆菌门丰度,连作20年的土壤中放线菌门的丰度和芽单胞菌门的丰度。生物炭施用后降低了连作10年和连作20年土壤中绿弯菌门、拟杆菌门的丰度。

Continuous cropping obstacle is a worldwide problem for soil remediation.With the extension of cultivation years,serious continuous cropping obstacle problems generally appear in China's protected cultivation.The imbalance of soil microbial flora and diversity is the most fundamental reason for the continuous cropping obstacle.Biochar can increase the content of soil organic matter,improve soil fertility and water holding capacity,and promote the absorption of nutrients by crops.For the vegetables under protected continuous cropping,it will be an important direction for vegetable science and technology to study the internal mechanism of biochar on rhizosphere microorganisms with continuous cropping obstacles,which has great application significance and development prospects for efficient green production of cucumber and improvement of soil environment quality and efficiency.In this experiment,greenhouse cucumber early spring stubble was used to study the effect of biochar on the rhizosphere bacterial community structure of greenhouse cucumber by taking greenhouse cucumber as the research object,field experiment method and normal soil as the control.Five treatments were carried out,i.e.no biochar was added to soil for 10 and 20 years,and biochar 2×10^(4)kg/hm^(2)was applied to soil for 10 and 20 years respectively.The effect of biochar on the bacterial community structure of continuous cropping cucumber rhizosphere and its interaction mechanism were explored.The results showed that the diversity and richness of bacterial communities in the rhizosphere soil of continuous cropping cucumber were improved after biochar treatment,and a total of 3048 bacteria were obtained.The addition of biochar to the soil for different continuous cropping years did not change the species of dominant microflora,but the relative abundance of dominant microflora in the soil for different continuous cropping years was changed through biochar treatment,and Proteobacteria was the first dominant microflora in each treatment,Acidobacteria was the second dominant phylum,and biochar treatment significantly increased the abundance of Acidobacteria in 10-year and 20-year continuous cropping soil,and the abundance of Actinobacteria and Gemmatimonadetes in 20-year continuous cropping soil.The application of biochar reduced the abundance of Chloroflexi and Bacteroidetes in soil after 10 and 20 years of continuous cropping.