除草剂残留下生物炭对土壤微生物的影响

Effects of Bio-char on Soil Microbes in Herbicide Residual Soils

采用盆栽试验，模拟农田土壤除草剂残留环境，研究异嗯草松残留下，生物炭对土壤微生物群落数量的影响，阐明生物炭及其结构特性对土壤微域环境的改善作用。结果表明：土壤中异嗯草松残留在0～0．72mg·kg-1对土壤真菌和放线菌影响趋势一致，随作物生育进程延长具有刺激增加的作用，尤其是高残留处理，但初期对细菌具有较强的抑制作用，至甜菜生长到第50d才恢复正常；加炭后，土壤真菌数量降低，但与对照差异不显著；异嗯草松土壤残留低于0．24mg·kg-1，加炭后土壤放线菌数量高于对照未施炭处理；异嗯草松残留低于0．12mg·kg-1，加炭后细菌数量先增加后降低；生物炭为“深层孔洞”结构，含有C、O、S等多种元素。试验结果表明，土壤中一定浓度的异嗯草松残留，对土壤真菌、放线菌有刺激增加作用，加入生物炭后，能够缓解除草剂高残留对细菌的抑制作用。

Effects of biological carbon （bio-char） on soil microbial community were studied by pot experiments simulating long residual herbicide residues in soil environment, which clarifed the improvement of biochar and its structural properties on soil microenvironment. The results showed that fungi and actinomycetes had the same effect tendency within 0-0.72 mg·kg-1 in clomazone residue which increased the role of stimulation with crop growth process prolonged, especially in high residue treatment, but strong inhibitory effect on bacteria community was occured early which returned to normal until sugar beet growth to fiftieth day. Soil fungi community decreased with bio-char adding, but had no significant difference with the control. When clomazone residue in soil was below 0.24 mg·kg-1, soil aetinomycetes community was higher than control without bio-char, bacteria increased first and then reduced after adding carbon as below 0.12 mg·kg-1. Bioehar was ＇deep hole＇ structure containing C, O, S and other elements. The results showed that a certain concentration clomazone residue in soil would stimulate soil fungi and actinomycetes to grow. After adding the biochar, the inhibition effect of high herbicides residual on bacterial would be alleviated.