Soil microbial remediation to soybean field of Northeast China: Dynamic changes of fomesafen residues and phospholipid fatty acids in the black soil after application of Shigella flexneri FB5

Abstract

Fomesafen is widely used to control broad-leaved weeds in oil-bearing crops such as soybean and peanut. However, fomesafen has a long residual period in soil. If it is not used properly, it will cause damage to sensitive crops in different degrees. In this paper, the effects of fomesafen-degrading strains on the residue of fomesafen and the structure of soil microbial community were studied. Under field experiments, a microbial solution containing fomesafen-degrading Shigella flexneri FB5 was sprayed. We then detected residual fomesafen in the soil using high-performance liquid chromatography and phospholipid fatty acid content using gas chromatography-mass spectrometry. Analysis of variance suggested that the addition of fomesafen-degrading strains had a significant effect on soil microorganisms, as revealed by changes in the fungi/bacteria index, gram-negative/gram-positive bacteria ratio, stress indicators, and total phospholipid fatty acids. To sum up, our results show that the use of fomesafen-degrading strains can reduce the toxicity of fomesafen.