Manure and Trichoderma harzianum increase cotton yield via regulating soil bacterial community and physicochemical properties.

A field experiment with four treatments (chemical fertilizer alone, CK; manure plus chemical fertilizer, CM; Trichoderma harzianum plus chemical fertilizer, CF; T. harzianum plus manure plus chemical fertilizer, CMF) was conducted to investigate changes in soil bacterial community and cotton yield in 2020 and 2021. Soil aggregate stability and economic feasibility of the four treatments were evaluated. Manure and T. harzianum application significantly improved soil organic carbon (SOC) and total nitrogen and increased soil aggregate stability. Increases of Proteobacteria abundance were 31.62% and 23.51% in 2020 and 2021, respectively, while the increases of Actinobacteria were increased by 21.65% in 2020 and 19.19% in 2021. Manure effects contributed to 46.15% variation of soil bacterial community while T. harzianum contributed to 40.67% variation. Relative abundances of Acidobacteria and Actinobacteria were negatively correlated with SOC. Differently, Chloroflexi was positively correlated with SOC. Concerning the economic feasibility, maximum appreciation was also obtained when manure combined with T. harzianum, which was better than sole manure or T. harzianum. Co-application of manure and T. harzianum improved soil fertility and regulated soil bacterial community which contributed to increases of cotton yield. Thus, it can be applied as a promising measure for promoting cotton production. [ABSTRACT FROM AUTHOR]