ABSTRACT

We conducted a 2.5-year field experiment to test the effects of straw incorporated evenly into the soil (EIS) on soil fungal community, SOC chemical composition, and particulate organic matter fractions via comparing with no straw returning (CK), straw mulching (SM), straw plowed into the soil (SP), and identified the linkages between soil fungal community as well as organic C accumulation and POM formation. Our results showed that EIS treatment significantly increased the concentrations of SOC and the proportion of carbohydrate C, di-O-alkyl C, and O-alkyl C in SOC structure, increased the mass proportion and OC contents of MA(c)POM and mM-POM in the upper 40 cm of soil. Meanwhile, EIS treatment increased the relative abundance of Ascomycota, Zygomycota, Chytridiomycota, and Dothideomycetes in 0–20 cm depths, and also had the highest relative abundance of Glomeromycetes and Dothideomycetes in the 20–40 cm soil. Also, our study suggests that straw return enhanced the relative abundances of fungi involved in the carbon cycle and sequestration, including Zygomycota, Chytridiomycota, and Glomeromycota, and Ascomycota. The shifts in fungal community structure can accelerate organic C accumulation and the formation of soil particulate organic matter, especially in EIS treatment.

摘要

我们进行了一项为期 2.5 年的田间试验，通过与不还秸秆 (CK)、秸秆覆盖 (SM )，秸秆犁入土壤 (SP)，并确定了土壤真菌群落以及有机碳积累和 POM 形成之间的联系。我们的结果表明，EIS处理显着增加了SOC的浓度和SOC结构中碳水化合物C、二-O-烷基C和O-烷基C的比例，增加了MA(c)POM和mM的质量比例和OC含量-POM 在土壤上部 40 厘米。同时，EIS 处理增加了子囊菌、接合菌、壶菌和Dothideomycetes的相对丰度在 0-20 cm 深度，并且在 20-40 cm 土壤中也具有最高的Glomeromycetes和Dothideomycetes 的相对丰度。此外，我们的研究表明，秸秆还田提高了参与碳循环和固存的真菌的相对丰度，包括接合菌门、壶菌门、球囊菌门和子囊菌门。真菌群落结构的变化可以加速有机碳的积累和土壤颗粒有机质的形成，尤其是在 EIS 处理中。