Reply on RC3

Abstract

In our previous studies, we filtered out fungus (Trichoderma reesei) to have the best ability to transform corn straw into a humic acid-like substance through laboratory incubation experiments. In order to further verify our former findings, we set up a 360 day-field experiment that included three treatments applied under equal C mass: (i) corn straw returned to the field (CS), (ii) fermented corn straw treated with Trichoderma reesei returned to the field (FCS-T), and (iii) blank control treatment (CK). Soil organic carbon (SOC), soil labile organic C components, soil humus composition, and the management levels of SOC pools under the three treatments were analyzed and compared. The results showed that the SOC content of CS and FCS-T treatments increased by 12.71 % and 18.81 %, respectively, compared with CK at 360 d. The humic acid carbon (HA-C) content of the FCS-T treatment was 0.77 g/kg higher than in the CS treatment. Application of FCS-T appeared to promote the significant increase of SOC, carbon pool activity index (CPAI) and carbon pool management index (CPMI) through accumulation of HA-C, humin carbon (HM-C), and easily oxidizable organic carbon (EOC) contents. Application of fermented corn straw treated with Trichoderma reesei (FCS-T) is more valuable and conducive to increasing soil EOC and humus C content than direct application of corn straw.