Soil carbon sequestration in paddy field and its simultaneous mineralization to supply available nutrients for the crops are affected by no-tillage with straw management: A meta-analysis

Abstract

No-tillage with straw management is an effective method to improve soil organic carbon (SOC) storage and to sustain soil health, but the impact of tillage with straw management on carbon (C) sequestration remains inconclusive. Therefore, a meta-analysis was conducted based on 319 observations from 95 research publications to assess the relevant effect of no-tillage with straw management on SOC storage and its mineralization. The results indicated that no-tillage significantly increases SOC and microbial biomass carbon (MBC), dehydrogenase (DHA), β-glucosidase (BG), and alkaline phosphatase (AlP), while significantly decreases global warming potential (GWP). The SOC is positively correlated to MBC, total nitrogen (TN), BG, and methane (CH4) emissions under no-tillage practice. SOC increases more over the treatment duration, particularly reaches a much higher level within the medium-term (5–10 years) under no-tillage practice. The response of SOC exhibits significant variations with a reduction from upper to lower soil layers under no-tillage when straw retention is only considered. We also found that no-tillage can promote SOC storage by increasing microbial biomass regardless of whether straw is removed, while the increment of SOC, owing to its simultaneous more mineralization under straw retention is lower than that under straw removal. Our findings suggest that no-tillage with straw management facilitates SOC storage and also provides more available nutrients for crop uptake and microbial utilization.