LAUSR

Abstract Soil organic carbon (SOC) mineralization is regulated by temperature and moisture. No-till (NT) and straw returning (SR) have been widely adopted to sequester SOC, but information about the effects of temperature and moisture on SOC mineralization in NT and SR is limited, particularly SOC mineralization in different aggregate size classes. To identify the responses of SOC mineralization to temperature and moisture in NT and SR, undisturbed soils were sampled from a factorial experiment of tillage (NT and plow tillage [PT]) and straw (SR and straw removal [S0]) in a wheat-maize cropping system and incubated at moisture levels of 40%, 70%, and 100% at 15 °C and 25 °C. The results showed that maize season increased SOC mineralization but decreased its temperature sensitivity (Q10) compared with the wheat season under different moisture levels. Because NT and SR promoted macro-aggregation and low mineralization was observed in macro-aggregates, NT significantly decreased the absolute (per unit soil) and specific (per unit SOC) mineralization compared with PT, regardless of the soil temperature, moisture, depth, and sample date (P