Li_2026

Carbon (C), nitrogen (N), and phosphorus (P) contents and their C:N:P stoichiometry in soils, microbial biomass, and extracellular enzymes play critical roles in regulating nutrient cycling in agroecosystems. Although no-tillage (NT) is widely considered to enhance soil C, N, and P contents as well as microbial biomass and extracellular enzyme activities, a comprehensive global assessment of how NT affects C:N:P stoichiometry remains lacking. Here, we conducted a global meta-analysis comprising 683 observations to quantify the effects of NT on the concentrations and stoichiometric ratios of C, N, and P in soils, microbial biomass, and extracellular enzymes. NT did not significantly affect the C:N:P stoichiometry of soils, microbial biomass, or extracellular enzymes, but it significantly increased soil C and N contents by 5.0% and 4.5%, respectively, and microbial biomass C and N by 9.1% and 9.3%. Aridity index and initial soil organic carbon were identified as key predictors of soil C:N and C:P response to NT, respectively. The increase in soil C and N content induced by NT was more pronounced under straw return and crop rotation. NT significantly increased the C, N, C:N, and C:P in extracellular enzymes in the cropping systems that included legumes. Under relatively low N application rates (< 200 kg/ha), NT significantly increased the C and N contents in soils, microbial biomass, and extracellular enzymes. Additionally, NT significantly increased the C:N ratio of extracellular enzymes while decreasing the soil C:N ratio under low N application rates. Overall, these findings enhance our understanding of how NT regulates soil nutrient cycling and underscore the importance of exogenous C, N, and P inputs in shaping stoichiometric responses under NT systems.