Litter Quality and Microbes Explain Aggregation Differences in a Tropical Sandy Soil

Abstract Soil aggregates store most soil organic carbon (SOC), but how does litter quality influence their formation? We hypothesized varying to facilitate differences in aggregate formation by altering the seasonal development of microbial biomass (MB) C and N, with MB driving a tropical sandy Thailand. Aggregate was studied long-term fallow experiment, receiving 10 Mg ha ?1 annual applications rice ( Oryza sativa ) straw (low N polyphenols (PP)), groundnut Arachis hypogaea stover (high low PP), tamarind Tamarindus indica (medium or dipterocarp Dipterocarpus tuberculatus leaf high PP) compared control. N-rich from led significantly higher MB, bulk than dipterocarp, straw, Bulk small macroaggregates treatments increased about 7% 30 weeks. Increasing explained increasing macroaggregate both, were important covariates explaining temporal variations stored themicroaggregates, silt clay. also fraction weights. With time, SMA only treatments, decreased other treatments. Connections weight substantiated importance activity for sequestration. By promoting longest time spans, medium-quality could best facilitateaggregate formation, increase clay C.