The Innovation Team of Saline-alkali Soils Amelioration of the Institute of Agricultural Resources and Regional Planning (IARRP) of the Chinese Academy of Agricultural Sciences (CAAS) has made significant progress in understanding the microbial regulation of aggregate stability and organic carbon sequestration under long-term conservation tillage. Their research findings contribute to an enhanced understanding of the mechanisms governing soil carbon sequestration and provide technological support for conservation tillage practices and climate change adaptation. The related research has been published in "Sustainable Production and Consumption" (IF 12.1).

The stability of aggregates plays a crucial role in soil organic carbon sequestration in conservation agriculture soils. However, the regulation of microorganisms within aggregates on aggregate stability and SOC sequestration remains elusive. Based on experiments involving different nitrogen application levels under long-term conservation tillage, the research team investigated the responses of aggregate stability, organic carbon and microbial communities within aggregates to long-term conservation tillage, quantifying the relationship between microbial characteristics within aggregates and aggregate stability.

The results indicated that under long-term no-till, nitrogen application had no significant impact on aggregate distribution but increased the soil organic carbon content at all aggregate levels. Long-term no-till practices combined with appropriate nitrogen application positively influenced the surface soil microbial community, particularly arbuscular mycorrhizal fungi and actinomycetes. The study explicitly identifies microbial strategies that regulate the characteristics of soil aggregates via multiple pathways. Actinomycetes may be recruited by crop residues and participate in aggregate formation through residue degradation, thereby increasing the soil organic carbon content in macroaggregates. Conversely, the biomass of desulfovibrio directly inhibits aggregate formation by reducing the inorganic colloidal substance sulfate to hydrogen sulfide or sulfur, leading to a reduction in soil organic carbon content in macroaggregates. The biomass of arbuscular mycorrhizal fungi indirectly promotes aggregate formation through co-metabolic processes with crop roots and increases the soil organic carbon content in macroaggregates.

Dr. Zhang Mengni, a doctoral student at the IARRP, is the first author of the paper, with Researcher Wu Xueping and Dr. Song Xiaojun as co-corresponding authors. This research was supported by the National Key Research and Development Program and the China Agricultural Science and Technology Innovation Project, among others.

Citation and Original Link: Zhang M, Song X, Wu X, et al. Microbial regulation of aggregate stability and carbon sequestration under long-term conservation tillage and nitrogen application[J]. Sustainable Production and Consumption, 2023. https://doi.org/10.1016/j.spc.2023.11.022