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 provided an improved insight into the mechanism of soil carbon sequestration under conservation tillage, whose findings have been published in "Science of The Total Environment" (IF = 9.8).

Conservation tillage can mitigate climate change by promoting soil carbon sequestration in agro-ecosystems. However, the mechanism on how conservation tillage promotes SOC accumulation is still limited, especially at soil aggregate scale.

Based on the 21-year field experiment of conservation tillage at the Key Laboratory of Dryland Agriculture of the Ministry of Agriculture in Luoyang, researchers measured the activities of hydrolytic and oxidative enzymes and soil organic carbon mineralization within soil aggregates at 0−10 cm depth. The carbon flows and pathways between the aggregates were also quantified using the 13C natural abundance method. All the results helped to elucidate the mechanisms on the effect of conservation tillage on soil organic carbon accumulation.

The results showed that compared to conventional and reduced tillage with straw removal, no-till and subsoiling with straw mulching reduced the activities hydrolases and oxidases in macroaggregates and the probability of carbon flow from macro- to micro-aggregates. Therefore, the young carbon is better protected in macro-aggregates, which reduced the loss of soil carbon and promoted the accumulation of soil carbon. These findings contribute to a deeper understanding of the mechanisms on soil carbon sequestration under conservation tillage and provide support for the mitigation of climate change.

Dr. Liu Xiaotong from the IARRP is the first author of this article, and Professor Wu Xueping is the corresponding author. This study was supported by the the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences.

[Citation and original article link]:

Liu, X.T., Song, X.J., Li, S.P., Liang, G.P., Wu, X.P., 2023. Understanding how conservation tillage promotes soil carbon accumulation: Insights into extracellular enzyme activities and carbon flows between aggregate fractions. Science of The Total Environment 897, 165408. DOI: 10.1016/j.scitotenv.2023.165408

Paper link: https://www.sciencedirect.com/science/article/pii/S0048969723040317