Effects of different straw returning methods on labile organic carbon distribution in upland meadow soil

• Main Authors: LI Yu-mei, WANG Gen-lin, MENG Xiang-hai, HU Ying-hui, WANG Wei, LI Jian-ying, ZHANG Dong-mei
• Format: Article
• Language: zho
• Published: Agro-Environmental Protection Institute, Ministry of Agriculture 2021-03-01
• Series: Journal of Agricultural Resources and Environment
• Subjects: meadow soil; labile organic carbon; straw returning; tillage; soil carbon management index
• Online Access: http://www.aed.org.cn/nyzyyhjxb/html/2021/2/20210215.htm
• ISSN: 2095-6819; 2095-6819

This study used field positioning experiments to clarify the distribution of organic carbon under different methods in which straw was returned to upland meadow soil. The labile organic carbon components of three deep soil layers in each treatment were compared to summarize the changes in soil organic carbon and labile components under different tillage and straw return methods. The results showed that the mineralization and decomposition of organic carbon in topsoil(0~20 cm) was accelerated and its content decreased under frequent tillage methods. This content increased in the same layer under no-tillage straw returning; tillage with straw returning increased the accumulation of organic carbon in the middle layer(20~40 cm). Continuous tillage with straw returning improved high and medium labile organic carbon content in this middle layer and the soil carbon management index. Furthermore, shallow tillage with straw returning increased low labile organic carbon in the surface and middle layers significantly more than that obtained when deep tillage with straw and no-tillage with straw were used. However, the difference in the soil carbon management index under tillage with straw returning treatments was not significant in the short-term experiment. Our results indicated the high and medium labile organic carbon levels in the soil were sensitive to changes in tillage depth while straw management methods mainly increased the content of low labile organic carbon and was the main reason for the increase in maize yield.