Aliphatic carbon regulates soil water repellency in a chronosequence of grassland enclosure in the Loess Hilly Region

• Published in: Soil & tillage research 2025-02, Vol.246, p.106356, Article 106356
• Main Authors: Wang, Junfeng, Wang, Weiwei, Ren, Xiuzi, Wu, Qinxuan, Chai, Xiaohong, Qu, Yuanyuan, Xu, Xuexuan, Du, Feng
• Format: Article
• Language: English
• Subjects: Grassland enclosure; Soil particle size; Soil water repellency; SOM composition
• ISSN: 0167-1987
• DOI: 10.1016/j.still.2024.106356

Considering the potential enhancement of soil water repellency (SWR) due to the increased accumulation of soil organic matter (SOM) under grassland enclosure, there may be an increased risk of soil erosion and degradation as it can reduce water infiltration and penetration into the soil. There remains a knowledge gap pertaining to the relationship between SWR and plant growth, soil physicochemical properties, SOM composition, and particle size in enclosed grassland. The main objective is to investigate the impact of different grassland enclosure years (14a, 23a, 32a, 40a, and 51a) on SWR in temperate grasslands of the Loess Hilly Region using the water drop penetration time (WDPT) method. Results showed that, at the early stage of enclosure (32 years) exhibited a transition towards strong water repellency, accompanied by the emergence of severe hydrophobicity. The potential SWR also exhibited a significantly higher trend in the 40a and 51a grassland compared to the previous 32 years of enclosed grassland. Moreover, the SWR increased as the soil particle size decreased, and exhibited an upward trend with increasing years of grassland enclosure. Notably, in the 40a and 51a grasslands, SWR for sieve size of soils 32 years).•Potential SWR increased as the soil particle size decreased, which was amplified by grassland enclosure.•SWR was primarily regulated by aliphatic carbon derived from plant properties.