Comparative assessment of soil aggregate stability in treated and untreated watersheds

Abstract

Soil aggregate stability is an important indicator of soil quality, especially in areas affected by land degradation due to water erosion. Increasing human activities over time have accelerated soil erosion, making it necessary to assess soil aggregate stability under different land use and land cover types within a watershed. This study examined the stability of surface soil aggregates in various land use/land cover classes in two watersheds: Hiware Bazar (1287.6 ha) and Daithane Gunjal (116.63 ha), located in drought-prone Ahilyanagar, Maharashtra. The area has slopes ranging from 3–25% and receives less than 400 mm of annual rainfall. Hiware Bazar is a treated watershed with soil and water conservation measures, while Daithane Gunjal is untreated. The results show the positive impact of watershed management on land use and soil stability. In Hiware Bazar, land use includes 65.5% cropland and fallow land, 19.75% forest, and 11.18% barren land. This watershed showed higher mean weight diameter (MWD) values, indicating better soil aggregate stability (forest: 1.13–0.99 mm, cropland: 0.84–0.70 mm, fallow: 0.50–0.42 mm, barren: 0.30–0.24 mm) compared to Daithane Gunjal (forest: 0.75–0.65 mm, cropland: 0.55–0.39 mm, fallow: 0.35–0.30 mm, barren: 0.26–0.21 mm). These findings confirm that long-term conservation measures and improved land management practices in Hiware Bazar have enhanced soil structure, aggregate formation and resistance to erosion.