Soil Erodibility Characteristics Under Modified Land-Use Systems as Against Shifting Cultivation in Hilly Ecosystems of Meghalaya, India

Abstract

A study was conducted to compare soil erodibility characteristics under modified land-use systems such as agriculture, agri-horti-silvi-pastoral, natural forest, livestock-based land use, natural fallow, and the locally most prevalent shifting cultivation system at the Indian Council of Agricultural Research Complex for Northeastern Hill Region, Umiam, Meghalaya, India. Surface (0 to 15 cm) soil samples were analyzed for various soil properties and different erodibility indices [i.e., Dispersion ratio = Suspension percentage/silt and clay under dispersed condition; Erosion ratio = Dispersion ratio/(clay/moisture equivalent ratio); Erosion index = Disperion ratio/(clay/half of the water holding capacity)] were worked out from the basic soil properties—mainly textural components, soil moisture at field capacity, etc., following the standard procedures. The experimental site had an acidic soil reaction (pH 4.33–5.12), clay loam texture, and medium to high organic carbon content (1.24–3.25%). Shifting cultivation showed the highest erosion ratio (12.46), followed by agriculture (10.42), indicating the need to adopt tree-based land-use systems for resource conservation. Soil loss was significantly higher in shifting cultivation (30.2–170.2 t ha−1 yr−1), agriculture (5.10–68.20 t ha−1 yr−1), and the livestock-based land-use systems (0.88–14.28 t ha−1 yr−1) as compared to other modified land-use systems. Among the modified land-use systems, the agri-horti-silvi-pastoral system performed the best, confirming its superiority over shifting cultivation—especially under the high rainfall, moderate to steep slopes, and shallow soil depth conditions of Meghalaya. The erosion ratio, dispersion ratio, and erosion index were also significantly correlated with soil physicochemical properties, indicating their suitability for assessing erodibility under such conditions of soil and climate.