Characterization and Suitability Evaluation of Soils of Chanavada Watershed in Aravalli Hills of Southern Rajasthan, for Optimum Land Use Planning

Abstract

A detailed soil survey was carried out to characterize and classify the soils of Chanavada micro-watershed in Girwa tehsil of Udaipur district, Rajasthan using cadastral map overlaid on IRS P6 LISS IV images of October 2007 and March 2008 as a base. Based on the visual interpretation of satellite data, other collateral data and local micro features six landforms units viz. Steeply sloping hills, Moderately steeply sloping hills, Moderately sloping foot slope, Inter hill valley, Narrow valley and Broad valley were delineated. Tentatively eight soil series were identified in the watershed and mapped into 15 soil mapping units at the level of phases of soil series on 1: 4000 scales after establishing soil landform relationship. These soils were classified as Entisols (Lithic Ustorthents, Typic Ustorthents) and Inceptisols (Typic Haplustepts, Fluventic Haplustepts). The soils of the steeply sloping and moderately steeply sloping hills are very shallow to moderately shallow, excessively drained, dark yellowish brown, gravelly loam to gravelly sandy loam (surface horizon) soils with very severe soil erosion. The soils of moderately sloping foot slope are moderately deep to deep, well-drained, dark brown (10 YR 3/3) to very dark greyish brown (10 YR 3/2) sandy clay loam soils with severe erosion. The soils of the valley are deep, well-drained, very dark greyish brown (10 YR 3/2) to dark yellowish-brown (10 YR 3/4), sandy clay loam to loam on the surface and dark grey (7.5YR3/1) silt loam in sub-surface horizons with severe erosion. The soils of the hills were slightly acidic to neutral in reaction whereas the soils of the valley were neutral to moderately alkaline in reaction. All these soil were very high in organic carbon content on the contrary the content of available nitrogen is low. Most of the soils are medium to high in available phosphorous and available potassium whereas the content of available micronutrients was adequate to high. The soils of the hills are not suitable for arable field crops and the soils of foot slope and narrow valley were marginal to moderately suitable for growing crops. The soils of the broad valley were good cultivable lands with minor soil problems such as gentle slope, fairly satisfactory texture and slight stoniness. All climatically adapted crops can be grown under irrigation.