Characterization and Map** of Soils for Sustainable Management Using Geospatial Techniques: A Case Study of Northeastern Bihar, India

Abstract

Poor knowledge on location specific data, mostly on soils, and of situation-specific recommendations has been the causes of failure for most of the agricultural related development schemes that operated in the country in the past. The land resource inventory (LRI) may be filled these gaps by generating data on location specific soil and other land resources. LRI involves systematic surveys of soils on 1:10,000 scale for land use planning scientifically in the GIS platform. The present work was undertaken in Kadwa block, Katihar district in northeastern Bihar, India. Four major landforms like old alluvial plains (9.12%), young alluvial plains (24.46%), meander plains (39.48%) and flood plains (4.61%) were identified after visual interpretation of Indian Remote Sensing Satellite (IRS) R2-LISS-IV data in conjunction with cadastral map. The detailed soil survey was carried out and eight soil series viz. Chauni, Sitalpur, Kumaripur, Asiani, Kaliganj, Sikarpur, Dangi and Mahinagar were identified in different landforms and mapped into 14 soil map** units (phases of series). Soils developed on meander plains are very deep, moderately well drained, brown to gray, loam to silt loam texture with reddish brown mottles and classified as Coarse-loamy, mixed hyperthermic Fluventic Endoaquepts (Kumaripur series), Coarse-loamy, mixed, hyperthermic Aquic Haplustepts (Asiani series) and Fine-loamy, mixed, hyperthermic Aeric Endoaquepts (Kaliganj series). Young alluvial plains soils are very deep, well to somewhat poorly drained, yellowish brown to dark gray, silt loam in texture with brown mottles and classified as Coarse-loamy, mixed, hyperthermic Typic Ustifluvents (Sikarpur series) and Fine-loamy, mixed, hyperthermic Typic Haplustepts (Dangi series). Soils developed on old alluvial plains are very deep, moderately well drained, light brownish gray to dark gray, silt loam to clay loam in texture dark brown mottles and classified as Coarse-loamy, mixed, hyperthermic Typic Haplustepts (Chauni series) and Fine-loamy, mixed, hyperthermic Typic Endoaquepts (Sitalpur series). Flood plains soil are very deep, well drained, light yellowish brown to brown, silt loam surface texture, severe erosion and very frequent flooding and classified as mixed, hyperthermic Typic Ustipsamments (Mahinagar series). Surface soils of the block were grouped into eight soil reaction classes. It was observed that very strongly acid to moderately acidic soils are occupying 50.84% and neutral soils 7.53% of total geographical area (TGA). Organic carbon status (medium to high) occupied 64.10% and available phosphorus is low in 45.82% of TGA. Based on interpretation of soil survey data, the study area is divided into three land capability classes viz. II, III and IV. The results on suitability indicates that crops grown in the study area are moderate to marginally suitable due to coarse texture, fertility and ponding of water for long period limitations. Considering the major problems and potentials four land management units (LMUs) were identified and suggested alternate land use for each LMU of the study area.