Signature capture of red soil patches and their acidity-A case study of Banka district, Bihar, India

Abstract

Colour in soils as well as other object is the visual perceptual property which is perceived by human eye. They are governed by spectrum of light corresponding to wavelength or reflected energy of the material. Developed model for soil acidity is based on visual interpretation, principal component and spectral enhancement techniques by using of the satellite image (IRS LISS III, 2014). In this context, red soil patch is much sensitive in red spectral band comparison to green and blue spectral bands and perceived as red tone by human eyes but same soil patch appears green in false colour composite (FCC) image of NIR (0.70-0.80?m), Red (0.60-0.70 ?m) and Green (0.50-0.60?m) bands. The maximum coverage of red soil patches having low pH < 6.5 (1:2.5) was recognized in 44.07 per cent of the total geographical area (3019.56 sq.km) under Banka district. Maximum red soil patches having their acidity were recognised in Katoria (18.56%), Chanan (15.15%), Bounsi (10.44%) and Banka (9.92%) blocks. Overall results indicated that variation of tone in different bands helps for the separation of red soil patches.