Characterization and classification of sugarcane-growing soils of Central and Eastern mandals of Chittoor district in Andhra Pradesh

Soil characterization was carried out to determine the morphological, physical and chemical and mineralogical characteristics of sugarcane-growing soils of Central and Eastern mandals of Chittoor district, Andhra Pradesh. Two physiographic units were identified and designated as uplands and plains. Seven profiles were excavated with three in uplands (P1, P2 and P3) and four in plains (P4, P5, P6 and P7). The soils were characterized as follows: Hues of 10YR-2.5YR, chroma 2 to 8, value 3 to 7, sand 56.89 to 93.94%, silt 2.02 to 18.57%, clay 1.99 to 32.84%, near neutral to strongly alkaline soil reaction (pH 6.90 to 8.84), low organic carbon(0.1 to 4.8 g kg⁻¹), moderateto high available P(7.33 to 24.50 mg kg⁻¹), cation exchange capacity (1.05 to 28.80 cmol (p⁺) kg⁻¹) and base saturation (54.29 to 91.75%). The USDA- Soil taxonomy classified the soils as fine-loamy, smectitic, isohyperthermic, Typic Ustorthents (P1 and P2) and sandy, mixed, isohyperthermic, Typic Ustorthents (P3) in uplands and sandy, smectitic, isohyperthermic, Typic Ustorthents (P4 and P5), sandy, siliceous, isohyperthermic, Typic Ustipsamments (P6) and coarse-loamy, kaolinitic, isohyperthermic, Typic Ustifluvents (P7) in plains.