Physical, physico-chemical and chemical properties of soils of newly established Agro-biodiversity Park of Acharya NG Ranga Agricultural University, Hyderabad, Andhra Pradesh

In the present study twenty representative pedons were selected based on topography from various physiographic units identified in Agro-biodiversity Park (ABDP) of Acharya NG Ranga Agricultural University, Rajendranagar, Hyderabad. On the basis of geomorphic units soils were selected from upland, midland and lowland. All the pedons were studied for their morphological characteristics and horizon wise samples were processed. Based on morphology and analytic data profiles were characterized. The soils were very shallow to deep (5 to 60 cm), dark red to very dark greyish brown (2.5 YR 3/6 – 10YR 3/2) and well drained. The results showed that variation in soil properties strongly influenced the land form and topography. The analysis of soils indicate that the upland soils were shallow, midland and lowland soils were medium to deep but along the slope the depth of soil increased along with other physical properties like clay, water holding capacity, infiltration rate and bulk density. Soil texture was sandy loam to sandy clay loam with variation in relation to physiography. The upland soils were exhibiting higher bulk density, particle density and lower water holding capacity; midland and lowland soils recorded higher infiltration rate and clay percentage. The pH was neutral to moderately alkaline (6.5 to 8.04) with low to high in organic carbon (0.18 to 0.96%) and low to medium in CEC (11.5 – 26.5 c mol (p+) kg⁻¹). The base saturation was non-fertile to very fertile and soil texture was sandy loam to sandy clay loam with variation in relation to physiography. The upland soils exhibited higher bulk density, particle density and lower water holding capacity; midland and lowland soils were recorded higher infiltration rate and clay percentage. In all soils pH, OC and CEC consistently increased with depth. The organic carbon content and CEC were higher in lowland soils which might be due to the clay translocation and organic carbon content accumulation. In all the pedons calcium was most dominant cation followed by magnesium, sodium, potassium throughout the profile. The upland pedons had low exchangeable cations than lowland soils because of excessive drainage from uplands. The base saturation was found to be between medium (uplands) to high (lowlands) in the study area due to variation in the texture and physiography.