Characterization, classification and fertility evaluation of vertisols and associated soils under different land use systems in seloo tehsil, wardha district, Maharashtra

Abstract:

Reliable information on the characterization, classification and fertility status of soils under prevailing land use systems is fundamental for rational land-use planning and sustainable crop management in swell-shrink (Vertisol) landscapes. The present study characterized and classified eight representative soil pedons occurring under agricultural, horticultural and forest land use systems in Seloo tehsil of Wardha district, Maharashtra, developed on Deccan basalt parent material under a hyperthermic temperature and ustic moisture regime. The soils were deep to moderately shallow (58-150 cm), well drained, predominantly clayey (13.2-65.1% clay) and displayed characteristic vertic features such as pressure faces, slickensides and seasonal cracks. Particle-size distribution showed sand, silt and clay contents ranging from 1.4-56.0, 23.6-42.5 and 13.2-65.1%, respectively, while bulk density (1.3-1.6 Mg m⁻³), saturated hydraulic conductivity (0.3-2.5 cm h⁻¹) and coefficient of linear extensibility (0.11-0.23) confirmed a moderate to high shrink-swell potential. The soils were slightly acidic to strongly alkaline in reaction (pH 5.7-8.9), non-saline (EC 0.013-0.090 dS m⁻¹), calcareous in the agricultural and horticultural profiles (CaCO₃ 3.4-11.5%) and dominated by exchangeable calcium over magnesium, sodium and potassium, with a high cation exchange capacity (5.72-63.70 cmol(p⁺) kg⁻¹) and base saturation (59.6-115.7%); exchangeable sodium percentage (0.6-4.7%) indicated the complete absence of sodicity hazard. Fertility evaluation revealed low to high available nitrogen (37.6-267.3 kg ha⁻¹), low to high available phosphorus (2.5-62.3 kg ha⁻¹) and medium to very high available potassium (120.1-466.1 kg ha⁻¹), together with adequate DTPA-extractable Fe, Mn, Zn and Cu, all of which declined with increasing depth and were comparatively higher under forest and horticultural systems than under continuous cultivation. Based on the diagnostic morphological, physical and chemical criteria of USDA Soil Taxonomy, the pedons were classified into the orders Inceptisols (Vertic and Typic Haplustepts) and Vertisols (Typic Haplusterts), reflecting differing degrees of expression of shrink-swell properties among land use systems. The study demonstrates that land use exerts a discernible influence on the physico-chemical make-up and fertility status of these basaltic Vertisols, and provides baseline benchmark information useful for soil-based land-use planning, fertility management and taxonomic mapping of similar swell-shrink soils of the Wardha basin.