Surface and sub-surface studies on physico-chemical properties of selected red soil type of Haveri district, Karnataka

Abstract

The twenty representative red soil types spreading over seven taluks of Haveri district of Karnataka were studied for selected physico-chemical properties during 2016-17 at UAS, Dharwad. In general, soil pH increased with depth in almost all samples except in Kengapur-1 and Medleri-4. This might be due to development of these soils by acidic parent materials which lack in basic cations. The electrical conductivity values were well within the range in both the soils at both the depths indicating that no harmful effects of salts. The red soils recorded low to high oxidation rates in surface and sub-surface samples it may be due to low addition of organic matter into soils and continuous cropping. The texture of red soils varied from sandy clay loam to clay loam in both the depths. The surface layer clay content was lower compared to sub-surface clay content. It may be because of chemical weathering resulted in formation of finer particles. The increase in CEC with depth was observed because of increase in clay content with depth. The Exchangeable Potassium Percentage (EPP) recorded higher values in surface layer compared to sub-surface layer of red soils. The high EPP values in surface may be due to high exchange sites offered for potassium. In surface soils, the Potassium Adsorption Ratio (PAR) values were more compared to sub-surface depth in red soils selected for the study. The surface samples of red soils recorded lower values due to low adsorptive sites and coarse texture, with increase in depth the texture changes from coarser to finer which might have offered high adsorptive sites. The available potassium in red soils was medium to high in status. The variation in K status might be due to cultural practices, application of fertilizers, organic manures and other inputs.