Soil Fertility Status of Major Coconut Growing Soils of Tumkur District, Karnataka, India

A study was conducted to assess the soil fertility status of major coconut growing soils of Tumkur district of Karnataka with soil pedon locations being Turuvekere and Gubbi. The results revealed that soils of the study area were slightly to strongly alkaline in reaction and non-saline in nature. The organic carbon content was varying from low to high and it followed decreasing trend with soil depth in both soil profiles (Turuvekere and Gubbi). The clay distribution, cation exchange capacity and base saturation of the soils varied from 17.83 to 60.37 per cent, 8.71 to 28.86 cmol (p+) kg-1 and 75.53 to 93.42 per cent, respectively. The macronutrient status of the soil samples indicated that the available nitrogen and phosphorus varied from low to medium, and available potassium content was varying from low to high. Analysis of secondary nutrients showed that exchangeable calcium and magnesium were found to be sufficient but available sulphur was varying from deficient to sufficient level in these soils. The DTPA extractable micronutrients viz., iron, manganese, zinc and boron were found to be deficient in entire study area where as copper was varying from deficient to adequate level with surface soil having relatively high copper content than subsurface soil.