Characterization of Available Major Nutrients in Dominant Soils of Rainfed Crop Production Systems of India

Nineteen representative soil profiles from arid, semi arid (moist and dry) and subhumid regions across eight major rainfed crop based production systems were characterized for available macronutrient status and distribution. Except in surface layers (0–15 cm) at few locations, most soil profiles were low in organic carbon. Profile mean (0–105 cm) of organic carbon content was less than 0.50 per cent in all the 19 soil profiles studied. Available N was low in all the profiles except of Vertisol at Indore. Other Vertisols at Rajkot, Kovilpatti, Bellary, Bijapur and Solapur showed extremely low available N. Surface soils of Rajkot, Akola, Solapur and Bellary were P deficient and that of Agra, S.K.Nagar, Bangalore, Hoshiarpur and Rakh Dhiansar were K deficient. Sulphur was deficient in surface layers of Faizabad, Rajkot, Akola, S.K.Nagar and Hoshiarpur. Light textured acidic soils at Phulbani, Anantapur, S.K.Nagar and Bangalore were Ca deficient. Magnesium deficiency was widespread among rainfed soils and Alfisols at Bangalore showed extremely low available Mg (0.07 me 100 g⁻¹). Correlation coefficients between various soil properties and available nutrients indicated that correlation coefficients varied from significantly negative to positive. Organic carbon showed significantly positive correlation with available N, P and K in most of the profiles and with S in many profiles.