Determining the Potassium Releasing Power of the Acid Soils of Nagaland

摘要

Soils across India differ too much and it's true for Nagaland soils also. In some soils available K status has been found to range from low to high (Srinivasa Rao et al. 2001). Despite wide variations in available K status, its application is negligible even in deficient soils because it has been assumed that Indian soils are rich in K. In addition to this, soils of Nagaland are acidic, do not receive any attention towards nutrient application and crops are often grown on marginal and sub-marginal lands as well as at high and low altitudes. Therefore, non-exchangeable K becomes a major source of K for the cropping systems being followed. Hence characterizations of soil reserve K and its release pattern is important to determine the K supplying capacity of soils. It is logical to study profile estimation of nutrient supply to have better understanding of nutrients. Potassium applied or released from left-over plant residues leaches down and accumulates in subsoil horizons. This K is often exploitedby deep-rooted crops in a rotation (Sparks et al. 1980). To verify the above condition, the present study examined the K release characteristics of acid soils of Nagaland. The laboratory experiment was conducted at School of Agricultural and Rural Development, Nagaland University, Nagaland during 2006 to study the K releasing power of Nagaland soils. Profile soil samples (15 cm depth interval) from 11 locations representing, Inceptisols (6), Alfisols (3) and Entisols (2) ranging from pH 4.48-4.85, werecollected, processed and analyzed for particle size, organic carbon, pH and EC by following standard methods (Jackson 1973).