Influence of Long-Term Use of Fertilizers, Manure and Lime on Phosphate Adsorption Parameters in Acid Alfisols of Ranchi

Influence of long-term use of fertilizers, manure and lime on phosphate adsorption parameters was studied using Langmuir adsorption equation in six soil samples drawn from the long-term fertilizer experiment of the ICAR. The rate and extent of P adsorption was considerably lower in soils which received recommended NPK plus lime or FYM. The adsorption maxima was highest in unfertilized soil and lowest in NPK plus FYM plot followed by NPK plus lime. The bonding energy constant (K) was highest where nitrogen source was ammonium sulphate in the NPK treatment. Buffering capacity of soils and P supply parameters followed a reverse trend. Buffering capacity was highest and P supply parameter was lowest in unfe.rtilized soil. P supply parameter was highest in soils treated with FYM followed closely by limed soil at different levels of added P.