Plant available nutrients in acidic inceptisols of Imphal Valley, Manipur

The present study was conducted to know available macronutrients (N, P and K) and micronutrients (Zn, Cu, Fe and Mn) content in relation to soil properties along depth of selected Inceptisols of Imphal West district located in the Manipur valley, which is traditionally under continuous transplanted rice based cropping. Available N, P and K content of surface soils (0–0.15 m depth) varied from 241.1 to 548.8, 5.0 to 14.9 and 12.5 to 452.5 kg ha⁻¹ with the mean values of 400.7, 9.8 and 166.9 kg ha⁻¹, respectively. Available micronutrients Zn, Cu, Fe and Mn content in surface soils were from 0.2 to 2.0, 0.7 to 5.4, 33.8 to 273.6 and 4.8 to 73.4 mg kg⁻¹ with the mean values of 0.9, 3.5, 172.3 and 26.4 mg kg⁻¹, respectively. Because of decrease in organic C and increase in pH, there was decrease in available nutrients, except P, along soil depth. The results indicated that the soils were medium in available N, low to medium in available P and low to high in available K; while all the tested soils were sufficient in available Cu, Fe and Mn, but 50 per cent soils were deficient in Zn. These results suggest for balanced fertilization to crops with inclusion of micronutrients (particularly Zn) based on soils test values for increasing yield of rice based cropping systems in acidic Inceptisols of Imphal West district of Manipur.