Leaching of potassium from organic manures, crop residues and inorganic fertilizer in two soils under flooded and upland moisture regimes

Effect of organic amendments on leaching loss of K under flooded and an upland moisture regime was studied in 60 cm long columns filled with loam and sandy loam soils. Leaching losses of K were more in amended soils than in controls. Among different treatments, rice straw and fertilizer K registered more losses of K via leaching under flooded conditions in both the soils. Leaching losses were also substantial in poultry manure treated soils. Losses of K did not differ significantly among wheat straw, farmyard manure and green manure treatments and were only slightly higher than that under control. About 60% higher leaching losses of K occurred in sandy loam soil than in loam soil possessing higher CEC. Only a limited movement of applied K occurred in both the soils maintained at field capacity moisture regime. The distribution pattern of available and water soluble K in soil columns indicated lower values of these fractions under waterlogged conditions than that at field capacity moisture condition.