Evaluation of Relative Efficiency of Paper Mill Sludge vis-Ã -vis Pure Lime in Neutralizing Soil Acidity of Alfisol and Inceptisol

Abstract

Laboratory incubation studies were undertaken for 35 days to determine the dose and efficiency of different liming materials in increasing the soil pH and neutralizing the exchangeable Al3+ of Alfisol and Inceptisol. Paper mill sludge (PMS), a byproduct of paper mill was compared with pure lime (CaCO3) at five levels viz., 0, 0.25, 0.5, 1.0 and 1.5 lime requirement (LR). With an increase in lime rates there was significant rise in soil pH of Alfisol and Inceptisol. With application of lime @ 0.25 LR, the exchangeable Al3+ was completely neutralized after seven days and remained at zero. Exchangeable Ca was increased with CaCO3 application, but only 0.5 LR rate had significant effect on ECEC. Combined application of lime @ 0.25 LR with FYM @ 6 t ha-1 or vermicompost @ 3 t ha-1 decreased the exchange acidity by 47-67 per cent over lime alone. Application of lime alone or in combination with organic matter increased phosphate availability by 25-35 per cent. A small dose (0.25 LR) of locally available PMS was comparable with pure lime in decreasing soil acidity for acid soils for better crop growth.