The Influence of Lime and Nitrogen Fertilizer on Soil Acidity, Growth and Nitrogen Uptake of Corn in Total Reclaimed Potential Acid Sulphate Soil

This study aims to determine the effect of lime and nitrogen fertilizer on soil acidities characters, growth and nitrogen uptake of corn in total reclaimed of potential acid sulphate soil. A pot experiment with a completely randomized design arranged in factorial with three replications was conducted in the Greenhouse of Indonesian Swampland Agricultural Research Institute (ISARI) from August 2014 to December 2015. The first factor was the rate of lime as dolomite- (i) 25 t ha-1, and (ii) 37.5 t ha-1. The second factor was the type of nitrogen fertilizer- (a) control (without N), (b) nitrogen 115 kg ha-1, (c) chicken manure 6 t ha-1 (the total N content is 1.98%) and (d) nitrogen 57.5 kg ha-1 + 3 t ha-1 chicken manure. Urea (N content is 39.76%) was used for fertilization. The observed variables were the soil acidities properties (pH, Electrical conductivity/EC, available-H, available-Al) before, after total reclamation, and at the maximum vegetative stage of corn, plant growth and uptake of shoot nitrogen. The results showed that the process of consecutively aeration-leaching of the potential acid sulphate soils able to increase the soil pH, declining the EC value, as well as availabe bases, available-H, available-Al and the content of pyrite. The application of dolomite increased soil pH, EC, and available-H, while available-Al decreased, its effect was more pronounced in higher rate. Application of dolomite 25 t ha-1 and 37.5 t ha-1 respectively increased soil pH from 3.29 to 4.36 and 4.87, EC from 0.70 mS cm-1 to 1.51 mS cm-1, available-H from 1.30 cmol(+) kg-1 to 2.68 cmol(+) kg-1 and 1.44 cmol(+) kg-1 and decreased available-Al from 14.04 cmol(+) kg-1 to 4.71 cmol(+) kg-1 and 2.66 cmol(+) kg-1. However, these rates was not able to neutralize the existing acidity due to the acidity still being produced out of remaining pyrite which was still in active stages. It was showed increasing pH soil followed by EC. The interaction between the application of dolomite and nitrogen fertilizer is significantly influenced plant height and shoot N uptake. The highest plant height and shoot N uptake were 112 cm and 267.69 mg plant-1 respectively, were obtained in application dolomite 25 t ha-1 combined with nitrogen 57.5 kg ha-1 plus chicken manure 3 t ha-1. The highest of averages shoot and root dry weight was 20.97 g and 6.40 g respectively which were obtained in the application of nitrogen 57.5 kg ha-1 + chicken manure 3 t ha-1.