IMPROVING PHOSPHORUS AVAILABILITY, NUTRIENT UPTAKE AND DRY MATTER PRODUCTION OF ZEA MAYS L. ON A TROPICAL ACID SOIL USING POULTRY MANURE BIOCHAR AND PINEAPPLE LEAVES COMPOST

摘要

Phosphorus deficiency in tropical acid soils is a problem because soluble inorganic phosphorus is fixed by aluminium and iron. Organic amendments could be used to overcome phosphorus fixation in acid soils. Thus, the objectives of this study were to (i) improve soil phosphorus availability using biochar and compost produced from poultry manure and pineapple leaves respectively, and (ii) determine whether the use of biochar and compost could improve phosphorus, nitrogen, potassium, calcium and magnesium uptake and dry matter production of Zea mays L. cultivation on a tropical acid soil. Organic amendments significantly increased soil pH compared with non-organic amendments. Organic amendments also significantly reduced exchangeable acidity and exchangeable forms of aluminium and iron, and effectively fixed aluminium and iron instead of phosphorus. As a result, phosphorus availability in soil increased. Besides increasing the availability of nitrogen, potassium, calcium and magnesium in soil, organic amendments improved nutrients uptake and dry matter production of Zea mays L. Biochar and compost can be used to improve the productivity of Zea mays L. on acid soils by reducing phosphorus fixation.