SOIL FERTILITY REQUIREMENTS OF FOOD CROPS ON EXTENSIVE, DEEP, WELL-DRAINED BUT RELATIVELY INFERTILE ACID SOILS OF THE HUMID TROPICS; PROGRESS REPORT, 1971/1972

Research conducted in these highly weathered and leached soils indicate that potential productivity can be achieved at a relatively low cost with the judicious use of fertilizers and lime in combination with good management practices. The soils are deep and well drained with good physical properties. The most effective and economic amounts and methods of application of nitrogen, phosphorous, potassium, liming materials, and micronutrients are examined. Study of clay mineralogy indicate valuable information on the reactions of applied nutrients in the soil and their availability to plants.