Movement of nutrients in a dark red latosol

Abstract

Soil solution samples were collected with porous ceramic cup during fifteen weeks at 20, 40, 60 and 80 cm depths in five plots of an experiment on the effect of lime, corrective phosphate fertilization, green manure and the application of a mixture of micronutrients and sulfur, observing the chemical characteristics of a dystrophic dark red latosol (LEd). From 1982 to 1985 the experiment was carried out with cultures of beans, wheat and rice in three sucessive crops per year. All crops were fertilized, in the row, with 300 kg of the formula 5-30-15 per ha (maintenance) plus nitrogen fertilization in top dressing. The results showed that the leaching of calcium, magnesium and potassium was very intense up to the depth of 80 cm. Among the anions, nitrate showed the greatest movement into the soil profile and its leaching curves were very similar to those of the cations which indicates participation of nitrate as an acompanying ion. In the plots with lime, phosphate fertilizer and green manure, leaching of cations was diminished compared with the maintenance fertilization plots.