NUTRIENT PROFILE IN A TROPICAL ALFISOL UNDER CONVENTIONAL AND NO-TILL SYSTEMS

The chemical properties and nutrient status of an Alfisol under no-tillage and conventional plowing were investigated after 6 years of continuous maize. No-tillage with crop residue mulching resulted in higher concentrations of organic C, total N, available P, and exchangeable Ca and K than the plowed plots in the 0 to 10-cm layer. No-tillage treatment lead to stratification of soil pH in the 0 to 50-cm profile. Nutrient depletion in the conventionally tilled plots was mainly due to accelerated soil erosion. Grain yield was consistently higher from the no-till than from the plowed treatment at the same rate of N application. © 1979 The Williams & Wilkins Co.