Métodos para avaliação da qualidade do solo em ambiente tropical

Abstract

The soil is an important component of an environmental system, where it works as a substrate for plant growth, and regulate the water flow and energy. The soil ability to provide all these functions defines the level of its quality, which can be assessed by various methods. This work aimed: a) to assess the methods proposed by Karlen & Stott (1994) and by Dexter (2004) to evaluate the soil physical quality, and b) to evaluate the elaboration method of the soil-water retention curve by a psychrometer WP4 and their usefulness for determinating the index S of soil physical quality. Soil samples were collected in three management systems: native forest and intercropping systems of coffee + coconut and cocoa + rubber, which were assessed in the following quality indicators: total porosity, macro and micro porosity; soil density; water retention; saturated soil hydraulic conductivity; pH; cation exchange capacity; base saturation; aluminum saturation; organic matter and soil penetration resistance. The results showed that the studied methods were coherent and sensitive in identifing changes in the soil due to the use and management. The method to elaborate the soil-water retention curve by the psychrometer WP4 change the shape and the fitting parameters of van Genuchten equation, and may underestimate attributes and soil quality indeces associated with it.