RELAÇÃO ENTRE POUSIO E RESTABELECIMENTO DE PROPRIEDADES FÍSICO-QUÍMICAS DO SOLO EM AGRICULTURA DE ROÇA-DE-TOCO

Abstract

The increased and uncontrolled occupancy of the hillslopes, driven forward mainly by current forms of possession and land use, and characterized by human activities on it, has garnered great attention and concern of professionals in various areas of soil study. The different managements of soil determine difference in procedures between environments. In Brazil, traditional agriculture is still practiced by small farmers; many of them still use the burning method for the cleaning of the land for planting, which is also called fallow agriculture or slash-and-burn agriculture. The fire causes several changes in the soil: physical, chemical, and biological. Among other effects, the fire affects the aggregates stability, it modifies infiltration, and it increases runoff and soil loss. While many studies have shown unfavorable physicochemical changes in the soil, others demonstrate that the slash-and-burn system is sustainable on the condition that the fallow management is done properly. However, little research has been conducted on the restoration of soil properties for better understanding the fallow system. Thus, this study evaluates and presents the recovery of physicochemical properties in soils that have undergone burning and which are in 6 different stages of a fallow period, on a scale from 0 to 12 years in a Faxinalense community, Tijuco Preto, located in the Prudentópolis municipality, Paraná. This study concludes that the chemical parameters are more sensitive to fire than are the physical parameters. Aggregates stability, water retention capacity, and infiltration showed improvements after burning. Most of the altered chemical and physical elements that come to undermine the environmental quality of soil can reach reference values of the natural forest after an average of 5 years of lying fallow.