SOIL PHYSICAL-WATER ATTRIBUTES IN THE SUBTROPICAL REGION OF BRAZIL

Abstract

Agricultural systems alter the soil physical and hydraulic attributes, and consequently its quality. We aimed to determine and associate the physical-water attributes of four soils type under a no-tillage system of the Subtropical region of Brazil, as well as to create a data set available to be explored by further studies. Disturbed and undisturbed soil samples were collected at three layers: 0.0 - 0.10 m; 0.10 - 0.25 m; and 0.25 - 0.40 m at six localities in the Paraná and São Paulo States. It was determined: soil texture, soil bulk and particle density, porosity (total, macro and micro), volumetric water content (permanent wilting point and field capacity), available water capacity and saturated hydraulic conductivity. The average soil bulk density is within the limit considered optimum according to the soil textures. The average soil porosity was close to the optimal condition for annual crop development under no-tillage system. The proportion between micro and macropores was approximately close to 3:1. The average values of soil available water capacity ranged from 48 mm (Tibagi) to 60 mm (Ponta Grossa and Socavão). The average saturated hydraulic conductivity was indicated as “moderate”, with the lowest values occurring in Castro. The soil physical-water properties did not show a possible negative impact of crop management in the region.