Propriedades físicas de um planossolo sob sistema de integração lavoura-pecuária-floresta no semiárido brasileiro

Abstract

The integrated crop-livestock-forestry (ICLF) system emerges as an efficient alternative for the recovery of degraded areas, through the sustainable management of soils, combining forest species, agricultural crops, and livestock in an appropriate organization of time and space. In this context, the objective was to evaluate and analyze the physical properties of a Planosol under ICLF in the semi-arid region of the Paraíba Agreste. The research was conducted in an area located at the Experimental Station of the Paraíba Company for Research, Rural Extension and Land Regularization – EMPAER, in the municipality of Alagoinha, PB. The experimental design used was randomized blocks (RBD) with six land use systems: T1) Gliricidia (Gliricidia sepium (Jacq.) Steud) + Brachiaria decumbens Stapf. (GC + BD); T2) Sabiá (Mimosa caesalpiniifolia Benth.) + Brachiaria decumbens Stapf. (SB + BD); T3) Corn (Zea mays L.) + Brachiaria decumbens Stapf. (ML + BD); T4) Brachiaria decumbens Stapf. (BD); The native vegetation area (T5) and the area of pasture considered degraded (T6) were studied at three depths (0.00-0.10; 0.10-0.20 and 0.20-0.30 m), with four repetitions. Undisturbed soil samples were collected in three layers to determine the following physical characteristics: texture, soil density (Ds), total porosity (Pt), macroporosity (Ma), microporosity (Mi), saturated hydraulic conductivity (KƟ), and penetration resistance (Rp). After 10 years of implementing the integrated system, it was not possible to identify significant differences between the land use systems and between depths for the properties studied. A significant relationship was observed between total porosity and the other evaluated attributes. There were changes in the physical characteristics of the soil, resulting from inadequate animal management. The native vegetation presents the lowest density and resistance to penetration, and the highest porosity, although the hydraulic conductivity shows slightly lower values. The SB+BD and GL+BD treatments at the three depths demonstrate potential for improving the physical structure of the soil, reducing density and resistance to penetration and improving porosity, aeration, and water infiltration.