Resistência mecânica a penetração em planossolo sob sistemas integrados de produção no agreste paraibano

Abstract

Soil compaction emerges as one of the main causes of resource degradation, caused especially by trampling by animals and loss of forage plants. Thus, the evaluation of soil quality based on mechanical resistance to penetration appears as one of the most effective indicators for indicating physical properties. Therefore, this work aimed to evaluate the mechanical resistance to penetration in Planossolo after six years of implementation of the Crop-Livestock-Forest Integration system in Agreste Paraíba. The experiment has been conducted since July 2015, in an experimental area of the Empresa Paraibana de Pesquisa, Rural Extension and Land Regularization (EMPAER) in the city of Alagoinha, Paraíba, Brazil. The experimental design adopted was in randomized blocks (DBC) with five treatments: I) Brachiaria decumbens Stapf. + Gliricidia (Gliricidia sepium); II) Brachiaria decumbens Stapf. + Thrush (Mimosa caesalpiniifolia); III) Brachiaria decumbens Stapf. + Ipê (Tabebuia alba (Chamiso) Sandwith); IV) Brachiaria decumbens Stapf. + Annual tillage and V) Brachiaria decumbens Stapf. with four repetitions. Determination of the mechanical resistance to penetration, in the field, up to 30 cm deep, was carried out using an impact penetrometer. The results showed that after six years of implantation of the systems, the mechanical resistance to penetration ranged from low to high between treatments. The treatment Brachiaria decumbens Stapf. + Ipê showed high resistance (2.0 – 4.0 MPa) and the treatment with Brachiaria decumbens showed low resistance (0.1 – 1.0 MPa). Still, in depth, it was observed that for most treatments, the surface layer showed less resistance, with emphasis on the treatment with Brachiaria decumbens.