Soil compaction of a Yellow Latosol under pasture submitted to different methods of introduction of forage legumes

Abstract

In Porto Velho, Rondônia, was evaluated the effects of different methods of introduction of forage legumes on the soil compaction and moisture of a dystrophic Yellow Latosol, clay texture, under pasture of Brachiaria brizantha cv. Marandu in the process of degradation. We adopted the experiment in design of randomized blocks with three replicates, in a factorial arrangement 2 x 5 x 2 x 10 to the legumes (Desmodium ovalifolium or Pueraria phaseoloides), methods of establishment/tillage (grazed, plowing, harrowing, plowing + harrowing and manual plantation), phosphate fertilization (50 and 100 kg ha-1 P2O5) and 10 depths of the soil (layer the 5 cm of the profile 0-50 cm) when measuring the penetration resistance, for moisture were 2 depths (layer the 15 cm of the profile 0-30 cm). The resistance to penetration was determined with the aid of an impact penetrometer, model IAA/Planalsucar-Stolf in five points of the plots, and moisture by difference in initial and final weight after drying of deformed samples. Independently of the intensity of tillage and phosphate the introduction of legumes caused a reduction in resistance to penetration of the soil, with emphasis on D. ovalifolium, this effect was more evident when reconciled the method more soil tillage, especially in the surface layer (0 to 15 cm).