Compactação do solo: efeito no perfilhamento e na produção de fitomassa fresca e seca de Brachiaria decumbens

Abstract

In the microregion of the Paraiban’s heath, the development of agriculture has been intimately linked to the extensive livestock farming, Brachiaria decumbens has been highlighted as the main trainer of pastures. However, inadequate management applied in the pasture areas has damaged vegetation, which in turn, becomes ineffective in protecting the soil, favoring excessive animal trampling, on the one hand causes breakdown of material and, secondly, causes soil compaction, which becomes a limiting factor for growth and root development of forage species, especially in places where there is greater traffic of animals. Thus, the main objective of a study was to evaluate the effect of compression in Red Yellow Argissoil in biomass production of Brachiaria decumbens and water consumption. The research was conducted in pots under greenhouse conditions belonging to the Center of Agrarian Sciences, Federal University of Paraiba, in Areia-PB. We evaluated the performance of Brachiaria decumbens subjected to six levels of soil bulk density (1.06 g cm-3 = uncompressed, 1.15 g cm-3, 1.20 g cm-3, 1.25 g cm-3, 1.30 g cm-3 and 1.35 g cm-3) in four sections of the shoot, held every 30 days. The experimental design was completely randomized (CID) with six treatments and four repetitions, totaling 24 experimental units. It was determined the following variables: plant height, tiller number, production of fresh and dry shoot and consumption of water by evapotranspiration. The increase of soil compaction did not affect the growth of Brachiaria decumbens and therefore did not interfere in its total production of fresh and dry shoot. However, provided a greater participation of mature tillers, thus increasing the number of dead tillers. The succession of cuts induced shoot tillering of the rosette stem and not with the production of smaller tillers, resulting in lower height of plants and phytomass production. The consumption of water decreased with the succession of cuts and was greater with higher compression. The mineral fertilizer was an important factor in the growth and productivity of the grass.