Características estruturais e produtivas do capim Mombaça sob sombreamento, na fase de estabelecimento

Abstract

It is estimated that more than half of the pastures in Brazil have some degree of degradation, thus making it impossible to sustain the levels of production and quality required by the animals. Brazilian livestock farming is an important activity for national agribusiness and it is known that Brazil is the largest exporter of beef in the world. However, due to inadequate management practices (lack of correction, soil fertility, wrong choice of forage, overcrowding of animals, among others), most areas have some level of degradation, therefore, degraded pastures need to be recovered. , in order to avoid economic, social and environmental losses. The Silvopastoral System is a technological alternative that enables the renewal and recovery of degraded pastures. And this system that allows intensive use of the soil integrates forest species, forage species and animals in the same area, its benefits are diverse, such as: soil conservation, preservation of natural resources, nutrient cycling, increased soil fertility , thermal comfort, improvements in performance and animal welfare. The purpose of this research was to evaluate the effect of four levels of light restriction (0, 30, 50 and 70%) on the productive and structural characteristics in the establishment phase of Mombaça grass (Megathyrsus maximus), for this purpose, 11 variables were evaluated: plant height - PH, tiller length - TL, leaf/stem ratio (LSR), leaf dry mass, stem, dead and total material, tiller population density, individual tiller weight, number of leaves living and dead. In this sense, it was conducted in a greenhouse at the Technological Diffusion Center – TDC in Imperatriz – Ma, using the Completely Randomized Experimental Design. The environment with 50% shading provided better production of total dry mass (TDM), however, no significant effect was observed for this variable for the full sun and 30% treatments. The number of tillers reduced with the light restriction, on the other hand, there was an increase in the height of the forage canopy. The lowest production of total dry mass of the aerial part and the lowest leaf:stalk ratio were found in 70% shading. Mombaça showed better morphological and structural acclimatization in the shade range of 30 to 50% to compensate for the effects of light restriction during the grass establishment phase. Given the importance of this production system for national livestock, it is essential to discuss the effects of shading on the forage component. This work presents a review of literature and scientific research, including concepts, information, discussions and studies on this topic.