Estudo das variáveis ecofisiológicas, produtivas e químicas de Urocloa Brizantha CV. Marandu sob sistema de manejo extensivo na região da bacia do Rio Vermelho

Abstract

Brazilian livestock consists of a triple support system, in which genetics, pasture and management are interconnected, contributing to the success of creation. In this activity, most of the herd's food is pasture, presenting a lower production cost when compared to other world meat exporters. Grazing management is characterized by the frequency and intensity of defoliation, which determines the structure of the forage canopy. In order to better understand the performance of forage as a function of grazing management, the work aimed to study the ecophysiological, productive and chemical variables of Urocloa brizantha cv. Marandu under an extensive management system in the Rio Vermelho Basin region. Monthly evaluations were carried out on pastures with extensive grazing system, in 4 properties of the hydrographic basin of Rio Vermelho-Go. The pasture was cut with the help of a cutter at a height of 3 cm from the ground in an area of 1 m2, constituting 3m2 per property for 11 months. The evaluated variables were: morphological composition of forage, interception of light and height of forage. A sample of approximately 500g was weighed and stratified into: leaf, stem and dead material, for the interception of light a solar monitor was used, performing three readings below the canopy and one above the canopy, and for the height, the evaluation was made with a metric measuring aid, with three measurements per square meter at random. For the analysis of the results obtained, the Mann- Whitney test statistic analysis, statistical program R, was used, and for all procedures the value of p = 0.10 was adopted. There was a significant effect for the variables: stem, leaf, dead material, leaf / stem ratio, total dry fodder mass. For the evaluation of forage height and interception, it can be observed that there was a correlation, where greater heights presented greater IL. The results allow to affirm that the property with the best total production of forage mass and leaves and the property C. While property A presented the worst total production of forage mass and leaves.