PRODUÇÃO FORRAGEIRA E EFICIÊNCIA DE UTILIZAÇÃO DA ÁGUA DO CAPIM SUDÃO SUBMETIDO A DIFERENTES LÂMINAS DE IRRIGAÇÃO1

The cultivated pastures are the most practical and economically feasible way for cattle feeding, however in the spring-summer period the quality and forage availability decline due to the irregularity of the rainfall, making it necessary to use irrigation to maintain the quality and the high productive indexes. Sudan grass, cultivar BRS Estribo has been outstanding in relation to the other summer grasses, but the optimal water supply is still unknown, since the research done diverges on the results. In this sense, the objective was to evaluate the productivity of the sudan grass under different irrigation slides, as well as to determine the efficiency of water use in two years of cultivation (2015/2016 and 2016/2017). The experiments were carried out at the Federal University of Santa Maria, with a randomized block design with six irrigation slides, 0, 25, 50, 75, 100 and 125% of the reference evapotranspiration, with four replications, totaling twenty four experiments. Seeds were sown in November of each year. There was a statistically significant difference for the variables analyzed in the two years of cultivation, with the irrigation blade with 100% of the reference evapotranspiration being the most productive, and with greater efficiency in water use.