Production function and efficiency in water use in irrigated forage sorghum

Abstract

Pastures are widely used due to characterizing a practical and economical way of feeding animals. In spring-summer, the availability and quality of natural pastures decline due to uneven precipitation, making cultivated and irrigated pastures essential. Thus, forage sorghum is characterized as one of the best cultivation options, to cut and silage however, it needs adequate water availability to reach its production potential. The objective with this work was to evaluate the yield of forage sorghum in different irrigation depths, as well as the water use efficiency, in two agricultural years (2015/2016 and 2016/2017). The experiment was carried out in Santa Maria-RS, Brazil, with 6 treatments (0, 25, 50, 75, 100 and 125% of reference evapotranspiration) and 4 replicates, totaling 24 experimental units. The experimental desing was a randomized blocks. Seeds were harvested in November 2015 and 2016 with the cultivar AG2501. Statistically significant differences were found for productivity between the different treatments and also, among the agricultural years, as well as for water use efficiency.