Irrigation Interval Effect on Yield and Quality of Forage Sorghum at Maricopa, AZ, 2015

9 pp.Sorghum has the advantage compared to corn in that it uses less water and fertilizer, but feeding quality of sorghum is usually less than corn. The purpose of this research is to compare the yield and quality of sorghum grown with differing frequency of irrigation water application. Forage sorghum was grown at the University of Arizona Maricopa Agricultural Center with irrigation intervals of 1, 2, and 3-weeks corresponding to 76, 44, and 37 inches of applied water. Forage yield at 72% moisture was 20.6, 18.8, and 16.5 tons/acre for the 1-, 2-, and 3-week irrigation intervals, respectively. Forage quality in terms of milk per ton of forage was not affected by irrigation interval, but some differences were measured in certain components of feed quality. Forage yield profit was maximized at the 2-week irrigation interval due since the increased water cost of the 1-week interval was not compensated by the yield increase at this irrigation frequency