AbstractsBiology & Animal Science

Sudangrass Hay Production in the Irrigated Deserts of Arizona and California

by Tim C. Knowles

Institution: University of Arizona
Year: 2015
Keywords: Water; Fertilization; Pests; nitrate; prussic acid; poisoning
Record ID: 2058216
Full text PDF: http://hdl.handle.net/10150/552964


Foreign sudangrass hay buyers want dust-free hay with a bleached light green color and a stem diameter less than one quarter of an inch. Two types of sudangrass hybrids are currently grown in the United States: true sudangrass hybrids and sorghum-sudan hybrids. Sudangrass and related hybrids are annual warm season grasses grown for pasture, green chop, silage, and hay. Sudangrass produces well on all soil types, however best yields are obtained on well-drained, deep loam soils that have a high capacity to absorb and hold water. Sufficient nitrogen should be applied at planting to ensure establishment of the crop and hasten development. Typically, 40 to 80 pounds of actual nitrogen per acre are suggested at planting, based on results from a preplant nitrate-nitrogen soil test. This should be followed by split applications of 60 to 120 pounds actual nitrogen per acre in irrigation water following each cutting. Harvest sudangrass when it is at least 18 to 24 inches tall at the first cutting. Nitrates present in hay crops are considered toxic to many classes of livestock. Most cases of hydrocyanic or prussic acid poisoning are caused by the ingestion of plants that contain cyanogenetic glucosides. Cyanogenetic glucoside itself is non-toxic but hydrocyanic acid.