Influence of Nitrogen on Irrigated Buffalograss Yield and Protein Content

Abstract

Buffalograss (Buchloe dactyloides), a shortgrass dominant in many plant communities throughout the Great Plains, was irrigated and fertilized with four rates of ammonium nitrate. Yield and crude protein were determined on six dates throughout the growing season. The highest nitrogen level (120 kg/ha) increased dry matter yield 130% while 30 kg/ha of nitrogen only increased yield 23% over the control. Peak crude protein concentration (16.71%) of herbage from the 120 kg of N/ha treatment was observed on July 8, while maximum crude protein (9.26%) in nonfertilized herbage was found a month earlier. In all fertilized treatments, peak protein yield preceded peak herbage yields by at least 1 month. Loss of proteins from herbage was greater in those plots receiving the higher rates of nitrogen than on those plots receiving lower nitrogen applications. It is important that grassland managers be aware of the "quality vs quantity" interaction when making management decisions. Based on results from this study, we can not recommend fertilization and irrigation of buffalograss range.