• Influence of Nitrogen and Irrigation on Carbohydrate Reserves of Buffalograss

      Pettit, R. D.; Fagan, R. E. (Society for Range Management, 1974-07-01)
      Five rates (0, 30, 60, 90, and 120 kg of N/ha) of nitrogen fertilizer were applied in April, 1971, to a deep hardland range site where buffalograss (Buchloe dactyloides Nutt.) predominated. The influence of these nitrogen applications on the carbohydrate reserve (TAC) concentration of irrigated and nonirrigated buffalograss roots and crowns was evaluated. In 1971 the TAC reserve concentration of the storage tissues varied inversely with rate of nitrogen application until the past ripe phenological stage. After this date, TAC's accumulated more rapidly in the heavier N treatments. In 1972, insignificantly more TAC were found in the control and 30 kg N/ha treatments at the hard seed stage. On all sampling dates buffalograss crowns contained more reserve carbohydrates than did the roots. Similarly, stolons contained 19% more TAC than did the crowns. Water applications reduced the carbohydrate reserves of this grass from 15 to 36%. Irrigation increased female spikelet yield by 44 kg/ha while stolon yield was similar regardless of water regime.
    • Influence of Nitrogen on Irrigated Buffalograss Yield and Protein Content

      Pettit, R. D.; Fagan, R. E. (Society for Range Management, 1974-11-01)
      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.