Kleingrass Yield and Quality under Three Irrigation Regimes when Harvested at Anthesis1

Abstract

AbstractKleingrass (Panicum coloratumL.) is a promising forage species for irrigated areas in the southwestern USA. However, the effect of different irrigation regimes on dry forage yield and forage quality has not yet been extensively investigated under field conditions. Accordingly, ‘Kleingrass‐75’ kleingrass was irrigated at intervals of 2, 3, and 5 weeks during the 1981 and 1982 growing seasons near Las Cruces, NM on a fine‐loamy, mixed, calcareous, thermic Typic Torrifluvent soil. Dry forage yields, in vitro dry matter disappearance (IVDMD), and Ca, Mg, N, and P concentrations were measured for forage harvested at anthesis. Significant (P≤0.01) negative relationships were found between amount of irrigation water applied and Ca concentration, Mg concentration, and IVDMD, respectively. In addition, there were significant (P≤0.01) negative relationships between dry forage yield and Ca concentration, Mg concentration, and IVDMD, respectively. No relationships between amount of irrigation water applied or dry forage yield and N or P concentration were found. It was concluded that Ca and Mg concentrations and IVDMD were higher with lower soil moisture contents, possibly due to higher leaf weight to stem weight ratios in the lower‐yielding, water‐stressed kleingrass.