Lehmann lovegrass live component biomass and chemical composition

Abstract

Lehmann lovegrass (Eragrostis lehmanniana Nees), a perennial bunchgrass from southern Africa, is replacing native grasses in Arizona. After the invasion, biomass production and quality may change. This study was conducted to determine the production and chemical composition of live Lehmann lovegrass leaves, culms, and seedheads during wet and dry years. During 3 years, green leaf biomass peaked at 78 +/- 14 g m-2 (mean +/- SE) in early August, green culms peaked at 103 +/- 21 g m-2 in mid October, and green seedheads peaked at 18 +/- 12 g m-2 in mid August. Leaf and culm growth peaks correspond with low crude protein (2.5%) and moderate phosphorus (0.23-0.25%) levels while seedhead growth peaks correspond with high crude protein (7-10%) and moderate phosphorus (0.19-0.29%) levels. There were no crude protein and phosphorus peaks in green culms. In Lehmann lovegrass forage, crude protein should meet animal requirements for about half the year while phosphorus should be adequate throughout the year. In native forages, crude protein is adequate throughout the year because animals selectively graze forbs, grasses, and shrubs but phosphorus does not meet animal requirements except in mid-summer.