LEHMANN LOVEGRASS IN SOUTHEASTERN ARIZONA - BIOMASS PRODUCTION AND DISAPPEARANCE

Eragrostis lehmanniana, a perennial bunchgrass from southern Africa, has recently replaced native grasses on 200 000 ha in SE Arizona. Live biomass was present throughout the year but August peaks were almost 2000 kg/ha in 1 wet summer, 1430 kg/ha in 2 normal summers, and 960 kg/ha in 1 dry summer. Recent-dead approached zero in August when live peaked, and slowly accumulated in fall and winter. Old-dead peaked before the summer rains when temperature peaked and rapidly disappeared following snow accumulations in winter. Litter was highly variable among sampling areas, plots and sampling dates but amounts usually peaked before the summer rains and decreased in winter and spring. Lehmann lovegrass annually produces 3-4 times more green forage than native grasses, but cattle prefer native grasses. -from Authors