Effect of Weed Control on Forage Production in the Nebraska sandhills

Abstract

Plots for the control of broadleaf weeds and for the determination of forage loss due to broadleaf weeds were established in the Nebraska sandhills. Herbicides were applied in the first year, the first and second years, the first, second and third years, and the first and third years in a four-year study. Forty lb/acre of N (40-N) were applied the fourth year. Herbicide treatments included 2,4-D amine, 2,4-D ester, 2,4,5-T, and silvex at 1 and 3 lb/acre; dicamba at 1/8 or 1/4 lb/acre in combination with 2 or 1 lb/acre 2,4-D amine, respectively; and picloram at 1/16 or 1/8 lb/acre in combination with 2 or 1 lb/acre 2,4-D amine, respectively. Control of broadleaf weeds with herbicide increased forage production up to 330 lb/acre when used without N. N applied following applications of dicamba at 1/4 lb/acre combined with 1 lb/acre 2,4-D amine increased forage production up to 660 lb/acre. Total herbage production increased when N was applied, but broadleaf weed production increased when weeds were not controlled. Herbicides and fertilizer can be effectively utilized to increase forage production, but they will not correct the mismanagement that results in weedy grazing lands.