NITROGEN-FERTILIZATION OF STOCKPILED TALL FESCUE IN THE MIDWESTERN USA

Stockpiled tall fescue (Festuca arundinacea Schreb.) has been shown to extend the grazing season in the mid-Atlantic states and upper-South, but has not been widely used in the Midwest. A 3-yr field study exami ned the effects of N fertilizer management strategies on stockpiled ta ll fescue yield and quality in the northern zone of tall fescue adapta tion. Varying levels of four treatment factors, including sward growth stage at the time of N application, N fertilization date, N fertiliza tion rate, and harvest date were imposed on a low-endophyte 'KY 31' ta ll fescue sward. Maximum dry matter (DM) accumulation of stockpiled ta ll fescue (2800 lb/acre) occurred in mid-November. Early-August N fert ilization increased (P < 0.01) stockpiled tall fescue yield by 30% com pared with late-August fertilization. Stockpiled tall fescue yield inc reased (P < 0.01) as fertilization increased from 0 to 120 lb N/acre, with summer precipitation determining the extent of the yield response . Nitrogen conversion efficiency was greatest (P < 0.05) for the first 40 lb N applied, then decreased about 60% and was similar for additio nal 40 lb/acre increments. Fertilization date did not affect forage qu ality. Increasing N from 0 to 120 lb/acre increased crude protein (CP) and lowered neutral detergent fiber (NDF) (P < 0.01) 2 out of 3 yr. S pring yield of tall fescue following fall stockpiling averaged 4000 lb /acre and was often higher (P < 0.05) with later and heavier N applica tion the previous fall. We conclude that early-August N fertilization of tall fescue produces favorable yields of high quality stockpiled fo rage for late season grazing in the Midwest.