Effects of N Fertilization and Cutting Schedules on Stockpiled Tall Fescue. II. Forage Quality¹

Abstract

Tall fescue (Festuca arundinacea Schreb.) is the coolseason grass used most frequently to extend the grazing season in mid‐latitude states of the midwestern and eastern United States. Insufficient information is available regarding the influence of fertilization and harvest management on the quality of stockpiled tall fescue forage available during winter. Results of two field experiments dealing with the influence of cutting and N fertilization management on stockpiled tall fescue quality and chemical composition are reported. In Exp. I, treatments consisted of four N rates: 0, 60, 120, and 180 kg/ha applied as split applications of one‐half in March and one‐half in August; three dates when stockpiling began (1) mid‐June, (2) early July, and (3) mid‐July; and three autumn and winter harvest dates (1) mid‐December, (2) mid‐January, and (3) mid‐February. The soil used in Exp. I was a well‐drained loam (Typic Hapludults) with high levels of P and K. The treatment with the greatest influence on in vitro dry matter disappearance (IVDMD) was winter harvest date. Forage IVDMD decreased from 47.3% hi mid‐December to 41.1% by mid‐February. Crude protein (CP) concentration increased from 7.4% at 0 N to 10.4% at the 180 kg/ha N rate averaged over all other treatments and 2 years. Forage P and Mg concentrations were below minimum requirements for dry beef cows by late whiter. In Exp. II, conducted on a silt loam soil (Typic Fragiudalfs), treatments included four N rates: 0, 75, 150, and 225 kg/ha applied at the last summer or autumn cutting which occurred in either early September, mid‐September, or early October. In this experiment, all accumulated forage was harvested in late winter. Nitrogen fertilization increased forage IVDMD and CP, water soluble carbohydrate, K, and Mg concentrations in the stockpiled forage. Data from the two experiments Indicate that supplementation of energy, P, and Mg may be necessary in utilizing stockpiled tall fescue during January and February.

Quality of Stockpiled Pasture and Hay Forages

“…Research has shown stockpiling forage to be economically beneficial to the producer (18,20) while maintaining adequate yield (8,15) and nutrition levels for various classes of livestock (3,6,17). The cost of producing and storing forage for the winter months is often the largest expense incurred and is usually the most labor‐intensive practice used by graziers.…”

“…Appropriate species selection can allow producers to claim the highest level of nutrients available and thus maximize livestock production. Among the species used for stockpiled forage, tall fescue has been found to be an excellent forage because of its ability to maintain yield and quality better than many other grasses throughout late autumn and early winter (2,3,13). In the spring following stockpiling, fescue continues to yield well (13).…”

Adequate Soil Phosphorus Decreases the Grass Tetany Potential of Tall Fescue Pasture

“…2). Research from West Virginia has shownthat stockpiled tall fescue has a seasonal low in Mg concentration duringmid‐February (3). The lack of a treatment difference early in our study waslikely a result of Mg leaching from the leaves over winter and little grassgrowth.…”

Characterization of Historical Precipitation Data in Relation to Production Risk of Fall‐stockpiled Tall Fescue

“…Stockpiled fescue provides many producers with deferred winter grazing that can reduce the need for conserved forages or supplements (11). The initiation date and N management of fescue stockpiles are two areas that have received research attention (4,6,11). In a companion report to the current study, we found that splitting applications of 40 or 80 lb N/acre increased the probability of achieving designated yield goals of stockpiled tall fescue but results were affected by rainfall (12).…”