Effects of nitrogen fertilization and cutting schedules on stockpiled tall fescue festuca arundinacea cultivar kentucky 31 2. forage quality
Collins, M.; Balasko, J.A.
Agronomy Journal 73(5): 821-826
ISSN/ISBN: 0002-1962 Accession: 005316426
Results of 2 field experiments dealing with the influence of cutting and N fertilization management on stockpiled tall fescue quality and chemical composition are reported. In Exp. [experiment] I, treatments consisted of 4 N rates: 0, 60, 120 and 180 kg/ha applied as split applications of half in March and half in Aug.; 3 dates when stockpiling began, mid-June, early July and mid-July; and 3 autumn and winter harvest dates, mid-Dec., mid-Jan., and mid-Feb. 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% in mid-Dec. to 41.1% by mid-Feb. 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 yr. Forage P and Mg concentrations were below minimum requirements for dry beef cows by late winter. In Exp. II, conducted on a silt loam soil (Typic Fragiudalfs), treatments included 4 N rates: 0, 75, 150 and 225 kg/ha applied at the last summer or autumn cutting which occurred in either early Sept., mid-Sept. or early Oct. In this experiment, all accumulated forage was harvested in late winter. N fertilization increased forage IVDMD and CP, water soluble carbohydrate, K and Mg concentrations in the stockpiled forage. Data from the 2 experiments indicate that supplementation of energy, P and Mg may be necessary in utilizing stockpiled tall fescue during Jan. and Feb.