Wetting and Maturity Effects on the Yield and Quality of Legume Hay1

Abstract

AbstractInformation is needed on the effects of rain on the magnitude of yield and quality losses of field cured legume hay. Two experiments were conducted to evaluate the influence of wetting on yield and quality losses of hay of alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) cut at two maturity stages. Three and one‐half kilogram samples of alfalfa and red clover forage grown on Plano silt loam soil (fine‐silty, mixed, mesic Typic Argiudoll) and harvested at early and late maturity stages were placed on wire screens and allowed to dry without wetting or were exposed to natural or artificial wetting in 1980 and 1981. A completely randomized design was used with three replications in 1980 and two in 1981. In 1980, 2.5 cm of water was applied to hay wetted during drying. In 1981, hay wetted during drying was exposed to 4.1 and 6.2 cm of precipitation, respectively. Mean dry matter (DM) losses during drying in 1980 were 8.1 and 17.0% from unwetted and wetted forage, respectively, but red clover harvested at the bud stage and wetted lost 25.8% of the total DM. In 1981 unwetted forage, forage wetted during drying and forage wetted after reaching 85% DM lost 10.5, 43.4, and 53.0% of the initial DM. Wetting did not change forage N concentration greatly in either year. Forage in vitro dry matter disappearance (IVDMD) was reduced by wetting in both years. In 1981 IVDMD was reduced from 66.4% for unwetted hay to 48.1% for hay wetted during drying. Mature forage of alfalfa was lower in IVDMD than bud stage alfalfa in both years regardless of wetting treatment. Neutral detergent fiber concentration was increased by wetting red clover forage in both years. Prolonged wetting in 1981 reduced the yield of N and TNC by 40.3 and 71.5%, respectively. Dry matter and quality losses due to wetting of legume forage during hay curing vary with legume species and the timing and duration of wetting. Results indicate that plant constituents differ in their susceptibility to loss due to wetting during hay curing.