Published online by Cambridge University Press: 30 October 2009
Management recommendations are needed f or low-input (no N fertilizer) Kentucky bluegrass-dominant/white clover swards, particularly to increase or maintain white clover content. We applied treatments involving different amounts of forage present pre- and postgrazing, with and without harrowing and soil aeration, to a well-established, naturally seeded pasture grazed by dairy cows. Pregrazing dry matter was 2350 or 2700 kg/ha (about 10 or 15 cm tall). Postgrazing dry matter was 1100 or 1575 kg/ha (about 2.5 or 5 cm tall). The sward was composed mainly of Kentucky bluegrass, orchardgrass, quackgrass, timothy, white clover, dandelion, and chicory. Soil aeration and harrowing did not affect botanical composition, plant components, or forage yield. Pre- and postgrazing mass (total forage dry matter per unit area) did not affect botanical composition or plant components, but did influence total forage yield. White clover tended to increase under all pasture-mass treatments. During the second year the lowest postgraz- ing mass produced the most forage (mean: 6685 kg DM/ha). Forage quality of all treatments was excellent (seasonal means: 26% crude protein; 1.6 Meal net energy lactation/kg DM).