Flexible Alfalfa Management: Early Spring Utilization1

Abstract

Providing low‐cost high quality grazing for livestock early in the spring when pasture and hay are limited may increase body weights at economical prices. Current alfalfa (Medicago sativa L.) varieties may be suitable for such grazing if either stands or yields are not greatly reduced by early spring harvests. To evaluate the possibilities of early spring alfalfa grazing, two severities of cutting to simulate grazing were imposed at several spring dates by removing one‐half the leaf area index (LAI) and all the LAI by cutting to a 5‐cm stubble height. Spring utilization dates, based on accumulating 1, 2, 3, and 4 LAI units, occurred on about 9 April, 27 April, 6 May, and 25 May, respectively. During the remainder of the season, harvesting hay at onetenth bloom was considered lenient management for recovery. The 9 April grazing cut, leaving about onehalf the LAI, enhanced the first hay yields as compared with removing nearly all the leaf area. However, at 6 May with an LAI of about 3, leaving one half the leaf area, resulted in lower yields and decreased quality of the following hay harvest as compared with a grazing cut at 5 cm which removed all leaf area. Regrowth from tall stubble remaining after the 6 May grazing cut generally orginated from branches at axillary buds which had smaller stems than those growing from crown buds. Early spring grazing cuts delayed the first hay harvest. This delay is desirable since favorable hay‐making weather is more likely later in the season. Number of regrowth days to one tenth bloom decreased between April and mid‐June and increased thereafter. Regrowth after early August cuts did not flower due to short days of late summer.Total season yields were similar for all treatments. Residual yields in subsequent years showed no detrimental effects due to date or severity of spring grazing cuts. Utilization of alfalfa in early srping by grazing and taking the first hay harvest about 3 weeks later than normal appears to be a feasible alternative system for flexible alfalfa management.