Seasonal changes in yield and nutritional quality of cicer milkvetch and alfalfa in northeastern Saskatchewan

Abstract

Cicer milkvetch (Astragalus cicer L.) is a winter hardy, non-bloating forage legume. In southern Alberta and Montana, cicer milkvetch retains its leaves longer and maintains forage quality later in the season than alfalfa (Medicago sativa L.). Consequently, it has the potential to provide nutritious forage in the fall, at a time when pasture productivity and quality is limited, particularly in northern areas. The objectives of this study were (i) to compare the yield and quality of monocultures of cicer milkvetch and alfalfa over the growing season and (ii) to evaluate the long-term productivity of cicer milkvetch under Parkland conditions. Studies were initiated in Melfort, Saskatchewan in 1986 and 1987, and subplots were harvested monthly during the growing season in the 2nd to 6th years. Cicer milkvetch peak yields were similar to or higher than alfalfa in 7 out of 10 harvest years. Forage yield of alfalfa was generally higher than that of cicer milkvetch in early season harvests, but cicer milkvetch had similar or higher yields later in the season. As the growing season progressed alfalfa declined in leafiness and in in vitro dry matter digestibility whereas corresponding values for cicer milkvetch were higher than those for alfalfa in all harvests. The protein content of both legumes was similar for all harvests, declining with plant maturity. Cicer milkvetch maintained its production similar to alfalfa over the 6-yr period studied. Key words: Cicer milkvetch, Astragalus cicer L., Medicago sativa L., leaf retention, protein, digestibility