Alfalfa (Medicago sativa L.) biomass yield at different pasture ages and cutting frequencies

Abstract

Cutting frequency and pasture age are strategic variables in defining alfalfa crop management aimed at increasing biomass yield. An analysis was done to identify the effects of three cutting frequencies (three, four and five weeks) in the spring-summer cycle on dry matter production, growth rate and performance variables in alfalfa (Medicago sativa L. Oaxaca criolla) in three pasture ages (one, two and three years). A random block design with a 3x3 factorial arrangement (cutting frequency and pasture age) was used. Highest (P<0.01) average dry matter yield (7,528 kg DM ha-1) and growth rate (257 kg DM ha-1 d-1) were recorded at the one-year pasture age. Average dry matter yield was highest at the four-week cutting frequency (6,844 kg DM ha-1), which was 29% higher than at three weeks and 16% higher than at five weeks. In the one-year pasture, leaf and stem production was 45% higher than in the three-year pasture and forage height was 32% higher. At the four-week cutting frequency leaf production was 21% higher than at the three-week frequency, while stem production was 49% higher and forage height was 33% higher. The evaluated variables and their interactions determined estimated alfalfa component yield.