Drying rate of alfalfa under different solar radiation conditions and raking widths

Ernesto Jahn B.1*, Patricio Soto O.1, Pedro Cofré B.1 y Rocío Sasmay M.1

A study was carried out to evaluate the effect of different levels of solar radiation and raking width on the drying rates of alfalfa (Medicago sativa L.) destined for silage or hay. The variables studied were three row widths: 0.9, 1.2, and 1.8 m, and three solar radiation levels obtained through the use of shading nets of 80%, 50% and no net. The alfalfa pasture was cut at 09:00 h with a mower-conditioner and placed in rows according to treatments. DM content was determined during two consecutive days at 09:00, 14:00 and 17:00 h. Solar radiation and row width significantly (P < 0.05) affected the DM percentage of the alfalfa. Wider rows increased drying rate and increasing the shading level decreased drying rate. The interactions hour x row width and hour x radiation were significant (P < 0.05). Between 09:20 and 17:00h, drying rate varied between 1.8% DM h-1 with 80% shading net and row width of 0.9 m and 4.4% DM h-1 for row width of 1.8 m without shading net, respectively. In the control 40% DM was obtained after 3 h and row width of 1.8 m and 9 h for 0.9 m, respectively. With 80% shading net, 40% DM was obtained in 5 h with the 1.8 m row and in over 20 h with 0.9 m row width..

Keywords: wilting, hay, silage, Medicago sativa L
1 Instituto de Investigaciones Agropecuarias, Centro Regional de Investigación, Casilla 426, Chillán, Chile. E-mail: ejahn@inia.cl * Autor para correspondencia