Effects of winter grazing on spring production of lucerne under Mediterranean conditions

Abstract

The effects of one severe winter-grazing of lucerne were studied over 3 years in an experiment in the Ebro Valley, Spain. In this region the crop is harvested six to seven times per season and winter grazing is a traditional practice. On average, winter-grazing reduced the yield at the first harvest in spring by 200 kg dry matter (DM) ha⁻¹. This limited yield reduction of 0·06 was accompanied by an increase in the proportion of lucerne in the herbage DM from 0·54 to 0·62, a reduction in the proportion of weeds from 0·39 to 0·36, and a reduction in the proportion of dead material from 0·06 to 0·02. The crude protein concentration and the in vitro DM digestibility increased by 20 g kg⁻¹ DM and 0·03, respectively. The traditional practice, i.e. of grazing lucerne with sheep once in the winter season, results in only a limited reduction in yield in the spring. In addition, the spring crop has a higher nutritive value.