Sheep-grazing with different foraging efficiencies in a Dutch mixed grassland.
Abstract
In 1972, 11 ha of woodland, heathland and previously manured pasture was fenced in for a sheep-grazing experiment and the different grazing intensities in the grassland area were quantified. Peak standing crop (including standing dead material, but excluding litter) reached 210 g/m2 in Leontodon autumnalis, 420 g in Holcus lanatus, 510 g in Agrostis capillaris, 730 g in Agrostis stolonifera, 830 g in Juncus acutiflorus and 1130 g in Juncus effusus communities in Oct. 1981. Grazing intensity expressed as efficiency of foraging was 0.89 in L. autumnalis, 0.30 in H. lanatus and 0.09 in A. capillaris communities over a 6 month period from June to Nov. 1981. Low species diversity was related to very low efficiency of foraging, whereas species diversity was relatively high for foraging efficiencies ranging from moderate to high. Grazing at an av. stocking of 3 sheep/ha resulted in a smaller area (13%) with a short turf (<15 cm), a larger area (18%) with greater roughness (>36 cm) and a much larger area (69%) with intermediate turf. It was considered that the proportions of short, rough and intermediate turf could be manipulated by adjusting the stocking rate.