THE POTENTIAL FOR CONTROL OF THE SOFT RUSH (JUNCUS-EFFUSUS) IN GRASS PASTURE BY GRAZING GOATS

Two experiments were conducted to examine the effect of inter-tussock grass height and stocking rate on the utilization of the rush (Juncus effusus) by grazing goats. In the first experiment, on rush-infested F estuca rubra/Trifolium repens pasture, the utilization of rushes by go ats grazing at a sward height of 3-4 cm or 5-6 cm was compared with th at occurring on plots grazed by sheep at a sward height of 3-4 cm. She ep grazed minimal amounts of rush. In contrast, it was estimated that 90% and 75% of current season's growth of rush was grazed by goats at sward heights of 3-4 and 5-6 cm respectively during the first year. Wi th continued goat grazing at 5-6 cm there was a dramatic reduction in the cover and vigour of the rushes, and at a sward height of 3-4 cm es tablished tussocks were eliminated from the pasture. The second experi ment compared the utilization of rushes invading predominantly Agrosti s swards stocked with goats at 10, 20 or 30 ha-1 and in which inter-tu ssock sward height was maintained at 4-5 cm on all treatments, by addi ng or subtracting sheep. On one site rush utilization increased with t he increase in stocking rate of goats and rush tussocks were eliminate d within 3 years at 30 goats ha-1. On another, there was no difference between plots stocked at 20 or 30 goats ha-1 and viable tussocks rema ined. The influence of the composition and productivity of the inter-t ussock herbage and the proportion of rush in the biomass are discussed . Goats can be used to control rushes in grassland but high stocking l evels and low inter-tussock pasture heights are required to promote ad equate levels of utilization.