Individual study: Use of goats for control of an invasive rose, Rosa multiflora, and the recovery of an overgrown hill pasture in Waynesville, North Carolina, USA
Harvey T.E., Green Jr. J.T., Poore M.H. & Mueller J.P. (1998) Use of goats as biological agents for the renovation of pastures in the Appalachian region of the United States. Agroforestry Systems, 44, 241-252
Much hill pasture in the Appalachian region of eastern USA is becoming invaded by scrub, including multiflora rose Rosa multiflora (imported from Japan in 1886), considered invasive in the area. R.multiflora bushes can be eliminated by herbicides but viable seeds may remain in the soil for up to 20 years from which new plants may develop, and also arise from animal-dispersed seeds. Therefore effective management is needed for years after eliminating the original plants. Therefore, low cost and environmentally acceptable control methods are needed.
This experiment evaluated the effectiveness of using domestic goats Capra hircus alone, or cattle with goats, to reclaim an abandoned orchard pasture suffering from R.multiflora invasion.
Study site: The study was undertaken at the North Carolina Department of Agriculture Research Station in Waynesville (35º50'N, 83º0'W) in an overgrown 5.9 ha orchard abandoned for 15 years.
Experimental design: The orchard was divided into six paddocks: two ungrazed controls, two grazed by goats alone (30 mature does/ha), and two grazed by goats and cattle (17 mature does/ha with two to three steers/ha) for four grazing seasons (1991 to 1994). Grazing occurred in May to July (for 45 to 60 days) and September and October (24 to 35 days). The number of days grazed was dependent upon having at least 5-10 cm of forage to graze within each paddock.
Rose monitoring: Rose bushes (nine in each control, nine and eight in goat-grazed, and 10 each in goat and cattle grazed paddocks) were monitored to determine the effects of browsing. For each bush the following were recorded through the study period: percent dead stems, live stem height, ground area covered by live stems, and canopy scored for percent leaf-out.
Herb and grass monitoring: Responses of herbs and grasses were also recorded, in a 100 x 10 cm block, in each paddock.
Over the four years there was a large increase in herb cover in paddocks grazed by goats alone (65 to 86%) and by goats with cattle (65 to 80%), compared with controls in which cover decreased from 70 to 22% (in response to increasing shrub cover). Similarly, average grass cover increased in the grazed plots (goats: 16 to 63%; goats and cattle: 13 to 54%) while averaging 10% in the controls.
R.multiflora bushes were practically eliminated after four grazing seasons (average reduction in height from 2.1 m to 0.6 m; stems all dead in the goat grazed, and 92% dead in the goat and cattle grazed, paddocks).
These results indicate that goat foraging eradicated R.multiflora bushes and led to increases in desirable herbs and grasses. It is estimated that most beef cattle farmers in the region have enough forage in cattle pastures to feed one to two goats per cow with no additional feed input, therefore this may be a practical, low-cost, method of R.multiflora control.
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