Livestock grazing for weed management - Ecological Management of Agricultural Weeds - page 426

Figure 9.6 Effects ofthree cattle-stocking rates on floristic composition and weedy
volunteer species ofpastures under coconut.(Adapted from Smith & Whiteman,
1985.)
legumes were likely to dominate under grazed coconut as they are less
affected by shade and may be less palatable than grasses under year-round
moist conditions necessary for coconut production.Smith & Whiteman (1985)
in cattle grazing trials under coconuts in the Solomon Islands found that
legumes dominated at all stocking densities (Figure 9.6). With an increasing
stocking rate and a diminished forage plant cover, weedy volunteer species
including the legume Mimosa pudica also increased.
Higher coconut yields were found with grazing than without (Santhirase-
garum, 1966; Rika, Nitis & Humphreys, 1981; Ferdinandez, 1973), and
grazing cattle also produced milk and meat. Rika, Nitis & Humphreys (1981)
found an increase from 263 to 454 nuts ha 1 month 1 with increasing stock-
ing rate from 2.7 to 6.3 cattle ha 1 .This increase was attributed to more rapid
nutrient cycling at higher stocking rates. Recommended stocking rates
depend, however, on light transmission. In the Soloman Islands, 0.7 animals
ha 1 were recommended with 35% transmission; 1.3 animals ha 1 with 50%;
and 2.5 animals ha 1 with 80% (Humphreys, 1991, p.15).
Grazing should be managed to maintain animal production (Humphreys,
1991, p. 15). A vigorous sward with abundant, high-quality leaf matter will
also reduce the invasion of unpalatable weedy species. The grazing schedule
may be arranged to coincide with nut harvesting.A short stubble right before
monthly harvest aids in the collection of fallen nuts.