Tropical Grasslands (2003) Volume 37, 2032
Evaluation of forage legumes and grasses on seasonally waterlogged sites in north-east Thailand
M.D. HARE, C. KAEWKUNYA, P. TATSAPONG and M. SAENGKHAM
Faculty of Agriculture, Ubon Ratchathani University, Ubon Ratchathani, Thailand
legumes sown in pure swards and 7 grasses sown with legumes and fertilised
with N were evaluated in a series of trials at 7 low lying infertile
sites in north-east Thailand over 2Ð3 years from 1997Ð2000. All sites
have an average annual rainfall of 1400 mm.
highest legume yield in pure swards was in the year of sowing from Aeschynomene
americana cv. Lee, which produced over 14 t/ha DM at one site. All
legumes failed to persist beyond the second wet season under cutting.
Stylosanthes guianensis cv. Tha Phra (CIAT 184) showed some promise
as a legume at some sites that were not deeply waterlogged but only
in a few places was it able to persist into the second dry season. No
legumes performed well enough to be recommended for such sites under
the existing management system.
The best grasses
on deeply waterlogged sites were Paspalum atratum cv. Ubon, P.
plicatulum (common Thailand type) and Setaria sphacelata
var. splendida cv. Splenda. These 3 grasses performed well at
all sites and were the most consistent in terms of persistence and yield.
On less waterlogged sites, Panicum maximum cv. Purple was very
productive, producing in excess of 30 t/ha DM in the second 6-month
wet season at 2 sites. Brachiaria ruziziensis (common Thailand
type), B. decumbens cv. Basilisk, and Digitaria milanjiana
cv. Jarra grew well only on sites that did not become inundated with
water. No legumes were able to persist in the nitrogen-fertilised (100Ð120
kg/ha N) grass swards beyond the second wet season.