Pasture agronomy research in northern Thailand highlands.

Abstract

Proc. Aust. Soc. Anim. Prod. (1978) 12: 203 PASTURE AGRONOMY RESEARCH IN NORTHERN THAILAND HIGHLANDS T.A. GIBSON* and A.C. ANDREWS** Species adaptation experiments showed that Desmodium intortum cv. greenleaf was the most successful legume; with moderate fertilization and infrequent defoliation greenleaf produced 8,000 kg dry,matter in ,the first year. Other successful legumes in order of importance were Stylosanthes -w-p guyanensis cvs. cook, endeavour and Schofield, Macrotyloma --I__ axillare, Desmodium - uncinatum cv. silverleaf, Trifolium semipilosum, Trifolium repens and Lotononis bainesii, Greenleaf is favoured for areas above 1,000 m by virtue of its ease of establishment, excellent production and persistence, palatability and competitiveness against weed s. s Stylosanthes p p . do better at lower ele vations; a t 800 m cook sty1 o has equalled green leaf in product ion over two years. Trifolium SPP- may be useful for e leva tions above 1,400 m; but their production is one-third of greenleaf and the presence of sown grasses is essentia 1 to provide bulk and to restrict weed invasion. P anceps cvs. Setaria maximum nandi, kazungula and narok, and Panicum P.P cv. hamil were the mos t successful grasses producing 10,000 kg dry matter in the first year ~ with 225 kg applied nitrogen per ha. Other successful grasses in order of importance were Brachiaria decumbens, Paspalum plicatulum, Panicum maximum cvs, green panic and guinea and Paspalum dilatatum. mFertilizer experiments led to the provisional fertilizer recommendation for the establishment' of gretnleaf based pasture of 40 kg P/ha as triple super phosphate (or 80-120 kg P/ha as rock phosphate) and 20 kg S/ha. Both rock phosphate and gypsum, mined in Thailand, have proved to be successful fertilizers. Establishment experiments have shown the importance of fertilizers in enhancing . legume competitiveness; successful pastures have been established by oversowing greenleaf seed onto either defoliated I, cylindrica or overgrazed weedy savanna with infrequent post--sowTng defoliation to control weeds. Small scale grazing trials have shown that greenleaf ' 'pastures can carry 2 native cattle/ha with liveweight gains of 150 kg/ha/yr equivalent to a thirty-fold increase in production per unit area over the current native range situation. Larger grazing trials are underway to verify these results. Improved pastures are now being .extended to tribal people, and a tropical pasture seed enterprise is being initiated. FALVEY, L. (19 77). Rumi .nants in the Highlands of Northern Thailand An Agro-sot iolog ical Survey . H.A.P. Chiang Mai (in press). - - - ---.- .-4--w- .---.a-m-.---..-.-I---- * ** UNPDAC, P.O. Box 156, Chiang Mai, Thailand. Thai-Australian Highland Agronomy Project, Chiang Mai, Thailand 203.