Growth of forage tree legumes at four agro-climatic sites in Indonesia.
The growth of the forage tree legumes Leucaena leucocephala, Gliricidia sepium, Sesbania sesban, Sesbania grandiflora, Albizia falcataria [Paraserianthes falcataria] and Calliandra calothyrsus, which have a potentially important role in improving ruminant production on farms, was evaluated at four sites in Indonesia (2 in West Java, 1 in East Java and 1 in North Sumatra) between 1983 and 1986. Tree seedlings were planted at 10 000 trees/ha, and after an establishment period of 9-12 months, harvested every 3 months for a 2-year period. At Bambu Apus, West Java (2040 mm annual rainfall, 1 month dry period, lowland, latosol with pH 5.6 decreasing with depth), G. sepium and C. calothyrsus produced 13 and 10 t/ha per year of leaf dry matter, respectively. Other species did not grow well at this site and fewer than 60% of the trees of these species survived until the end of the experimental period. At Sei Putih, North Sumatra (1550 mm annual rainfall, 3 months dry period, lowland, podzolic with pH 5.5 increasing with depth), no species produced >6 t/ha per year of leaf dry matter. The highest yielding species were L. leucocephala and P. falcataria. At Cisarua, West Java (3340 mm annual rainfall, no dry periods, 925 m altitude, latosol with pH 5.6 increasing with depth) only C. calothyrsus grew well and produced 9 t/ha per year of leaf dry matter. At Grati, East Java (1500 mm annual rainfall, 6 months dry period, lowland, alluvial with pH 6.6 increasing with depth) L. leucocephala produced >8 t/ha per year of leaf dry matter, while none of the C. calothyrsus and P. falcataria trees survived the first dry season. Although L. leucocephala has been the most widely grown tree legume species in the tropics, C. calothyrsus and G. sepium performed better at the wetter sites and at high altitude.