Forage tree legumes. I. Productivity and N economy of Leucaena, Gliricidia, Calliandra and Sesbania and tree/green panic mixtures

Abstract

A field experiment was conducted at Gowa, S. Sulawesi, Indonesia, to assess the productivity of 4 tree legumes. The experiment consisted of an establishment phase of 6 months, a tree only phase of 8 months, followed by a tree/grass phase of 14 months. After the initial cutting to 1 m, trees were lopped to 1 m when they reached heights of 1.5, 2.0 and 2.5 m above the soil surface. Leaf production was unaffected by cutting at the various attainment heights. Over the 14 month establishment and tree phase, yields totalled 2 1.8 t DM ha-1 in leucaena, 19.2 t DM ha-1 in gliricidia, 18.2 t ha-1 in calliandra and 6.7 t ha-1 in sesbania, which did not survive cutting. Stem production increased as attainment height increased. Yield of the understorey grass (Panicum maximum cv. Riversdale) in the 14 month tree/grass phase was unaffected by tree attainment height and was highest in the grass monoculture plots (12.0 tha-1), and lowest under leucaena and gliricidia. Nitrogen yields totalled 103 kg ha-1 in the grass monoculture and 901 kg ha-l in the tree monoculture and tree/grass mixtures. There was little N transfer from the tree legume to the grass.