BIOMASS OF SOME LEGUMINOUS SPECIES UNDER DIFFERENT AGES AND SPACINGS OF MELIA AZEDARACH Linn. PLANTATION

Abstract

The study on biomass of three leguminous species, namely Centrosema pubescens Benth., Macroptilium atropurpureum Urb. and Lablab purpureus Linn. under 4 x 4 m and 2 x 8 m spacings of Melia azedarach Linn. plantation at Ongpra Reforestation Unit, Suphan Buri Province, were carried out during May 1984 to June 1985. The experimental method used in the study was a completely randomized factorial design. Statistical analysis of biomass showed that there was significant difference (P <0.01) existed among leguminous species Centrosema pubescens Benth. (1,116.25 kg.ha^-1) followed by Macroptilium atropurpureum Urb. (804.52 kg.ha^-1) and Lablab purpureus Linn. (158.06 kg.ha^-1), and also significant difference (P <0.01) between spacings. Apparently, the biomass varied with the amount of rainfall. During the dry season Centrosema pubescens Benth. and Macroptilium atropurpureum Urd. are still green and tend to produce higher biomass than Lablab purpureus Linn. The average dry matter of leguminous species in 2 x 8 m spacing was higher than that of 4 x 4 m spacing of Melia azedarach Linn. plantation. They were 879.63 kg.ha^-1 of biomass under 2 x 8 m spacing and 506.25 kg.ha^-1 under 4 x 4 m spacing. It was recommended that the appropriate spacing for the agroforestry practice under the forest plantation should be 2x 8 m rather than 4 x 4 m.