Tropical Grasslands (2000) Volume 34, 103109
Associative effects of tree legumes and effect of cutting height on the yield and nutritive value of Panicum maximum cv. Guinea
THAKSHALA SERESINHE and K.K. PATHIRANA
Department of Animal Science, Faculty of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya, Sri Lanka
Performance of Panicum maximum cv. Guinea, cut at 10 and 15 cm above ground level (every 5 weeks) was tested in pure and mixed swards with Gliricidia sepium and Erythrina lithosperma (cut at 100 cm above ground, every 12 weeks). Cutting height had an effect (P < 0.05) only on crude protein concentration (CP%) of grass and E. lithosperma, crude protein yield (CPY) of grass and acid detergent fibre concentration (ADF%) of grass grown with G. sepium favouring the lower cutting height. E. lithosperma increased (P < 0.05) the dry matter yield of grass while total yield of swards was highest with G. sepium and lowest with grass alone (P < 0.05). The only effect on cell wall composition was a reduction (P < 0.05) in neutral detergent fibre and cellulose concentration in grass when grown with legumes. CP% and CPY of grass increased (P < 0.05) with legumes. Total CPY was highest (P < 0.05) with G. sepium (538 kg/ha/cut) and lowest with pure grass (67.5 kg/ha/cut). DM digestibility and its yield of grass were enhanced when grown with the legumes. Soil nitrogen concentration increased (P < 0.05) with E. lithosperma. It is concluded that growing leguminous trees and grass in mixed forage systems enhances yield and quality of the understorey grass and total output from the system.