Some aspects of Eco-Physiological Adaptability of Three Leguminous Creeping Cover Species

Abstract

Eco-physiological adaptability of three creeping legume cover species, Mucuna utilis Adans, Macroptilium atropurpureum (DC) Urb. and Pueraria phaseoloides Benth were studied under coconut, and under artificial shade. Adaptability of legume species to shade in diverse soil and climatic conditions was evaluated in Wet,. Intermediate and Dry zones with soil types, Ultisols and Entisols under coconut. Seedlings of M. utilis and M. atropurpureum emerged and covered ground rapidly, smothering weeds effectiveliyn all locations while P. phaseoloides had a reduced seedling emergence, particularly in early stages. Germination response to temperature was also higher in M. utilis and M. atropurpureum than in P.phaseoloides. In the Dry zone, M. utilis and M. atropurpureum produced higher above ground dry matter (DM) and leaf litter yields while in the Intermediate zone, M. atropurpurem and P. phaseoloides produced more. In the Wet zone, P. phaseoloides was superior to others in DM and leaf litter production. « Shade induced a marked reduction in N fixation of three species. Nitrogen fixing capacity of P. phaseoloides was highest in all shade | levels although it had a greater reduction in heavy shade (70%). Reduction in N fixation with increased shade was moderate in M. atropurpureum while M. utilis had the least reduction in heavy shade. i N translocated from nodules to other parts was highest with P. phaseoloides at three months after planting (MAP), however, later all species had around 96-98% translocation. A strong positive correlation existed between total plant N and dry weights of plant parts of species, irrespective of shade levels.