Decomposition and nutrients release pattern of leaves,stems / vines and roots of selected leguminous and non-leguminous plant species

Decomposition and nutrients release pattern of leaves,stems/vines and roots of leguminous plants (pueraria phaseoloides and centrosema brasilianum) and non-leguminous plants (chromolaena odorata and panicum maximum) were examined for a period of 98 days. the decomposition rate declined in the order p. maximum > c. odorata > p. phaseoloides > c. brasilianum. on the 98th day,between 63% and 71% of stems/vines only had decomposed. the % mass of the remaining materials were in the order of c. odorata > p. phaseoloides > c. brasilianum > p. maximum and the decomposition rate was in the reverse order. the mass loss and decomposition rates of the parts of the plant species followed the initial n concentrations of the residues in the order of leaves > roots > stems/vines. the initial n contents in plant residues varied from 0.42 to 3.19 g/kg and p from 0.03 to 0.27 g/kg. the pattern of n remaining in the stems/vines of the species at 98 days after placements (dap) was in the order p. phaseoloides (49%) > c. odorata (42%) > c. brasilianum (41%) > p. maximum (36%). the chemical composition of the residues shows that the leaves are richer in n and p than the roots and least in stems/vines in the order c. odorata > c. brasilianum > p. phaseoloides > p. maximum. a direct relationship was observed between the initial n contents of the residues and initial polyphenol contents (r = 0.72,p > 0.01),but no relationships with the p content of the residues. the data reported in this study shows that the decomposition patterns of above and below - ground residues of leguminous and non-leguminous plant species could have positive effect on nutrients requirement of crops.