Leaf Decomposition and the Nutrients Release from Multipurpose Trees for Crop Production

Decomposition and pattern of nutrients in the residual leaf material is important in assessing suita bility of MPTs species to provide nutrients for growing crop. The rate of decomposition of organic matter, mineralization and release of nitrogen, phosphorus, potassium, calcium, magnesium of fresh leaf litter of five multipurpose trees (MPTs) were measured using litter bags for 12 weeks at the CSIR-Crops Research Institute’s field at Kwadaso-Kumasi. Nitrogen concentration in leaf biomass sample of the MPTs ranged from 3.08 to 4.76% in the order Albizia lebbeck > Leucaena leucocephala > Senna spectabilis > Gliricidia sepium > Senna siamea. Potassium contents ranged from 0.43 to 0.68%. The decomposition process was slow in S. siamea and A. lebbeck which lost 45.2% and 43.3% respectively. Decomposition was highest in the 6 th week, S. spectabilis and L. leucocephala losing 50.9% and 59.2% respectively. By the end of the 12 th week S. spectabilis, L. leucocephala and G. sepium lost 75.8%, 75.9% and 79.1% respectively, representing 189.6g, 189.8g and 197.8g of leaves respectively. N release is considerably faster in the first six to eight weeks. On the basis of the results obtained from this study Leucaena leucocephala and Gliricidia sepium showed promise as materials that could be applied for the release of nutrient to growing crop especially nitrogen, phosphorus, potassium and