caa a22 4500 477112498 CHVBK 20180405111613.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/BF00011437 doi (NATIONALLICENCE)springer-10.1007/BF00011437 Impact of residue quality on the C and N mineralization of leaf and root residues of three agroforestry species [Elektronische Daten] [B. Vanlauwe, O. Nwoke, N. Sanginga, R. Merckx] A laboratory incubation experiment with 15N labeled root and leaf residues of 3 agroforestry species (Leucaena leucocephala, Dactyladenia barteri and Flemingia macrophylla) was conducted under controlled conditions (25 C) for 56 days to quantify residue C and N mineralization and its relationship with residue quality. No uniform relation was found between the chemical composition of the above and below residues. The leucaena and dactyladenia roots contained more lignin (8 and 26% respectively) and less N (2.0 and 1.0% respectively) than the respective leaves (2 and 13% lignin and 2.9 and 1.4% N, respectively), whereas the differences between the lignin and N contents of the flemingia leaves and roots were not significant (4.6 and 3.0% lignin and 2.63 and 2.68% N, respectively). The leucaena leaves contained more polyphenols than the roots (6.4 and 3.6%), while the polyphenol content of the leaves and roots of the other residues was similar (5.0 and 5.1% for dactyladenia and 4.0 and 3.5% for flemingia). Three patterns of N mineralization could be distinguished. A first pattern, followed by residues producing the highest amounts of CO2, showed an initial immobilization of soil derived N, followed by a net release of both soil and residue derived N after 7 days of incubation. A second pattern, followed by the flemingia leaf residues which produced intermediate amounts of CO2 and had an intermediate quality, showed no significant immobilization of soil derived N, and significant mineralization of residue N. A third pattern, followed by both low quality dactyladenia residues, showed a low release of residue derived N and a continued inmobilization of soil derived N. Residue C mineralization was significantly (p<0.05) correlated with the residue lignin content, C-to-N ratio, and polyphenol-to-N ratio. The proportion of residue N mineralized (immobilized) after 56 days of incubation was significantly correlated with the residue N content (p<0.01) and the C-to-N ratio (p<0.05). The relations were quadratic, rather than linear. The ratio of the proportion of residue N mineralized (immobilized) over the proportion of residue C mineralized after 56 days was highly significantly correlated with the lignin content (p<0.01) and C-to-N (p<0.001), lignin-to-N (p<0.01), polyphenol-to-N (p<0.01) and (lignin+polyphenol)-to-N ratios (p<0.01) in a linear way. This indicates that due to the low availability of the residue C, relatively less N is immobilized for the very low quality residues ((lignin+polyphenol)-to-N ratio: 29.7) than for the residues with a relatively higher quality ((lignin+polyphenol)-to-N ratios between 3.3 and 12.5). Kluwer Academic Publishers, 1996 Dactyladenia barteri nationallicence Flemingia macrophylla nationallicence Leucaena leucocephala nationallicence lignin nationallicence N-immobilization nationallicence 15N labeled residues nationallicence polyphenols nationallicence Vanlauwe B. Soil Microbiology, IITA, Ibadan, Nigeria aut Nwoke O. Soil Microbiology, IITA, Ibadan, Nigeria aut Sanginga N. Soil Microbiology, IITA, Ibadan, Nigeria aut Merckx R. Laboratory of Soil Fertility and Soil Biology, Faculty of Agricultural Sciences, K.U. Leuven, Kardinaal Mercierlaan 92, 3001, Leuven/Heverlee, Belgium aut Plant and Soil Kluwer Academic Publishers; http://www.wkap.nl 183/2(1996-09-01), 221-231 0032-079X 183:2<221 1996 183 11104 https://doi.org/10.1007/BF00011437 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00011437 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Vanlauwe B. Soil Microbiology, IITA, Ibadan, Nigeria aut NATIONALLICENCE 700 1- Nwoke O. Soil Microbiology, IITA, Ibadan, Nigeria aut NATIONALLICENCE 700 1- Sanginga N. Soil Microbiology, IITA, Ibadan, Nigeria aut NATIONALLICENCE 700 1- Merckx R. Laboratory of Soil Fertility and Soil Biology, Faculty of Agricultural Sciences, K.U. Leuven, Kardinaal Mercierlaan 92, 3001, Leuven/Heverlee, Belgium aut NATIONALLICENCE 773 0- Plant and Soil Kluwer Academic Publishers; http://www.wkap.nl 183/2(1996-09-01), 221-231 0032-079X 183:2<221 1996 183 11104 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer