Decomposition of Leaves and Roots of Different Crops in Peat.

Peatland is one of the most important and largest stores of carbon. Carbon accumulates in peatland because plant production is faster than decomposition. A study to determine the decomposition rate of leaves and roots for oil palm (Elaeis guineensis), pineapple (Ananas comosus) and sago (Metroxylon sagu) residues on peat was done. The decomposition of the residues was conducted for 14 and 7 months in pot and field trial respectively. Results from the 14 months pot trial show that, for leaves decomposition, the highest and lowest mass loss of 90% and 30% was found in pineapple and sago crops respectively and for roots decomposition, the highest and lowest mass loss of 70% and 50% were found in sago and pineapple crops respectively. For pineapple plant decomposition, the leaves decomposed faster than the roots. Different pattern was found in sago decomposition where roots decomposed faster than the leaves. Oil palm shows a similar mass loss in leaves and roots. Initial analysis shows that sago and pineapple leaves have the highest and the lowest substrate quality expressed by C:N and lignin:N respectively and in the roots the highest and lowest substrate quality were found in pineapple and sago. In a parallel field decomposition study, the results show that the field trial data for weight loss and lignin follow similar trend to that of pot study. Thus, prediction can be made for field from pot trial for these variables. Choice of crop is crucial to peatland because higher decomposition may lead to less CO₂ storage.