Phenolic acids in boreal peats from Finland and comparison with those from tropical and temperate areas

Abstract

Lignin-related phenolic acids have been implicated in rice sterility problem on peatlands in Southeast Asia. Therefore, a comparison was made of phenolic constituents in peat soils from three zones; tropical Malaysia, temperate Japan and boreal Finland. From peat samples were extracted lignin-derived phenolic acids: 4-hydroxybenzoic, vanillic, syringic, trans-4-hydroxycinnamic and ferulic acids. The amounts of all the phenolic acids were greater in the tropical and temperate peat soils than in the boreal peat. Between the tropical and temperate peats, there was a marked difference in the quantitative distribution of the five phenolic acids. The ratio of the total amount of trans-4-hydroxycinnamic and ferulic acids to that of 4-hydroxybenzoic, vanillic and syringic acids was 0.12 for tropical and 2.7 for temperate peats. The substituted hydroxycinnamic acids, therefore, occurred in a smaller amount in the tropical than in the temperate peat soils. The polymerisation of these phenolic acids may cause rice sterility problem in the tropical peat soils.