Incorporation of natural hydrocarbons from plant residues into an hydromorphic humic podzol following afforestation and fertilization

SUMMARY The content and composition of natural hydrocarbons from plant residues ( Pinus maritima sp.) of a hydromorphic humic podzol were investigated following the addition of NPK and P fertilizers. L and F layers and the A, horizon from non‐fertilized and fertilized soil were analysed for total lipids and hydrocarbons, and non‐linear and linear hydrocarbons. The decrease in non‐linear hydrocarbons extracted following the addition of fertilizers was attributed to the incorporation of non‐linear hydrocarbons into humus, rather than to their biodegradation by soil micro‐organisms. Short‐ and medium‐chain linear hydrocarbons from plant residues or of microbial origin were rapidly biodegraded or fixed by soil micro‐organisms, resulting in a very low concentration in the A, horizon. In contrast, long‐chain linear hydrocarbons of plant origin accumulated in the non‐fertilized soil, while the addition of P fertilizer slightly stimulated their biodegradation. oration is needed before firm conclusions can be drawn.