Nitrogen in revegetated China clay sand waste—Part 1: Decomposition of plant material

The decomposition rates of a grass/clover mixture buried in revegetated china clay sand wastes of varying age and management were compared. Rates of weight loss compared favourably with those obtained by other workers on litter decomposition and were generally negatively related to C:N ratio and positively related to organic matter and total nitrogen concentration.

The decomposition rates of grass and clover shoots and roots were compared in the field and in laboratory incubation experiments. Clover shoots and roots decomposed at a significantly faster rate in the field than grass shoots and roots. Net nitrogen release was detected only from clover shoots and roots in the laboratory.

The lack of nitrogen accumulation in the sand waste was attributed to the removal of shoot material from exposed sand tips and the rapid leaching of inorganic nitrogen.