Ecosystem development of reclaimed china clay wastes. IV. Recycling of above-ground plant nutrients.
The accumulation of nutrients in the standing crop and standing dead material in naturally grazed and sheep-grazed grass/clover vegetation on reclaimed china clay wastes was monitored. The standing dead pool as a store of nutrients and as a potential blockage to nutrient cycling was discussed. Sheep grazing as a management tool to reduce the aboveground plant material, and in particular the standing dead, was demonstrated. A preliminary attempt was made to quantify the rates of internal nutrient cycling from the aboveground plant pool and nutrient returns from a sheep grazing regime. Internal cycling and sheep grazing might have been important supplies of nutrients in these nutrient deficient wastes. For N, inputs from atmospheric and measured cycling sources compared favourably with additions from inorganic fertilizers.