Nutrient-depleted post-industrial land

Stannon Pit, near Camelford, Cornwall, is a 150-hectare former China clay pit deficient in most of the major and minor nutrients. At a five hectare test area, owned by South West Water the use of biofertiliser, sewage sludge, and BSI PAS 100 compost were trialled to assess the suitability of biofertiliser in aiding the establishment of heathland and acid grassland.

Code 7 Consulting Ltd, which is conducting the trial, found that in the first five months, the highest applied rate of anaerobic digestate blended with PAS 100 compost showed the most favourable improvement in soil function and sward recruitment. However, at such an early stage it is difficult to predict whether these outcomes will persist, or if the enhanced nutrient status will prove positive for acid grassland plants, but less inviting for heathland vegetation. Further monitoring continues.