Berland Gravel Pit

Objective:

To assess the impact of applying sludge to an abandoned gravel pit.

Methods

  • ANC sludge was spread on the Berland Gravel Pit located at km 167 of the ANC Resources Road in Spring 2000. 
  • The sludge was spread  by blading the stockpiled material in depths ranging from 5 to 30 cm. 
  • The site had an overall slope of approximately 9% with the steepest portion approximately 15%.
  • No trees were planted at this site.
  • Vegetative progress was monitored between 2000 and 2010.
  • Soil samples were obtained from 2000 to 2002 and in 2010.

Results

  • Although no trees were planted at the Gravel Pit, by 2010 there were several woody species well established on the site including willow (Salix spp.), green alder (Alnus crispa), and aspen (Populus tremuloides).
  • Green alder present on the site fixes nitrogen and has likely had a very positive effect on neighboring vegetation and soil development. 
  • In combination with the sludge, the grasses and herbaceous cover established on the site have created an organic soil layer over top of the coarse textured gravel ranging from 5 to 10 cm.
  • Soil chemistry data indicated that there were no concerns with surface pH, EC or SAR.  
  • Soluble ions were elevated at the surface indicating additional nutrients were present for plant use. 
  • Nitrate values declined significantly in each of the depth intervals between 2000 and 2001 indicating that leaching was occurring and that the nitrates had moved beyond the 1 m depth in these coarse materials.