Soil Nutrient Studies

Soil nutrient studies have been conducted for agronomic and environmental purposes, in three regions of British Columbia: Hullcar Valley (2016 and 2017), the Lower Fraser Valley (2012 and 2005), and the Okanagan-Similkameen Valley (2007).

2017 Post-Harvest Nitrate Study: Hullcar Valley


  • Monitoring the year-to-year trends of post-harvest soil nitrate is useful for improving the efficiency of nitrogen use
  • In the fall of 2017, 39 agricultural fields over or near the Hullcar Aquifer 103 were sampled for a Post-Harvest (Soil) Nitrate Test (PHNT) to compare with 2016 results
  • Overall, producers managed N optimally in most fields in 2017 and there was less post-harvest (residual) soil nitrate in 2017 than in 2016
  • In 2017, PHNT values were high or very high in 5 (or 13%) fields, and low or medium in 34 (or 87%) fields
  • Weather conditions from the fall of 2017 to early spring 2018 caused nitrate in the top 30 cm of soil to leach below the 90 cm depth among three sites with coarse-textured soils, or to the 30-60 cm and 60-90 cm layers at three sites with finer-textured soil.
  • On its own, the PHNT soil test does not predict the amount of nitrate that will leach over the non-growing season, but it is prudent to minimize the amount of post-harvest soil nitrate

Read the Final Report:

Past reports:

Raw data:

Previous Studies

2012 Fraser Valley Soil Nutrient Survey - Results by Crop Group: