Soil Nutrient Studies

Soil nutrient studies have been conducted for agronomic and environmental purposes, in three regions of British Columbia: Hullcar Valley (2016, 2017, and 2018), the Lower Fraser Valley (2012 and 2005), and the Okanagan-Similkameen Valley (2007).

2018 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 2018, 39 agricultural fields over or near the Hullcar Aquifer 103 were sampled for a Post-Harvest (Soil) Nitrate Test (PHNT) to compare with 2017 results
  • On its own, the PHNT 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
  • Overall, 80% of the total sampled land area (31 fields) had PHNT ratings of ‘Low’ or ‘Medium’
  • The area-weighted average PHNT was 25% greater (15 kg N/ha) in 2018 than in 2017, and the median PHNT of the overall study area was 36% (18 kg N/ha) greater in 2018 than in 2017
  • Among the fields sampled, 64% of the nitrate in the top 90 cm of soil was found in the 0-30 cm layer on average, while 19% and 17% was found in the 30-60 cm and 60-90 cm layers, respectively.

Read the Progress Report:

Past reports:

Raw data:

Previous Studies

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