Demonstration trials can be used to show the effects of alternative fertilization practices on crop yields on real farms. Results can lead to adjustments in nutrient application practices that improve crop yield or quality, reduce fertilizer costs, or minimize the risks of nitrogen and phosphorus losses to the environment.
Berry fertilizer demonstration trials
22 berry farms across the Lower Fraser Valley have implemented reduced nitrogen fertilizer rates as part of the trials and are monitoring the effects of the adjusted rates relative to their normal practices. Established in 2017, this work was designed as a long term effort to monitor the effect changes in nutrient management may have on soil nutrient status and overall productivity.
Interim reports from the end of the 2019 season have so far indicated that there is room in blueberry and raspberry crops for reducing nitrogen application rates without impact on productivity.
- Interim blueberry fertilizer demonstration trial results (PDF, 220 KB)
- Interim raspberry fertilizer demonstration trial results (PDF, 217 KB)
Potato phosphorus fertilization
Soil Nutrient Surveys in the Fraser Valley have noted high soil test phosphorus levels and opportunity for improved nutrient management of field vegetables. Fertilizer trials were conducted on commercial farms in Delta in 2016 and 2017 to demonstrate the use of reduced phosphorus fertilizer rates compared with standard farm rates.
The trials demonstrated that when soil phosphorus is high, yields were not negatively impacted by reducing phosphorus fertilizer rates by as much as 50% relative to the typical farm rate.
- 2017 Project Overview and Results (PDF)
- 2017 Field Reports (PDF)
- 2016 Project Overview and Results (PDF)
- 2016 Field Reports (PDF)
Blueberry nitrogen fertilization
In some blueberry varieties, excess nitrogen can delay dormancy, reduce bud set, and ultimately decrease yield potential. A trial was started in 2014 to evaluate the effects of different nitrogen application treatments (rates) over several years. The objective is to determine optimal treatments to optimize nitrogen use.
Presentation at the B.C. Blueberry Council field day on November 20, 2014:
The nitrogen fertilization trial was featured in a June 2015 article published in Orchard & Vine Online:
- Article in Orchard & Vine
- Correction: the breeding research in Pitt Meadows is separate from the nitrogen trials.
In the early 1990’s, vegetable producers in Cloverdale, B.C. participated in fertilizer trials that evaluated the effects of varying fertilizer rates, application timing and cover crops on yields among other things. In many cases, the producers could reduce input costs without risking a loss in profitability. The results are still very much relevant today.