Agnew: Determining Best Practices for Summer Storage of Canola in Western Canada
Date: December 2014
Term: 2 years
Status: Completed
Researcher(s): Joy Agnew, Les Hill and Bryan Lung, PAMI, Humboldt SK
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: ADF, ACPC, MCGA, AAFC
Project Summary
In 2014 researchers initiated a project to collect baseline information on how management practices affect the storage conditions of canola over the summer months. The objectives of the project were to gather baseline data on the effect of bin management (aeration, turning, leaving it alone) on the temperature and relative humidity profile in-bin throughout the summer months. The key recommendation from this project, for canola that is overdry and frozen over the winter, is to leave the bin alone but monitor the temperature profile and have a plan in place to move the seed if problems arise.
In 2014 researchers at PAMI in Saskatchewan initiated a project to collect baseline information on how management practices affect the storage conditions of canola over the summer months. The objectives of the project were to gather in-bin data on the effect of bin management (aeration, turning, leaving it alone) on the temperature and relative humidity profile in-bin throughout the summer months (June and July). The project included a commercial bin-scale trial and additional bench-scale trials to provide data on the warming rate of canola with different airflow rates. The data collected included the temperature profile in a bin of cooled canola throughout the summer months, the effect of turning and aeration on temperature profile, the warming rate of canola due to aeration and the effect of airflow rate on the warming rate of canola.
Starting in June, researchers monitored the in-bin grain temperature and relative humidity of three bins full of canola on a commercial farm over the summer. Three different treatments included one bin left alone as a baseline, a second bin had 700 of its 4,000 bushels removed and returned to the same bin (“turned”) and the third bin was aerated during the evening to slowly warm up the grain. All three bins contained dry canola (average moisture content = 6.5%) that had been frozen during the previous winter by aerating when the ambient temperature was below -30°C. At the start of the project on June 6, 2014, the temperature of the core of the bins was still as cold as -17°C. The data from the bin-scale testing was collected for a minimum of 6 weeks or until grain was removed from bin. The data was provided to producers and agronomists in realtime via a live feed display of the temperature and relative humidity data and blog updates were provided discussing the implications of the data.
Overall, the project provided clear results for the conditions tested, showing that if canola is overdry and frozen over the winter, leaving it alone results in the best conditions for storage over the summer. There was very little moisture migration in all three bins throughout June and July, therefore, no spoilage or condensation was observed for any treatment. However, lack of moisture migration may have been partially due to the lack of moisture in the canola (the canola moisture content was 6%).
The study also showed there were large temperature differences in each bin throughout the summer. The baseline bin had a large temperature differential of 28°C, 25°C at the edge and -3°C in the core for most of July, but the temperature difference was gradual, resulting in generally stable conditions. Although the temperature in the bin headspace fluctuated widely from day to night (reaching as high as 55°C), the relative humidity of the air in the headspace was very low (<40%). The temperature of the grain at the top of the bin (within 2ft of headspace) did not fluctuate during the day. The warming rate of canola was approximately equal to the cooling rate when using aeration flowrates (0.1 to 0.5 cfm/bu).
The key recommendation from this project is to leave the bin alone but monitor the temperature profile and have a plan in place to move the seed if problems arise. However, researchers caution that these results were limited to overdry canola that had been frozen over the winter and stored in an 18 ft diameter bin. Canola starting at a higher moisture content or at a higher temperature or stored in a different sized bin might behave differently during the summer.
In 2016, researchers repeated the bin-scale data collection for canola with a higher starting moisture content of 9%. The results were very similar; the baseline bin had the most stable conditions throughout the summer. No moisture migration was observed in any of the bins. Researchers plan to continue the project and monitor bins of larger diameter with different starting conditions to provide additional information to help producers make better storage management decisions.
Full Report PDF: Determining Best Practices for Summer Storage of Canola in Western Canada