To Bag or Not to Bag – that is the Question?
By Sherri Roberts, PAg. Crops Extension Specialist, Weyburn
If you’ve been considering temporary storage options for your grain, grain bags may be the solution you have been looking for. However, you need to do your research as not all bags are created equal. The principal behind grain bags is once the bag is properly sealed, the levels of oxygen in the bag decrease while the levels of carbon dioxide increase. This carbon dioxide rich environment is meant to reduce the level of insect and disease organisms. Does this really happen?
Research conducted in Indiana on corn concluded that the moisture content of the crop at the time of placement into the bag is a deciding factor in whether or not insect and disease organisms are halted. It is also a factor in grain quality. High moisture grain, with greater than 25 per cent moisture, will in fact become ensiled, if placed in a grain bag.
Work done at the University of Manitoba, compared three different moisture content levels in canola that was stored in hermetically sealed bags for a 40-week storage period. They found that in dry moisture canola (8.9 per cent moisture content), germination was maintained above 90 per cent and free fatty acid value (FAV) stayed within safe storage limits. The germination of straight moisture (10.5 per cent moisture content) canola was maintained at initial values in most parts of the silo bags, except the top layer. However, the germination of damp moisture (14.4 per cent moisture content) canola dropped to below 80 per cent and FAV doubled its initial value within eight weeks of storage. High levels of CO2 and localized hotspots in damp moisture canola seeds indicated greater biological activity. Canola seeds graded as Canada Grade 1 at the beginning of the storage, were considered to be Grade 1, Grade 2 and Feed Grade for the dry, straight and damp moisture canola seeds, respectively at the end of the 40-week storage study.
The orientation of your grain bag is a consideration when choosing a site. Bags should be placed from north to south so as to expose the grain bag to the sun evenly. This alignment minimizes temperature variations that can cause moisture migration and localized heating. If the bag is positioned east to west, the sun will beat down on the south side of the bag all day long and may lead to overstretching and possible bag failure. The bag should also be placed on an elevated, slightly sloped, firm site location where there is no chance of flooding. Don’t place your bag across a slope to prevent water buildup along the edge of the bag which can cause stress on the bag and possibly cause it to overstretch. Areas where tree branches could be an issue should be avoided as broken branches could lead to bag damage and even possible catastrophic failure.
Grain bags are not all created equal. When purchasing, check the “mil” thickness and number of layers a bag has. Overfilling can also lead to premature bag failure. Bags are only meant to stretch up to ten per cent. Animal damage can also create weak points in the bag. Weekly checks along the whole bag should be done and repairs with bag quality tape should be performed.
While grain bags are a short term way to handle your bumper crop, they still require your due diligence to keep the grain quality. If you have any further questions in regards to grain bags, please contact your local crops extension specialist or the Agricultural Knowledge Centre at 1-866-457-2377.