Grain bags need more study

1/20/2010 | By Laura Rance, Co-operator Editor

Digvir Jayas is a professor of biosystems engineering at the University of Manitoba. (Laura Rance photo)

Grain bags may seem like an easy solution to the problem of where to store that bin-buster of a crop.

But a University of Manitoba grain storage research had some cautionary words about a product that has seen precious little study when he spoke to farmers attending Manitoba Ag Days Wenesday.

Digvir Jayas, a professor of biosystems engineering, said the three-layered polyethene bags -- sometimes called silo bags or grain sausages -- were initially developed in Argentina to address the lack of grain storage on farms and the long distances to delivery points.

The bags measuring nine or 10 feet by 250 feet long can hold 8,000 to 12,000 bushels of grain. In Argentina, they provided temporary storage until the farmer had finished harvest and could start delivering it to market.

"They were meant to store dry grain for a short duration," Jayas said. "They were never intended to replace long-term storage structures."

The bags can be breached by weather, birds, or sharp objects on the ground so care must be taken when selecting a site. Once moisture gets in, the grain can spoil rapidly.

Plus, using them requires an investment in a grain bagger and an unloader that have a combined cost about $60,000.

However, their use has since spread to Australia, Canada, and the U.S. even though there has been limited evaluation of their performance under different conditions.

The most comprehensive study to date was conducted in Argentina, where researchers assessed its performance for wheat bagged for 150 days at 12.5 per cent moisture and at 16.4 per cent.

The study showed that the dry grain was cooler by 5.8C after 150 days. There was also a significant drop in the germination rate of the damp grain. But there was no sign of self-heating in the grain that was stored at higher moisture.

Jayas is attempting to get funding from the Canola Council of Canada and the Canadian Wheat Board to conduct a more comprehensive study of the bags using three commodities over two years. Until more research is available, farmers can take some precautions to protect the quality of their grain.

He recommended making sure the grain was one to two degrees below dry before placing it into the bag. "You should be able to store grain safety for up to six months."

(Source: Manitoba Ag Day ShowNews Jan/2010)

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