Knowing how to manage moisture in your grain bins is very important, especially now that more and more growers are building on-farm grain storage systems. “Having the capacity to store grain gives producers marketing options and flexibility,” notes Eric Richter, an agronomic sales representative with Syngenta Canada. “However, there is a lot of risk involved. There is the potential to lose hundreds of thousands of dollars if the grain is not cared for correctly.”
The key is to purchase the right technology and ensure it’s working properly over time. “The first step is finding out the moisture content of your newly stored grain using a good-quality moisture tester,” says Helmut Spieser, a field crop conditioning and environment engineer with the Ontario Ministry of Agriculture, Food and Rural Affairs. “It’s worth it to purchase a good new one.” However, he stresses that proper care of the unit is also very important.
Devin Homick, a grain originator with Great Lakes Grain in Delhi, Ontario, agrees. “Hand-held moisture meters on a farm tend to get thrown around, which can cause dysfunction,” he says.
“Farmers don’t get them checked often enough, and they assume they’re getting correct readings, but that’s often not the case.” He also notes that many growers have stationary moisture meters, but that these are also very delicate, and can easily become inaccurate with being bumped.
The answer is to check your moisture tester regularly for accuracy.
“An easy way to do this is to moisture test a sample with your unit, and then have the elevator test it to see if the readings are the same,” says Spieser. “If it’s not working, contact the company and a technician will calibrate it for you. However, keep in mind that it isn’t possible to calibrate some older units.” Homick also encourages farmers to check their moisture meter readings with those taken at their local elevator. “We have two at every facility and they’re calibrated professionally on an ongoing basis,” he says. “We change the setting for soybeans, corn, etc. and the newer portable ones for farms have settings as well.” He notes that while the readings of two meters will never be exactly the same, anything within 0.1 is acceptable. “If the difference is in that range or beyond that range, you definitely need to calibrate your tester,” he says. “The newer testers also have a scale incorporated, so that you don’t have to weigh the sample beforehand. The tester lets you know when you’ve added enough grain or beans.”
Driving moisture out
There were high incidences of ear moulds this year in southern Ontario, and Richter hopes growers over-dried their corn slightly to stop mould growth. “If you don’t over-dry it a bit, and you try to store slightly damp corn with just fans to dry it, you can easily see accelerated mould growth,” he says. “The storage temperature matters, and a warm temperature can also contribute to mould growth in storage, so make sure you have a temperature sensor inside your bins.”
Richter notes that there are three major factors in corn drying costs. “It’s a variable expense on an annual basis, anywhere from $40 to $100 an acre, depending on fuel costs (natural gas or propane), growing season conditions and hybrid portfolio,” he explains. “’Hybrid portfolio’ means the practice of choosing hybrids so you can spread out your maturity dates to maximize yields and minimize drying costs.” Full season hybrids will have higher yields, but will be more expensive to dry. Richter says having different maturity dates also means that you won’t have large volumes of wet corn that need drying at the same time.
Richter also advises adjusting the combine before switching to harvesting a different hybrid. “This will produce clean grain for storage, with a low percentage of fines, stalks and cobs, and also save you drying costs,” he says. “I also recommend a pre-clean before storage to remove fines. When you have a lot of debris, it’s harder to dry the corn, and it’s also more difficult to run air through your grain during storage.”
Once the grain is stored, farmers have the option of opening bins over the winter season to try to decrease the moisture content of their grain or soybeans. Homick says it’s not easy in southern Ontario to get low-humidity days. “The amount of moisture coming off the Great Lakes makes it a challenge to find a day where you won’t be putting high-humidity air in your bin,” he says. “That’s why investing in a high-quality relative humidity tester is important.”
Spieser agrees. “Do numerous moisture tests in different parts of the bin at various depths to get an accurate picture of your grain, but also test the relative humidity of the outside air,” he says. “Invest in a good-quality tester. You can buy hand-held units that measure wind speed, temperature and relative humidity with a digital readout. By knowing the air temperature and relative humidity you can determine the equilibrium moisture content (EMC) of the grain. If you move air with these properties through the grain for a long enough period, the grain will approach its EMC.” He notes that cereal grains and soybeans give up and absorb moisture very easily, but high-temperature dried corn does not.
After you’ve decided to open your bin, you must also keep an eye out for frost formation. “As the moisture leaves the grain, you can get rime frost depositing on the cold wire of the bird screen,” notes Spieser. “This frost can build up and completely block the exhaust vents. The fan is still running and enough pressure can build up that you can damage the bin roof. So keep an eye on your vent screens, and shut the fan off if it’s getting covered in frost.
With red lentils, quality is paramount, and as the red lentil industry grows, quality issues related to long-term storage need to be addressed.
“Canada has become an important producer and exporter of red lentils, and there is the potential for this production to keep growing if the quality of red lentils can be maintained during long-term storage. The problem that Canadian red lentil producers face is that the Western Canadian climate is very different from other lentil producing countries,” says Dr. Stefan Cenkowski, a professor of biosystems engineering at the University of Manitoba.
Canada is the leading exporter of lentils, and Saskatchewan producers grow 99 percent of Canada’s lentil crop. Lentils grown in Canada are often subjected to high temperatures in the summer, followed by cold winter temperatures. Depending on the crop year, lentils may also be dried while going into storage. When Canadian lentils are shipped to warmer climates, they can undergo physical changes, such as absorbing moisture in the ship’s hold and at the point of destination. Although producers have no control over the weather or shipping, by optimizing their storage conditions, they can better maintain the quality of the crop. With that in mind, the Saskatchewan Pulse Growers funded research examining the effects of post-harvest handling.
Cenkowski teamed up with Dr. Lope Tabil, a professor of chemical and biological engineering at the University of Saskatchewan. They obtained several hundred kilograms of Robin and Impact lentils from two different crop years for testing. The lentils were stored and pre-treated to mimic post-harvest operations.
Researchers wanted to mimic the industrial dehulling process as closely as possible, so for the first year they used two dehulling units. The first unit was a small Satake mill, which they ran at a speed of 110 r.p.m. for 40 seconds. The lentils were processed at a pre-milling moisture content of 10.4 percent to 15.3 percent wet basis.
For the second dehuller, researchers followed a protocol established by the Canadian International Grain Institute in Winnipeg. The seeds were pitted just enough to open the seed coat and expose cotyledon. The moisture was tempered to 15 percent for four hours, and then dried at 70 degrees Celsius for 20 minutes. The seeds, which now had a moisture content of about six per cent, were cooled overnight with ambient air. The next day the lentils were dehulled and split, and the loose hulls were collected.
The Satake mill was more comparable to industrial dehulling, so after the first year, they only used the second dehuller to verify the results of the Satake mill.
Once the lentils were processed, researchers measured the dehulling efficiency and the cooking time. The Manitoba researchers also used visual imaging technology to analyze seed wrinkling and staining.
Samples were stored for up to 12 months at various temperatures to mimic summer, fall and winter storage conditions. “We didn’t see any difference in cooking time of the material, as well as the dehulling efficiency, except that the dehulling efficiency would decrease with respect to storage time,” says Tabil.
Researchers also found a method that may reduce the negative effects of long storage times on dehulling efficiency. “What we also noticed, based on our experiments, was that when adjusting moisture content of red lentils 48 hours before milling, that influences quality. The moisture adjustment step could be used partially to alleviate the effect of storage conditions. We could probably gain a couple of percentages on the dehulling efficiency,” says Cenkowski.
The factor that was most detrimental to seed quality was not storage time. “I think the most important of all the conditions was the drying and wetting cycles. That was the most critical,” says Dr. Tabil.
Wet and dry cycles occur in storage when the sun warms one side of the bin. As air warms, it rises and picks up moisture. The air then circulates to the cooler side of the bin, dumping the moisture. As temperatures drop at night, this process reverses. This natural convection causes a one or two per cent change in moisture, which is enough to wrinkle and stain the seed. It also decreases the dehulling efficiency of the lentils, which leads to more waste when the lentils are processed. The cooking time of the lentils also increases.
“Forced convection is needed to stop the natural convection, and also forced convection will remove the respiration heat, which would also be responsible for enhancing wet pockets if moisture in the bin is not uniform,” says Cenkowski. He adds that producers need to be careful when they ventilate. For example, they should not ventilate when it’s very humid or raining.
Ultimately, producers do have some tools to help them maintain the quality of their red lentil crops. Cleaning seeds as soon as possible and not mixing seeds from multiple years are also beneficial management practices, Cenkowski explains.
“It is not completely out of hand, if we can control the cyclic moisture changes,” says Cenkowski.
This pneumatic grain handling system definitely does not suck; it literally blows grain into storage. And it is how the Sawatzkys, who farm near MacGregor, Manitoba, updated their grain handling system to reduce manpower and improve grain drying efficiencies.
In 2010, Dan, Tim and Ron Sawatzky equipped Sawatzky Enterprises Ltd. with a pneumatic system for distributing grain to a generation of new and larger bins than their father, Glen, had used. They also extended the tubing to deliver grain overhead about 80 feet to the out-of-date grain leg for the system their father had built around 1978. “The old system just became obsolete. We farm about 5000 acres today and have been growing the storage for about five years (since about 2006). We went to the pneumatic system last summer when we upgraded our dryer,” says Dan Sawatzky.
With Dad now semi-retired, his sons grow canola, red spring wheat, winter wheat, oats, soybeans, corn and rye. The 70-foot-tall grain leg still serves the original twin rows of four 2700-bushel flat-bottom bins as well as two 1500-bushel hoppers and a pair of 6500-bushel bins built later.
Today’s primary storage system is west of the original system. It has capacity for about 215,000 bushels of storage in a U-shaped bin arrangement. It has four 29,000-bushel flat-bottom bins, one 45,000-bushel bin, and a dozen 4400-bushel hopper bins. Trucks arriving from the field also can unload to a pair of new 6000-bushel wet bins feeding the new grain dryer. All of the bins have full-aeration floors and fans.
The two systems, old and new, are separated by about 32 feet for a truck roadway. The original system, still in use, is about 100 feet long. The new system spans about 300 feet west and up to 300 feet south from the leg. Each bin in the new system is tied in with its own six-inch pneumatic pipe running from a pair of distribution boxes close to the central airlock.
The complex storage is a solid example of a “good fit” for a pneumatic grain system today, says Adrian Caillier, owner/manager of A.R.K. New-Tech Ltd., in Manitou, Manitoba. A.R.K. designs, delivers and services systems for grain handling and conditioning throughout Western Canada. It is a retailer for products, including Farm Fans dryers and high-capacity blowers by Kongskilde and ConveyAir.
As storage systems go, the Sawatzky project was mid-sized, says Caillier. A.R.K. had a project underway at about the same time at Englefeld, Saskatchewan, providing pneumatic handling for an 850,000-bushel system. It also was installing much smaller pneumatic conveyors to solve issues like manpower, grain drying, grain handling and mixed bin storage.
Sawatzky Farms required the most powerful motor in the arsenal, a 75-horsepower three-phase unit, for the long push and 45-foot elevation. The system delivers about 2200 bushels per hour to a maximum run of about 350 feet.
A small system can operate with as little as a 10-horsepower single phase motor. Typical farms, with single-phase power, can use up to two 15-horsepower motors.
In about 2006, ConveyAir introduced distributor boxes. Each distributor has one inlet at the bottom and up to six outlets at the top. When it is time to redirect grain to a different bin, the operator turns the rotary switch on the distributor.
Three-phase power was available for the Sawatsky project. Manitoba Hydro only needed to install three poles.
The Sawatzky brothers took one further precaution in the summer of 2011: They had an electrician install sensors to prevent over-filling at every bin. The sensor will shut down the whole pneumatic system until an operator can redirect the grain and restart the system. “As manpower is harder to find on farms, there’s more and more demand for a total grain handling system where one man can haul the grain into the yard, dry the grain and put it into final storage,” Caillier says. “Prior to this pneumatic conveying system for Sawatzky Enterprises, it took a lot of trucking and would be a two- or three-man operation.”
Crunch-time came for the Sawatzky brothers when they needed to add a high-capacity dryer to the new system. They needed the dryer, but the dryer would need another person in the yard to operate continuously while trucks were arriving with new loads from fields.
They decided that air was the best option. A bucket elevator is limited by height, a chain or U-trough-driven grain delivery system would be cheaper for bins in a short straight row, but not for their irregular bin arrangement. “A bucket elevator would never fill all those bins,” Caillier says. “If you want to convey 200 feet away with a grain leg, the grain leg has to be 200 feet higher than the bin to get the 45-degree slope. For a U-trough conveyor on top of your bins, they all have to be in line. Then, you’re limited on how long your conveyor can be based on horsepower.”
Bushels-per-hour capacity favours other systems. Wheat delivery with air in the largest six-inch tube is limited to about 2200 bushels per hour. Other high-capacity grain systems can deliver more than 10,000 bushels an hour.
However, the air route can be longer and it can be routed in any direction, including upwards to a 150-foot tall grain terminal. “Normally, the pipeline is 300 to 400 feet but we have gone as far as 900 feet. At 900 feet you lose quite a bit of capacity, but sometimes if you don’t have to truck it, it doesn’t matter if it takes a little more time getting it out there,” Caillier says.
The A.R.K. system also is very gentle with seed. Comparing systems, Caillier points to two other things favouring air. “Number one, it’s kernel in, kernel out. If you want to preserve the integrity of your commodity, for seed or even for keeping grains separate, kernel in, kernel out is a big feature. Second, it’s flexible. Your bins don’t need to be lined up and they can be different heights. Once your basic package or infrastructure is installed, if you add a bin it’s just a little bit more piping. It’s a system that can easily grow.”
‘Works for us’
The new dryer and pneumatic conveyor system solved the issues they wanted it to address in the first season of operation during the fall of 2010, according to Dan Sawatzky.
The brothers selected a propane-fired Farm Fan 370 continuous batch dryer. It can fill and unload at the same time without losing drying capacity. It has continuous automatic capability, although for the first year and without bin-full sensors, they ran it as a batch dryer.
Trucks arriving with a fresh load for the system can deliver to two 105-foot, 13-inch augers. If grain comes in dry enough from the field, one auger can put it directly into final storage. The other auger unloads into one of the two wet hopper bins. The dryer is fed by an auger out of those bins. “The air lock system was set up more for moving grain out of the dryer and being able to access every bin on the yard,” Sawatzky says. “We may go to a central fill to avoid moving augers, but with bigger bins it’s just as well to set up the auger and load them separately. The auger will sit there a long time.”
One of the 4400-bushel hopper bins feeds the system. The air lock is below that bin, powered by the adjacent 75-horsepower motor and six-inch blower fan.
System controls are easily accessible in a small circle. There is a metering switch and a fan switch, with gauges for amperage use. Two manual distributor boxes are adjacent and mounted on the pneumatic bin. Dryer controls, including a safety shutdown switch, also are nearby. “Back 30 years ago when we set up our old dryer, we could access all our grain storage from the dryer, through the leg. That was something we didn’t want to give up,” Sawatzky says. “That was the biggest reason we went to the air handling; it could accommodate that for us. We were trying to get away from one person being there full-time, and I think we’ve accomplished that, especially now that we’ve had our safety shutoff sensors installed. We should be able to let it go this fall without a person around.”
With red lentils, quality is paramount, and as the red lentil industry grows, quality issues related to long-term storage need to be addressed.
Sept. 27, 2010 -A hard and wet growing season is now being compounded by an even more frustrating harvest. But one idea that has been floated, first to columnist Kevin Hursh, and now to his readers, is for the Saskatchewan government to provide a tax incentive for the purchase of proper grain drying and storage equipment. READ MORE
Saskatchewan could assist farmers
A hard and wet growing season is now being compounded by an even more frustrating harvest. But one idea that has been floated is for the Saskatchewan government to provide a tax incentive for the purchase of proper grain drying and storage equipment.
Oct. 29, 2009 -The Canola Council of Canada is sharing some tips for late-harvested canola, acknowledging the impacts of a cold, wet harvest and the effect those will have on storage and other issues.
Canola growers reminded to avoid malathion
In this summer of mixed conditions, the Canola Council of Canada reminds growers that the use of malathion, is not registered and could reduce exports to countries with residue restrictions.
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