have been following your work the last few years and it is good stuff. I do have a few questions though on how best to use the info based on a normal year and secondly advice for this year. I farm close to Drumheller, AB and normally we get enough heat to harvest a dry crop. This year not quite as nice, though it may turn warm yet.
Question 1.
How best to use natural air drying in a normal year for me.
In a normal harvest here, the crop gets preharvest roundup and the immature plants get desicated and are dry to ambient conditions when my combine arrives 2 weeks later. It sounds like farmers might lose the ability to use preharvest roundup in the future. Previous to preharvest roundup my crops would come in with varying moisture levels due to immature seeds. The grain will average dry. I have aeration in most of my bins, but they are all spread out in various fields and right now I use a generator to cool the grain overnight after storage and then again a night 2 weeks later when it is cooler and once more in December when it is cold. Fuel for the generator is expensive and I would like to keep my costs down.
So my question is how the immature kernels affect natural air drying? Looks like the grain will lose 1.5% moisture by the time it is cooled to final storage temperature. So with immature kernels, I assume that it is safe to store when averaging dry if the fan runs somewhat to make sure the moisture equalizes in the bin. Because some of the kernels are high moisture, should the bin sit for 24 hours before turning the fan on the first time to allow for moisture migration from the tougher kernels to the surrounding dryer kernels? No, turn your fan on immediately, even while it is being filled — get the grain cooled as soon as possible to prevent spoilage, especially if it is tough and has green seeds in it.
Also, if by final storage the moisture is going to drop by say 1.5%, does that mean I could bin grain that is 1.5% average higher than dry even with uncure/immature kernels in it and the bin will average dry after final storage and the grain condition will keep for 6-8 months until sold? I would say yes, it will keep without spoilage provided it is kept cold — really cold, below freezing.
I am just trying to come up with a workable system in case preharvest glyphosate is removed as a harvest tool. I really dont want to go back to swathing as a way to kill the plants. I would certainly get the jump on harvest by starting when the crop is a couple of points above dry, and then use your aeration to get it cold and dry. Aeration is way cheaper than swathing!
Question 2.
How to deal with grain that might get harvested tough this fall.
I have read most of your articles and it sounds like if the grain is 20 degrees C or more and only 2% above dry that it will dry during the cooling process by running the fans at night. Once the core grain temperature drops close to freezing the amount of drying that occurs is minimal. So assume grain will still be too tough to sell after cooling it (and hopefully drying it 1-2% in cooling). I see 2 options and perhaps you can expand on these please or inject some ideas that I have not thought of short of getting a grain dryer.
Option A. Dry in Spring
Cool the tough grain at night and if the moisture is low enough for safe storage, it could be dried in the spring. Just not sure what proper procedure would be in the spring and what the economic numbers would look like. Outside air would be warm, so if supplemental heat is added I assume the condensation at the roof thing would not be an issue. I assume that the grain mass would have to be warmed up with supplemental heat, but perhaps it could be warmed up during the day, then shut fan off, resume heating the following day and once the grain temp is warm enough you start cooling at night and removing moisture. Just not sure how warming up a mass of tough grain slowly would work as spoilage might be an issue. Your work showing you add moisture during the day and removing moisture at night is going to come into play here, but not sure how the grain can get warmed up with ambient air and not add moisture to the grain during warm up. If you get your grain as cold as possible by running your fan in late December for one cold night, we might get the grain down to -20 C. Even if it is tough, it will not be spoiling. Now seal the bin up the best you can, for two reasons: 1. We want to keep the grain as cold as possible, for as long as possible, and 2. We don’t want warm spring breezes, containing lots of water, from hitting your cold grain and condensation forming. During the winter the grain will warm about 1 C per week with the bin kind of acting like a solar collector, and heat coming in through the walls and roof. Monitor the temperature of the grain, and when it naturally gets to 15 to 20 C, start pulling it back down as cold as you can. This will probably be in August or Sept. and continue with the practice of getting the grain as cold as possible. Let’s say we pull it down again from 20 to 0 — we will have taken another point out and it should be close to dry by now, but even if it isn’t, keep the grain temp as low as possible; seal the bin up at Xmas and repeat yearly. Your grain should end up dry, and more importantly with no spoilage and no expensive supplemental heat.
Option B.
Add supplemental heat to the natural air drying fans. I see your work in the blogs about condensation at the roof being a problem. Is it possible that you are missing the effect that heating may have on the roof panels themselves? If enough heat is passing through the grain, could it be heating the roof panels and changing the condensation point to allow more humid air to escape the bin and condensate outside. Would higher airflow rates, higher plenum temperatures, much fuller or shallower grain depths make the condensation different? I am thinking there is a strategy here that is being overlooked, much like people were overlooking the effect grain temperature was having on running the aeration fans at night to dry grain (which you proved). Type of aeration system (full floor, pit, rocket, round tube, inverted v) probably all work different. Biggest downfall that I see is severely overdry grain in the bottom of the bin by adding enough heat and airflow to keep condensation at the roof minimized. Not sure if the whole bin could be over dried and then mixed with untouched tough grain and be mixed together, moved to a different aeration bin and run the fan a little to equalize? Your blog showing the 50,000 btu heater and removing 0.3% moisture every night is good, but too slow for what I need to do. I would require a huge power service to run that many fans, which I do not have, so trying to explore other options. I would only use supplemental heat if you were in a hurry to sell your grain as dry. As my blog says: heat the grain during the day, and cool it at night. and you don’t have to worry about over heating the grain, it takes 12 hours to heat 5000 bushels, see
Supplemental Heat: Act III How Long to Heat Grain 5 C