SilliamWhale
Member
Thats the ploughing for you
How long for grain to dry in the field?
- Thread starter teslacoils
- Start date
Thats the ploughing for you
- Location
- Lincolnshire
Yeah, it's expected to get to humidities in the 40s this week. With breeze. So for a given breeze and temp, dies grain dry quicker at lower humidity, or does it just dry to a lower level of moisture? I'd guess that at a fixed humidity and temperature, increased wind would dry more quickly?
It's just that I get these predictions which have temp, humidity and windspeed on them, and thought I could use this to give me an idea where to cut first - do I make the ten mile trip with combine to cut a block of wheat which can be done at 18 percent due to drying, or do I stay home where it needs to be under 15 percent? Was more an idea of a planning tool. Also to give an idea if the night Temps etc would mean early start or heavy dew.
It's just that I get these predictions which have temp, humidity and windspeed on them, and thought I could use this to give me an idea where to cut first - do I make the ten mile trip with combine to cut a block of wheat which can be done at 18 percent due to drying, or do I stay home where it needs to be under 15 percent? Was more an idea of a planning tool. Also to give an idea if the night Temps etc would mean early start or heavy dew.
- Location
- Bedfordshire
The important variable is the forecast, and as we all know that is never accurate for everyone!!
As a rough guide, I work on the following;
- Its not really starting to dry until my humidity controlled flat store fan has come on and the straw is crackling in the field
- 1%/hour on a sunny breezy day, quicker in osr, slower in brackled barley, flat or sheltered fields
- The more often you look at it, the slower it will dry
- Take the best representative hand rubbed sample you can, use a ground sample in the meter (not whole grains) and add 2% that the combine will add to it from the wet straw
solo
Member
- Location
- worcestershire
The grain store drying charts give a reasonable guide to moistures and drying times.
1. When Can I Begin to Harvest?
With a complete Grain Guard system in place, crops can be taken off at 4% - 6% moisture above the level they would normally be harvested at (example: wheat 18% - 20%). Under warm, low relative humidity conditions you should see 3/4 - 1% of drying taking place per day. This allows a 7-10 day advance on harvest time as well as more harvesting hours per day.
NOTE: Natural air drying should be used as a management tool and not as a late harvest emergency drying system. Late harvest conditions are cool and damp and will result in slow natural air drying. Monitoring the condition of the stored grain is required during the process.
2. At What Temperature Does Natural Air Drying Begin?
Grain drying begins at +10 degrees celsius (50 degrees fahrenheit). Anything less than +10 degrees celsius means the air is too cold and can only hold a small amount of moisture, therefore moisture movement from grain will be very slow.
3. When Should I Start My Fan?
In order to create a uniform drying front, you must have the height of at least half of the bin's diameter above the aeration system. (Example: 14' diameter bin needs to have a minimum of 7' of grain above the aeration system).
The best uniform drying front can be produced by filling your bin and then turning on the fan. Turning your fan on too soon can cause uneven drying, wet pockets and negative results.
4. Should I Shut My Fan Off at Night or When it Rains?
No! High moisture grain drying (16% - 20%), requires continuous air flow to prevent the drying front from crusting over and restricting the airflow.
How it works
5. Does Fan Operation at Night or in High Humidity Conditions Reverse the Drying Process?
We tend to think that a fan will force moisture back into a bin in high humidity conditions. However, it is much more difficult to put moisture back into the grain than it is to take it out. In fact, grain in the bottom of the bin which may be a little over-dried would benefit from taking on a little moisture.
At 19% moisture, grain that hasn't been dried will remain constant as the 86% relative humidity moisture level in the air equals the moisture in the grain.
Relative Humidity Wheat Equilibrium Canola Equilibrium
of Air % Moisture Content Moisture content
at 25ºC at 10ºC at 25ºC at 10ºC
58 12 13 7.5 8.6
64 13 14 8.2 9.4
70 14 15 9.0 10.3
75 15 16 9.8 11.1
79 16 17 10.8 12.0
83 17 18 12.0 13.2
86 18 19 13.4 14.5
6. If I Add Supplemental Heat, Can I Dry in High Humidity Conditions?
Adding supplemental heat to the aeration/drying process will reduce relative humidity and increase the rate of moisture movement. Therefore, a low temperature supplemental heater will increase the drying rate and reduce the drying time.
7. Can Low Temperature Supplemental Heat Cut My Drying Time Without Increasing Costs?
A rule of thumb relating temperature increase to relative humidity decrease is: A temperature increase of 10 degrees Celsius (18 degrees Fahrenheit) above outside air temperature will reduce the relative humidity by half.
With the average harvest period generally 30 - 40 days, it's comforting to know you can depend on supplemental heat - not the weather - to get the job done.
NOTE: Care should be taken when operating a supplemental heater under low humidity conditions. This can cause severe over-drying in the bottom of the bin.
8. How Do I Know When My Grain is Dry?
(Approximate drying chart based on a complete Grain Guard System)
Approximate Condition Approximate Drying %
Ideal warm days/dry conditions 1% per day
Warm days and cool nights 1/2% per day
Cool days and cool damp nights 1/4% per day
Cold days and cold nights 0% per day
Warm days and cool nights
(supplemental heat added) 3/4% per day
1. When Can I Begin to Harvest?
With a complete Grain Guard system in place, crops can be taken off at 4% - 6% moisture above the level they would normally be harvested at (example: wheat 18% - 20%). Under warm, low relative humidity conditions you should see 3/4 - 1% of drying taking place per day. This allows a 7-10 day advance on harvest time as well as more harvesting hours per day.
NOTE: Natural air drying should be used as a management tool and not as a late harvest emergency drying system. Late harvest conditions are cool and damp and will result in slow natural air drying. Monitoring the condition of the stored grain is required during the process.
2. At What Temperature Does Natural Air Drying Begin?
Grain drying begins at +10 degrees celsius (50 degrees fahrenheit). Anything less than +10 degrees celsius means the air is too cold and can only hold a small amount of moisture, therefore moisture movement from grain will be very slow.
3. When Should I Start My Fan?
In order to create a uniform drying front, you must have the height of at least half of the bin's diameter above the aeration system. (Example: 14' diameter bin needs to have a minimum of 7' of grain above the aeration system).
The best uniform drying front can be produced by filling your bin and then turning on the fan. Turning your fan on too soon can cause uneven drying, wet pockets and negative results.
4. Should I Shut My Fan Off at Night or When it Rains?
No! High moisture grain drying (16% - 20%), requires continuous air flow to prevent the drying front from crusting over and restricting the airflow.
How it works
5. Does Fan Operation at Night or in High Humidity Conditions Reverse the Drying Process?
We tend to think that a fan will force moisture back into a bin in high humidity conditions. However, it is much more difficult to put moisture back into the grain than it is to take it out. In fact, grain in the bottom of the bin which may be a little over-dried would benefit from taking on a little moisture.
At 19% moisture, grain that hasn't been dried will remain constant as the 86% relative humidity moisture level in the air equals the moisture in the grain.
Relative Humidity Wheat Equilibrium Canola Equilibrium
of Air % Moisture Content Moisture content
at 25ºC at 10ºC at 25ºC at 10ºC
58 12 13 7.5 8.6
64 13 14 8.2 9.4
70 14 15 9.0 10.3
75 15 16 9.8 11.1
79 16 17 10.8 12.0
83 17 18 12.0 13.2
86 18 19 13.4 14.5
6. If I Add Supplemental Heat, Can I Dry in High Humidity Conditions?
Adding supplemental heat to the aeration/drying process will reduce relative humidity and increase the rate of moisture movement. Therefore, a low temperature supplemental heater will increase the drying rate and reduce the drying time.
7. Can Low Temperature Supplemental Heat Cut My Drying Time Without Increasing Costs?
A rule of thumb relating temperature increase to relative humidity decrease is: A temperature increase of 10 degrees Celsius (18 degrees Fahrenheit) above outside air temperature will reduce the relative humidity by half.
When low temperature heat is added in high humidity conditions, drying times can be reduced up to 8 days. By reducing operating time, over-all costs are less than operating only the fan under these conditions.
With the average harvest period generally 30 - 40 days, it's comforting to know you can depend on supplemental heat - not the weather - to get the job done.
NOTE: Care should be taken when operating a supplemental heater under low humidity conditions. This can cause severe over-drying in the bottom of the bin.
8. How Do I Know When My Grain is Dry?
(Approximate drying chart based on a complete Grain Guard System)
Approximate Condition Approximate Drying %
Ideal warm days/dry conditions 1% per day
Warm days and cool nights 1/2% per day
Cool days and cool damp nights 1/4% per day
Cold days and cold nights 0% per day
Warm days and cool nights
(supplemental heat added) 3/4% per day
- If you add 1 or 2 loads of grain at 18% moisture into the bin, assume the bin to be at 18% average moisture - don't reduce the average if some loads are at a lower percentage.
- Do not count the first day in the drying process as it takes 14 - 16 hours for the bin to equalize its temperature
shakerator
Member
- Location
- LINCS
- Location
- East yorks
Go and count how many wheat ears have sprouted that’ll cheer u up 
Ha ha. No it’s what’s come from above .
- Location
- Lincolnshire
Go and count how many wheat ears have sprouted that’ll cheer u up
Can't really find any.
If it's like this tomorrow and I can find some at 18 percent after church (where I shall be praying for a sustained spell of warmth and dry) I think I'll have Sunday evening and Monday filling a drier shed, then home for some dry crop Tuesday.
SilliamWhale
Member
But you will always sink quicker in cultivated soils, they just don't have any structure
Yes dear.....
Often wondered the same thing. I'm sure a clever physicist would be able to show the equation. I know its an equilibrium so the greater the difference between the the air humidity and the grain moisture the faster it will dry, but i wish i what the time scale was.
There is a way yes - Clear Ag (premium) weather uses temp, humidity and wind to tell you what moisture grain will be at times in the future
It’s a service we are looking to add to TFF weather soon along with leaf canopy wetness prediction and loads of other really useful ag tools they have
The algorithm does exist as in my post above - I’ve tested it and it’s really very good
- Location
- Lincolnshire
Is there a link - Google sends me to sites for child car seats!
You can’t access it privately - I have a demo version as we are looking at adding it to TFF weather (if we can find a way to cover the cost)
Question - if genuinely useful would members pay for such premium ag based weather services ? Soil moisture deficits, grain drying, canopy wetness, spray window prediction etc ?
- Location
- East yorks
We have some sprouting now and pretty much all the laid stuff is, I will go tomorrow after for a bit regardless I think
- Location
- Lincolnshire
I'd pay for it as part of a dedicated weather service, if shown to be either more personal or just better than BBC, or more able to take a trustworthy punt on the week ahead.