# Relative humidity chart??



## Nate926 (Apr 6, 2014)

Does anyone know of a relative humidity chart to go by if the alfalfa stems are snapping dry prior to baling? Example at this % relative humidity next to the windrow the hay is 20% moisture. Or at this % RH you will have to much leaf shatter. Also what is a accurate RH tester to buy when checking RH down at the wind row. Thanks guys!!


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## haygrl59 (May 19, 2014)

I can't find a specific relative humidity chart but I have found a lot of helpful articles here http://www.uwex.edu/ces/forage/

I've printed off a few for my own use and perhaps you can find the chart you are looking for.


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## Nate926 (Apr 6, 2014)

Haygrl59 I appreciate it!


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## hay wilson in TX (Jan 28, 2009)

Pull up Forage Management, Proper handling & Curing of Hay from West Virginia. Has lots of information and charts.

In Round Numbers for the Humid East, 90% RH the hay will be no less than 40% moisture

70% RH down next to the windrow the hay will be no less than 18% misture ( small Squares)

65% RH the hay will be no less than 13% Moisture. These two the stems should be stem snapping dry at sunset. Then the hay will bale with the dew. Leaf Moisture

I built a chart to use based on Windrow width. Yield of that cutting, and Accumulated Pan Evaporation.

Questions try [email protected]


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## eastsidehayguy (Aug 12, 2013)

How can you use realitve humidity at the windrow to check moisture of hay? Take for example last year the ground in my area was soo wet but yet the hay was dry. Relative humidity for myself 7 miles off lake huron is always high but yet I still bale dry hay. I feel I have a much harder time then those inland but I do get it done. With living so close to the lake and having wet ground and dry hay can I still use realitive humidity to check my hay? Sorry if dumb question I know absloutely nothing about relative humidity and drying hay.


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## hay wilson in TX (Jan 28, 2009)

so close to the lake and having wet ground and dry hay can I still use realitive humidity to check my hay??

Our friends in WV have the same problem. It matters not what the Humidity is at eye level or at the radio station, the key is what the humidity is down next to the windrow.

With a 80% RH down next to the ground and the windrow the hay will be too high to bale. Even if the stems are bone dry. The leaves will be carrying the moisture from the humidity.

The key is if the stems are fully cured and 5% or less moisture then the leaves can be up in the 30% moisture range the average will be roughly 21% moisture and that surface will evaporate, in the bale. With both stems and leaves are in the 20% moisture range the hay will heat, you will loose some feed value to respiration.

Now with the stems in the 30% range and the leaves are bone dry at 5% moisture the product will be a bundle of moldy stems.

We here enjoy a climate where our hay at dusk can average 5% moisture. The next day the leaves will have enough moisture to hold on the stem but not so much to allow mold in the hay.

WV is saying at 70% humidity the hay will be no drier than 18 to 20% moisture. Works Here but as you say it may not work THERE.

Typically we can plan to have hay dry enough to bale for 2 hours, but some times in as little as 1 hour and some times as long as 3 hours. A buddy form the Hills of TN assures me that they MUST stack their hay in a drying barn to keep their hay.


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## rjmoses (Apr 4, 2010)

hay wilson in TX said:


> Our friends in WV have the same problem. It matters not what the Humidity is at eye level or at the radio station, the key is what the humidity is down next to the windrow.
> 
> With a 80% RH down next to the ground and the windrow the hay will be too high to bale. Even if the stems are bone dry. The leaves will be carrying the moisture from the humidity.


I'm wondering if it has anything to do with soil type and soil moisture level. I'm thinking that sandy soils would maybe wick moisture downward where as clay soils types might act more as a moisture barrier and cause the water to move more upwards through evaporation.

I'm also wondering if soil temperatures have a noticeable effect. Warmer soils might cause more evaporation as opposed to cooler soil temps.

For me, low humidity runs about 60%. I bale when the stem moisture is right. I know I'm risking leaf shatter, but it's a balancing act.

Just thinking.

Ralph


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## endrow (Dec 15, 2011)

rjmoses said:


> I'm wondering if it has anything to do with soil type and soil moisture level. I'm thinking that sandy soils would maybe wick moisture downward where as clay soils types might act more as a moisture barrier and cause the water to move more upwards through evaporation.
> 
> I'm also wondering if soil temperatures have a noticeable effect. Warmer soils might cause more evaporation as opposed to cooler soil temps.
> 
> ...


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## endrow (Dec 15, 2011)

My grandpa was very old school and had this very old saying and I know you' probably never heard it before.. Gotta make hay when the sun shines.


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## matt scks (Feb 20, 2014)

I use the NWS web site. When the temperature and dew point lines get within 1 and 1/2 boxes of each other, you better be checking hay. Varies with time of day,(morning or night) and time of year(spring vs. late summer) but it will give you someplace to start. This is if the hay is stem popping dry before you start.


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## Vol (Jul 5, 2009)

matt scks said:


> I use the NWS web site. When the temperature and dew point lines get within 1 and 1/2 boxes of each other, you better be checking hay. Varies with time of day,(morning or night) and time of year(spring vs. late summer) but it will give you someplace to start. This is if the hay is stem popping dry before you start.


Hey Matt....you might want to re-think or re-do your screen name. When I saw it, the first thought that crossed my mind is that Matt sucks. Lol...I really like the time I have spent in Kansas, but scks does ring South Central Kansas very well....maybe; matt ks-sc?

Regards, Mike


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## deadmoose (Oct 30, 2011)

I wondered the same. Did a double take.


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