Microwave Moisture Test

Any one use the microwave moisture test to determine hay moisture prior to baling? Is it a reliable/trustworthy measurement technique?

Reason I ask is we did the test on some hay that basically that was cut on Wednesday, laid in the sun on Thursday, was raked on Friday and tested for baling today (Saturday) via the microwave test. Moisture content was around 10%. The hay looked and felt dry, but failed the old 3 twist rule I've read so much about. IMHO, this hay was ready to be baled and we did.

While we were testing the hay mentioned above, we also tested another batch of hay. Part of it was cut late evening Thursday and the balance was cut early Friday morning. Dew was on the hay when cut. This hay had from the time the dew burned off, about 11 am to about 7 pm with direct sunlight, clear skies and maybe a slight breeze from time. This hay had a repeat of weather conditions today (Saturday), but around 3pm, we tested the moisture via microwave and the moisture content was around 10-13%. It looked and felt dry, but failed the old 3 twist test. If I rely on the microwave test and my eyes and feel, I think I could have baled this hay today too - but I'm thinking without a tedder or crimped, I need to wait longer. BTW, the hay isn't crazy thick, but it ain't super thin either.

Question is - is the moisture test a reliable measure for hay? Anyone use it? Anyone cut hay early one day and bale late the next?

Thanks!
Bill

Use it on all of my hay and trust it 100% if done correctly. The microwave or oven method is how moisture contents of many substances are measured in the scientific world.

I agree 100% with Chevytahoe. If you did the microwave test "correctly" then believe it 100%. Do NOT believe your eyes or your sense of touch. I talked to some company reps of moisture testers and they compare their equipment readings to the microwave test. Basicly, believe your intruments....in this case, your microwave. Ask any airplane pilot who flys via IFR (instrument flight rules).

One thing you fail to mention was what was the moisture content of the forages when they were cut? This makes a big difference it how long it takes for them to dry down. Another BIG factor is the humidity levels.

I own (and use) both hand held moisture testers and bale chamber mounted moisture testers. I will routinely compare those tests to samples I take to the house and run through the microwave. I seldom ever have much more than a 1-2% difference. That difference is related to the particular sample. That's close enough in the hay business

The 3 twist rule matters on lots of factors and is not reliable because you can have waxy moist stems and over dry leaves. The microwave test is the most accurate but the least practical because you have to run the house. The hand held tester are based on electrical conductivity and are calibrated for alfalfa and measure a couple points higher on grass hay according to Agritronix who manufactures a line of testers. Yes, in optimal weather here in Southeast Michigan I can mow in the morning and bale the next afternoon. If you mow in afternoon and into evening or at night you can add another extra day to drying, so always have hay cut by mid afternoon unless you have long windows.

Don't know what the moisture content was when we cut, I'll check that next time we cut.

I think the drying time this batch of hay was shorter because of a couple factors. First the hay was not super heavy, so the thickness of it laying on the ground wasn't crazy dense. Second, I cut with a sickle bar and the windrows were 7ish foot wide from the get go, so a lot of sun got to the hay. Thirdly, no rain, only dew to burn off.

Thanks!
Bill

Thanks everyone for your comments - very helpful info!

Bill