Buyers' Guide: Hay Moisture Testers

The feel test has been used by many hay producers for years. You know what that's like – just grab a fistful of hay, twist it, and it just feels like it's ready to go.

Still, feel is hard to define from person to person. "One person might think something feels dry, " says Ray Smith, a University of Kentucky Extension forage specialist. "Another person may determine that more drying time is needed."

Complications multiply when trying to peg a specific moisture content.

"Even when you can't squeeze any more water out, 60% moisture in hay can still remain," says Smith. "That can work with silage, but it doesn't work with hay."

A larger factor looms, too. Stored wet hay puts microbes into overdrive. Their activity creates high heat that can spur spontaneous combustion. The resulting fire then burns down hay storage buildings.

"Hay can also be put up too dry. This can break off leaves that boost nutrient quality and palatability," says Jeremy Oakes, John Deere parts marketing specialist.

Tester investment

Enter hay moisture testers. "They are a small investment to protect hay shed and barn fires from happening," says Oakes.

Moisture testers can help you put up hay in the recommended sub-18% range for small square bales and sub-16% for big round bales, says Smith. Oakes aims for 12% to 16% for large square bales. Aiming for these moisture percentages helps ensure quality while keeping moisture levels in check to lower the odds of spontaneous combustion occurring.

Hay moisture tester models run the gamut – from those that quickly test hay in the windrows to heat-based stainless steel stationary units to near-infrared moisture meters. As with most products, you get what you pay for.

Some units, such as one offered by Deere, use a dish-style probe for sampling and testing hay on-the-go in the windrow.

"It also measures a higher percentage of moisture (13% to 70%), meaning it can be used for regular-moisture hay or if you want to bale haylage when moisture is 55%," says Oakes.

Other portable testers can assess moisture in hay bales. Some are in one piece; others have a meter with a pistol grip. Oakes says pistol-grip testers are popular.

"You can hold it in one hand and check the readout with the other. If you are testing multiple bales at a time, the pistol-grip tester is ideal," Oakes says.

"For our customers, moisture is the main factor that we consider," says Andy LaFlame, sales and product manager for AgraTronix, which is a moisture tester supplier for Deere. "We also have units that also can test both moisture and temperature."

Baler-mounted testers are another option that can give readings every three to five seconds as hay is baled. They often have a range between 8% and 30%-plus moisture.

"Units like these give you a good idea of moisture content, but they don't give exact readings," says Smith. "When a meter says 18%, it could be closer to 16%."

Stationary stainless steel heat-based units used for moisture testing give more accurate readings. They require that samples be brought to the unit.

"Ours uses USDA methodology," says Mark Drouse, sales manager for Best Harvest. He notes that the Best Harvest units require 100 grams of hay to be tested and are accurate down to .1% moisture in a moisture range from 0% to 85%.

If you really want to accurately peg moisture even further to 100 parts per million not only for hay but also for haylage and other feedstuffs, there's a gold standard. Kett's KJT 130 near-infrared moisture meter "is the only one of its kind in the world," says John Bogart, managing direct for Kett US.

Its real-time measuring capacity enables it to detect moisture differences within the feedstuff being sampled, whether it is hay, haylage, or beans. The data that is captured can be transferred back to a personal computer.

You pay for these features, as its manufacturer's suggested retail price is $16,500. Still, it allows you to moisture-test a wide variety of materials in otherwise difficult or impossible locations, says Bogart.