This season’s unusually wet weather has created many problems for farmers. Particularly when it comes to hay, we have had few weather windows long and dry enough to produce good quality, dry bales. Many hay fields appear to still be standing and waiting for the first cut of the season. If we continue to only have short weather windows between rainfalls, there are several strategies that can be implemented to help preserve forage quality.
The best option to make high quality forage with short weather windows is by making haylage or baleage. Relatively speaking, very little moisture must be removed from the forage to ensure it can be properly ensiled. At mowing, most forages contain approximately 75% moisture, which needs to be dried down to 60% to make proper baleage. Under ideal conditions, this can be accomplished in as little as six hours to make “hay in a day.” Wet soils, high humidity and minimal wind will slow down this process, but forages should drop to the required moisture content within two days.
There are several ways to measure forage moisture. The most accurate way is to use a dedicated forage dryer, which uses warm air to remove the water from the forage. The weight of the wet sample is recorded before being placed in the dryer. The sample weight continues to be measured throughout the drying process. Once the weight stabilizes, or does not drop anymore, the moisture content can be calculated by dividing the dry weight by the wet weight and then multiplying by 100. In place of a dedicated forage dryer, you can also use a microwave with the protocol developed by Michigan State, (www.canr.msu.edu/uploads/236/58572/Methods_for_Determining_Dry_Matter.pdf) but be aware that forages may catch fire if left unattended.
Making dry hay in short windows is a little more challenging, especially with wet soils and high humidity. Hay needs to be dried down to below 20% moisture — or even lower for larger bales — to prevent mold and combustion. On average this will take about three days, but it could take four days if the soil is wet, as the dry hay will continue to soak up moisture from the wet ground. Normally, to speed up the drying process, a farmer would lay a wide swath behind the mower to expose more of the forage to sunlight. This year, I have heard of several farmers having success narrowing the swath, allowing the soil to dry first before using a tedder to spread the hay back out. If your soils are soggy, this may be a practice you want to consider.
I know more than a few farmers who could not get their hay to dry down to less than 20% moisture, even after four days of dry time. If you find yourself in this scenario, you still have the option to wrap the hay. While this is not ideal, wrapping low moisture hay can preserve nutrients and provides the option to store the bales outside, which limits concerns about combustion and barn fires. Of course, mold can still be an issue, though fermentation will be limited, and a minimum of eight wraps of plastic should be used. Plan to feed this low moisture wrapped hay within six months to limit spoilage.
Some farmers may also try to use a higher rate of hay preservative to bale “dry” hay above 20% moisture. Preservatives have their place, but they will not always prevent spontaneous heating if the hay still has a lot of moisture. Hay can be monitored for heating with a hay probe, a metal pipe driven into the bale or a compost thermometer that can reach the center of the bale. Temperatures should be taken every couple of days for six to eight weeks to ensure temperatures don’t spike.
