The war on rain

Rain is both a blessing and a curse to the haymaker. On the one hand, water in the form of rainfall or irrigation is needed to maximize yields and perhaps even quality. However, an untimely rain that delays a harvest or, even worse, falls on cut forage can kill any chances of harvesting a high-yielding, high-quality crop.

Whenever visiting a farm, one of the questions I routinely ask is “What’s your biggest challenge producing hay?” You would think the answer would sometimes be related to a soil fertility issue, a particular insect, or perhaps a plant disease. Never does that happen.

Rather, the answer is always the same . . . weather, specifically rain.

This answer isn’t surprising coming from someone in the Midwest, Northeast, or Southeast. The humid regions of the U.S. have always offered a challenge for getting hay dry. Frequent rainfall is not uncommon.

What’s surprising is that the same answer also comes from haymakers whose acres typically receive less than a foot of rain per year. Even hay producers on the desert bemoan the stray summer thunderstorm as their biggest haymaking threat.

The war on rain has been an ongoing battle with numerous weapons employed.

Dairy farmers in the Midwest and Northeast, who can’t compromise on quality, have mostly given up on making dry hay and choose to chop and store higher moisture haylage, especially for early cuttings. This has now been the norm for many years.

More recently, baleage has become popular in virtually all humid regions of the United States. The utility of baleage for the livestock producer is obvious, but even many commercial hay producers have found the product to be both saleable and shippable.

Reducing the time between cutting and harvest lowers the risk of getting a wilted crop rained on and baleage makes that happen. The bonus is often a higher quality product that is consumed readily by cattle.

Another recent trend in the war on rain has been the rapid adoption of cutting hay in wide swaths. The narrow swath, which requires no raking or merging before chopping, has become the exception rather than the rule. Exposing as much of the crop as possible to sunlight has cut drying times dramatically and helped avert the negative effects caused by those pesky, unexpected rain events.

Perhaps the latest weapon to be made available for haymakers is alfalfa varieties developed with lower concentrations of lignin. These varieties come with the promise of higher levels of digestible fiber when cut on conventional cutting schedules; however, they also provide some level of rain insurance if a cutting is delayed by bad weather.

High stakes

Is there good reason to invest in strategies and tools that help negate the effects of rain?

The simple answer is “Yes,” especially if you’re in a high-rainfall area.

If wilting hay gets rained on, soluble carbohydrates (sugars) are leached from the forage. This has a profound impact on forage quality, especially the energy value.

The loss of carbohydrates occurs in two different ways. There is the direct leaching of sugars out of the plant tissue, but it also comes from the fact that the forage is rewetted. This can reactivate plant respiration and cause additional plant carbohydrates to be lost.

Rain also can contribute to additional microbial activity that metabolizes soluble carbohydrates, raising the risk for mold and mycotoxin development.

The combined impact of rainfall on wilting forage is higher neutral detergent fiber (NDF) content, lower NDF digestibility, more ash, and a significantly lower relative forage quality (RFQ). It’s common to see NDF concentrations elevate by 5 to 10 percentage units when intense or long-duration rainfall occurs.

In addition to forage quality losses, forage yield is also reduced. This comes from the leaching out of soluble carbohydrates, leaf shatter, and the need for additional mechanical manipulation of the windrow or swath. Yield losses in research trials have ranged from minimal to as much as one-third of the crop.

Needless to say, we’ll never be able to control the weather, but with each passing year there appears to be more strategies and tools that can help reduce its impact. Higher moisture feeds such as baleage, cutting hay in wide swaths, and using improved plant genetics are three relatively recent technologies that are experiencing an impressive adoption rate.