Although growers in the West and the South are well underway with this year’s alfalfa harvest, those in the Northern half of the U.S. are still greasing their mowers. It’s the start of another clash between the ability to make high-quality forage and Mother Nature.
In regions where long underwear is staple apparel during January and February, the initial spring cutting of alfalfa can make or break a harvest season. Forage quality at this point in the year can change on a dime or move at a snail’s pace.
Given the current historically bloated corn and soybean prices, the need for making top-quality forage as a feed ration cost-cutting measure has never been higher.
No alfalfa cutting grows under the environmental conditions offered by spring. Early on, temperatures are mostly cool, which keeps forage quality from spiraling. As the calendar turns to May, the possible environmental outcomes rival those of a roulette table.
This range of environmental conditions makes it difficult to predict forage quality. Calendar dates have proven useless, as has phenotypic maturity stage. Relative forage quality (RFQ) can be as much as 100 points different from year-to-year on the same date, and the same can be said for forage quality at a given maturity stage.
Mother Nature calls the shots on forage quality when it comes to first cutting. Hot and wet weather brings much different results than cool and dry. Further, environmental conditions change from day-to-day more in the spring than at any other point in the growing season. This explains the changing nature of first cutting. It also explains why it’s so critical to pay attention and monitor forage quality in the spring more so than any other cutting.
From highest to lowest
First-cut fiber digestibility can be the best of the season even with those large stems. Mostly cool days and nights are the hay producer’s friend. Once warm to hot weather sets in, or if wet weather delays the harvest, fiber digestibility can quickly move from the best to the worst of the year. The decline in fiber digestibility is even more profound in grasses where the optimum cutting window can close with a loud bang.
Although the potential for high fiber digestibility exists, the rate of fiber digestibility decline is unmatched by any other alfalfa cutting. This means that the harvest window is usually smaller, unless an extended bout of cool weather prevails. Here’s where new alfalfa genetics that can lower lignin content and raise neutral detergent fiber digestibility (NDFD) by as much as 15% will help widen this window.
There’s a yield trade-off
No cutting of alfalfa offers the opportunity for high yields more than the first. In fact, it usually comprises the highest percentage of total-season yield compared to subsequent harvests. Research in Wisconsin from commercial production fields has documented first cutting yields in a four-cut system averaging 35% of the total-season yield.
As with forage quality, alfalfa yield changes more dramatically during its initial spring growth cycle than for any other cutting. Estimates are that alfalfa packs on 100 to 150 pounds of dry matter per acre per day during the late-vegetative to late-bud stages. In five days, dry matter yield jumps 1/4 to over 1/3 ton per acre. The yield x quality trade-off is never so in play as it is with first cutting.
First cutting sets the pace
First cutting is the only one of the year when there is no set number of days since the previous harvest. The first-cut harvest decision often dictates the schedule for the rest of the season. When the first cut is completed often impacts how many future cuttings will be possible, the interval between cuttings, and how late in the fall the final cutting will be harvested.
First cutting is complicated, unique, and fickle. Losing a first cutting to the weather or other mechanical factors will have long-term ramifications. The harvest stakes are greater during this period of high commodity prices.
The consequences of when first cutting is taken will influence the remaining alfalfa harvest schedule, but more importantly, it will impact future livestock performance or the ability to sell the hay at a premium price.
It’s alfalfa go time.
