As spring slowly makes its arrival in Ohio, fields sowed with overwintering crops will start to show some life again. Once green up occurs in alfalfa fields, yield potential can begin to be assessed.
“What we are looking at for an established alfalfa stand is a stem count of greater than 55 stems per square foot,” said Kyle Poling, a DuPont Pioneer Field Agronomist. “Forty to 55 stems per square foot is still a really nice stand, but as we get under 40 stems that is going to severely limit yield and the farmer may want to consider tearing that field up and if they need that alfalfa for the upcoming year, consider replacement.”
For the 2017 fall seeding of alfalfa, a grower may have planted up to 25 to 30 plants per square foot. Alfalfa tends to be a tender crop, so if the stem count is at a viable level that will usually equate to 4 to 5 healthy plants per square foot in the spring.
“Roots are also an important piece to check in an alfalfa stand,” Poling said. “If more than 50% of a root is black when it is split open, which is root rot, that is an indication that plant will not likely survive the 2018 growing season.”
Alfalfa quality depends on a number of factors, and weather is a major one. Once alfalfa genetics have done their best with what Mother Nature has provided, it’s up to the grower to preserve as much of the nutritional quality as possible. The first cutting of the season is the most significant. As much as half the season’s total yield can be from the first cutting.
Growers should try to balance yield with quality. Generally, quality is highest when alfalfa plants are younger. As they grow, they add tonnage, but nutrient density begins to drop. Farmers can use systems such as the Predictive Equation for Alfalfa Quality (PEAQ) tool to monitor quality changes.