Dry conditions in some parts of the country during the growing season have taken a toll on alfalfa production, leaving affected farmers wondering whether their stands will survive the winter or if it’s time to rotate those fields into another crop. However, reduced yields don’t necessarily mean an alfalfa stand has suffered permanent damage.
Randy Welch, national alfalfa agronomist with CROPLAN, says alfalfa is naturally equipped to withstand extended periods of dry weather. He explains that the plant’s genetics originated in arid regions, making it particularly resilient during drought conditions. With improved moisture conditions this fall, plants have also had an opportunity to produce the carbohydrates and sugars needed for winter survival.
Welch says one of the challenges for producers is distinguishing between temporary drought stress and a stand that is genuinely declining. When moisture becomes limited, alfalfa can essentially suspend its growth until conditions improve.
While this response can significantly reduce production during the growing season, it doesn’t necessarily affect the plant’s ability to recover the following year. Welch points to alfalfa production in the western United States, where growers often take only one or two cuttings before relying on grazing for the remainder of the season.
However, not every struggling alfalfa field can be blamed on drought. Stand age, disease pressure, and declining plant populations can also contribute to reduced production.
Welch recommends evaluating stem counts to determine whether an existing stand still has adequate productive potential. He says growers should look for approximately 55 stems per square foot, which typically corresponds to four or five plants per square foot.
Beyond stem counts, examining the crowns can help identify disease or deterioration that might justify replacing an older stand. Welch says a four-year-old stand showing signs of disease may be a good candidate for rotation.
For producers considering establishing alfalfa after corn or soybeans next spring, this year’s dry conditions could present another challenge: herbicide carryover.
Welch cautions that certain herbicides used in corn and soybean production can remain active in the soil longer than expected when moisture is limited. Dry soil can reduce the biological activity responsible for breaking down some of those chemicals, potentially increasing the risk of injury to newly established alfalfa.
Even growers who have used the same herbicide programs successfully for several years may encounter problems following an unusually dry growing season.
Welch encourages producers planning new alfalfa seedings to carefully review their herbicide application histories and consult with seed suppliers about varieties offering strong disease resistance.
Ultimately, the decision to keep or replace an alfalfa stand should involve more than simply evaluating this year’s yields. A field that struggled through drought may still have several productive years remaining, while an aging stand with declining stem counts or disease issues could warrant replacement.
Taking time to evaluate stand health and consider potential herbicide carryover now can help producers make more informed decisions and avoid unnecessary costs heading into the next growing season.
