With fall just around the corner, now is the time to think about applying fertilizer to perennial forages like alfalfa, clover and timothy. According to Dr. Mark Sulc, professor and extension forage specialist, and Greg LaBarge, agronomic field specialist, both from Ohio State University, September is a prime time to prep perennial forage soil.
“Soils are usually firm in September, and autumn topdressing provides needed nutrients for good winter survival of the forage stand and vigorous regrowth the following spring,” the duo state. “Hay crops will remove about 50 lb. of K2O and 12 lb. of P2O5 per ton of dry hay harvested. Adequate amounts of soil P and K are important for the productivity and persistence of forage stands. However, nutrient over-application harms the environment and can harm animals fed those forages.”
Before heading to the fields, there are a few steps farmers should follow. These include:
- Have recent soil tests available to help guide you in what nutrients to apply and how much.
- If you are applying high rates of phosphorus or potassium, consider splitting applications. There is an advantage to splitting the application, with half applied this autumn and the remainder applied next spring after the first cutting when soils are firm.
- Don’t over apply P and K. According to the extension agents, many dairy farms have high levels of soil P, making the expense of fertilizer P unnecessary. When soil test P exceeds the agronomic level of 50 ppm, there is an increased potential for P losses into streams and lakes. Applying too much K will result in luxury consumption by the forage plants, leading to excessive levels of K in the forage that can cause animal health problems.
- Apply at the right rate. Your soil test should give you indicators as to what rate you should apply fertilizer on different fields. For help determining what rate to apply, check out this free tool.
For more on forages, read:
- Build Better Baleage for a Better Bottom Line
- Take a Better Hay Sample with These 8 Tips
- Forage Myths Are Costly: Forage Quality Impacts Your Bottom Line
