Consider Previous Crop Before Seeding Alfalfa
Dry growing conditions in 2012, followed by an ongoing drought, have caused some growers to question whether or not to rip up their alfalfa seeding. While farmers should manage alfalfa based on winter injury, it’s taking longer than usual to see just how much damage has occurred.
Usually at this time of year, alfalfa is waking up from dormancy. But, the Midwest weather has been anything but typical this spring! Although snow has fallen in mid-April, it can’t last long. Spring planting season will soon get underway, and we want to do all that we can to set up seeding for success.
Here are some things to take into consideration before deciding to reseed alfalfa:
Seed bed preparation is key. A firm seedbed, before and after seeding, allows for consistent seed depth and good seed-to-soil contact.
a) Personally, I prefer smaller residue particle sizes as I believe it helps get better seed-to-soil contact. Otherwise, seed can either be buried under a large particle of corn stalk, or the seed just sits on top of the soil. Make sure corn stalks are chopped well.
b) If you’re seeding alfalfa where corn was planted in 2012, I would disk the ground. A couple of passes will help the stalks breakdown more; then chisel plow or moldboard plow to cover up most of the residue.
c) Seed alfalfa with a brillion or seeder with press wheels to ensure best seed-to-soil contact.
When seeding alfalfa fields back into alfalfa, your fields may be at risk for autotoxity. Autotoxicity in alfalfa is described as a process in which established alfalfa plants produce a chemical or chemicals that escape into the soil and reduce establishment and growth of new alfalfa if seeded too soon following the old stand.
Take soil tests in alfalfa fields. I’m a big fan of soil testing because it provides a benchmark of current soil health and helps us better understand fertilizer needs. One of the biggest concerns is the soil pH, or its acidity level. If the soil’s pH is marginal, we can begin to correct it more rapidly by applying Pell lime or something similar.