Dealing With Winter Injured Forage Stands

Alfalfa field  damaged by excessive wetness during winter and spring. Source: J. Stachler

I’ve been hearing reports from around the state of forage stands that look poor, especially where flooded soil conditions developed over the past few months. Alfalfa fields that were cut mid- to late fall also are looking rough compared with stands where the last cutting was taken by early September and no fall cutting was taken.

In anticipation of questions about how to manage these forage stands that look rough coming out of the winter, I’ve outlined some ideas in this article to consider.

The first step is to assess how extensive and serious is the damage. Review the article about assessing forage legume stands posted here the first week of April 2, (https://agcrops.osu.edu/newsletter/corn-newsletter/2022-07/time-assess-forage-legume-stands). Grass stands should be growing well by now and any damage should be fairly obvious by now.

If the damage is extensive and widespread over the entire field, it usually is best to destroy the stand, rotate to another crop, or plant an emergency forage. In these cases, corn silage is the number one choice for an annual forage in terms of yield and nutritive value. But corn silage won’t be an option in some situations. Forage might be needed before corn silage can be ready, equipment and storage infrastructure for silage may not be available, or field topography may not be conducive for corn.

Other acceptable short-season forage options include spring oat, spring triticale, spring barley, and Italian ryegrass planted as soon as possible now and harvested at the proper stage of maturity this summer. For more details on these species, see the Ohio Agronomy Guide and information resources at https://forages.osu.edu/forage-management/forage-species-varieties/annual-forages.

Other options, particularly for beef cattle or sheep, include the brassicas. When planting in late May and June, summer annual grasses will do better, such as sudangrass, sorghum-sudan, forage sorghum, pearl millet, and teff.

If the forage stand is damaged, but still salvageable, below are a few suggestions to increase forage production this year and longer term. These were adapted from an article written by Dr. Bruce Anderson, Emeritus Professor and Extension Forage Specialist at University of Nebraska:

  • For fields planted last year, try to interseed this spring to thicken up the thin spots. Even in alfalfa, autotoxicity is not a problem until after stands are more than one year old.
  • For alfalfa fields greater than one year old, autotoxicity and other problems make interseeding alfalfa risky.  But interseeding is still possible in other forage species, and older alfalfa stands can also be interseeded with species other than alfalfa. Consider adding red clover for longer term stands, or if legume production is desirable for this year, consider interseeding crimson clover or berseem clover (they will not do much after this first year though).
  • Annuals like oats, spring triticale, and Italian ryegrass can be interseeded as early as possible now. Italian ryegrass planted now will establish rapidly and will continue to produce all year and might even continue into next spring. Oats will produce only a single cutting. Another option is to interseed summer annual grasses right after taking the first cutting. For example, several years ago after an excessively rainy spring in western Ohio, a very successful approach was to interseed sudangrass and sorghum sudangrass hybrids into the damaged alfalfa stands. The summer annual grasses established well in the thin alfalfa stands and greatly increased forage yields while competing against weed encroachment in those stands.
  • Perennials like orchardgrass, festulolium, meadow fescue, and red clover can be interseeded into existing stands and will bring long-term help but won’t add much to this year’s production.

If you do interseed damaged stands, the competition by the surviving plants for sunlight is a potential serious threat to success. It only takes about one week of shading by a full canopy to kill seedlings below. The only way to open up a canopy once it develops over new interseeded forages is to harvest the existing stand extra early.  This will lower first harvest yield and may further weaken already stressed older plants.  But it’s the only way to get enough sunlight to the new seedlings you interseeded into the existing stand.

In some situations, it might be better to wait until late summer to interseed damaged stands (this of course doesn’t help forage supplies this year though). Forage cut in late August or early September regrows more slowly than in spring, thus causing less competition. Interseeding right after that last harvest will give a better chance for success, provided there is adequate soil moisture.

The excessive wet conditions this winter and late fall cutting last year have reduced stands and will reduce forage production in many forage fields this year. Make a careful assessment of the existing stand and then act quickly to minimize long-term losses.

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.

Author(s):