Information gathered from the Midwest Cover Crops Council (MCCC) was used to compile this summary on how to use sweetclover as a cover crop in Ohio. For more information, see the Midwest Cover Crops Field Guide, Third Edition, and the Cover Crop Selector Tool found at: midwestcovercrops.org/selector-tool/.
Identification
- Plant has serrated leaflet edges, three leaflets per leaf, and an extensive taproot.
- White-flowered sweetclover (M. alba) is taller, coarser-stemmed, and has coarser leaves than the yellow-flowered type (M. officinalis).
- Yellow sweetclover is more drought tolerant, more vigorous as a seedling, flowers earlier, and has spreading growth as compared to the white-flowered type.
Cultural Traits
- Biennial or summer annual
- Minimum germination temperature: 42 degrees Fahrenheit
- Reliable establishment window (state average): Mar. 29–May 20: July 25–Sept. 6
- Upright growth habit: 1.5–7.0 feet
- Preferred soil pH: 6.5–7.5
| Heat tolerance | Very good |
| Drought tolerance | Excellent |
| Shade tolerance | Good |
| Flood tolerance | Very good |
| Low fertility tolerance | Excellent |
| Winter survival | Expected |
Planting
- Drilled at ¼–½ inch
- 6–10 lb./acre (pure live seed)
- Broadcast with shallow incorporation
- 7–11 lb./acre (pure live seed)
- Broadcast without incorporation
- 8–12 lb./acre (pure live seed)
Additional planting information:
- 258,600 seeds per lb.
- Inoculation type: alfalfa, sweetclover.
- Sweetclover may also be frost-seeded.
- When planting on slopes or using for forage/grazing, increase seeding rate.
- Broadcasting without incorporation is usually less dependable than drilling or broadcasting with incorporation.
- When interseeding, time the seeding to match appropriate crop growth/maturity.
Disclaimer: Rules for Financial Assistance Program Recipients
Individuals participating in financial assistance programs are required to follow Natural Resources Conservation Service (NRCS) Appendix A regarding seeding rates and dates. Failure to do so will jeopardize payments. Appendix A can be found in Ohio’s Field Office Technical Guide, Section 4, Ecological Sciences Tools: efotg.sc.egov.usda.gov/#/state/OH/documents/section=4&folder=-6.
Performance
- Dry matter = 3,000–5,000 lb. per acre, per year
- Biomass quantity is highly dependent on planting/termination dates and precipitation.
- Total nitrogen = 90–170 lb. of N per acre (not fertilizer replacement).
Additional performance information:
- Deep-rooted after establishment
- Contains coumarin; when moldy, turns into an anticoagulant than can harm or kill livestock
- Bloat hazard
- Slow to establish compared to other cover crops
- Good for underseeding
- Does not host soybean cyst, root lesion, and root-knot nematodes
- Susceptible to damage from harvest wheel traffic and from being buried with residue
- Host for bean yellow mosaic virus
| Nitrogen source | Excellent |
| Soil builder | Very good |
| Erosion fighter | Very good |
| Weed fighter | Very good |
| Grazing | Good |
| Quick growth | Good |
| Lasting residue | Good |
| Mechanical forage harvest | Very good |
| Grain seed harvest | Excellent |
| Cash crop interseed | Good |
Termination Information
- Tillage
- If terminating with only tillage, multiple passes are often required.
- Chemical
Additional termination information:
- Follow NRCS guidelines for cover crop termination dates to comply with crop insurance.
| Soil Impacts | |
|
Subsoiler
|
Excellent |
| Frees phosphorus (P) and potassium (K) | Excellent |
|
Compaction fighter
|
Very good |
|
Chokes weeds
|
Good |
| Other | |
| Attracts beneficials | Excellent |
| Bears traffic | Good |
Potential Disadvantages
Delayed emergence: could be a major problem
Increased weed potential: could be a moderate problem
- Hard seeds reseed.
Increased insects/nematodes: could be a moderate problem
Hinders crops: could be a minor problem
Establishment challenges: occasionally a minor problem
Mature incorporation challenges: could be a moderate problem
Contributors
This publication was adapted with consent from the Midwest Cover Crops Council (MCCC) with content from the Midwest Cover Crops Field Guide, Third Edition, and Cover Crop Selector Tool (midwestcovercrops.org/selector-tool/). It was created under a joint project with MCCC to produce customized introductory guidance about cover crops for all member states/provinces. Ohio cover crop recipes can be found at midwestcovercrops.org/statesprovince/ohio/.
The Midwest Cover Crops Council (midwestcovercrops.org) aims to facilitate widespread adoption of cover crops throughout the Midwest by providing educational/outreach resources and programs, conducting new research, and communicating about cover crops to the public.
Funding for this project was provided by the McKnight Foundation.
