Table 1.10-5. Characteristics of common cover crops.
| Species | Life cyclea | Maturity zone |
Seeding rateb (lb/A) |
Seeding date |
N-fixation (lb/A) |
Avg. cost ($) |
Advantages | Disadvantages |
|---|---|---|---|---|---|---|---|---|
| Legumes | ||||||||
| aA=annual; WA=winter annual; B=biennial; SLP=short-lived perennial; LLP=long-lived perennial; NFT= no frost tolerance bHigher rates may be necessary for broadcast seedings *Species name abbreviations |
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| Hairy vetch (Visa villosa Roth) | WA | 1 | 20 - 40 | Aug / early Sept. | 80 - 250 | 1.50/lb | Most cold tolerant and highest yielding of all winter annual legumes; above-average drought tolerance; adapted to wide range of soil types | Requires early fall establishment, and slow to establish; little winter cover possible; matures in late spring; high P and K requirement for maximum growth; can harbor pests; potential weed problem in winter grains |
| Crimson clover (Trifolium incarnatum L.) | WA / SA | 4 | 9 - 40 (avg 18 - 20) | Aug | 70 - 130 | 1.80/lb | Rapid growth; above-average shade tolerance; forage use (no bloat); good nematode resistance | Poor heat and drought tolerance; no-till planting in residue is difficult to steminess |
| Red clover (Trifolium pratense L.) | SLP (2-3 yr) | 1 | 7 - 18 | Aug | 100 - 110 | 0.60 - 1.90/lb | Thick deep taproot; adapted to humid areas; tolerates wet soil conditions and shade; forage use only if mixed with grasses | Initial growth slow; high P and K requirements for maximum growth; seed can persist creating volunteer problems; pure stand forage causes bloat; vulnerable to some pathogens, insects |
| White clover (Trifolium repens L.) | LLP | 1 | 6 - 14 | Aug or spring | 100 - 130 | 2.30/lb | Adapted to most temperate zones; good heat, flood, srought, shade tolerance; low-maintenance and tolerates high traffic; forage use with grasses (better yields) | As a living mulch, may become competitive with crop if not mowed or tilled under; no yield during hot-dry weather; good nutrient management necessary; susceptible to some diseases, insects |
| Field peas (Pisum spp.) (e.g. Austrian winter pea) | SA / WA | 7 | 70 - 220 | Aug or spring | 50 - 150 | 0.40/lb | Rapid growth in cool weather; versatile legume; interseed with cereal and brassica spp.; used as food or feed | Austrian winter pea will not overwinter north of MD; shallow root system; sensitive to heat and humidity; susceptible to diseases, insect pests |
| Crownvetch (Coronilla varia L.) | LLP | 1 | 5 - 20 | Spring or early summer | 40 (suppressed) | 8.00 - 11.50/lb | Deep rooted and long-lived; good tolerance to heat, drought, and cold; no known insect or disease problems; excellent erosion control; fixes own nitrogen; can be managed as living mulch | Slow germination and establisment; high degree of management necessary; competes with crop if not suppressed |
| Birdsfoot trefoil (Lotus corniculatus L.) | SLP | 1 | 5 - 10 | Spring or early summer | 40 | 3.90/lb | Quick establishment; tolerates poorly drained soils and low pH; fixes own nitrogen; can be managed as living mulch | Competes with crop if not suppressed or killed; does not spread and fill in on its own |
| Grasses (Cool season) |
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| Cereal rye (Secale cereale L.) | WA | 1 | 60-200 | Fall | Excellent nutrient and moisture scavenger (esp. N) | 8.00/bu | Most cold tolerant of commonly used cover crops, late seedlings possible, germinates and grows rapidly; tolerates poor soil conditions and drought; rapid growth may provide some weed control; various uses: cover crop to food source | Regrowth may occur if not completely controlled (mature rye difficult to manage); possible crop suppresion due to allelopathy or nutrient tye-up by rye; pest problems; small grain insects, diseases |
| Spring oats (Avena sativa L.) | SA | 8 | 100 (3 bu) | Spring or fall | Good nutrient scavenger (less if fall seeded) | 4.50 - 5.65/bu | Rapid growth in cool weather; ideal for quick fall cover or nurse crop with legumes; winter kills; various uses: cover crop to food source | High lodging potential; susceptible to diseases and insect pests; winter kills |
| Annual / perennial rye grass (Lolium spp.) Tall/Fine fescue (Festuca spp.) Blegrass spp. (Poa spp.) Smooth bromegrass (Bromus inermis) Orchardgrass (Datylis glomerata) Timothy (Phleum pratense) | Spp. Variation | 1 | 15-15+ | Spring or fall | Fair - excellent nutrient and moisture scavenger | 1.10/lb | Tolerant to wide range of soil conditions (TF, SBG, PRG*); rapid establishment (RG, OG, Tim); tolerate shade, low pH and fertility (FF, TF); drought and heat tolerant (TF, SBG); winter-hardy (KBG, SBG, FF); form dense sod (KBG, SBG); most can be used as feed; adapted for orchard / ornamental uses (FF, TF, KBG, PRG) | Slow establishment (KGB, SBG, FF*); low heat tolerance (PRB, FF, Tim); may winter kill (PRB, TF, OG); bunch type growth (FF,TF, PRG, OG, Tim); may harbor insects and disease; living mulch requires high management |
| Other Crops | ||||||||
| Buckwheat (Cruciferae family) (e.g., rape, kale, turnip, radish) | A/B | 4 | 5-12 | Spring or fall | Fair-good nutrient scavenger (esp. N, P, Ca) | Varies | Quick establishment in cool weather; withstands light frost (but winter kills); deep, thick root systems; drought tolerant; highly digestable forage crop and other uses; continuous growth even with shorter days; may help insect and weed management | Low tolerance to wet soils; potential bloat problems (mix with 25% grass); long-term "weed" problem if allowed to set seed (spread by seed); occasional pests; winter kills |