Cover Crop Seeding: Methods, Rates, and Dates - NRCS Ohio, Exams of Agronomy

Download Cover Crop Seeding: Methods, Rates, and Dates - NRCS Ohio and more Exams Agronomy in PDF only on Docsity! USDA is an equal opportunity provider, employer and lender. United States Department of Agriculture Natural Resources Conservation Service 200 North High Street, Room 522 Updated June 2019 Columbus, Ohio 43215 Appendix – A (Cover Crop) Introduction This practice guide contains information for planning and applying seasonal vegetative cover according to NRCS Ohio’s Conservation Practice Standard Cover Crop (340). Use this guide to develop implementation requirements to apply the practice in the planned location. References used to develop this guide are listed at the end of the document. The following documents are the primary sources of the characteristics of cover crop species identified in this guide. Review the sources directly for further details needed to meet client objectives and socio-economic considerations. 1. Managing Cover Crops Profitably, 3 rd edition, 2007 2. Midwest Cover Crops Council website 3. USDA ARS Cover Crop Chart, V2.1 4. USDA NRCS Plants Database website 5. OSU Bulletin 472 - Ohio Agronomy Guide 14th Edition Seed Quality The quality of seed used in conservation practices can have a dramatic effect on the success of the practice. The seeding rate for cover crops used by NRCS in this document assumes a level of seed quality. As a result there may be an adjustment that needs to be added to the minimum seeding rate to account for the site specific seed quality being used if the seed quality does not meet the criteria assumed in the calculation. Additionally, NRCS is committed to preventing the spread of noxious, invasive and herbicide resistant weed species. Therefore all seed used in conservation practices must have a seed tag or be tested for seed quality and percent weed seed prior to use. The use of “bin run” seed is allowed in NRCS conservation practices as long as the seed has been tested, the seeding rate has been adjusted for seed quality if needed and the seed meets the minimum quality as specified in all applicable laws. Seed Testing Producers wishing to use uncertified seed sources (bin run, client harvest, or bulk seed sources) for NRCS program practices must have that seed tested by a reputable lab that reports the following: 1. Purity 2. Germination 3. % weed seeds For additional information on seed testing contact: Ohio Department of Agriculture Division of Plant Health Grain, Feed, & Seed Section 8995 E. Main St Reynoldsburg, OH 43068 Phone: (614) 728-6410 USDA is an equal opportunity provider, employer and lender. All seeding rates in fig 1 are reported as an actual seeding rate. This seeding rate is based on the assumption of high quality seed with higher levels of germination and purity. The Seed Quality Adjustment Factor table above should be used if the seed quality is lower than the assumed value. The equation below is to be used to adjust the seeding rate to account for the site specific seed quality. If an adjustment factor is not listed in the table for the germination and purity then the specific quality of the seed is equal to or greater than the assumed level and no adjustment is needed. Listed Seeding Rate (Fig 1) x Adjustment Factor = Actual Seeding rate Cover Crop Seeding Methods The method of cover crop establishment can also have a dramatic effect on the success of the practice. Planting cover crops early within the recommended planting date window and at the proper seeding depth and rate with good soil seed contact will reduce the risk of poor and slow establishment. When selecting the cover crop seeding method one should consider the advantages and disadvantages of each available method before implementation. Drilling, narrow row planting, harrow seeding and broadcast seeding before light tillage (rotary harrows, vertical tillage) will result in greater soil/seed contact and improved depth control. Although these methods generally result in improved seed emergence they can be time consuming and limit inter-seeding options. Broadcast seeding and aerial applications of seed on the soil surface are great options to implement cover crops on large acres in a short time and/or inter- seeding into an existing crop. However these methods can have reduced crop emergence as a result of poor soil/seed contact. For this document all seeding rates are assumed to be seeded with some seed depth control; if a method is used that does not have seed depth control such as broadcast or aerial seeding a 20% increase in the seeding rate should be included to account for increased risk of poor emergence. If seed is treated with a pesticide do not broadcast on the soil surface and follow manufactures recommendations on minimum seeding depths. USDA is an equal opportunity provider, employer and lender. Fig 1. Cover crop seeding dates, seeding rates and seeding depths. Seeding rate (lb/ac)1 Planting Date Range2 Plant Species Life cycle3 Pure Stand ¾ ½ ⅓ ¼ Forage Stand Seeding depth (in) Northern Southern Cool-Season Growth Non-Legumes Winter Rye (Secale cereale) nwk 50 38 25 17 13 88 ¾ to 1 ½ 7-15 to 11-1 8-1 to 11-15 Winter Triticale (× Triticosecale) nwk 60 45 30 20 15 94 ¾ to 1 ½ 7-15 to 10-22 8-1 to 11-1 Winter Barley (Hordeum vulgare) nwk4 59 44 29 19 15 - ¾ to 1 ½ 7-15 to 10-22 or 3-15 to 5-1 8-1 to 11-1 or 3-1 to 4-20 Winter Wheat5 (Triticum aestivum) nwk 64 48 32 21 16 94 ¾ to 1 ½ 9-22 to 10-22 9-30 to 11-1 Spelt5 (Triticum aestivum var. spelta) nwk 64 48 32 21 16 94 1 to 1 ¾ 9-22 to 10-22 9-30 to 11-1 Annual Ryegrass (Lolium multiflorum) nwk4 18 13 9 6 4 28 ¼ to ½ 8-1 to 9-20 or 3-15 to 5-1 8-1 to 9-30 or 3-1 to 4-20 Oats (Avena sativa) wk 40 30 20 14 10 88 ½ to 1 ½ 8-1 to 9-20 or 3-15 to 5-1 8-1 to 9-30 or 3-1 to 4-20 Oilseed Radish (Raphanus sativus) wk - - - 0.7 1 12 ¼ to ¾ 7-15 to 9-15 or 3-15 to 5-1 7-15 to 9-30 or 3-1 to 4-20 Rapeseed/Canola/Kale (Brassica napus) nwk6 4 3 2 1.5 1 8 ¼ to ½ 7-15 to 9-15 or 3-15 to 5-1 7-15 to 9-30 or 3-1 to 4-20 Turnip (Brassica rapa) wk 2.5 2 1 .75 .5 6 ¼ to ½ 7-15 to 9-15 or 3-15 to 5-1 7-15 to 9-30 or 3-1 to 4-20 Legumes Alfalfa (Medicago sativa)7 nwk 16 12 8 6 4 - ¼ 8-1 to 8-15 or 4-1 to 5-1 8-1 to 8-30 or 3-30 to 4-25 Red Clover (Trifolium pretense) nwk 9 7 5 3 2 - ¼ to ½ 7-20 to 8-30 or 2-1 to 5-1 8-1 to 9-15 or 2-1 to 4-15 Yellow Sweet Clover (Melilotus officinalis) nwk 8 6 4 3 2 - ¼ to ½ 7-20 to 8-30 or 2-1 to 5-1 8-1 to 9-15 or 2-1 to 4-15 Crimson Clover (Trifolium incarnatum) nwk 12 9 6 4 3 - ¼ to ½ 6-1 to 9-15 6-1 to 9-30 Balansa Clover (Trifolium michelianum Savi) nwk 3 2.2 1.5 1 0.8 - ¼ to ½ 6-1 to 9-15 6-1 to 9-30 Winter Pea (Pisum sativum) wk 40 30 20 14 10 - 1 to 1 ½ 7-20 to 9-20 or 3-10 to 4-30 8-1 to 10-1 or 3-1 to 4-20 Hairy Vetch (Vicia villosa) nwk 15 11 8 5 4 - ½ to 1 ½ 7-20 to 9-20 or 3-10 to 4-30 8-1 to 10-1 or 3-1 to 4-20 USDA is an equal opportunity provider, employer and lender. Seeding rate (lb/ac)1 Planting Date Range2 Plant Species Life cycle3 Pure Stand ¾ ½ ⅓ ¼ Forage Stand Seeding depth (in) Northern Southern Warm-Season Growth Non-Legumes Sorghum-Sudangrass (Sorghum bicolor x S. 2udanese) wk 24 18 12 8 6 35 ½ to 1 ½ 5-15 to 8-1 5-1 to 8-15 Sorghum (Sorghum bicolor) wk 5 3.7 2.5 1.6 1.2 8 ¾ to 1 ½ 5-15 to 8-1 5-1 to 8-15 Sudangrass (Sorghum bicolor) wk 20 15 10 7 5 25 ½ to 1 5-15 to 8-1 5-1 to 8-15 Pearl Millet (Pennisetum Glaucum) wk 12 9 6 4 3 23 ½ to 1 5-15 to 8-1 5-1 to 8-15 Japanese Millet (Enchinochloa frumentacea) wk 14 11 7 5 4 28 ½ to ¾ 5-15 to 8-1 5-1 to 8-15 Teff (Eragrostis tef) wk 7.5 5.5 3.8 2.5 1.9 12 1 8� 5-15 to 8-1 5-1 to 8-15 Sugarbeet (Beta vulgaris subsp. Vulgaris) wk - - 1.3 0.8 0.6 - ½ to 1 5-15 to 8-1 5-1 to 8-15 Sunflower (Helianthus annuus) wk - - - 1.3 1 - 1 to 1 ½ 5-15 to 8-1 5-1 to 8-15 Buckwheat (Fagopyrum esculentum) wk - - 12 8 6 - ½ to 1 7-15 to 8-15 7-1 to 9-1 Flax (Linum usitatissimum) wk - - 9 6 4.5 - ½ to ¾ 7-15 to 8-15 7-1 to 9-1 Legumes Cowpea (Vigna unguiculata) wk 60 45 30 20 15 - 1 to 1 ½ 6-15 to 8-1 6-1 to 8-15 Sunn Hemp (Crotalaria juncea) wk 12 9 6 4 3 - ¼ to ½ 6-15 to 8-1 6-1 to 8-15 Soybean (Glycine max) wk 54 40 27 18 13 - 1 to 2 6-15 to 8-15 6-1 to 8-30 Faba Bean (Vicia faba) wk 15 11 8 5 8 - 1 to 2 6-1 to 8-1 5-15 to 8-15 Berseem Clover (Trifolium alexandrinum) wk 10 7.5 5 3.3 2 - ¼ to ½ 5-15 to 8-15 5-1 to 8-30 1. Seeding rates are listed as “pure stand” with the assumption to be seeded with some seed depth control; if a method is used that does not have seed depth control such as broadcast or aerial seeding a 20% increase in the seeding rate should be included to account for increased risk of poor emergence. The ¾, ½, ⅓ and ¼ seeding rates are to be used in creating mixes. The forage stand rate are to be used if the cover crop is to also serve as a livestock forage. If a rate is not listed (-) the seeding selected is generally not recommended. 2. Northern Ohio is generally north of I70 and Southern Ohio is generally south of I70. 3. wk = winter killed cover crops; nwk = non-winter killed cover crops 4. Non-winter killed only when planted during the fall dates. 5. Do not plant until after the Hessian fly free date; dates varies from Sept 22 in northern Ohio to Oct 5 in southern Ohio. Wheat and spelt cover crops can be planted up to 20 days past the fly free date. See the Ohio Agronomy Guide for specific county dates. 6. Fall planted varieties planted in the fall are “non-winter killed”; spring planted varieties planted in the fall or spring are winter killed. 7. In order to meet the intent and definition of cover crops (seasonal vegetative cover) alfalfa must be terminated and managed as an annual. Alfalfa planted to provide forage for multiple seasons should be implemented under forage and biomass planting (512). USDA is an equal opportunity provider, employer and lender. Fig 2. Cover crop plant species suitability ratings to support practice purposes (Midwest Cover Crops Field Guide, 2nd edition, 2014). Ratings: 0= no information, 1= Poor, 2=Fair, 3=Good, 4=Excellent Practice Purposes Plant Species Reduce Erosion1 Increase soil health & organic matter1 Utilize (scavenge) excess nutrients2 Suppress weeds/pests Minimize Compaction3 N fixation4 Subsoil Surface soil Cool-Season Growth Non-Legumes Winter Rye 4 4 4 4 2 3 N Winter Barley 4 3 3 3 3 3 N Winter Wheat 4 3 3 3 2 2 N Winter Triticale 4 3 3 3 2 2 N Spelt 4 3 3 4 0 3 N Annual Ryegrass 4 4 4 2 4 4 N Oats 4 3 3 4 3 3 N Oilseed Radish 1 3 4 3 4 3 N Rapeseed/Canola/Kale 1 2 3 2 2 3 N Mustards 3 3 2 3 1 3 N Turnip 1 1 3 3 0 3 N Legumes Alfalfa 3 4 1 2 4 2 Y Red Clover 3 4 1 3 2 3 Y Yellow Sweet Clover 3 4 1 3 4 4 Y Crimson Clover 3 4 1 2 2 3 Y Winter Pea 2 2 1 2 1 3 Y Hairy Vetch 2 3 1 3 2 3 Y Warm-Season Growth Non-Legumes Sorghum-Sudangrass Hybrid 4 4 4 4 2-45 2-45 N Sudangrass 4 4 4 3 1-35 2-45 N Pearl Millet 4 3 4 3 2-35 1-35 N Japanese Millet 4 3 4 2 1-35 1-35 N Buckwheat 1 2 1 4 0 3 N Sunflower 3 3 4 3 3 1 N Legumes Cowpea 4 2 1 4 2 3 Y Sunn Hemp 3 3 1 3 3 3 Y Berseem Clover 3 4 1 2 1 3 Y Soybean 4 2 1 4 2 2 Y 1. Cover crops effect on soil erosion and soil organic matter will be evaluated with current NRCS prediction tools (RUSLE 2). 2. Cover crops that utilize (scavenge) excess nutrients may not address water quality if there is a lot of time between when they are killed and the next crop’s utilization of the nutrients. 3. Cover crops can be used to minimize soil compaction but should be planned with other practices and/or management techniques to minimize the future damage. 4. All legume cover crops should be inoculated with the proper inoculant to maximize growth. 5. For Warm-Season grasses, subsoil and surface soil compaction depends upon management factors like mowing and grazing which increase root mass and decrease soil compaction.