Spring no-tillage seeding of forages into corn and soybean stubble is now being practiced on many Ohio farms. This allows early planting, which in turn permits emerging forage seedlings to compete more effectively with germinating annual weeds. Other advantages include seeding on a firm seedbed and reduced labor requirements. Likewise, users gain the weed and pest control provided by the previous crop rotation and residue. An important requirement for success is pre-planning so there are no damaging herbicide residues from the previous crop to jeopardize forage establishment. Spring no-till seedings in row crop residues should increase in future years as farmers strive to meet the conservation provisions of the 1985 and 1990 farm bills. They mandate retention of 30% ground residue cover until after the succeeding crop has been planted.
Success rates with no-till alfalfa spring seeded into grain crop residues have been consistently higher than seedings into killed sod. The clovers, birdsfoot trefoil (where adapted), cool season grasses, brassicas, sudangrass, sorghum-sudangrass hybrids and millets can also be successfully established in row crop residues in the spring. No-till establishment of forages in early August as described in Agronomy Facts AGF-005 (No-Tillage Forage Seedings Following Small Grain Harvest) is equally successful. Occasionally, changes in crop plans or severe winter injury to small grain stands may necessitate complete kill of the small grain followed by no tillage seeding of forages.
Most no-tillage drills can operate in corn stubble but some do not perform as well in chopped corn stalks. Ideally the drill should have individual row flexibility, easily changed depth adjustments, ability to penetrate soil and/or residue, plant a variety of crop seeds and perform well in many kinds of crop residues.
Proper use of herbicides and no-tillage drills have made no-tillage forage establishment a reality, but success is largely dependent upon adherance to the following management practices:
Drainage - productive forage species require adequate surface and subsurface drainage. The better drained the soil, the greater the potential for establishment success.
Soil - no-tillage seedings are most successful on silt loam soils and usually less successful on clay soils.
The analysis of a representative soil sample is the only method to determine existing soil nutrient levels and develop fertilization recommendations. Soil pH, lime requirement and existing levels of phosphorus and potassium are determined by soil analysis. Soil for analysis may be submitted to the REAL Testing Laboratory through county Extension offices.
Many no-till drills do not have fertilizer attachments; thus, early seedling growth is largely dependent upon inherent soil fertility. It often is possible to incorporate corrective lime, phosphorus and potassium by soil tillage before a prior crop. Thus, new seedings in cropland field rotation may be less dependent upon surface lime and fertilizer applications than permanent pastures and long lay meadows. No-tillage alfalfa seedings are rarely successful when soil pH, phosphorus or potassium soil test levels are below recommended levels EVEN IF CORRECTIVE APPLICATIONS ARE SURFACE APPLIED PRIOR TO DRILLING.
Closely inspect the field to determine kinds of weeds that may be present. Use of a contact-type herbicide may not be necessary with March seedings if weeds are not present in the field.
Where perennial weeds are minimal and winter annual weeds or small emerging weeds are present:
In cases where many perennial broadleaf or grass weeds are present in addition to winter annual broadleaf and/or tiny emerging grass and broadleaf weeds:
Similar Roundup applications can be utilized where winter small grain stands are to be killed prior to a spring no-tillage seeding. Roundup also may be the most appropriate herbicide choice prior to May-July no-till seedings of summer annual grasses such as sorghum- sudangrass or brassicas for forage. Consult product labels and the current issue of OSU Bul. 789, "Weed Control Guide", for possible post-emergence herbicide options with certain forages, particularly alfalfa and clover.
Consult the OSU Agronomy Guide, Bul. 472, and other OSU Extension publications for recommended seeding dates. Seeding rates and variety selection are similar for conventional and no-tillage seeded forages. Seed when soil is dry enough to crumble and flow to close seed furrows. Use a seeding depth appropriate for species being seeded. Inspect the crop for insect damage and treat if infestations develop. Potato leafhopper can be especially devestating to alfalfa seedlings. Flea beetles can be very damaging to brassica seedlings.
Clipping or a short period of heavy animal grazing may be necessary with new perennial forage seedings to control weeds approximately 45-50 days after emergence, if post-emergence herbicides are not utilized. Adequate stands of brassicas and annual forages such as sudangrass and forage millets usually shade the soil surface rapidly, resulting in good weed control.
Annual fertilization of perennial forages is required for stand retention and high production in years ahead. The summer annual forages (sudangrass, sorghum-sudangrass and forage millets) produce maximum yield only when they receive adequate nitrogen fertilization following recommendations found in the Ohio Agronomy Guide, OSU Extension Bulletin 472.
Prepared by:
John F. Underwood
District Agronomy Specialist
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