30 July 2007

3 minute read

 It is also a good time to seed in bare or thin spots in forage stands established this spring. The following steps will improve the chances for successful forage stand establishment in late summer.

1. Apply lime and fertilizer according to soil test and control problem perennial weeds ahead of seeding. Be careful with herbicide selection because some have residual soil activity and will harm new forage seedings in proper waiting periods are not observed. Read the labels for details.
   
   
2. Prepare a firm seedbed if using tillage. Loose seedbeds dry out very quickly. Deep tillage is not ideal for late summer seedings, but if done should be completed several weeks ahead of seeding so rains can settle the soil before final seedbed preparation. A cultipacker or cultimulcher is an excellent last-pass tillage tool. The soil should be firm enough for a footprint to sink no deeper than 3/8 to 0.5 inch.
   
   
3. No-till seedings conserve moisture, and can be very successful provided weeds are controlled prior to seeding. Remove all straw after small grains. Any remaining stubble should either be left standing, or clipped and removed. Do not leave clipped stubble in fields as it forms a dense mat that prevents good emergence.
   
   CAUTION: No-till or reduced-till summer seedings of legumes are at risk of infection by Sclerotinia crown and stem rot, especially in fields where clover or alfalfa were present recently. Mid- to late-August plantings dramatically increase the risk of damage by this disease compared with planting earlier.
   
   
4. Don't plant alfalfa immediately after older established alfalfa. Autotoxic compounds are released by old alfalfa plants, which inhibit growth and productivity of new alfalfa seedlings. It is best to rotate to another crop for a year before going back to alfalfa; however, thickening up spring seedings is fine because autotoxicity is only an issue with older, established alfalfa plants.
   
   
5. Seed when soil moisture is adequate or a good rain system is in the forecast. This is especially critical this summer after the dry weather we've experienced. It is risky to place seeds into dry soil, because there may be just enough moisture to germinate the seed but not enough for establishment.
   
   
6. Seed as early as possible. Seedlings require 6 to 8 weeks of growth after emergence to have adequate vigor to survive the winter. Seed by August 15-20 in northern Ohio and by September 1 in southern Ohio. Slow establishing species like birdsfoot trefoil or reed canarygrass should be planted in early August. Fast establishing species like red clover, alfalfa, and orchardgrass can be seeded up to the dates listed above if moisture is present. Kentucky bluegrass and timothy can actually be seeded 15 days or more later than the dates listed above. Keep in mind that the above dates assume sufficient moisture to establish the crop. Planting later than the dates mentioned above is sometimes successful depending on fall and winter weather patterns, but there is increased risk of failure and reduced yield potential for the stand as planting is delayed. A good rule of thumb for alfalfa is to have 6-8" of growth before a killing frost.
   
   
7. Plant seed shallow and in firm contact with the soil. Carefully check seeding depth, especially when no-tilling. Drills with press wheels usually provide the greatest success in the summer. Broadcasting seed on the surface without good soil coverage and without firm packing is usually a recipe for failure in the summer.
   
   
8. Use high quality seed of known varieties. Cheap seed often results in lower yield and shorter stand life. Make sure legume seed has fresh inoculum of the proper rhizobium.
   
   
9. Do not harvest new summer seedings this fall. The only exception to this rule is perennial ryegrass. If perennial ryegrass has tillered and has more than six inches of growth in late fall, clip it back to 3 to 4 inches before snowfall.
   
   
10. Scout new seedings for winter annual weeds in October to November, and apply herbicides as needed. Winter annual weeds are much easier to control in late fall than in the spring.