Agronomy Library > Annual Weeds

What Exactly is Sod Seeding and How Does It Work?
Author: Ron Heller
Date Created: April 30, 2009
Last Reviewed: April 30, 2009
Sod seeding, as referred to in a reduced tillage cropping system, is best defined as the practice of replacing unwanted perennial forage with annual crops. Although the term may imply planting or reseeding new forage grass, it actually centres on being able to establish a crop like barley, oats, canola (or even peas) in dead sod without tillage. In order to prepare old pasture or hayland for sod seeding, it is recommended that any active growth first be terminated, or sprayed to kill the forage. The timing and limitations of the initial application using glyphosate are described on the herbicide labels of several products, and is planned to allow the field to die and decay over-winter. This also permits normal use and harvest of the existing forage by hay or grazing during the take-out year. Almost any common rotational crop can be sod seeded, with the right machinery and experience. All of the basic principles that make direct seeding (no-till) work in standing stubble can be applied for successful sod seeding. Trial and error suggest that low disturbance disc or narrow knife openers perform best overall. Careful implement setup is important, and adjustments for speed and depth essential to ensure thatch penetration, seed placement (with safe fertilizer separation if required) and proper seedrow closure. Considerable on-farm trails and research has been done over time on the prairies to come up with methods for adding new forage to old (ie: rejuvenation with legume alfalfa). Unless there was sufficient suppression of the forage, overall results have been poor, either not working quickly enough or consistently to change forage species. Various renovation techniques have been attempted to find profitable solutions, however the most effective way is to start new. With appropriate agronomic steps, direct seeding can successfully complete a transition or return to perennial forage in rotation. Again, the proven reduced tillage principles of moisture conservation, pre-seed weed control, and shallow seeding into a firm seedbed with low disturbance openers makes it possible to establish a strong and healthy stand – without the risk and compromise of companion crops or intensive field work (tillage). The key point in making sod seeding work is choosing to terminate the old sod first (not always an easy decision, especially for cattlemen with hungry cows). The risk can appear high when forage resources are already scarce. Nevertheless, compared to the time and energy demands of a traditional tillage-break system, there are advantages. Perhaps it’s more about taking the easier path than finding a true short-cut! Sod seeding is really a management tool – one of many that farmers or ranchers can select to improve the productivity of the land – not that different from the dynamic balance between rest and recovery that even a natural grazing system must have. It can actually account for real benefits, both in money saved plus adequate return on investment in effort and outcome. Isn’t that exactly what farming should be? Check out out Agronomy Library for more sod seeding articles