Using cornfield annuals and other species as nurse cover
In certain situations it is necessary or desirable to obtain a rapid establishment of ground cover. For example:
• To stabilise soil surface of engineered banks
• To effect a rapid green cover for aesthetic reasons
Meadow and grassland mixtures are mainly composed of slow growing perennials which, sown at the required low seeding rates, are designed to take several months to attain full ground cover. Pushing the establishment of these components by increasing the sowing rate, or adding fertilisers is not advisable as in most situations it would seriously compromise the end result. An alternative approach is required.
The best solution currently available is to sow a temporary cover of additional species in combination with the main mixture; these species should have the following properties:
• Short term: Rapid establishment on a range of soils types
• Medium term: Not too competitive, and not a nitrogen fixer (not clovers & legumes)
• Long term: Annual or short lived life cycle so will not persist in established grassland
This technique borrowed from agriculture is called sowing a nurse cover crop. Potentially a wide variety of seeds could be used in this role:
- Cornfield annual wild flower mixtures
- Annual crop grass:Westerwolds Ryegrass
Other species such as wheat or barley have also been tried.
Generally nurse species or mixtures can be applied at 2g/m2 in addition to the main sowing of 4g/m2 (giving a combined sowing rate of 6g/m2).
Some degree of compromise is inevitably associated with using two sowings together each to achieve a different objective; careful planning and aftercare will minimise this.