INTRODUCING FORBS INTO CRP OR EXISTING NATIVE GRASS STANDS
A number of native grass plantings have been planted without incorporating forbs in the original seeding mixture. There are a number of reasons for this but primarily these plantings have been for wildlife habitat or Conservation Reserve Program (CRP) acres. Also, most of these plantings were done a number of years ago. Only within the last 5 or so years have wildlife managers been recommending forbs in native grass plantings and early CRP regulations did not require forb seed in with the native grass seed. New CRP regulations have required forbs or given incentive points to landowners for incorporating forbs, increasing their chances of being accepted into the program. Most recently, if a landowner wanted to re-enroll CRP acres under a new CRP contract and if forbs were not included in their earlier contract, they have been required to introduce forbs to gain enough points for their bid to be competitive.
Therein lies the problem. It has not been easy to introduce forbs into a well established native grass stand. A number of techniques have been tried with limited results. The most common accepted method has been to burn the native grasses in the spring followed by drilling seed into the blackened earth. There have been some successes with this method but the results have been less than desirable when compared to planting the forb seed at the same time with the grasses. The other most common technique has been to broadcast forb seed either in the fall or spring, sometimes following, and sometimes not, following a burn. If you are patient, this method has actually shown the best results. However it typically takes 7 to 10 years to see much response using this method. I have had a number of people tell me they tried this method, or some variation, only to deem it a failure but years later see the planted species appear.
A few years ago, native grass drill manufacturer, Truax Company, introduced a no-till option called the trash plow. The no-till blade is an angular, notched blade that is mounted at a camber. The effect is, when pulled across the ground, it creates a small zone of disturbance where the seed is placed in the following row openers. Once I began using this equipment to inter-seed stands I saw good results. At least they were considerably better than the previous methods and much quicker than waiting 7 to 10 years. Though it was an improvement, it still left some to be desired. In addition, not everyone has access to a Truax native grass drill with trash plow technology.
Through several trial and error projects I have been able to improve upon the initial, but slightly less than satisfactory, earlier results. The following combination of manipulation techniques has proven to be very successful for introducing or increasing forbs in established native grass plantings. The process starts with a prescribed burn in the fall. In the middle of the country, November seems to be the best. Regardless of where, it should be done during the dormant season. Following the burn, lightly disc the filed or portion of the field to be planted. After discing, you can broadcast or drill the forb seed and leave for Mother Nature to do the rest. Since employing this method I have seen a great increase not only in the number of forbs present but also the diversity.
It is important to define light discing. By light discing I do not mean to disc down to bare dirt as you would to prepare a seedbed. Light discing is usually only one pass, discing no deeper than 3 or 4 inches. It is important to only disturb the soil, not turn it or destroy the existing vegetation. Light discing is also the key to reducing the competitiveness of the grasses allowing the forbs to get a foot hold before the grasses become too competitive.
Light discing is allowable on CRP in most states, however, if using this method on CRP, be sure to get permission from your local Natural Resources Conservation Service office. It will require a contract modification. Depending upon your state CRP regulations, you may be further restricted by only being able to treat one third of your acreage each year.
|
