Cover Crop Interseeder and Applicator
(upbeat piano music)
- [Voiceover] Cover crops can play important roles in our cropping systems.
Reducing runoff, limiting nutrient loss, and building soil health.
And they've become very popular.
But cover cropping is often difficult when crops like corn for grain or soybeans are not harvested until late October or November.
For these fields, the opportunity for cover cropping has been limited in the past.
Attempts to broadcast seed in standing crops in our region has had only spotty success, and has been heavily dependent on rainfall after seeding.
Another option is to interseed a cover crop, early in the season.
And then that crop will grow under the growing corn crop and be there in the fall when the crop is harvested.
Our team's been evaluating interseeding for the past several years on farms in Pennsylvania, New York, and Maryland with some good success.
To accomplish this, we've developed a machine to interseed cover crops in young corn and other crops.
This machine can also apply herbicides and fertilizer while interseeding.
The machine can also be converted to a grain drill by adding additional row units.
This multi-functionality helps reduce the cost and risk associated with interseeding, so that cover-cropping costs are reduced.
Let's discuss a few of the important steps for successful interseeding.
The first step is to use a herbicde program that will allow the interseeded crops to establish.
Examples of some short residual herbicides are shown on the Penn State interseeding web site.
The second step is to decide on a cover-crop seeding mixture.
Some of the most successful species have been annual ryegrass, red clover, and radish.
Then, when the corn is in the V5 to V7 stage, the interseeder can plant the cover crop between the corn rows.
Planting at this stage allows the cover crop to establish before the corn becomes too competitive.
With the interseeder, the goods seed the soil contact, and the seeding depth control can be achieved even in high-residue conditions.
This is also a good time to apply a second herbicide application or a sidedress N application if desired.
The N application can be applied adjacent to the corn growth for maximum effectiveness, and avoid stimulating the cover crop.
At four weeks after seeding, the cover crop has established and is growing under the canopy of the developing corn crop.
Our work has shown that with these cover crops, the corn yield is often not impacted.
In the fall, as we approach harvest, the cover crops have survived and then resumed growth in the fall as the corn crop matures.
In this example, a pure ryegrass stand has established.
In this plot, a pure stand of red clover has established.
Another option are mixtures.
Here we see some ryegrass, radish, and legume mixtures that have established.
Many fields will not have much cover over the winter to take up any excess soil nitrates or to provide living roots in the soil.
During the rest of the fall and over the winter, the cover crops will survive and begin to grow again early in the spring.
If fields are manured, the cover crops can help prevent runoff and take up excess nutrients.
Often, prior to planting, significant growth can occur in the spring.
When planting corn back with corn in these fields, the corn will planted into a grass or legume cover crop.
This is an example of what a lot of corn fields look like across the country as we get ready for planting in the spring.
There hasn't been a lot of cover crops, obviously.
There's bare soil.
Some weeds starting up.
And adjacent you can see what's possible with some interseeded cover crops, protecting the soil and providing other benefits as well.
Our work has shown that this system has the potential to provide an additional opportunity for cover cropping in areas with limited opportunity for cover-crop establishment following the main crop.
Our hope is that in future studies, we'll be able to show that the interseeding has a beneficial yield impact on the subsequent corn crop and also saves some nutrients from leeching over the winter.
In some cases, we've actually taken a backhoe and dug up these interseeded cover crops.
And there's a surprising amount of root growth under some of these crops, sometimes extending down to four feet deep, through old worm channels and other cracks in the soil.
So it's surprising how some of these crops can develop in the soil over winter after an interseeding last June.
As with any practice, there can be some subtle management changes with the timing of planting, with the species necessary to adapt to local conditions.
And as a result of our program, farmers in many states are starting to do some interseeding and reporting some good initial success.
(upbeat piano music)
Frequently Asked Questions