Cover Crop Windows - Interseeding into Wide Rows
“We don’t have a window for seeding cover crops.”
Lucky number three post in our series explaining the various windows for cover crops on most farms. Key word there is most, every farm is different and this can be adjusted in ways that work for you. Disclaimer: The dates of these windows will vary based on region!
Planting both grain and silage corn in an array of wide-row patterns has become a hot topic:
The goal of this type of cover crop seeding is very similar to Early Interseeding in the beginning few weeks. The difference is, with wider rows, we have more sunlight which gives us more time! There is not as much of a rush because the canopy in the wider rows does not close as much as 30-inch spacing. Just like with early interseeding, the blend you choose to seed depends greatly on the goals of your operation and the resource concern you are trying to address. Compaction? Have brassicas and annual ryegrass in your blend. Soil building and fixing nitrogen for the following crop? Use a heavy legume blend. Grazing in the fall? Use a combination of annual grasses, brassicas, and legumes!
At the beginning of this seeding window, many with wide row corn still use a drill to plant their selected species. With such a wide window of seeding opportunity, that corn is going to get tall towards the end. This is where a broadcasting seeding method becomes the most useful and some of the larger seeded cover crop species are no longer an option, unfortunately. Once drilling is not an option, many use some type of high clearance equipment with a seeder mounted and drop tubes attached link to youtube. This allows the cover crop seed to get as close to the ground as possible when it is seeded, avoiding too much getting caught in the whorl of the corn leaves. Timely rains when interseeding into wide rows is important for a quick establishment, especially when broadcasting.
Towards the end of this window, aerial application is also an option for both wide rows and regular corn rows. When flying cover crops onto corn, we aim for the corn to be at black layer so that when the seeds germinate there will be sunlight getting down through the drying leaves. If you are flying covers onto beans, we look for them to be starting to turn yellow for the same reason. The downfalls of aerial seeding are the need for a higher rate and, if there is not rain after the application to get those seeds sprouted, establishment can be difficult. There are many who still prefer this method to make sure cover crops get on all of their ground.
There is a lot of variability among options for this seeding window, but that just means there is a lot of room to adjust to what works on your operation!