Cover Crop Windows - Early Interseeding
“We don’t have a window for seeding cover crops.”
This is the second post of a 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!
Timing and moisture. Those are the two critical factors that we have seen affect early interseeding into standing corn (we have yet to see early interseeding be successfully applied in soybean crops). As you can see above, this is the narrowest window that this series is going to cover. Regardless of the seeding method you are using (we will get to that), getting the cover crop seeded between V3 and V6, or even earlier, is where we have seen the most success. The sooner the species you are seeding can get in there and begin building their carbohydrate reserves in their roots, the more they will thrive during the “dormant” shaded period and have a stronger start up when they receive light again.
The other critical factor is more out of our control. Moisture is important to get the cover crop started, especially when it is broadcast. Establishment can be difficult when our timely rains do not occur during this window or on very sandy ground that does not hold moisture well. If you do have good soil moisture, drilling can be a more successful option. How does someone drill or broadcast into standing corn? Take a look at some farmer-innovation examples:
Drill units can be lifted or turned off, air seeders can be mounted on just about anything, or use something else that you have on your farm! What types of seed are these machines sowing? For broadcasting or drilling, we often recommend our Interseeder Plus as a starting point. These are the species we have seen handle shade the best and provide grazing in the fall after harvest. If you are getting the seed incorporated, your options can increase to some large seeded options such as cowpeas, sunn hemp, mung beans, and buckwheat to name a few. These will also provide the option to graze in the fall! The actual species you seed depend greatly on the resource concern you are trying to address.
Having diversity in between your corn rows not only protects the soil from erosion and increase water holding capacity, but will also give your soil biology more to feed on making it more active. A more active soil biology will make more nutrients available for your growing crop in season. Legumes in your blends will not pass much of the nitrogen that they fix to your corn in-season, but they will be storing it in their tissues to release to the following crop.
If you want to add these benefits to your corn acres and have some additional grazing in the fall, consider this seeding window as an option!