Overseeding

Overseeding is a seed planting technique involving planting seeds over existing crops without disturbing the soil. Timing is a critical factor when overseeding because the seeds can germinate and get moldy if they are overseeded in low light and moist situations, causing loss of seed and seeding method costs. Overseeding can be used to help build up grazing fields and for preparing winter cover crops .

Overseeding for Grazing

Managing grazing fields is necessary to maintain sustainable farming practices and healthy livestock. Overseeding is used to revive full pastures or smaller patches that are missing. Pastures with poor management can lead to weed problems, which can be harmful for livestock. Overgrazing is the main contributor to weeds infiltrating grazing fields. Overseeding is a simple method that can replenish pasture and soil health, leading to healthier livestock.

Depending on the geographic location, pastures are typically overseeded in the early spring months to suppress weed growth and fill in patches. Diverse species of cover crops should be overseeded during this time to help with soil health, disease control, and reduced use of herbicides. Once the pasture is ready, graze the fields and prepare for another rotation of overseeding in the fall months. Ensure the correct amount of grazing for the seeds to have just enough sunlight, because grazing the field too short can allow weeds to germinate and sprout.

Overseeding can be managed by aerial or machine processes for a good spread of seed. A benefit of overseeding is a reduction of herbicide use, reducing the risk of harm to livestock. In locations known to experience hurricanes, it is recommended to overseed prior to the hurricane as they provide an ideal setting for seed germination and are a great opportunity to make grazing fields denser. Make note to use appropriate cover crops based on the season.

Overseeding Cover Crops

In some areas, cover crops typically don’t have enough time to grow, especially in the fall months when temperatures start to drop. In order to manage cover crops, they need to be intercropped into existing cash crops. Some methods of overseeding cover crops are aerial, push seeders, and using an inter-seeder, which has the option of using tubes to drop the seeds below or above the cash crop.

To ensure a sufficient window of time for the cover crop to grow, overseeding prior to harvest may be necessary. A minimum of four to six weeks is usually required to grow cover crops, so overseed earlier if post-harvest seeding does not allow for that timeframe. It is important to have at least 50 percent of the sunlight passing the cover of cash crops to the ground. Certain crops can grow in low temperature conditions, such as winter cereals like wheat, rye or barley and can be planted later. Avoid seeding in immature corn as it can cause seeds to germinate and get moldy due to moist and low-light conditions.

Aerial overseeding is ideal for larger farmland or when it is cost effective. It is recommended to use manual or inter-seeders on smaller land or when dealing with land occupied by wind turbines. When dealing with soybeans or corn, wait till the leaves yellow and begin to wilt before overseeding. The leaves act as a cover to hold moisture and seeds are more likely to land in soil, providing ideal conditions for germination.