Soil Building Cover Crops
We have talked about the benefits of cover crops and the many options of what to seed, but we want to talk about how to use cover crops to build soil compared to using cover crops as forage.
Photo 1: Forage Max in the Fall Photo 2: Forage Max in the Spring
Using Cover Crops to Build Soil
Cover crops can be great tools to build soil. A growing cover crop acts like a sponge soaking up available nutrients and holding them in the tissues of the plants (Photo 1). When those cover crops are not harvested and are left to winterkill or are terminated mechanically or chemically, the above ground growth is able to break down and release those nutrients into the soil (Photo 2). We sometimes refer to this practice as a soil building year.
This process of leaving cover crops whole and then terminating allows that above ground growth to feed your soil biology. As the biology feeds on the residue, that contributes to building organic matter in the soil. Increasing organic matter improves soil structure and water infiltration to help you catch the rain you get and keep it where plants need it. All of this and we haven’t even mentioned the role cover crop residue has in protecting the soil from temperature changes, erosion control, and more!
Using Cover Crops as Forage
Cover crops harvested as forage can provide high-quality stored feed, and none of the following information is intended to discount that fact. If the goal of your cover crop is providing forage, many blends can meet that perfectly, but that goal does not go hand in hand with soil building.
The benefits gained from harvesting a cover crop include having that living root in the ground, cover growing on your soil, and when the cover crop is terminated the below ground growth will break down and feed biology. However, the benefits of the above ground residue that we listed above are removed. The thing to remember here is that the nutrients that the cover crop sequesters will feed your livestock, but will not be returned directly to your soils.
All of this is a reminder that it is important to know the goal or goals of your cover crop and how well they go together, let us know if you have questions!