Cover Crops or Companion Cropping?

Article Written by: Dennis Schwartzkopf & Greg Winter

The use of cover crops in a crop rotation is a well-known practice to build soil health and put nutrients back into the ground. But have you ever thought about planting a cover crop with your cash crop? This practice is called companion cropping. Before we jump into the benefits about companion cropping, let’s review what cover crops are and the benefits they provide.

Cover Crops are plants or a mixture of plants that are grown during a fallow period between cash crops. These cover crops are usually either grazed or left for decomposition. This becomes a vital part of the regenerative agricultural system by providing a unique delivery system for many ecosystems. Cover crops are known to improve soil in a number of ways including protecting against soil loss from erosion as well as providing organic matter, which encourages beneficial soil microbial life. For every 1% of organic matter increased in the top foot of soil, you will have an additional 20,000 gallons of water holding capacity per acre. They also:

1. Catch nutrients before they leach out of the soil profile
2. Roots that unlock nutrients, converting them into more available forms
3. Provide habitat or food source for important soil organisms
4. Break up compacted soil layers
5. Increase the soil’s ability to absorb and hold water through improvement in pore structure

Companion Crops are a cover crop grown with a cash crop at a lower seeding rate. The companion crop consists of a diverse mixture of plant species to feed the cash crop as well as provide a habitat for a beneficial insect population. This is a new technique but has grown tremendously in the past five years. We have especially seen an increase in seeding a companion crop during the corn V4-V7 state with a seeding rate of 10-14 pounds per acre. Seventy five percent of the fields where this has been done have shown a yield increase.

In addition to the above benefits of cover crops, when you use cover crops as a companion crop in your field, you will also see these benefits:

1. Suppressed weeds, the cover crop acts as a smother crop, outcompeting weeds for water and nutrients
2. Growing leaf canopy that creates its own micro-environment to:
   • Blocks light, altering the frequency of light waves which lowers the soil surface and air temperature by ten degrees or more.
   • Lower the evaporation rate
3. Beneficial microbial life that discourages disease by creating an inhospitable soil environment for many soil borne diseases
4. Beneficial insect predators and parasitoids that can reduce insect damage below economic thresholds and produce compounds that reduce nematode pest populations

We encourage you to experiment with companion cropping on a small scale this year! Be sure to check with your crop insurance agent to make sure you maintain compliance before doing so.