Don’t forget about cover crops to hold in moisture |

Don’t forget about cover crops to hold in moisture

Bob Fanning
SDSU Plant Pathology Field Specialist

Much has been written about cover crops recently, but reminders are often good. There are many good reasons to plant cover crops, but an important one is to have something growing on prevented plant acres rather than leave them bare.

The Natural Resources Conservation Service recently posted a new publication, “Cover Crops to Improve Soil in Prevented Planting Fields,” available at: The publication discusses the benefits of healthy soil, and lists four keys to soil health. (See information box.)

Prevented plant fields can be vulnerable to water and wind erosion. Depending on the next crop to be planted, “fallow syndrome” can pose problems due to the lack of biological activity. It is also well documented that many of the soils in central and western South Dakota have limited water holding capacity, so the areas that have received ample rainfall this spring and summer will not be able to capture all of the moisture for the next crop.

One of the theories behind planting cover crops is to use some of the moisture that cannot be stored to grow biomass, both above and below ground to rebuild topsoil and add organic matter. Having growing plants in place on the fields will actually allow more of the rainfall that occurs to soak into the soil than if is left bare and some of it runs off. If producers will be planting winter wheat on prevented plant acres, cover crops will allow them to grow some residue, terminate them 10-14 days before planting and plant at the recommended time, Sept 15 – Oct 15 with less risk of wind erosion or fall aphid or wheat curl mite infestations. Cover crops may also provide grazing for livestock producers, but check with the Farm Service Agency and your crop insurance agent regarding prevented planting requirements and harvest restrictions.

A number of information resources on cover crops are available online and listed below. For paper copies of any of these, or additional information, visit and/or contact your Regional Extension Center.

NRCS Cover Crop information:, SD No-till Association:, National Sustainable Agriculture Information Service:, Michigan Cover Crops:, Pennsylvania State Univ, Cover Crops:, Managing Cover Crops Profitably, 3rd Edition (free online):, Potential Cover Crop Seed Suppliers:

–SDSU Extension