PLANT & SOIL HEALTH Cover crop mixes Select the right seed species and rates BY VICKI MORRONE AND ANN BYBEE-FINLEY C over crop mixes have piqued many farmers' interests. The cost to buy and plant cover crop seed and terminate or incorporate the crop all need to be considered when selecting which ones to include. Choosing the right mixes will help assure a fair return on your investment. Here are ways to reduce the cost while maximizing the return. Know your growing conditions Get a sense of the growing conditions of your fields. Try growing the cover crop as a sole cover crop. Note the conditions when it thrives - and doesn't - and how aggressive it is. If it grows fast and fills in gaps, it is a strong competitor. Experience is key to selecting the right species at the right seed rates for your mix to grow successfully. Seed rate is not an easy determination when planning to grow several species together. Recommended rates generally listed are intended for sole crop production. Combining cover crop species to be planted in a single pass can offer a means to address several goals to improve the soil. For example, to improve nutrient cycling, a dense stand (lots of biomass) will take up excess nutrients that otherwise may be leached. To reduce erosion, just ensuring your soil is covered might suffice. As unprecedented weather events occur more frequently, cover crop mixes should be selected 20 | DECEMBER 2023 The Fauquier Education Farm in Warrenton, Virginia, utilizes three cover crops: annual rye, crimson clover and vetch. Photo by Debbie Eisele. to withstand less than " normal conditions, " such as changes in soil moisture and air temperature. Think of this mix (vs. a single crop) as a way to hedge your bets against less predictable weather.