Sam Bennett of Galva, IA is a die-hard cover cropper, but last year the drought had him second guessing the time and money necessary for implementing cover crops. “We chickened out last fall,” Sam says, “after seeing neighbors’ cover crops [seeded in mid-August] that germinated, grew a bit, then died. We could have done it and still have had okay spring growth.”
Despite the dry conditions, Sam will aerially apply cereal rye at his typical rate of one bushel/acre around Labor Day. Below are some of his thoughts on the importance of cover crops during dry years. Sam emphasized that long-term cover cropping drastically increases the water-holding capacity of soils, which will help withstand drought in the future.
Nitrogen retention: “If you apply nitrogen at a rate expecting to get 250 bushel/acre corn, and yield closer to 150 bushel/acre, there is a lot of nitrogen left in the soil. The rye cover crop helps to keep nitrogen from leaching below the rootzone,” notes Sam. “We want to retain this N for future crops, and I think it is our responsibility to keep that nitrogen out of the water bodies.”
Addressing next year’s drought-stressed weeds: We may continue to have dry weather in upcoming years, and herbicide products are less effective on drought-stressed weeds that are not growing and metabolizing the product. Sam explains that even if he terminates the cover when it is small, he still sees some additional waterhemp control: important when lack of moisture inhibits herbicide efficacy.
Tips for seeding into dry conditions: Watch for herbicide carry-over interfering with cover crop establishment. Lack of soil moisture means that certain products are not metabolized as quickly as a normal year. To check to see if your herbicide program affects cover crop establishment, Sam suggests digging up an inch of soil, bringing it inside, and trial-seeding your intended cover crop species to see how it does before seeding a field.
