Crop Rotations, Cover Crops Armor Soil Against Weather Extremes

June 8, 2022

Extreme weather and soaring input costs has producers in situations where they may consider extending their crop rotation and/or adding cover crops to their system. Farmers need to weigh their program, insurance, and agronomic options to ensure long term profitability.

Diversified rotations and cover crops can provide crop residue as armor for the soil surface and protect it from wind and water erosion. Diversifying crop rotations also helps break troublesome weed, insect, and disease cycles.

Rye Spring 2022 – Rye cover crop planted in the fall 2021 after silage. There was enough spring growth for grazing prior to planting the 2022 soybean crop.

Fall 2021 a cover crop mix after oats – This diverse cover crop mix was seeded after oat harvest in 2021 in Clay County, SD, to protect the soil over winter and build the beneficial arbuscular mycorrhizal fungi (AMF) population. Photo taken Oct. 14, 2021.

“Additional benefits from residue or cover crops include stabilizing soil temperatures, suppressing weeds, and adding nutrients,” explains Jason Miller, Conservation Agronomist with the Natural Resources Conservation Service (NRCS) in Pierre, SD.

With the markets, some farmers may have planted soybeans for a second year on fields that grew a bean crop last year. Much of that soybean residue will have decomposed by the next season so Miller encourages reviewing the crop rotation for how to rebuild the residue to protect the soil. Miller recommends to “have a mixture of low and high residue producing crops in your rotation, and sequencing those to always have residue cover for soil armor,” Miller said.

“Diversified rotations with corn, wheat, and other small grains are high in carbon, and the residue left behind after harvest, have a role in protecting the ground and benefiting soil health.” explains Miller.

Cover crops can build considerable yield potential for the following crops when managed correctly. Cover crops have the potential to capture applied nutrients left at the end of the season, fix additional nitrogen, build organic matter, help suppress weeds, control erosion, and improve soil quality during the remainder of the season.

12″ rye cover crop producing roots extending more than 7 inches in the soil profile by May 4, 2021 help to use excess moisture to prep soil for planting equipment.

Rye cover crop roots in May 2021 prior to corn planting helping create more granular soil structure

Rye cover crop roots holding soil aggregates together to help prevent spring erosion from wind and water erosion.

Proper application of crop rotations can increase yields and reduce market risk, explains Doug Fiedler, NRCS Conservation Agronomist, Brookings, SD. Improving soil health positively affects farm economics by reducing weed, disease, and insect pressure and resistance. Fiedler explains, “Diversifying your crop rotation also spreads out the planting and harvest season and diversifies income while minimizing weather risks.”

Producers are advised to check with USDA’s Risk Management Agency (RMA) and their individual crop insurance agents on prevented planting requirements, as well as haying, grazing, and harvest restrictions for cover crops grown on prevented planting acres. RMA also has restrictions to be aware of on cover crop termination dates in spring prior to commodity crops.

USDA NRCS South Dakota additional cover crops resources including “Table 1” with Common Cover Crop Species and Properties for South Dakota: Questions? Contact the staff at your local USDA NRCS, conservation district, SD Soil Health Coalition, or SDSU Extension.

Cover crop mix after oats.

Cover crop mix after oats.