50 The Cost of Tillage and Bare Soil in Extreme Conditions
In this podcast, Buz Kloot talks to Dan Mehlhaf, District Conservationist for the USDA NRCS, currently stationed at Yankton, South Dakota. Dan was raised on a farm and has a degree in agriculture from South Dakota State University and he actively farms with his son on land they own in Hutchinson County, about 30 miles from his work.
The discussion centers around Dan’s experience in April and May 2022, that culminated in the May 12, 2022, windstorm (or derecho) that occurred in South Dakota. Prior to the derecho, the entire spring was extremely windy and warm; and on April 14, 2022 there was a day of constant 40-50 mile an hour winds that caused wind erosion in the fields. Dan went to investigate a relative's report of severe wind erosion about 30 miles northeast of Yankton and saw soil coming off the field due to the tilled, dry soil and the absence of any residue or canopy cover. Dan looked up the soil to find this was an Egan-Ethan soil, which is a silty clay loam, considered a very good soil. Five days later, Dan revisited the site on a sunny day, and the road ditch was completely full of soil that had come off the field, Dan noticed that the soil in the road ditch was sand, not the texture on the field which was a silty clay loam. Dan realized that the silts and clays that made up the soil had gone airborne and disappeared, and the only particle left was the sand left in the ditch. He took a soil sample to be tested and found high to very high levels of nitrogen, phosphorus, sulfur and other nutrients which ought not to be in a sand, and calculated that over $900 of fertilizer per acre were in the ditch sand, what about the rest of the silts and the clays that blew off the property?
Buz and Dan turn to the topic of the importance of cover (small grains, standing residue, cover crops) and no-till agriculture in the context of wind erosion was raised. Dan highlighted his experience on April 14th, 2022 (a full month before the May 12th 2022 derecho) in the significant difference in wind erosion between two fields of the same soil series (Egan-Ethan), where one was bare ground and tilled, while the other had a cover crop of cereal rye. The field with the cover crop experienced virtually no erosion compared to the other field, which was blowing soil around even with a moderate wind. Dan emphasizes that the adoption of no-till and the use of cover crops are slowly changing farmer's attitudes towards conservation tillage. Dan does note that a well-planned cover crop can protect against a 25 mile an hour wind fairly easily, while a 50 mile an hour wind requires a good, intact residue from the cover crop to prevent significant erosion.
Dan notes that adoption of no-till and the use of cover crops is slowly gaining momentum, in both and wet dry years, and that the attitude of farmers towards reduced tillage is changing. Dan hopes that the change in attitude towards cover crops and no-till agriculture is a long-term change and not just a temporary response to the dry years. Dan highlights that there is still a need for more education and awareness on the importance of cover crops and no-till agriculture to protect soil quality and water quality.
MORE ON THE DERECHO
See: https://www.growingresiliencesd.com/ for more on the derecho and find our Growing Resilience name for videos wherever you get your social media.
OTHER REFERENCES:
Description of a Derecho: https://www.weather.gov/lmk/derecho
May 12 derecho summary: https://www.weather.gov/abr/StormsummaryMay122022
