Erosion: How Much Is Too Much To Sustain Agriculture?

Erosion: How Much Is Too Much To Sustain Agriculture?

Farm field showing water erosion
Photo courtesy of National Resources Conservation Service South Dakota

Tolerable soil loss is determined for each farm field depending on characteristics such as soil type and slope. What is the range of tolerable soil loss across the Driftless Area?

A. 2 to 4 tons of soil per acre, per year (quarter a dump truck load)

B. 5 to 6 tons of soil per acre, per year (half a dump truck load)

C. 10 to 12 tons of soil per acre, per year (whole dump truck load)

D. 20 to 40 tons of soil per acre, per year (two to four dump truck loads)

Answer is A: 2 to 4 tons of soil per acre, per year (quarter a dump truck load)

According to the government report, Soil Erosion on Cropland (2007), the average soil loss across the lakes states was 4.6 tons per acre, per year. There has been consistent and steady improvement each year going back to the report’s first year, 1982, when the average losses were 6.1 tons per acre, per year.

While trends are in the right direction, the average soil losses are higher than the tolerable level for the entire Driftless Area. As always, there is room for improvement.