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How did dry farming conserve soil moisture on the Great Plains?
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Cotton combine harvesting a cotton field.
Dry farming conserves soil moisture on the Great Plains through a combination of strategic tillage, fallow systems, and moisture-retention techniques designed to maximize the use of limited precipitation.12
Key methods include:
- Fallow Systems: Land is left unseeded for a growing season after being plowed and tilled. This practice allows moisture to accumulate in the soil for the subsequent crop season while simultaneously controlling weeds that would otherwise deplete water reserves.2
- Moisture-Conserving Tillage: Farmers use tools like chisels and sweeps that loosen the soil without burying crop residues. Leaving this "trashy" mulch on the surface helps trap moisture, reduce runoff, and prevent erosion.12
- Runoff Prevention: Techniques such as contour farming and the use of lister plows create water-impounding ridges that promote infiltration. Broad terraces are also utilized to slow water movement across slopes.32
- Weed Control: Keeping fields free of weeds is essential, as weeds compete with crops for scarce moisture. This is often managed through timely tillage or the use of rod weeders.12
While these methods aim to preserve moisture, it is important to note that historical misuse—such as deep plowing and the removal of native grasses—contributed to the catastrophic soil erosion seen during the Dust Bowl.45