It's Not Just No-Till: Crop Rotations are Key to Improving Soil Quality and Grain Yields at Dakota Lakes Research Farm
Thesis - Open Access
Master of Science (MS)
Department / School
Agronomy, Horticulture, and Plant Science
Crop rotations, No-till, Soil quality
No-till is increasingly promoted as a vital agricultural practice to address the challenge of improving soil quality while maintaining the ability to produce food, feed, fuel, and fiber. However, questions remain regarding 1) how different crop rotations impact soil quality under no-till management specifically and 2) whether significant improvements in soil quality can be made without negatively impacted crop yields. In this study, we demonstrate that even under the same long-term no-till management, differences in grain yields and soil biological, chemical, and physical properties exist between crop rotations at Dakota Lakes Research Farm in central South Dakota. We propose that these differences in soil quality and grain yields are due to the proportions of high residue producing crops and the diversity of crops included in the crop rotations. In this study, irrigated rotations included corn-soy (low diversity, 50% high residue crops), corn-corn-soy-wheat/cover crop-soy (high diversity, 60% high residue crops), corn-cornsoy- wheat/cover crop (medium diversity, 75% high residue crops), and continuous corn (low diversity, 100% high residue crops). Dryland rotations included wheat-broadleafcorn- broadleaf (high diversity, 50% high residue crops), wheat-corn-broadleaf (medium diversity, 67% high residue crops), and wheat-wheat-sorghum-corn-broadleaf (high diversity, 80% high residue crops). Rotations which had both mid to high crop diversity and mid to high proportions of high residue crops exhibited enhanced soil quality properties (such as larger mean soil aggregate sizes and higher soil organic carbon contents) and maintained or increased grain yields over time (1991-2021) at Dakota Lakes Research Farm. These results suggest that crop rotation management must be promoted in addition to no-till management to simultaneously improve soil quality, crop yields, and agricultural sustainability.
Library of Congress Subject Headings
No-tillage -- South Dakota.
Crop rotation -- South Dakota.
Soils -- Quality -- South Dakota.
Grain -- Yields -- South Dakota.
Number of Pages
South Dakota State University
Sturm, Natalie, "It's Not Just No-Till: Crop Rotations are Key to Improving Soil Quality and Grain Yields at Dakota Lakes Research Farm" (2022). Electronic Theses and Dissertations. 366.