By Scout Nelson
Research conducted by South Dakota State University at the SDSU Southeast Research Farm examines how organic sweet corn performs when grown with clover living mulch systems under changing weather conditions.
Sweet corn is a warm season crop that prefers warm soil and well drained conditions. In South Dakota, spring weather is often unpredictable, with sudden cold snaps or heavy rainfall. These conditions can strongly affect crop emergence and early growth, making sweet corn production challenging for organic farmers.
The study took place during 2024 and 2025 growing seasons in a USDA certified organic field. Researchers compared sweet corn grown with three clover living mulch systems to a bare ground control. Living mulch is a cover crop grown alongside the main crop. The clover types included white clover, kura clover, and red clover. The clover plots were planted two years before sweet corn. All treatments were strip-tilled to allow direct seeding. Sweet corn is planted in mid-May and harvested in early August each year.
Weather plays a major role in crop performance. In 2024, heavy rainfall occurs after planting but did not cause major delays. In 2025, a late spring cold period slowed sweet corn emergence. During this time, clover grew faster than the crop, creating early competition that affected plant height and yield.
Clover type also influenced results. Red clover caused the most challenges and produced the lowest number of marketable ears in both years. After mowing, red clover did not recover well and weeds became dominant. White clover and kura clover performed better in wet conditions, and spread through stolons, and rhizomes, helping suppress weeds later in the season.
Yield results show that bare ground systems produced the highest quality sweet corn in both years. In 2024, the total marketable yield was similar across treatments. In 2025, clover systems produced much lower marketable yields than bare ground.
The study showed that living mulch systems can improve weed control but also increase production risks. Farmers should consider strong planting beds and proper early season fertility before adopting these systems.
Photo Credit: gettyimages-oticki
Categories: South Dakota, Crops, Corn