Cover crops - A balancing act for soil moisture and health

By Scout Nelson

In the Strategic Farming session Dan Smith and Dr. Anna Cates delved into the complex relationship between cover crops and soil moisture, highlighting how these plants can both consume and conserve water.

Despite experiencing a severe drought in Southern Wisconsin, where no rain fell for two months, research revealed that cover crops could still benefit the soil and subsequent crops.

Investigations into different farming practices, including full tillage and planting green systems, showed that cover crops like cereal rye could help retain soil moisture, contrary to the expectation that they might deplete it.

This was particularly evident in the planting green system, where soil moisture was preserved in the topsoil layers, offering a stark contrast to the dry conditions found in full tillage treatments.

A nitrogen rate study revealed that corn planted into cereal rye residue remained healthy and yielded well, even without additional fertilizer nitrogen. This suggests that cover crops can play a role in nutrient management by retaining soil moisture and preventing nutrient leaching.

The challenge of when to terminate cover crops to avoid competition with cash crops remains. Research from Wisconsin and Minnesota indicated that timely termination of cover crops is crucial, especially in dry years, to prevent yield drag on main crops like corn and soybeans.

Cover crop management strategies such as adjusting seeding rates and planting dates were also discussed. Tools and adjustments for planting equipment can help farmers succeed with cover crops without needing to invest in new machinery.

The session emphasized the importance of cover crops in building drought resilience through improved soil structure and fertility. Cereal rye was praised for its reliability and growth potential within short rotation windows.

As for management recommendations for 2024, experts advise a cautious approach to cover crop termination timing, especially under dry conditions, to minimize competition and maximize crop success.

Photo Credits -minnesota-corn-growers-association