Soybean Gains from Salinity Control

By Scout Nelson

Soil salinity is a growing concern in North Dakota, affecting productivity over 1.9 million acres. Recognized by a white crust, these soils disrupt crop yields due to high levels of soluble salts. Specifically, soybeans suffer a yield decline as salinity levels rise, with significant losses observed beyond certain thresholds.

To combat this, researchers are turning to cover crops, which offer a promising solution. Winter varieties such as rye, barley, and camelina, when planted in spring, do not bloom but serve as green mulch. This practice conserves moisture, enhances soil structure, and promotes beneficial microbial activity—all crucial for healthy crop growth.

A recent study conducted in Carrington, ND, in 2024 underlined the efficacy of these cover crops. Planted alongside soybeans, they notably reduced surface evaporation and improved water drainage through the soil profile. This was part of a systematic approach where different cover crop regimes were tested to gauge their impact on soybean yields.

The findings indicated a potential yield increase of 5-8% in plots with cover crops compared to those without. This boost, while not statistically significant in this initial trial, points to the beneficial role of cover crops in soybean production. The most effective were winter barley and rye, which maintained high green cover and biomass, proving to be the best in facilitating water management and soil health.

However, the research highlighted the need for precise management of cover crop seeding rates and their timely termination to maximize benefits without hindering soybean development.

Supported by the North Dakota Soybean Council, this research is just the beginning. Continuous exploration and refinement of cover crop use could lead to more resilient agricultural practices, helping mitigate salinity issues and bolstering soybean yields in affected areas. This innovative approach to farming holds significant promise for the future of agriculture in North Dakota, aiming for sustainability and higher productivity.

Photo Credits:istock-ds70