As leaders in sustainability, Illinois soybean growers have a long history of increasing productivity while reducing negative environmental impacts. However, there is a need for agriculture to continue to improve by adopting the latest tools and technologies.

The good news is that increasing efficiency and minimizing environmental impact helps keep more money in your pocket. Use the “4Rs” of nutrient stewardship—right source, right rate, right place and right time—as your guide to establish a solid foundation for nutrient management on your farm.

1. Consider the source

The right fertilizer source plays a significant role in ensuring that crops receive a balanced nutrient supply that maximizes yield and minimizes environmental impact.

Consider the difference in nutrient loss risk between various fertilizers and plan your application strategy accordingly. Especially when it comes to manure type, the inevitable variation in nutrient composition and crop availability must also be addressed.

Poultry manure, for example, has low nitrogen availability compared to swine manure. Supplying the nitrogen needs of corn or wheat in turn provides phosphorus levels needed for multiple crops in the rotation. It’s important to familiarize yourself with the nutrient profile of any organic fertilizer you use.

2. Remember rate

Examine the crop rotation schedule in each field to determine plants’ nutrient requirements. Every rotation has unique nutritional demands.

Take advantage of available precision agriculture tools to help you determine appropriate application for portions of fields with different soil test values and a yield monitor to assess variations in nutrient removal rates.

Good soil sampling methods combined with variable rate technologies to best match application rates to plant needs will maximize yield and profit potential.

3. Emphasize placement

Be receptive to experimenting with best practices for fertilizer placement. In some areas of the north central region, banding of phosphorus leads to more efficient nutrient use by plants, while in many other areas, broadcasting is just as effective, even with no-till management.

However, most growers will see benefits from subsurface banding of injection to reduce the risk of phosphorus loss with surface runoff.

4. Coordinate the timing

Timing of phosphorus application is the variable most dependent on region and weather. Monitor weather patterns closely and surface-apply fertilizers when risk of severe storm events is low.

There is likely no crop response to phosphorus in high-testing soils. Avoid broadcast application and switch to smaller starter rates to increase profitability and reduce risk of loss. 

Consider using cover crops and residue management to keep those soil particles and fertilizers where they belong—in your field. Cover crops will do an excellent job of protecting your investment and the environment.

Now is the time to voluntarily adopt best practices for reducing risk of nutrient loss. Use the 4Rs of nutrient stewardship as the building blocks for establishing your own nutrient loss reduction strategy.

Pete Fandel is an associate professor of agriculture at Illinois Central College as well as a Cover Crop Specialist with the Illinois Council on Best Management Practices. Previously, Pete spent 18 years as a crops educator with the University of Illinois. He also conducts research on cover crops and farms his family’s land in central Illinois.