Sustainable Ag 101: 4Rs Protect the Earth and Farmers’ Budgets

This is the fifth installment of our series on sustainable farming practices, where we take a closer look at how each practice can bring long-term economic and environmental benefits.

If you purchased fertilizer this spring, you probably experienced sticker shock.

Fertilizer prices jumped significantly from last fall. According to the University of Illinois’ farmdoc daily, the price of anhydrous ammonia was $432 per ton in September 2020. By April 2021, it was $691 per ton. That’s a near 60% increase.

Fertilizer becomes even more costly when you consider one-third of annual nitrogen fertilizer application for U.S. corn merely compensates for the long-term loss of soil fertility due to erosion and the depletion of soil organic matter.

This loss isn’t just a hit to farmers’ bottom lines. Nitrogen fertilizer runoff has resulted in the Gulf of Mexico’s Dead Zone and tainted Iowa’s drinking water. The harmful algal blooms in Lake Erie — which once shut down Toledo’s drinking water — are largely attributed to phosphorus fertilizer entering the waterways.

Preventing fertilizer from leaving the farm isn’t a simple process. But there is a simple framework farmers can implement to use their fertilizer more efficiently and effectively. And in doing so, they can help protect the environment and their pocketbook.

4Rs of Nutrient Stewardship

The sustainable ag framework is called the 4Rs of Nutrient Stewardship, which stands for:

  • Applying the right fertilizer source…
  • At the right rate…
  • At the right time…
  • And in the right place.

The Fertilizer Institute says there’s evidence this approach to nutrient management supports the goals of sustainable agriculture. Implementing the 4Rs improves crop performance, reduces environmental pollution and protects wildlife, while improving farmer profits.

Several best management practices fall under the 4R principles. For example:

  • Banding fertilizer in the soil so the nutrients are accessible to plant roots while reducing the odds of runoff
  • Taking soil and plant samples to determine nutrient deficiencies and appropriate fertilizer rates
  • Using variable-rate technology to apply fertilizer in the precise amount needed for specific areas vs. “blanket” applications
  • Including inhibitor technology with nitrogen applications to prevent leaching

The International Fertilizer Association recommends all four “Rs” be paid equal attention to, as overlooking any will likely compromise the efficiency of the nutrient management program.

Benefits Beyond Fertilizer

Even though the 4Rs focus exclusively on fertility, they help promote other sustainable ag practices. The Fertilizer Institute says the best management practices required to achieve the 4Rs are most effective when used with other conservation practices.

One example of this is cover cropping. Cover crops can capture and store leftover nutrients in the soil, preventing them from running off the farm when fields are typically bare. Then when the cover crops die and decompose, the nutrients are released back for cash crops to tap into. Research shows cover crops can reduce nitrogen losses by an average 48% and lower the average total phosphorus loads to waterways by 15% to 92%.

But cover crops also help reduce soil erosion, capture carbon, improve water infiltration and holding capacity, and increase soil organic matter. All of which benefit the environment and the soil health.

Other conservation practices growers can use to maximize the benefits of 4Rs include contour farming, reduced tillage and installing grass waterways.

Real-World Savings and Environmental Impact

Committing to the 4Rs can translate into real differences to farmers’ bottom lines.

Consider this cow-calf beef farm in central Illinois. In a case study published on, the operation made several changes to their corn fields to advance their use of the framework between 2014 and 2018. This included more frequent soil samplings on a smaller grid size, split nitrogen applications on their no-tilled fields, variable-rating phosphorus and potassium, and cover cropping.

Even with the increased costs of taking more soil samples more often, plus the additional expense of cover crops, adopting advanced 4R practices still paid off. On no-tilled fields, they saw a cost savings of $40.71 per acre, and their strip-tilled fields saved $67.71 per acre. At the same time, their greenhouse gas emissions decreased by a maximum of 17.5%.

Other farms can attest to similar results. A Michigan potato farm saw slightly lower nitrogen use by switching from multiple in-season nitrogen application to fertigation, saving nearly $30 per acre. While in Florida, a tomato farm reduced nitrogen rates by 60% and lowered costs by almost $900 per acre by changing the source, timing and placement of its nitrogen applications.

Tailor the 4Rs to Your Farm

While the 4Rs are simple and easy to remember, the best way to apply them to your farm will likely take some thought and effort. The 4R Nutrient Stewardship website provides a condensed pocketbook of implementing 4Rs. For more in-depth information, the International Plant Nutrition Institute offers a complete manual on committing to this sustainable farming practice.

Conterra Ag lends exclusively to American agriculture and has expertise in a variety of farm and ranch operations utilizing both traditional and sustainable farming practices. If you’re ready to refinance, or looking to grow your operation, let’s talk ag — contact your Conterra relationship manager today.

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