Iowa farmers boosted cover crop acres by nearly 43% for the 2020 crop year and made steady progress in adding and maintaining other proven conservation practices, according to a new report that tracks ag retailer sales data to determine conservation progress in the state.

The annual report, developed by the Iowa Nutrient Research and Education Council (INREC), tracks progress farmers are making on a wide range of conservation practices that are in­­strumental to improving water quality and reducing soil erosion. INREC gathers the conservation information using a statistically sound study of sales data from ag retailers and certified crop advisors to measure and demonstrate progress in conservation practices.

“The numbers show that farmers continue to make strong progress implementing practices that are known to reduce our losses of nitrogen and phosphorus,” said Shawn Richmond, INREC’s director of environmental services. “The continued growth of cover crops is very encouraging.”

The new INREC data showed that Iowa farmers planted 3.1 million acres of cover crops in fall 2019 for the 2020 crop year. That meant that 13.3% of the state’s nearly 23 million crop acres were planted with cover crops going into the 2020 planting season.

Richmond noted that farmers have nearly doubled cover crop acreage in the four years that INREC has been gathering data on conservation practices. The 2020 total of cover crop acres is 94% higher than the 1.6 million acres planted for the 2017 crop year.

The gains in cover crops re­flect the tremendous progress in cover crops throughout Iowa. Prior to the 2013 adoption of the Iowa Nutrient Reduction Strategy (INRS), Iowa’s cover crop acreage was estimated at only around 10,000 acres.

Other practices

Another promising signal, Richmond said, is Iowa farmers’ increased use of nitrification inhibitors. 

Farmers used inhibitors, which keep nitrogen fertilizer in place until it can be accessed by crop roots, on nearly 84% of the acres treated with anhydrous ammonia in 2020. That was up from 72.6% in 2017.

The INREC data also showed that almost all Iowa farmers, some 99%, apply phosphorus only when soil testing shows that the nutrient is deficient in the soil. The practice of making applications only when the soil is deficient has steadily grown over the years and is up from only 74% in 2017, when the INREC data was first collected. 

“This is very encouraging and shows that farmers are using the technology available to tailor their phosphorus applications to the needs of their soil,” Richmond said.

The INREC data also showed continued gains in no-till on both acres being planted to corn or to soybeans. Farmers used a no-till program on nearly 37% of Iowa’s crop acreage 2020, a gain of nearly 10% since 2017.

INREC is in the process of compiling data for its 2021 re­­port on conservation practices and plans to have it completed later this year, Richmond said.

“We really believe that this is a very solid source of information on Iowa farmers' adoption of conservation practices and progress of Iowa’s Nutrient Reduction Strategy,” Richmond said.

Launched in 2014, INREC is a private, nonprofit organization that represents major farm and commodity organizations, including the Iowa Farm Bureau Federation, along with fertilizer and crop production companies, agricultural retailers and crop advisers, to help lead the environmental efforts of agriculture in Iowa. 

The entire INREC progress re­­port can be accessed at