CAR Table of Potential Management Practices for Improving Nitrogen Use Efficiency

Use of Nitrification and Urease Inhibitors

Use of Nitrification Inhibitors (only)

Switch from anhydrous to urea

Switch from Fall to Spring Application

Change to Slow-Release Fertilizer

Change to Fertigation

Apply N Closer to Roots

Add N Scavenging Cover Crops


The newly announced CAR N-management protocol is technical enough to likely require help from an aggregator to interpret and implement on the farm, CAR’s Broekhoff says. N2O aggregators are yet to form, but they would conceptually resemble earlier carbon-credit aggregators, which included several farm organizations and commodity groups.

N2O-reduction credits would need to be independently verified before credit is granted for reducing qualifying N fertilizer applications, which in turn could earn N2O-reduction credits.

The first version of CAR's N-management protocol applies to corn crops in 12 Midwestern states: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota and Wisconsin. “However, the N-management protocol is designed to accommodate additional crop systems, geographic regions, and agricultural management practices as data and analysis warrant their inclusion,” Broekhoff says.

“There is a market for these credits: emitters looking to voluntarily reduce their emissions by purchasing to meet their own voluntary climate change mitigation goals. There is also the prospect that these credits could be sold into next year’s California cap and trade market.”

Regulated companies in California, like power plants and factories, may be required to reduce their emissions, and “they could meet their obligations by counting these farm-generated credits against their emissions,” Broekhoff says.

The California Air Resources Board has adopted CAR’s air resources standards for its compliance program and has expressed interest in the N-reduction protocol, he adds.

Since California is often a trendsetter, what other cap and trade mechanisms might develop in the future in agriculture?

Reducing methane emissions of California rice producers was the focus of a CAR protocol adopted last December, Broekhoff says. “Farmers here are waiting to see whether the California Air Resources Board adopts that standard before going to the trouble of registering for those credits.

“CAR is also looking to develop a soil-carbon sequestration credit for preserving carbon in soils and grasslands, avoiding the conversion of grasslands to cropland so as to enhance soil-carbon sequestration,” he adds.

“Carbon offsets are the 21st Century crop for the agricultural sector,” says Reed. “Protocols such as this are absolutely necessary to allow farmers to harvest carbon in order to achieve a successful yield of reductions in greenhouse gas emissions and increases revenue streams. Market incentives can reward farmers for stewardship activities, and done correctly, will ensure that the agriculture sector will play a serious and needed role in climate stabilization.”