Emerging technology may give farmers instant read in the field on soil-carbon changes
Pennsylvania funds The Rodale Institute to find out whether new system can document agricultural carbon sequestration for carbon-credit trading.

By Christine Ziegler Ulsh

November 16, 2007: Farmers interested in opening up a new revenue stream by selling carbon credits for proven soil-building practices may soon have a new technology to document their carbon-sequestration success.

The Rodale Institute has received funding to develop a way to do “Rapid, Cost-Effective Soil Measurements for Accurate Agricultural Carbon Crediting.” Granting $208,000 for the work was the Pennsylvania Energy Development Authority (PEDA), a division of the Pennsylvania Department of Environmental Protection.

Previous research at The Rodale Institute has demonstrated that the use of cover crops and diversified production crops in a multi-year organic crop rotation can sequester up to 1,000 pounds of atmospheric carbon per acre per year, and that the incorporation of compost can sequester up 2,000 pounds of carbon per acre annually.

These carbon sequestration rates are more than twice that of conventional (non-organic) no-till management, which typically uses no overwintering cover crop but utilizes a thick layer of residue on the surface. The Institute wishes to promote these sustainable agriculture practices as substantial, largely-untapped vehicles to sequester greenhouse gases in the form of beneficial soil organic matter, especially if they can be applied to most or all of Pennsylvania’s five million farm acres.

In order for Pennsylvania’s farmers to measure how much carbon they’re trapping in their soils for carbon-credit programs, they need a quick, cost-effective, accurate method to measure soil organic constituents at their farms—preferably right in their fields.

Current soil carbon and nitrogen measurement techniques involve either high-temperature combustion and gas spectrographic analysis, or expensive and hazardous chemical digestion and neutralization. Neither of these methods can be done practically on the farm; farmers must send their soil samples to a testing lab, which often requires more time and money than most farmers can spare. Without a significant improvement in testing, tracking soil carbon changes won’t be practical enough to help farmers learn what is working on their farms. The change will better track what works to build soil organic matter and to offset atmospheric carbon.

Checking new technology

To address this problem, The Rodale Institute will evaluate a new piece of soil-testing equipment. The Near Infrared Reflectance Spectrometer (NIRS) shows promise to be a safer, less expensive, more flexible alternative for soil carbon testing than current lab work. With this equipment, our goal is to streamline soil carbon testing enough to bring it on-farm and in-field to support a verifiable agricultural carbon crediting program.

The PEDA grant will allow the institute to 1) establish an NIRS laboratory facility at The Rodale Institute, 2) test NIRS accuracy in measuring soil carbon and nitrogen by comparing their readings against standard independent lab analyses, and 3) calculate sampling and analysis expenses to determine the economic viability of the new system.

If the results are sufficiently positive, the Institute will proceed to evaluate a mobile soil-testing unit, mounted on a field implement or vehicle, to assess its ability to perform rapid on-farm soil evaluation.

By bringing this location-specific, on-the-go assessment capacity into the field, the hope is to get farmers thinking and talking about how different farming practices can increase or reduce greenhouse gas emissions, as well as discussing the ways carbon-crediting programs might work for them.

The objectives of this project are to

  • Create a NIRS soil-testing laboratory to assess the technology’s speed, accuracy and costs in measuring soil organic matter.
  • Measure and compare soil carbon changes under organic and conventional agricultural production practices, including standard tillage and no-till systems.
  • Design and test mobile NIRS equipment to assess its accuracy in measuring soil organic matter in the field.
  • Outline business models that will encourage Pennsylvania farmers and other agricultural entrepreneurs to develop this new technology as a means to help farmers improve their management practices and enter the emerging nationwide carbon crediting market.

The focus of the project is carbon sequestration in agricultural soils, but it will also help to reduce on-farm energy use and improve livestock manure management. Carbon sequestration directly correlates with increased soil organic matter, a key factor in soil quality and agronomic performance. Soils high in organic matter are easier to work, produce healthier, higher-yielding crops and are more resistant to erosion and drought.

Carbon sequestration is also becoming a saleable commodity itself, thanks to a market for carbon credits, providing potential for additional farm revenue via best management practices such as conservation tillage, composting and the use of cover crops. Accurately quantifying the levels of carbon sequestration will demonstrate the benefits of integrating these practices in multi-year rotations, as required in certified-organic systems.

For any carbon crediting program to be effective, it has to be backed up by "a [soil] sampling program that achieves a level of precision high enough to detect tons of sequestered carbon without incurring untenable costs" (Willey, 2007). The Rodale Institute researchers want to establish if NIRS soil measurement will do just that: reduce costs, maintain precision and make carbon crediting options available to a wider segment of farmers.

Veris Technologies (www.veristech.com), an agricultural engineering firm based in Salina, Kansas, will supply equipment for the project and offer technical assistance in the development of experimental protocols. Veris Technologies developed the first commercially available NIRS unit adapted and integrated for mobile, in-field testing, enabling detailed mapping of carbon variability and more accurate values for fields as a whole. Alain Plante, PhD., a biogeochemist in the Department of Earth and Environmental Science at the University of Pennsylvania, will also collaborate on the project. Possessing a keen interest in developing alternative soil measurement methods, Dr. Plainte will provide expertise on the quantification and characterization of soil organic matter.

The Rodale Institute will post bi-annual project updates of research results on The New Farm website. We will also host annual field days in 2008 and 2009 to outreach agricultural carbon sequestration practices, as well as carbon measuring and crediting information, to farmers. Finally, we will produce a printed fact sheet or small booklet to provide similar information to farmers and agricultural professionals, in hard copy and online versions.

If the technology proves to be successful and practical for the task, the printed materials will include a report outlining ways for entrepreneurs to develop the mobile NIRS equipment into a soil carbon measurement/crediting business.

Work will begin in early 2008. For comments or questions, click here.