New UF test could help third world farmers improve soil, fight global warming

May 24, 2005

GAINESVILLE, Fla. — A process developed at the University of Florida will help Third World farmers keep nutrients in their soil and could eventually allow them to join the fight against global warming.

The process provides a cost-effective way to measure carbon in large plots of land, said James W. Jones, a distinguished professor of agricultural and biological engineering with UF’s Institute of Food and Agricultural Sciences.

Crop soils in poor countries are often carbon-depleted due to farmers’ reliance on primitive agricultural practices that remove carbon — a crucial nutrient that helps soil resist erosion and promotes plant growth — but never replace it, Jones said.

Carbon left in soil could one day be used as part of an emissions trading program under the Kyoto Protocol to reduce carbon dioxide and other greenhouse gases. But first, researchers will need to develop pilot projects to demonstrate that the amount of carbon stored in the soil can be measured accurately through time, said Sandra Brown, a senior scientist at Winrock International, a nonprofit agricultural research organization in Little Rock, Ark.

And, she said, the global warming treaty would need to be amended as well to allow richer countries to exceed their greenhouse emissions limits in exchange for investing in agriculture projects.

Agricultural soils could absorb more than 10 percent of man-made carbon dioxide emissions worldwide, according to the Food and Agriculture Organization of the United Nations.

“It’s going to be a long time before anyone will pay to store carbon in farmlands in poor countries in a significant way,” Brown said.

“I agree with Dr. Brown that this isn’t going to happen overnight,” Jones said. “However, research like ours is necessary to advance the field such that soil carbon credits will become a reality.”

Jones and other researchers involved in a U.S. Agency for International Development soil management program are already working with farmers in developing nations to determine which carbon-saving agricultural practices work best under specific climate and soil conditions. Jones said methods under investigation include no-till farming, in which unharvested plant material is plowed back into the soil, and ridge tilling, where farmers discourage erosion by digging furrows into crop fields.

“We’re doing all we can to bring the benefits of emissions trading to farmers who need it,” Jones said. “We believe our approach has great potential, and we will continue to move forward.”

Field tests in the African nations of Ghana and Mali indicate the new process, which combines computer models and soil measurements, out-performed existing methods that rely exclusively on one or the other, he said.

“The computer models can account for a wide range of crops, climates and land management practices, and improve on the accuracy of previous models. In addition, our process requires fewer costly soil measurements than earlier methods based on soil sampling,” Jones said.

Jones’ research can help farmers in poor countries improve their soils, increase crop yields and extend the useful life of farmland, particularly if they adopt carbon-saving agricultural practices, he said.

Foreign investments could provide much-needed funds to pay for improvements, said John Antle, a professor of economics and agricultural economics at Montana State University who is working with Jones on the USAID-sponsored program. Currently, investors have few reasons to support Third World agriculture but that might change eventually if the Kyoto Protocol recognizes agricultural land as a subject for its emissions trading program, Antle said.

The Kyoto treaty, which took effect in February, has already spurred investments in forestry, Antle said. In Europe, brokers help industrial firms purchase the right to emit specific amounts of carbon dioxide above their government-mandated limits, in exchange for making investments in projects that plant or protect trees. Like all green plants, trees absorb carbon dioxide from the atmosphere and store it in their cells.

In mid-April, a company seeking to exceed its allotment of carbon dioxide emissions paid about $20 in forestry investment per ton of emissions, according to Point Carbon, a European emissions broker in London. Analysts at the firm expect $3.2 billion in worldwide carbon dioxide emissions trading this year, and predict more than $40 billion per year by 2010.