In the end, what will be produced is a high-resolution soil map rendering data in pixels, tiny digital squares. Rather than indulge in the arcana of soil terminology ("Honeoye silt loam," "mesic Glossic Hapludalf"), each sample will list in probable terms the properties of the soil: its water storage, carbon density, acidity and density, and even its electrical conductivity.
The map would have a resolution of two football fields, 100 meters square, said Bob MacMillan, who is taking over scientific coordination of the project next month.
Several pilot projects are under way to support their theories, including on the border between North Dakota and Manitoba, Canada, and in the Danube region. Australia is the most advanced soil mapper, MacMillan noted, effectively testing their model on the entire continent.
It did not go entirely smoothly.
According to the project's managers, "There were areas where they got it pretty good, and areas where they got it pretty badly," MacMillan said. The team is refining its models now, and the project's initial results are online, providing a rough model of maps to come.
The largest test bed for the digital map is the African project, announced in January. Sanchez, a noted soil scientist, also leads the Millenium Villages project at the Earth Institute of Columbia University, a community development program that works with African villages to build sustainable farms. Having a robust digital map would be a boon for planners, he said.
Currently, much of Africa suffers from a shortage of phosphorus in its soil, an essential nutrient used by plants for photosynthesis and energy transport. Typically, phosphorus, depleted by harvests and erosion, is replenished by fertilizer; in Africa, however, fertilizer use sits at 10 percent of the world average.
Put another way: Thanks to its poor soil, the average farm in Africa produces 1 ton of corn. In the United States and Europe, the average is 8 tons, according to Sanchez.
To build the African map, the service will compile all existing data sets and then sample 60 sites across sub-Saharan Africa and Madagascar -- a region covering 18.1 million square kilometers. Their "spatially stratified random sampling approach," the service says, will provide the first "unbiased sample of the subcontinent."
In a continent that is home to nearly a billion people and diverse ecosystems, 60 sites may seem like a small sample. This is where the technology comes in, the service's supporters say. Eventual testing will prove their accuracy, but, as MacMillan notes, analog soil maps are already unreliable, with rates hovering between 55 and 65 percent.
"What we're doing here is not so much magic, it is replicating and validating our logic," MacMillan said.
This month, the project is establishing a North African base in Jordan, and around the world -- academic centers in the United States, Brazil, China, Australia, Kenya and France are collaborators -- its researchers are "chasing money," Hartemink said.
The map has the growing support of scientists in the United States, said Karl Glasener, the director of science policy for the Soil Science Society of America.
At the Group of Eight industrial nations meeting last month, President Obama said he would ask Congress to double U.S. agricultural development assistance to more than $1 billion in 2010.
"With the president's announcement of new support for agricultural development assistance," Glasener said, "perhaps the opportunity will arise to channel funding to the global digital mapping project."