Molecular fields forever

You may have heard that green is the new black, but did you know carbon as the new cash crop alongside corn or beans?
Maybe, if the farmers can get paid for burying — but not growing — greenhouse gas emissions.
Agricultural researchers see potential for sequestration in both soil and in waters of wetlands.
Even now, scientists are conducting experiments to find out if wetlands grown with cattails and other plants can provide the world some breathing room from global warming by capturing carbon dioxide under dirt and water.
U.S. Geological Survey have a lot of information posted about their efforts in California's Sacramento-San Joaquin Delta to trap the gas, as well as stop land subsidence.
Robin Miller, who has the very cool title of biogeochemist with the geological survey, explains it pretty well at http://www.usgs.gov/corecast/details.asp?ep=68.
"A carbon-capture farm is a wetland built specifically to grow very productive emergent marsh vegetation, in our case, cattails and tules that use photosynthesis to capture carbon dioxide from the atmosphere and put it into their plant tissue," he said.
Normal farming methods on the delta for the last 100 years has stripped the land of its soil, Miller added. Farmers drained the fields to grow corn and other row crops.
Exposure of the soil infused more oxygen into it and encouraged microbial growth.
These microbes ate the organic matter in the peat soils.
"And so under traditional farming practices, the islands lose up to an inch of surface elevation a year," Miller continued. "And now many of the islands are subsided more than 20 feet below sea level and the ground water has to be kept even lower than the land surface to grow crops."
In turn, the water tables have dropped substantially, creating pressure on the region's levees.
If the levees broke, the delta would see a salt water intrusion covering the land, creating 20-foot-deep lakes in their place.
This could cause a catastrophic loss in the fresh water supply to Los Angeles and California's important agricultural pursuits, Miller said.
Growing generation after generation of cattails in wetlands could build the land back up, after they die and turn to peat moss. It would take decades, however, to regenerate the soil.
Selling carbon capture credits to an emission intensive industry could provide revenue for the farmer, Miller said. "And although the carbon-credit market is not yet established in California, our hope is that carbon farms will be able to sell their credits and make money, essentially replacing conventional farming in the Delta with carbon-capture farming."
California Department of Water Resources has given a $12.3 million grant to fund the 400-acre wetlands plot, partnering with the USGS and the University of California at Davis.
The federal and state agencies had previously partnered on a pilot project at a place known as Twitchell Island in the same area. 
During these tests, scientists recorded "elevation gains" of more than 10 inches from 1997 to 2005 "as cattails, tules and other plants grew, died and decomposed.
"The process leaves behind roots and plant remnants that compact into a material similar to what formed the peat soils initially," a press release about the wetlands farming project says. 
These could be considered passive carbon farms — there are ideas out there for more aggressive pollution controls through wetlands.
Such "marsh farms" could address the problems caused by excess nitrates, which come from fertilizers used to grow grains, according to Science News Online. 
"Cities and farms throughout the upper Midwest provide a large share of the nitrate pollution responsible for the annual creation of a huge zone of oxygen-starved water—the so-called Gulf dead zone—1,000 miles downstream in the Gulf of Mexico," the article stated.
The problem causing nitrogen can be removed from the waters by bacterial found in wetlands, helping to prevent the dreaded dead in the oceans from growing larger.
Where carbon capture by wetlands could be a fairly low-tech business, nitrogen would require more intensive engineering and monitoring, Science News' information indicates.
But it's effective, at least for a time, as shown by the results of a test done by research Amy Poe at the University of North Carolina. A built-from-scratch 12-acre marsh handled about 50 percent of the nitrates washed off of a 2,200 acres of corn and beans for about three years.
Hopefully, a system of economic rewards can be developed to reward farmers for returning the land to this natural and important kind of productivity.
While the harvest might be more abstract, it's no less important than the air that we breathe.