Farmers advised to consider big picture with carbon
By JONATHAN CRIBBS
COLLEGE PARK, Md. (Jan. 31, 2017) — In a world where increasing rates of carbon in the atmosphere are fueling unpredictable weather, Kristine Nichols said farmers must do more than grow food on their fields.
They need to be “carbon farmers,” she said.
“We have a carbon problem,” Nichols, chief scientist at the Rodale Institute, said during her keynote address at Future Harvest CASA’s yearly conference on Jan. 13. “It’s the fact that you don’t have the carbon in the right place. … We don’t bank enough carbon in the (soil) system.”
More carbon must be stored in the soil to keep agriculture environmentally sustainable, she said.
It’s a message Nichols and Rodale, a Kutztown, Pa., nonprofit dedicated to organic agricultural research and support, has been advocating for several years.
Nichols said proper management of grassland and cropland can pull carbon dioxide out of the air and store it in the ground as soil organic carbon — a process known as soil sequestration, which she said can build healthier soils, improve farm profitability and ease an environmentally strained planet.
“We’re still losing about two billion metric tons of top soil each year in this country,” she told hundreds of conference attendees. “This is not sustainable.”
Soil sequestration improves biological activity in the soil, water infiltration, soil tilth and structure and reduces erosion, soil compaction and air pollution, she said.
Nichols pointed to Rodale’s well-known, long-standing Farming Systems Trial, which compares organic and conventional agriculture.
Since its start in the early 1980s, the study has shown that an organic farming system matches or surpasses the results of conventional farming, according to the institute.
The trial’s soil results show, among other things, higher rates of water infiltration, including a 45 percent increase in porosity and that water holding capacity doubles when soil organic matter increases. In 2015, for instance, organically grown corn produced an 18 percent higher yield than conventional corn. Richer soil allows the farmer to better manage increasingly variable weather, including rainfall and drought.
“If you’re able to manage water, it doesn’t matter how much moisture you get,” she said.
Organic, reduced or no-till farming practices also reduce energy inputs and greenhouse gas emissions while boosting profits and yields, Nichols said. Fertilizer and herbicide costs are reduced.
To improve soil health, Nichols said it’s important to minimize soil disturbance by reducing tillage, using cover crops, composting and mulching.
Diversify and lengthen rotations while keeping the soil covered. Also, grazing livestock on crops can also improve soils, adding carbon.
“We have the potential to be able to utilize our system much more efficiently,” Nichols said. “Your soil cannot be healthy without that biology.”
Nichols was one of several agricultural experts who gave keynote speeches at the conference, which brings together hundreds of regional agriculturalists each year to network and learn about progressive, local food systems and farming.