Speaker warns of carbon sequestration
WARREN TOWNSHIP — The contributions of agriculture to climate change are significant, Eric Toensmeier told the Northeast Organic Farming Association-New Jersey’s Winter Conference on Jan. 31.
He is senior biosequestration fellow with Project Drawdown a non-profit whose mission statement explains is trying to help the world reach drawdown, the point when levels of greenhouse gases in the atmosphere stop climbing and start to steadily decline.
He is also an appointed lecturer at Yale University and the author of Paradise Lot and Perennial Vegetables.
Toensmeier explained the two greenhouses gases that are problems from agriculture are methane and nitrous oxide.
A lot of conversation in the non-farm community centers around methane from cow burps, he noted, but that is hardly the only source.
Much metheneare problems, he said, and much methane comes from rice production, although that is hardly an issue in New Jersey.
Enteric fermentation can be minimized, he said, using feed additives such as seaweed or by improving forage quality with tree fodder such as black locust and willow or adding longleaf plantains, sorghum, fodder beets and forage rape.
These shift the tannins from excretion in urine to excretion in manure where they can be minimized through composting or bio-digestion, he said..
Other agricultural sources of climate change gases can be mitigated by reducing tillage, using legumes as a cover crop, eliminating burning and using biochar.
Toensmeier believes no-till is the best choice.
After photosynthesis, some carbon always remains in the soil and it remains longer if there has been no tillage. In addition, cover crops put more carbon into the soil.
In colder weather areas more carbon remains in the soil.
The drawback to no till is that sequestration can be reversed if the area is plowed or if cover crops are stopped.
Project Drawdown is doing presentations on biochar which has an impressive potential for reducing emissions, although that isn’t its only use.
Biochar is a woody material with a “high affinity for a variety of pollutants including phosphorus,” according to Lake Hopatcong Commission Administrator Colleen Lyons.
It is used by the commission as a low-cost option for phosphorus removal in the lake and other fresh-water lakes.
It is placed in floatation balls or cages and tethered along a beach area or where an inlet enters the lake. It is composted after it exhausts its capacity for absorption.
Plant roots grow into the material and uptake phosphorus directly from the soil, leaving the carbon in place.
A problem for both New Jersey and Toensmeier’s native Massachusetts comes from cranberry bogs which are created by draining wetlands.
He noted many cranberry growers are leaving Massachusetts for the upper Midwest which creates an opportunity to find ways to sequester carbon in these wet areas.
Toensmeier said Drawdown is also trying to find better ways to farm peat lands while maintaining carbon sequestration.
Emission reduction is permanent, he pointed out. Carbon is hard to measure below ground.
Livestock farmers can also take measures to sequester carbon.
Silvapasture systems are the gold standard, Toensmeier said. Trees are either planted or those that are present are allowed to grow.
Some farmers and ranchers graze their stock in orchards or use fodder banks and others provide perennial feeds from the trees such as acorns, which pigs really enjoy, or black walnuts.
Farmers near the ocean “have been feeding seaweed forever,” Toensmeier said, but other farmers can also add it to feed sacks or salt licks.
Toensmeier said an unrecognized benefit of organic agriculture is its help in reducing methane.
He also advocates growing more on the farmland we have and increasing farmland without cutting forests. “Agricultural has to be combined with forest protection,” he said.
Biointensive farming, better pest control, IPM and intercropping are all part of the picture.
So is using less farmland as grazing land. Steep, rocky and remote areas can be used for grazing.
“It is a loss when we feed livestock things people can eat,” he emphasized.
He suggested visiting the Carbon Farming Solution website for more information.