Earth Day Special Highlights Soil-Based Solutions

PBS NC State of Change: Natural Solutions title slide

April transfers environmental news above the fold for Earth Month. North Carolina’s climate and environmental challenges affect all citizens, but none more than the farmers who live and make their livelihoods from the land. 

In a new Earth Day broadcast special, PBS NC examines natural solutions to carbon removal and carbon capture to mitigate North Carolina’s evolving climate impacts. The in-depth special explores statewide environmental concerns told by the people they affect and the research addressing them, including two soil programs from NC State’s Department of Crop and Soil Sciences.

Preserving Coastal Farmland

Coastal North Carolina farmers have a unique relationship with water. Millenia underwater preserved the valuable carbon in their Blackland soils. Now, networks of drainage systems keep the sea at bay while the fertile land produces a large proportion of NC’s agricultural crops. But the saltwater is intruding, impacting crop growth and reclaiming the soil. 

Cropland in Hyde County, NC that is impacted by saltwater intrusion
Cropland in Hyde County, NC, shows areas impacted by saltwater intrusion. Photo by Brynna Bruxellas.

Soil science researcher Matt Ricker heads an interdisciplinary team in the university’s Climate Adaptation through Agriculture and Soil Management (CASM) group that is documenting and sourcing solutions to mitigate the profound effects of saltwater intrusion.

“Most of our coastal farmland is three to five feet above sea level, but some are as little as 18 inches above,” Ricker said. “Projections are for three feet of sea level rise by the year 2100. So you can imagine the impacts on this prime agricultural land.”

“Prime agricultural soils have good soil structure held together by clays and organic matter,” Ricker said. “Salt in the system leads to loss of structure that reduces water movement and increases erosion and carbon losses.”

Soil scientist Matt Ricker examines a soil sample in Hyde County, NC.
Soil scientist Matt Ricker examines a soil sample in Hyde County, NC. Photo by PBS NC.

His group is pursuing a two-pronged approach to address saltwater-impact farmland: reclassification or remediation. 

Farmland with prolonged, significant salinity (soluble salt index above 150) would be mapped and placed in conservation reserve programs. Expanding these wetland buffers can store carbon long-term and act as a sponge, absorbing saltwater and protecting productive nearby farmland. But the existing land use maps are over 60 years old and significantly outdated on this issue. Ricker’s group is working with the USDA-NRCS to update the system.

Ricker calls this carbon defense a good farm offense.

“Carbon accumulation leads to building land. By locking up carbon in soil, you’re actually increasing elevation and fighting sea level rise.”

Cropland with modest or episodic salinity (from storm events) can be remediated with minimal crop impact if mitigated quickly. Ricker’s group is working to develop rapid-assessment soil kits that would help farmers perform on-farm soil tests with immediate results rather than waiting potentially weeks for lab results. 

Ph.D. student Julia Fleiner tests soil samples for salinity at a coastal field day.
Ph.D. student Julia Fleiner tests Hyde County, NC, soil samples for salinity at a coastal field day. Photo by PBSNC.

“Some of these farmers have losses in the millions of dollars,” Ricker said. “These are large farm family systems that are losing productivity on land that they have farmed traditionally for over 50 years. They have a desperate need for this information.”

The saltwater intrusion segment of “State of Change: Natural Solutions” is called “Of Salt and Soil” and features Hyde County Extension Agent Adrea Gibbs working with growers like Dawson Pugh, who farms on the saltwater frontlines.

“Saltwater intrusion is a problem, but we are here to provide solutions,” Gibbs said. “My role in Extension is to connect farmers with unbiased research-based information from NC State and other land-grant institutions. We are coming together to find solutions for the farmer.”

NC Extension agent Andrea Gibbs works with a Hyde County, NC farmer on saltwater problems.
NC Extension agent Andrea Gibbs troubleshoots saltwater problems with a Hyde County, NC, farmer. Photo by PBSNC.

Building More Carbon With Less Tillage

Carbon is the central player in climate discussions and soil health. Nutrient cycling in productive soils depends on carbon, but tillage can negatively impact this crop-producing powerhouse. Frequent, invasive tillage to prepare planting ground inverts the soil exposing subsurface carbon to erosion and accelerating greenhouse gas emissions. 

But increasing droughts and concentrated storm events are causing some growers to reconsider traditional farming practices. To improve their soil productivity with less disturbance, some farmers employ low-till or no-till methods to reduce erosion, retain carbon, build soil biology and conserve soil moisture. 

Fellow NC State CASM member and soil scientist Alex Woodley heads a N.C. Plant Sciences Initiative group assessing soil-based emissions and one of several soils faculty conducting long-term tillage experiments.

“Over the long term, when we till, we’re slowly degrading the soil,” Woodley said. “We’re losing  soil carbon and aggregates so that when rain does occur, it causes surface crusting that reduces water movement into the soil.”

The long-term tillage study at the Reidsville, NC, research station started in 1984. It compares the dramatic impacts of a gradient of tillage practices from invasive moldboard plowing to no-till planting. 

Two soil samples on a plate comparing moldboard and no-till practices at a Reidsville, NC, research station.
Two soil samples compare moldboard and no-till practices at a Reidsville, NC, research station. Photo by PBSNC.

Woodley says that growers can fundamentally change the direction of how their soils behave from simple management practices like no-till.

“It takes centuries to build up topsoil. We’ve seen topsoil savings of up to six inches from no-till practices at this site. The no-till plots also show higher yields and better resilience in drought conditions.”

Soil scientist Alex Woodley and former graduate student Cara Mathers kneel in a tillage research field.
Soil scientist Alex Woodley and former graduate student Cara Mathers investigate soil impacts in a tillage research field. Photo by PBSNC.

PBS’ tillage segment called “Thinking Outside the Box with No-Till Farming” illustrates the visible impact of no-till at research plots and on-farm at Blackwell’s Farm. Her family adopted conservation tillage and no-till in 2019 to seed their livestock pastures and row crops.

“As a farmer, it’s all about efficiency,” Beverly Blackwell Bowen said. “We were able to build soil quality and cut down on fertilizer costs as a result of going with regenerative agriculture.”

Farmer Beverly Blackwell Bowen stands with a herd of cattle in her Reidsville, NC, pasture.
Farmer Beverly Blackwell Bowen stands with a herd of cattle in her Reidsville, NC, pasture. Photo by PBCNC.

Live Screening Event

State of Change: Natural Solutions premiers on PBS NC on April 19, 2023, at 7:30 pm. PBS is also hosting a live screening event of the special on April 20, 2023, at the North Carolina Museum of Natural Sciences in Raleigh, NC. 

The hybrid live and virtual event includes a viewing of the special and a panel discussion. The event is free and open to the public, but registration is required.

Want More Natural Impact?

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Improving NC’s agricultural economy through soil science is just part of how we are growing the future.