As Dorian continues to make its way up the East Coast this week, agriculture producers are warned extreme weather and flooding could devastate crops. Two Cornell University experts – David Wolfe and Harold van Es – explain the impacts Dorian could have on crop harvest and the soil in the Southeast, as well as preventative measures farmers are taking to combat damage from these reoccurring destructive storms.
David Wolfe is a professor of plant and soil ecology at Cornell and a leading expert on climate change impacts on crops, soils and ecosystems. He says farmers are investing in proactive measures to combat extreme weather, but financial devastation may still strike due to coastal surges or prolonged flooding.
“Dorian has hit the Southeast at the peak harvest season for many crops. At this point farmers have invested not only money, but months of labor into producing a product that they are counting on to pay the bills for the remainder of the year and to pay for next year’s planting investments.
“The losses are not just direct damage to crops from rain and wind, but also wet conditions that do not allow field access, or road closures that impede transport of perishable crops like fruits and vegetables to markets.
“Many farmers have been investing in recent years in rebuilding ‘healthy’—high organic matter—soils that are more resilient to both flooding and drought, but this cannot fully protect them from a coastal surge or prolonged river flooding of their cropland.
“Loss of soil due to erosion from heavy rains and flooding has a very long-term effect on farm productivity, which is why many farmers are including non-cash cover crops in their rotations, which can help to hold the soil in place during this sort of extreme weather."
Harold van Es, faculty fellow at the Atkinson Center for a Sustainable Future and a professor of soil and water management at Cornell University, says that flooding from hurricanes — whether saltwater or freshwater — may cause damage to crops, but soil resiliency helps to mitigate compounding agricultural devastation.
“There are two types of flooding from hurricanes that impact soil health. The biggest concern is when ocean water floods an area due to storm surges. The saltwater makes it more difficult for plants to grow. Over time, the salt will be washed out of the soil through natural rainfall or irrigation, so it tends to be a short-term problem.
“The second type of flooding comes from high rainfall amounts. Prolonged anaerobic conditions may persist, and plants may suffer or die from that and a potential concern occurs when the floodwaters contain a lot of contaminants from industrial areas.
“Another problem with high rainfall from hurricanes is the potential for erosion in the upper parts of the landscapes, where the runoff is derived that causes the flooding in the lower areas. Fortunately, at this time of the year most soils are protected from erosion by a standing crop, but there will surely be some erosion.
“Farmers often implement conservation practices that can help reduce runoff, erosion, and flooding associated with high rainfall events. Practices like no tillage and better crop rotations improve the health of the soil and reduce the potential for runoff and erosion, and downstream flooding.
“The concern here is mostly economical, when farmers experience crop damage for multiple years. In many cases they will have crop insurance that would protect them from big financial losses. There is not a big concern with compounding effects as the soils have some resilience and recover from previous events.”