$1.9 Million Awarded to Study Use of Biochar on Water Quality

"Arkansas is the third-largest poultry-producing state in the nation," Speir explained, "which means we have an enormous waste stream and an enormous opportunity! Our research asks whether we can transform that litter using biochar to create a resource that actively protects local water quality and builds a more sustainable agricultural system in the region."  

Biochar is created when organic material like forest residue or agricultural waste is burned in low-oxygen, high-heat kilns. The resulting charcoal is known to increase soil quality by improving its ability to absorb moisture, resist drought and retain nutrients. Adding biochar to poultry litter, which is recycled as fertilizer for crops, can reduce the amount of nutrients like phosphorus and nitrogen that are washed into streams, rivers and lakes. These nutrients are good for the soil, but when they enter water systems can lead to algal blooms from eutrophication, habitat degradation and biodiversity loss. 

The first phase of the three-year grant will be spent in the lab experimenting with biochar and poultry litter mixes and assessing biochar's role in nutrient leaching and retention.  

The next phase of the award will take Speir and her collaborators into the Brush Creek watershed, which covers a broad valley east of Springdale and Fayetteville and is part of the larger Beaver Lake watershed. The researchers will establish a new Discovery Farm, as part of the Arkansas Discovery Farm Program, in which farm operators volunteer to assist in water quality studies for five to seven years. Of particular interest to the researchers will be edge-of-field monitoring, the transition point where runoff is leaving agricultural land and entering waterways. 

For the next two years, the researchers will monitor runoff at the edge-of-field and watershed scale. They anticipate a 15%-25% reduction in nitrate loss and 5%-10% reduction in phosphorus loss. Several fields will be given biochar treatments while a control field will also be maintained without the use of biochar.  

The last component of the project will be recruitment of additional volunteer farms to implement use of biochar on their fields to document the water quality impacts across the Brush Creek watershed, while providing training and technical assistance in best practices. 

Speir notes "that voluntary conservation plays a key role in providing safe, healthy drinking water to the public and is essential to ensuring access to clean, abundant water resources to future generations. Farmer to farmer training on conservation practices such as biochar can greatly accelerate adoption." 

Ultimately, she says, this project is pioneering in its use of biochar amended poultry litter by demonstrating its efficacy at a watershed scale, explicitly linking field-level biochar amendments to measurable improvements in downstream water quality. 

Speir's research partners in the project include the U of A Division of Agriculture's Cooperative Extension Service, the UADA Agricultural Experiment Station, the Beaver Watershed Alliance and the Carbon Chicken Project.