SAM Initiative: Achieving Subsurface Application of Manures in the Chesapeake Bay Basin
The SAM Initiative is a regional, collaborative, team effort led by Land Grant University nutrient management and engineering specialists to advance the deployment of both liquid and solid manure injection technologies in high-density animal production regions of the Chesapeake Bay watershed.
In 2014, the National Fish and Wildlife Foundation’s (NFWF) Chesapeake Bay Stewardship Fund received support for the SAM Initiative from the National Resources Conservation Service Conservation Innovation Grant Program. With funding in place, the team focused on design for research and commercial-scale poultry litter injectors and expanded adoption of liquid manure injection.
The project team developed three design prototypes, including a pneumatic system to demonstrate the potential for commercial-scale application. The team also laid the foundation for expanded adoption of liquid manure in the Chesapeake Bay region.
Building a better poultry litter Subsurfer: The project team developed two different designs that improve on the original poultry litter Subsurfer by the USDA ARS team in Arkansas. The first Subsurfer re-design was completed by Dr. Amy Shober and Shawn Tingle (University of Delaware) and Dr. Josh McGrath and Gene Hahn (University of Kentucky). They re-engineered the Subsurfer augers and hydraulic system to address performance problems and added a liquid injection system to evaluate the benefits of injecting poultry litter with a nitrification inhibitor. Although limited to an eight foot wide injection width, field trials indicate this system works as designed. A second design, developed by Dr. Pete Kleinman (USDA-ARS Pasture Systems and Watershed Management Research Unit), Dr. Arthur Allen (University of Maryland Eastern Shore), and Stoltzfus Manufacturing, uses a drag chain system to move litter to the injection ports. They suggest that the next prototype could be constructed independent of the Subsurfer and incorporate folding wings to expand the width of poultry litter injection.
Next Steps: Construction of additional prototypes will build on lessons learned. Additional field demonstrations and work with regional farmers will determine commercial market potential.
Designing and building a commercial-grade poultry litter injector: With leadership from Dr. John Long (Oklahoma State University) the team designed and constructed a commercial-grade poultry litter injection prototype that uses a pneumatic air delivery system to inject poultry litter. Similar in concept to commercial air seeders, the injector is designed to apply poultry litter at widths comparable to commercial spreaders. The design allows for spreader rows to “fold up” for transportation along roadways from one farm to another. Although this technology is still in the research and development phase, the prototype demonstrates a promising design approach for a commercial-grade poultry litter injector.
Next Steps: Additional research and development is needed to bring this technology to commercial markets.
Expanding adoption of proven liquid manure injection technologies: Traditional cost share programs that reward farmers on a per-acre basis and outreach and education efforts were not moving the dial on liquid manure injection in the Bay region, so partners tried new approaches:
— Engaging nutrient management planners to help expand adoption. In Pennsylvania, Red Barn Consulting’s nutrient management planners identified 49 of their clients they thought would be interested in learning about manure injection. During the nutrient management planning process, the planners would explain how manure injection would impact the farm’s nutrient management plan. About a third of the farmers were interested in trying it. Another third said “no,” because their custom applicator did not have manure injection equipment.
— Making manure injection work for custom applicators. Building on lessons learned from previous collaborations with custom applicators, SAM partners enlisted the support of Maryland partners to try a different cost share approach. Instead of offering financial incentives to farmers injecting manure, the team tried offering the financial incentive directly to the custom applicator. The custom applicators in turn encouraged their clients to try manure injection. With funding support from the Maryland Chesapeake and Atlantic Coastal Bay Trust Fund, after two years of effort, three new manure injection systems have been purchased, and two custom applicators have worked with over 45 farmers to inject manure on 7,500 acres. Building on this success, NFWF recently funded an effort to expand manure injection into south central Pennsylvania using this approach.
— Outreach and extension efforts supported expanded adoption:
o Land grant university and extension partners designed field and laboratory trials to answer farmer questions about manure injection.
o Hundreds of farmers and conservation professionals participated in field day events showcasing manure injection equipment. SAM team members and collaborators shared information about the nutrient management benefits of manure injection as well as results from laboratory and field trials to address farmer questions about adoption.
Next Steps: Continue building on lessons learned to engage the private sector in expanding adoption of proven and commercially available manure injection technologies in the region.