CICEET Progress Report for the period 3/01/09 Through 8/31/09

Project Title: Direct Incorporation of Poultry Litter into No-till Soils to Minimize Nutrient Runoff to Chesapeake Bay
Principal Investigator(s): Peter J.A. Kleinman
Additional Investigator(s): Thomas Way, Dan Pote, Arthur Allen
Project Start Date: Sept. 1, 2006
Report compiled by: Peter Kleinman, Dan Pote, Arthur Allen

A. Progress on Objectives for this Reporting Period:
This reporting period represents the final reporting period of the grant, with an emphasis on completing field demonstrations and outreach activities related to the subsurface litter application technology and summarizing research findings. Public interest in the litter application technology has peaked considerably with the receipt of a widely publicized Chesapeake Stewardship Fund grant to expand the efforts of this project across five of the six states in the Chesapeake Bay Watershed. With the second generation of poultry litter applicator officially unveiled, Dr. Pote and Dr. Allen led demonstration activities (see next section). Dr. Pote’s applicator overcomes a key limitation to the first generation of applicator, enabling farmers to directly load litter from barns into the applicator without first grinding the litter. The spacing of applicator implements is fixed on the new unit (12” spacings), something that turns out not to be a priority concern of most local poultry farmers.

In addition to Dr. Pote’s efforts, Dr.s Kleinman and Allen finalized field research. Dr. Allen led demonstration activities at the University of Maryland Eastern Shore site, highlighting findings of the project and the future of the subsurface litter application project on the Delmarva Peninsula. In addition, Dr. Allen supervised a University of Maryland Eastern Shore master’s student, Leonard Kibet, who has completed a thesis on the effects of the subsurface poultry application on phosphorus and trace element runoff. In addition to the two manuscripts developed from Mr. Kibet’s thesis, a third manuscript on phosphorus leaching dynamics with subsurface placement of manure was submitted to Journal of Soil and Water Conservation and is currently in press.

Our research at the University of Maryland Eastern Shore revealed that subsurface application of poultry litter decreases phosphorus and nitrogen loadings in surface runoff by as much as 90% compared with broadcasting litter to no-till soils. We also found that subsurface application of litter essentially eliminates volatilization of ammonia (one third of the nitrogen loads to the Chesapeake Bay are estimated to have originally derived from atmospheric deposition of nitrogen). Perhaps most important to farmer adoption, we found that corn grain yields with subsurface application average 37% more than with surface applied litter (138 vs. 101 bu/ac). This greater efficiency in transferring manure nutrients to crops supports lower recommended rates of manure application, and lower need for fertilizer, key requirements of an agroecosystem in nutrient balance.

We are quite pleased with the outcome of the project and deeply appreciative of CICEET for it’s support of our technology development and transfer activities. Through our outreach efforts and related media activity, the poultry litter applicator is now widely recognized as a new technology for farmers that can simultaneously improve production potential and protect estuarine water quality. We believe that the project has achieved much greater success than we initially anticipated, and we expect that in the next several years the new poultry litter application technology will be certified as a Best Management Practice for use in conserving manure nutrients and protecting air and water quality.

B. Dissemination activities during reporting period:
Dr. Pote carried out three dissemination activities for the project, highlighting the second generation of subsurface poultry litter applicator. Events included:

• Northeast Regional Meetings of National Association of Conservation Districts, California, MD (July 28). The meetings were attended by approximately 60 farmers, state politicians and conservation district staff.

• Southern Conservation Agricultural Systems Conference, Melfa, VA (July 21). Approximately 80 attendees, including farmers, conservationists and researchers.

• Virginia Tech Eastern Shore Agricultural Research and Extension Centre, Painter, VA (July 23). Approximately 100 farmers, conservationists and general public.

In addition, Dr. Allen hosted a field day demonstrating project findings and discussing the future of the subsurface placement technology:

• University of Maryland Eastern Shore Field Day, Princess Anne, MD (September 12). The field day was attended by approximately 275 farmers, federal and state agricultural extension agents and members of the general public.

C. Have results identified changes required in the technology:
Yes. One finding from our research at the University of Maryland Eastern Shore is that leaching losses of phosphorus through coastal plain soils are greater  with subsurface placement of the litter than with conventional broadcasting. We note that this finding was derived from the first generation of litter applicator using 30” inch application spacings (as opposed to 12” with the new applicator). At 30”, each furrow contains more than twice the litter as is found at a 12” spacing, resulting in a greater concentration of litter-related nutrient that is available for leaching. We anticipate that with the narrower row spacing leaching losses will be less, a key issue that will be addressed with subsequent research after the conclusion of this project. In addition, we have identified several implements that can be attached to the applicator’s trenching apparatus that should break up macropores connected with a furrow and therefore curtail phosphorus leaching losses. We have found phosphorus leaching to be dominated by preferential flow along soil macropores, and have found that tillage effectively eliminates this preferential flow. Therefore, with modest modifications the subsurface litter application technology should be able to minimize litter-derived losses via all major environmental pathways.

D. Collaborative activities with stakeholders:
Our outreach activities involved farmers, equipment dealerships, cooperative extension agents and environmental groups. We did conduct unplanned collaborative work with a variety of university stakeholders, who are now partnered with us in transferring the subsurface applicator across the Chesapeake Bay Watershed. Specifically, we have initiated a second phase of activity in which four new applicators are being constructed for use on farms in Delaware, New York, Pennsylvania and Virginia, as well as Maryland. We anticipate that construction of these applicators will be completed in February 2010, after the conclusion of this grant. These new applicators will extend the impact of the current project to farms across the region.

E. Describe objectives for next reporting period:
This is the last reporting period for the project. However, we plan to continue our research and technology transfer activities related to the project. Our goal is to deliver the subsurface application technology as a best management practice to farmers across the Chesapeake Bay Watershed.

F. Obstacles not addressed:
None that we observed.