Seattle, WA | slb@uw.edu
Sally has her MS and PhD from the University of Maryland. She is a born and bread New Yorker who has successfully transitioned to the Pacific Northwest. She is a true devotee of all recycled organics.
Session Code: 1E
Track: Uses, Markets and Marketing
Session Name: P in my Compost? Navigating Challenges to Phosphorus Limits
Session Time: Tuesday, January 25, 8:15 AM to 9:45 AM
Presentation Title: Paradigm shift: Changing recommendations for phosphorus fertilization
Presentation Description: Add more- that was the official extension recommendation for phosphorus fertilization for many decades. Phosphorus is tightly bound in most soils. This nutrient has a strong affinity for reactive groups on soil particles including iron, aluminum and calcium. In order to make sure plants had access to enough P, extension agents typically recommended applications well in excess of plant requirements. That paradigm had a sudden shift about 30 years ago when scientists realized that heavily loaded soils could release P in cases of erosion and even by movement through the soil profile. The era of excess P was born. New soil tests have been developed to measure excess P. New rules restricting use of P have been promulgated in many areas. This new paradigm does not typically recognize the importance of recycling P through use of residuals -based amendments. At about the same time, there has been a recognition of the limited P reserves for production of additional P fertilizers. Reuse of residuals can be the answer to both P saturated soils and low reserves of phosphorus ore. Residuals typically provide slow release P and increase the soils’ ability to bind P, and reduces the movement of water that leaches P. Also, in areas where excess P is an issue, other materials can be added to compost to help bind P, as a designer compost product.
Workshop Time: Tuesday, January 24, 1:00 – 4:30
Workshop Title: Compost Carbon Connection
Workshop Description: Detailed overview of the connection between compost and climate change, and the opportunity for composting operations and use to help reduce the impacts of climate change. Participants will leave with a good understanding of the connection between climate and composting, and with an understanding of compost operations factors impacting greenhouse gas emissions as well as potential (although still limited) opportunities for developing carbon credits associated with composting operations and sales.
