TRIPARTITE: DUAL-FUNCTION ENGINEERED BIOCHAR FOR EXCESS SOIL PHOSPHORUS SORPTION WITH SUBSEQUENT SLOW RELEASE FOR COST-EFFECTIVE AND SUSTAINABLE CROP PRODUCTION

The long-term goal of this project is to develop a dual-function substrate that captures excess phosphorus in soils and releases it slowly to meet plant needs. Herein, we propose to engineer biochar as a template to capture phosphorus (P) and release it to meet the dynamic needs of plants (hereafter, duo-biochar). Biochar, a carbonaceous material produced from the thermochemical conversion of biomass, contains a hierarchy of micro-, meso-, and macro-pore networks, functional groups, and inorganic compounds that can absorb and co-precipitate P in the network of pores. Unfortunately, biochars are not commonly tuned to maximize P capture and re-release according to plant needs. This is because fundamental science on transient nutrient retention/release of biochar is lacking. This collaborative team (U.S., Republic of Ireland-ROI, and Northern Ireland-NI) proposes to engineer next-generation duo-biochar by developing fundamental knowledge using state-of-the-art material characterization techniques and ground-truthing the efficacy on the slow P release properties in greenhouses and field trials using winter wheat and ryegrass as model crops. We will also develop educational and extension materials related to improving nutrient use efficiency, soil health, and carbon sequestration by using duo-biochar.The five specific objectives of the project are: Obj. 1: Develop duo-biochar with functionalization of surface and internal pore networks with high surface potential to absorb and co-precipitate phosphorus and fine-tune the slow-release properties; Obj. 2: Develop a fundamental understanding of surface and interfacial chemistries of three-dimensional (3-D) pore networks of duo-biochar and correlate with the form, composition, and content of P; Obj. 3: Optimize P release efficiency of the duo-biochar to meet P needs during the growth of winter wheat and grass crops; Obj. 4: Assess on-farm economic benefits of using biochar in the participating states (Alabama, Delaware and New Mexico) and in Ireland and Northern Ireland; and Obj. 5: Develop extension materials and organize farmers field days to inform and educate stakeholders on the benefits of duo-biochar.