Biogeochemical Mechanisms Optimizing Soil Carbon Storage and Nutrient Use Efficiency in Agroecosystems

Presentation by Stuart Grandy :

Professor, Soil Biogeochemistry and Fertility/ co-director, Center of Soil Biogeochemistry and Microbial Ecology / University of New Hampshire

There is an urgent need to increase yields in agroecosystems while  minimizing environmental impacts of nitrogen fertilization, such as trace gas emissions and water pollution. Soil organic nitrogen is key to this goal. It is a massive pool of nitrogen, and a sink for inorganic fertilizer inputs that cycle through microbial biomass. But, the question remains, how do we both accumulate soil carbon and simultaneously mobilize soil organic matter-derived nitrogen to reduce inorganic fertilizer inputs? Here I will examine this problem, using data from my own and others research programs and integrating these data into conceptual models.

Specifically, I will:
1. Establish a framework showing mechanisms to augment soil organic carbon, detailing the pools and processes facilitating its accumulation.
2. Show the role of synergistic interactions among plants, minerals, and microbes in enhancing efficient nitrogen uptake from specific  reservoirs.

3. Integrate the relationship between soil carbon storage and bioavailable nitrogen mobilization to explore how we can balance production goals with environmental quality.