Soil health is ideally a central part of organic farm management. One key question is how diversification practices (e.g., diversified crop rotations, cover crops, etc.) that build soil health influence how and when nitrogen is made available from soil organic matter. This question is particularly important to consider when determining the timing and choice of organic fertilizer application on diversified organic farms. The over-arching goal of this project seeks to address this question by providing farmers in Yolo County, California—an area with a high concentration of diversified organic farms—with both technical support and a community of practice that allows for more informed decision-making about nutrient management on their farms. Specically, this project will link how diversification practices and organic fertilizers interact to influence soil nitrogen flows and nitrogen availability across diversified organic farms in the region.
While it is true that nitrogen mineralization has been widely studied, this project proposes a novel approach to understand nitrogen flows on working organic farms. Whereas previous studies have focused on measuring pools of nitrogen and/or relying on proximate indicators of nitrogen cycling (i.e., soil proteins), we will explicitly quantify nitrogen fluxes (i.e., gross nitrogen mineralization) on organic farms. To do so, we will incorporate experiential knowledge of organic farmers around soil health and fertility, in combination with technical, in situ measurements of nitrogen flows in their soil—from the ground up. The results of this project will provide organic farmers with more precise information for support in making more informed decisions about organic fertilizer application. We expect this will assist organic farmers in the region in reducing 1) added costs and 2) environmental impacts associated with nutrient losses from organic fertilizers.