2017 ASHS Annual Conference

Maximizing the efficacy of locally available resources to benefit crop yield and quality is fundamental to sustaining productive agriculture. This is particularly true in an isolated island environment. In response to stakeholder input, a series of laboratory, greenhouse, field and on-farm trials were conducted 2012-2017 across multiple vegetable crops and environments in Hawai'i to evaluate locally available inputs for their fertilizer value. Materials evaluated included composts, rendered animal products, fish effluent, pyrogenic organic matter and marine algae, among others. Research centered on predicting nitrogen (N) mineralization in high N materials, optimizing N availability through combination of multiple amendments, identifying patterns and mechanisms of potassium release from invasive algae waste, and evaluating the productivity of recirculating aquaponic systems. Results have largely validated findings reported from other locations and have identified patterns and mechanisms of nutrient availability that have improved our understanding of sustainable nutrient management in the Tropics. This research was funded by the Hawai'i Department of Agriculture and the USDA WSARE, AFRI and OREI programs.