Controlled Environment Agriculture Effluent Use in Specialty Crop Production

Abstract

The escalating demand for sustainable crop production necessitates innovations within Controlled Environment Agriculture (CEA) that address resource scarcity, waste valorization, and economic viability. This body of work investigates the strategic utilization of aquaponic and hydroponic effluents in CEA, focusing on their impact on strawberry and lemongrass transplant production, and oyster mushroom cultivation. Using data collected, further analysis of comparative nutrient dynamics across plant species and development of an engineering based economic model for mushroom operations is evaluated. Experimental results demonstrate that pure aquaponic effluents require supplementation for optimal plant performance (as seen in strawberries and lemongrass) and blended solutions yield comparable results to conventional hydroponic solution. Aquaponic solution with supplemented nutrients to match the Yamazaki solution formulation can be used to grow strawberry and lemongrass transplants. Comparative nutrient analyses revealed crop-specific uptake patterns and complex ionic interactions, as well as common patterns and trends across the two species. This highlights the need for tailored nutrient management that may incorporate generalized components that are not crop specific, easing the burden of crop specific formulation. Agricultural effluents used for hydrating mushroom substrates demonstrated comparable yields to the water control and enhanced the nutritional profiles of fruiting bodies in certain metrics such as crude protein. This presents a pathway for food production with the potential for added functional nutrition. Further using effluents allows for waste valorization and remediation. Economic modeling identified bio-efficiency and substrate cost as dominant profitability drivers in addition to design parameters such as insulation and equipment efficiency. This emphasizes the necessity of robust engineering-economic models to guide investment and operational strategies in CEA. The different studies demonstrated the potential of integrating agricultural effluents for improved resource use efficiency and reduced operational costs in production. The diverse specialty crops studied can be complimentary to existing or planned CEA and aquaculture operations providing a diverse set of products. With presently small markets compared to other common CEA crops, the potential for effectual market entry is higher, however there is still risk. In addition to growing demand, some potential opportunity is capturing imports of crops like lemongrass and oyster mushrooms for domestic growth. This research in CEA can be applied to further serve the need of year-round strawberry transplant production, introduce a dynamically valuable crop like lemongrass, improve nutrient solution formulations, affect yield and nutrition of oyster mushrooms, and create economically sound production facilities through the suggested production model. This dissertation collectively offers a thought process to analyze production which can be implemented at small and medium scales.