Clean WateR³: Developing tools to help specialty crop growers understand the costs and benefits of recycling water

What motivates growers to make changes in their business? Some growers are motivated by saving time or money, while for others, reducing environmental impacts or improving consumer perceptions is key. Growers may not always consider all of the impacts of irrigation and fertilization management on other decisions (i.e., cost, labor intensity, sustainability). Helping growers understand and modify current practices, using operation-specific information is critical to addressing this question. Models can help growers address questions specific to their operation, can demonstrate the impact of current practices, and predict the impact of changes on cost, labor, environmental benefits, etc. A disinfection model is the first in a series of models being developed to simulate what happens when irrigation water is recycled. The model series will incorporate published research data and user-supplied data to inform growers about the impacts (and benefits) of current and prospective practices. An important caveat is that models are valid only to the extent of the precision of their underlying data. Model assumptions, input parameters, and any data gaps need to be identified, and guidance for their use provided. This model series uses a system dynamics framework implemented in isee Stella^® to simulate responses over time. Stella^® permits the development of models with varied complexities, has both a user-friendly interface and the capacity to publish and download completed models from an Internet library. Developed models can function both independently or sequentially. The overarching goal of this model series is to help assess the impacts of current practices, and understand how various changes may impact the business, either positively or negatively. Other models under development will aid in understanding pond dynamics, irrigation and runoff dynamics, nutrient uptake and loss, pesticide movement, plant pathogen dynamics, and water treatment systems, which will use data from published research and ongoing experiments in these areas.