Technical Abstract: Fruit yield is a critical component in the long-term profitability of citrus growers in Florida. Increasingly, two factors outside the control of the growers are forcing Florida citrus growers to re-evaluate the sustainability of their current operations. These factors are: 1) impact of canker and greening diseases on tree health and yields and 2) continued urbanization within the state. A key to increased profitability may be improved early and sustained production on high density groves. Improved early and sustained yields may allow growers to reach earlier return on investment and thus, better deal with potential decreased production due to tree loss from disease. The use of automated irrigation systems and intensive nutrient management may provide critical enhancement to production systems for achieving increased tree growth and yield. A widely discussed approach for maintenance of soil moisture and nutrient concentrations in the tree root zone near optimum levels is known as The Open Hydroponic System (OHS). The system must be adapted for the Florida summer rainy season and sandy soil characteristics so that current fertilizer best management practices (BMPs) are not exceeded and nutrient leaching is not increased. Current OHS management practices utilized in selected citrus producing countries around the world will be reviewed and compared to proposed Advanced Production Systems practices for high density citrus plantings in Florida. Practices considered will be nutrient ratios and application timing, irrigation scheduling and methods, root density distribution, and girdling. Adoption of these intensive citrus management practices has the potential of conserving water, improving nutrient use efficiency, reducing leaching in addition to improving tree growth and yield.