My current areas of focus include the following: Nutrient requirements for Arizona crops, especially pecans, turfgrass, and vegetables; nutrient requirements and management in contaminated soils, concentrating on effects of nitrogen on soil water potential and microbial petroleum biodegradation; irrigation water and soil salinity management in agricultural soils; and application of waste materials to soils, studying rates of degradation of soil-applied animal manures and environmental impacts of on-site human waste disposal systems. I received my B.S. (1976) and M.S. (1980) in Soil Science from the University of Wisconsin - Madison, and Ph.D. (1985) in Agronomy from the University of Georgia.

My current research focuses on two areas: precision agriculture and algae production for biofuels. The precision agriculture model is called Wastewater, Irrigation, Nitrogen, Drainage, and Salinity (WINDS). It is a spatial and temporal model of agricultural irrigation systems. It also includes drainage and soil profile modeling of water, salinity, and nitrogen. The model automatically downloads daily weather data from Arizona weather stations and predicts the date of the next irrigation based on the statistical average of field water contents. Previous experiments have validated the water and evapotranspiration algorithms in the model. Upcoming experiments will focus on validation of the nitrogen algorithms with continued validation of the water algorithms. The algae work focuses on use of the ARID raceway for algae production. My focus in this endeavor is temperature modeling, hydraulic systems, and harvesting systems. In the coming year, I will incorporate chemical and algae uptake parameters into the model. I received my B.S. (1981), M.S. (1989), and Ph.D. (1992) in Agricultural Engineering from the University of California at Davis.