On May the 28th, 2004, I successfully defended my Dissertation and, soon after that, it was accepted as electronic publication by the Editorial Office of the Graduate School of the University of Florida. The dissertation document and the actual decision support system are publicly available through the UF library: Modeling north florida dairy farm management strategies to alleviate ecological impacts under varying climatic conditions: an interdisciplinary approach (cabrera_v.pdf) and the Dynamic North Florida Dairy Farm Model (DyNoFlo).

My Dissertation research started in middle 2002 and it was about ways of decreasing environmental impacts of north Florida dairy farm operations (especially nitrogen pollution to groundwater) while maintaining farm profitability in an interdisciplinary approach. I used innovative simulation methodologies to represent these dairy farms and test best management practices (BMP) that result in better outputs.

I had a very rich Dissertation process, including a series of activities as: a sondeo, focus groups, profound interactions with stakeholders, research of similar issues, some GIS databases and interpolation works, and the development of a prototype model. Many other interesting things also happened as the formal farmers’ interviews, the participatory model validation, the analyses and take home messages, and the preparation of professional articles for publication.

As an exercise of students from Farming Systems Research and Extension course about interview methodologies, a rapid rural appraisal interview or sondeo was realized with stakeholders in the issue nutrient management and nitrogen pollution in the Suwannee River Basin. A Report was the final product that is now part of the South Eastern Consortium Paper Series.

Inherent conditions of my research are the participatory approaches and because of that many interactions were achieved.

Nutrient pollution from dairy farms in north Florida and the realized actions to its alleviation are contrasting from those in south Florida. While in north Florida the main issue is groundwater nitrogen pollution, in south Florida the problem is phosphorus run-off. A quick assessment of the phosphorus issue in south Florida was also done in order to compare it with the north Florida situation.

Part of the study requires calibration of complementary models (mostly crop models), which will estimate the nitrogen uptake and the dry matter accumulation by manure applied crops. Some studies were carried out as a way to better understand these processes in the area of study as this Simulation of Nitrogen Leaching and Pasture Production in a Diary Farm that includes a series of simulations at the farm level. Another project was Temporal and Spatial Nitrogen Modeling in a Suwannee Farm using GIS.

For suggestion of one stakeholder a prototype model was set up with its correspondent documentation. This model is an user-friendly, stochastic, empirical model constructed on an Excel spreadsheet using Visual Basic embedded software. The model, called Dynamic North Florida Dairy Farm Model (DNFDFM), estimates monthly rates of nitrogen lost and profitability for a dairy farm using parameters input by user. This model was not a final version, but is a useful tool for analyses and interaction with farmers. You can download the DNFDFM model and run it.