A CSTAF-sponsored research project to study environmental benefits of agroforestry is showing promising results for the use of silvopasture to absorb nutrients that otherwise could contaminate groundwater, and to sequester carbon.  The research teams consists of graduate students Gerard-Alain Michel of Haiti, Solomon Haile of Eretria, Africa, and post-doctoral researcher Sam Allen, working under the guidance of Vimala Nair in the Department of Soil and Water Science, and CSTAF Director P.K. Nair. Michel’s research centers on the removal of phosphorous and nitrogen. Haile’s research involves carbon sequestration.  Study sites are located in Alachua, Osceola, Suwannee and Hardee counties, representing two Florida soil types: Spodosol and Ultisol.

Phosphorous and nitrogen are applied to crops in large quantities as fertilizers. Because Florida’s soils are sandy and lack natural barriers, a portion of these nutrients is washed away to groundwater, causing serious environmental damage. Compared to crops, tree roots extend deeper into the soil and trees have a larger capacity to absorb nutrients. Researchers measured the concentrations of nutrients at different depths in the soil to indicate the relative effectiveness of nutrient removal. They hypothesized that trees would be more effective in removing these nutrients than typical agricultural crops.

In a related study on the same sites, the research team is assessing the effectiveness of trees in carbon sequestration. They believe that the presence of trees in silvopastoral systems will positively enhances carbon storage and dynamics in soil as compared to the conventional tree-less pasture under similar ecological settings.  The study is in the final stages of data analysis; preliminary results indicate that silvopasture may be effective at solving environmental problems.