(from left) Sarah Gatzke, Darren Ficklin,
and Yuzhou Luo use GIS to model
best management practices.

Newsletter - Spring 2008

Current Research - Sustainable Agriculture

Best management practices for California farms.

Drive around after a big winter storm in the Central Valley and the word “runoff” can take on new meaning.  Where does all that water go, and what does it carry with it?  What can farmers do to minimize the pesticide content of all that water leaving their fields?  Associate Professor Minghua Zhang is using Geographic Information Systems (GIS) modeling and analysis to find out.  Together with graduate students Darren Ficklin and Sarah Gatzke and post-doctoral researcher Yuzhou Luo, this group works with farmers in the San Joaquin and Sacramento watersheds to model best management practices (BMPs) for water quality.  Dormant season pesticide sprays on orchards are of particular concern because large winter storms can move a lot of water through an orchard and out into the rivers.

“A good thing about models is that you can easily change their parameters to assess the impacts of future changes,” notes Ficklin.  These researchers use field data from US Geological Survey (USGS) and other project members that are sampling in the field to analyze the effects of various management practices on water quality.  GIS analysis allows them to apply those findings to entire watersheds, a scale that would be impossible to sample by hand.

BMPs that will reduce river pesticide and sediment loads include practices such as integrated pest management, erosion control and appropriate pesticide applications.  This group hopes that their results will be useful to the growers they work with, and others all over the valley, in their efforts to improve the sustainability of orchard operations.