Geographic Nutrient Management Zones for Winegrape Production

Soil Pit

We developed a model from digital soil survey data in a geographic information system (GIS) to predict potassium (K) availability for winegrape production. The goal of this project was to repackage soil survey information in the form of maps that depict the inherent ability of soil landscapes to fix K in unavailable forms or readily supply K to plants. Our model describes five soil regions that would benefit from different K management strategies. Results from this study are intended to guide nutrient management strategies in the Lodi Woodbridge Wine District (O’Geen, Pettygrove and Southard).

Modeled potassium management regions in the Lodi Woodbridge Winegrape District. Exchangeable- and fixed-K classes are based on the profile weighted average of each representative soil. Class range for Exchangeable K (mg/kg): high >200, moderate 200-100, and low <100. Class cutoffs for fixed K: High>100, moderate 100-0, none <0.

GIS winegrape map
GIS winegrape map legend
GIS winegrape map 2
GIS winegrape map legend 2