BS in Soil Science
Natural Resources Management and Environmental Sciences Department
Thomas J. Rice
Despite cultivation for close to a decade, the soils at the Cal Poly vineyard have never been studied in detail. This study was designed to gain a better understanding of the soils for better management. Soil pits and auger holes were dug throughout the site to accurately classify soils. Soils were classified using USDA-NRCS Soil Taxonomy, and samples were taken from each horizon of each soil pit for chemical analysis. Four soil map units were delineated on the site. The pH, EC, total percent carbon and nitrogen, and plant available nitrate, sulfate, phosphate, base cations, and metal micronutrients of each soil sample were determined by laboratory analysis. Based on morphologic and physical data, management recommendations were made to improve soil quality at the vineyard. Issues with high historic erosion and nutrient imbalance caused by excessive magnesium were found and addressed.