Using a mass balance approach, this technical report documents the extent and magnitude of nitrogen loading from anthropogenic and natural sources to groundwater in the Tulare Lake Basin and Salinas  Valley. Our approach considers crop demand, fertilization, harvest, and volatilization in cropland agriculture, in addition to accounting for animal agriculture and localized sources, for the period of study (~1940–present). Cropland agriculture is the primary vehicle for nitrate loading to groundwater.

Website: https://ucanr.edu/sites/groundwaternitrate/files/139110.pdf