Nitrates Issue Is Forum’s Focus

California’s Weed Science Society usually focuses its attention on – well – weeds but fertilizer was a hot topic during the group’s recent Sacramento conference.
Nitrogen is needed to grow crops and weeds but its use has been elevated to a top issue confronting California agriculture with release a University of California study citing nitrates in groundwater as a major contaminant of drinking water.
Concurrently, regional water quality control boards such as one in the Central Valley have been pushing hard to frame and impose regulations and fees on nitrates discharged to the aquifer through farm irrigation.
Nitrates, although frequently a legacy issue from past generations,  have contaminated drinking water systems in many rural, impoverished communities, including several in and near the Friant Division service area. Karen Ross, California Secretary of Food and Agriculture, said CDFA has been put in the bull’s-eye of efforts to tax fertilizer sales and develop farm nutrient management plans.“We are working with the regional water boards to come up with alternatives for nutrient management,” Ross said. She said nutrient use reporting is “very different” from pesticide use reporting now mandated.
Nitrogen can come from many sources, such as, manure, compost, crop residue, residual soil nitrogen, irrigation water, rotation crops (like alfalfa)  and synthetic fertilizers.That makes it difficult to report accurate nitrogen sources.