Managing nitrates: What California dairy is doing
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TULARE, Calif. – The California dairy industry is working hard to ensure all people have safe food and water and clean air, but it will take a coordinated partnership to meet those goals, according to Western United Dairymen’s Paul Martin, director of environmental services.
“This is a big problem and It’s not going to be resolved by any one group,” Martin said during an agricultural nitrogen (N) management seminar early this week, sponsored by the University off California ANR California Institute for Water Resources and the California Department of Food & Agriculture’s Fertilizer Research and Education Program. “We are going to have to work together to do it, and we’ll have to build partnerships necessary to do that work.”
Martin said that while adequate N fertilizers are necessary for growing successful crops, excessive nitrate in the wrong place can be harmful.
“Nitrogen is slippery and easily changes forms,” he explained. ”It moves through and between environmental reservoirs with ease. Our job is clear – keep nitrates in the crop and out of the water.”
Dairy industry opened their farms to early N research, which identified nitrates as an issue. That led to the formation of the Waste Discharge Requirement (WDR) regulations, imposed on the California dairy industry in 2007 by the Central Valley Region Water Quality Control Board. Those regulations focused on groundwater protection, and required a strict accounting of N use on the dairies.
Martin provided a recap of dairy water regulations. All Central California dairies must have a Waste Management Plan, approved by a civil engineer, that includes a manure management system adequate for each operation. Dairies are also required to have a Nutrient Management Plan (NMP), which mandates the equivalent of 72% nitrogen use efficiency (NUE). The plan must be prepared by a NMP specialist.
Industry authorities estimate there are more than 4,000 irrigation and domestic wells in the region that dairy producers are testing. Finally, he said, there is a well-defined enforcement process in place for those producers who are not in compliance with the regulations.
Martin commented the NMP allows producers to apply no more N than 1.4 times the amount of N removed by the crop, which is an extremely difficult target. Results are validated by soil tests, plant tissue tests and harvest data.
“Everything has to go perfectly,” he said. “Poor weather or bugs in crops can reduce yields and ruin a producer’s ability to hit the mark.”
In addition, with the assistance of the regional water board, the dairy industry has created the Central Valley Dairy Representative Monitoring Program. It is an intensive groundwater monitoring of clusters of local dairy farms, rather than having monitoring wells on every dairy.
Currently, 108 new wells and about 20 existing wells are in the cluster. The program, which is designed to track the progress of N management and identify effective management practices (BMPs), is governed and funded by the dairy industry themselves, working under the supervision of the regional board staff.
In addition to the regulatory goal to avoid further movement of N to drinking water and respond to existing conditions, Martin stressed that the industry is testing for N in soils, irrigation water, crops and manure to properly balance N applications. They are monitoring to see how they are doing, and will develop a focused research plan.
“Food and water is a large system, and the dairy industry is working hard to keep it safe,” he concluded.
