Take-Home Lessons from California on Nitrates and Water Quality
California water coalitions are leading the way in addressing nitrate contamination. What can growers learn about nitrogen management from their progress?
Nitrate contamination is one of the biggest threats to water quality in our nation, particularly in California, where it affects vast areas of irrigated farmland. As farmers in California go through the regulation process, what are they learning and how can other growers benefit from their experience.
The Proof is in the Data
One thing California growers will have to do in the near future is track and report their nitrogen use. Parry Klassen, fruit grower and executive director of the East San Joaquin Water Quality Coalition, was part of the Department of Food and Agriculture committee tasked with developing an approach for farmers to track nitrogen use and report information to aggregators.
“I believe that nitrogen tracking and reporting will help us better define what we in agriculture already do with nitrate fertilizers,” says Klassen. “Ultimately, what growers will have to do is prove to the regulators that we are taking steps to manage nitrogen properly. I say this because I believe many growers are following best management practices. We just don’t have the data to prove it.”
Know Your Water
As part of the tracking process, farmers in California are testing their irrigation and well water for nitrates and accounting for those levels in their annual fertilizer budgets, a good practice for any grower looking to reduce nitrate leaching.
“The amount of nitrates in well water is site specific and varies according to region,” says Klassen. “In the East San Joaquin area, we have a lot of nitrates in our well water, some areas have the equivalent of 50 nitrogen units per season. If you need 300 pounds of nitrogen for your crop, you would plan on putting out 250 to account for the 50 in your groundwater.”
In addition to testing water supplies, California growers have implemented basic agronomic practices that are long-proven methods to help reduce nitrogen leaching.
Back to the Basics
“We often focus too much on sustainability at the expense of going back to basic agronomic practices for nitrogen management,” says Klassen. “For example, proper timing of nitrogen application based on crop demands and matching fertilizer rates to individual crops.”
Other examples — split applications to spread nitrogen use out over the consumptive period for better efficiency and uptake, soil and tissue analysis, the use of drip and micro systems for spoon feeding the crop and nitrogen budgets based on known crop consumption levels.
While there are several best practices for nitrogen management, nothing is a one-size-fits-all solution. It often takes a combination of several practices, tailor-made to site-specific conditions, to effectively reduce nitrogen leaching.
Responsible Nutrient Management
Much of effective nitrogen management boils down to managing nutrients responsibly by using less fertilizer applied, taking advantage of precision placement, utilizing prescription programs and applying balanced formulations that include micronutrients. Agro-Culture Liquid Fertilizers is an advocate of Responsible Nutrient Management®, which incorporates these principles.
In California and elsewhere, AgroLiquid recognizes the challenges growers face in trying to manage nitrogen for maximum uptake by the crop. Their N-Suite™ of products, High NRG-N, NResponse and eNhance, offer a wide variety of application options to support nitrogen management practices and effectively meet the cropping needs of the grower.