After three years of public hearings, numerous revisions, and intense deliberations, on April 15, 2021, the Central Coast Water Quality Control Board approved a new agricultural order regulating discharges from irrigated lands.
The new regulations in Ag Order 4.0 are likely to go too far for many farmers and not far enough for environmental justice advocates, who point to nitrate contamination in regional drinking water wells as an ongoing problem that is not being addressed, even through tighter regulations on agriculture.
One key change is that, in addition to reporting total nitrogen (N) applied for each crop, growers will also have to report N removed by crop harvests and calculate the difference, which the water board considers to be the amount of N discharged to groundwater and surface water. Ag Order 4.0 establishes N discharge targets and limits over time, ratcheting down allowed values of N applied minus N removed from 500 pounds per acre by the end of 2023 to 50 pounds per acre by the end of 2051.
Limits to fertilizer application rates will also be imposed. Growers will likely have to use tools such as the nitrate quick test to adjust their fertilizer rates to more closely meet crop needs and to avoid excessive N application.
But there were some wins for the organic farming sector, including N correction factors for compost and many organic fertilizers, plus a credit for N-scavenging cover crops. A credit for high-carbon, N-scavenging amendments is also included. Cover cropping is likely to emerge as an important strategy for meeting N targets and limits for both organic and conventional growers.
Still, Ag Order 4.0 requires more water quality and crop production monitoring and reporting than the previous ag order, which may pose a challenge, particularly to small-scale and beginner growers and farmers with limited resources who don’t have staff devoted to regulatory compliance.
Monitoring and reporting requirements include the following:
- N applied. Total N present in the soil, applied from all sources, including irrigation water, with adjustment factors for compost and organic fertilizers.
- N removed. Crop yield multiplied by a crop-specific N coefficient, with credits given for cover crops and high-carbon amendments.
- Annual sampling of all on-farm domestic drinking water wells and notification to users of the results.
- Annual sampling of all irrigation wells.
- Groundwater quality trend monitoring and reporting.
- Surface receiving water quality trends.
New requirements will be phased in over the next two to six years, depending on the location of your farm and its adjacency to impaired bodies of water.
The role of third-party monitoring will likely expand in the region because Ag Order 4.0 offers a cooperative compliance pathway for groundwater protection and trend monitoring, which should reduce costs of individual monitoring. Even so, growers will see their regulatory costs increase. CCOF has advocated for the water board to consider offsetting these economic impacts by subsidizing third-party monitoring fees, phasing in or reducing reporting requirements, and offering fee waivers.
Testimony by a panel of cover crop researchers and advocates resulted in the last-minute adoption of the calculated cover crop N credit—which more accurately credits the N taken up by nitrogen-scavenging cover crops—as an alternative to a flat credit of 30 pounds per acre. To qualify for this credit, the cover crop must be a non-legume grown for at least three months, have a minimum of 4,500 pounds of oven-dry biomass, and have a carbon to nitrogen ratio greater than 20-to-1. For more information, watch the video on cover crop nitrogen credits on Eric Brennan’s YouTube channel.
U.S. Department of Agriculture Agricultural Research Service (USDA-ARS) scientist Dr. Eric Brennan, the first and only dedicated organic USDA-ARS researcher in the country, played a key role in the water board’s acceptance of the calculated cover crop credit by presenting data from his long-term organic trials in Salinas. Other experts on the technical panel were Michael Cahn and Richard Smith (UC Cooperative Extension), Karen Lowell (USDA Natural Resources Conservation Service), Sacha Lozano (Resource Conservation District of Santa Cruz County), and Kelli McCune (Sustainable Conservation).
Dr. Brennan posted a YouTube video, “Historic Win for Farmers, Cover Crops, Soil & Ground Water Protection in California’s Central Coast,” documenting the technical panel’s testimony on cover crops and water board deliberations. Follow Dr. Brennan on Twitter @EBrennanScience for updates on his organic research.
For more information:
Ag Order 4.0 drafts and other documents are available on the Central Coast Water Board’s Irrigated Lands Program – Agricultural Order Renewal 4.0 website.
The final approved order will be posted to the Central Coast Water Board’s Adopted Orders, Permits, Resolutions, and Settlements website in the next several weeks.
Central Coast Water Board press release on Approval of Ag Order 4.0.
UC Cooperative Extension, Salinas Valley, training series on organic soil fertility management, March 2021.