Requirements under Ag Order 4.0 could make the practice of cover cropping more necessary for Central Coast growers. Certain types of cover crops can help growers to better manage nitrogen, a cornerstone of the new requirements. Research Horticulturalist with the U.S. Department of Agriculture, Eric Brennan explained the order provides incentives for growers who use cover crops.
“When you grow a cover crop, you can get this credit,” said Brennan. “When you are growing that cover crop it slows the movement of nitrogen down into the aquifer. It makes our use of that nitrogen that’s left over more efficient.”
A recent study using satellite imagery indicates that roughly five percent of irrigated land in the area has winter cover crops. With growers able to obtain credits under the order, it will likely increase cover cropping in the Central Coast. “I wouldn’t think it would be unreasonable to think it would at least go to 10 percent or even quite a bit higher,” Brennan noted.
POTENTIAL CHALLENGES WITH WIDER COVER CROP ADOPTION
Seed for certain types of cover crops like Merced rye consistently sells out by late fall, even prior to the ag order. Brennan explains that the order incentivizes non-legume cover crops “because those are the best nitrogen scavengers.” A cereal crop can be the most effective in minimizing the amount of nitrogen moving down into the groundwater. If adoption increases, it could put more strain on seed supplies. Brennan has been researching seeding rates to help determine how to maximize the value of the seeds growers buy.
“We want to make sure there’s enough seed supply. But we also want to make sure that growers know when they plant the seed, how many seeds they’re planting per acre, and what density is needed for weed suppression,” Brennan noted. “These are some really important questions that we still need to work on some more.”