Some organic farms in the western United States may have been duped into using non-organic fertilizer, and consumers who thought they were buying organic food may instead have been paying a premium for goods grown with synthetic chemicals.

An indictment handed down by a federal grand jury in California Thursday alleges that fertilizers supplied by companies owned by Kenneth Noel Nelson Jr. were made with synthetic ingredients not approved for organic farming, U.S. Attorney Benjamin Wagner announced in a news release.

Nelson, of Bakersfield, CA, was charged with 28 counts of mail fraud. The largest seller of “organic” fertilizer in the West, Nelson has owned and operated various companies, including Port Organic Products Ltd., AgroMar Inc., Sail-On Ag Products Inc., Desert Organic Express Inc., Action Fertilizer, and Microbial Assisted Soil Health Inc. 

As alleged in the indictment, from at least 2004 to January 2009, liquid fertilizer Nelson labeled and marketed as made with all-natural ingredients such as fish meal, bird guano, or blood meal, instead contained aqueous ammonia, ammonium sulfate, synthetic urea, and other nonorganic, synthetic substances — additives in conventional fertilizers that are not permitted in organic-crop production.

The indictment accuses Nelson of submitting false applications and renewal applications to obtain and maintain organic listings for his fertilizers from Organic Materials Review Institute and Washington State Department of Agriculture.

If convicted, Nelson faces a maximum sentence for each count of 20 years in prison, a $250,000 fine, and up to three years of supervised release.

According to the LA Times’ P.J. Hufstutter, the indictment, the second in recent months, is part of an effort by the U.S. Department of Agriculture’s Office of the Inspector General to crack down on fraud and corruption in the more than $24 billion organic industry.