California prides itself on feeding America.

It also has the dubious distinction of being America’s biggest dope supplier.

Approximately 75 percent of the marijuana sold in the U.S. is grown in California — not Mexico, according to Sgt. Mike Horne of the Ventura County (Calif.) Sheriff's Department narcotics bureau. Horne heads a six-man commando-like unit that uses helicopters and rugged all-terrain vehicles to search and destroy marijuana growing operations in the national forest of his county.

This is not the typical article you find in an agricultural publication. However, Horne made his comments in a very typical agricultural setting, the recent California Weed Science Society annual meeting in Santa Barbara, Calif. The weed Horne was talking about has likely never been the topic of the society’s annual meeting in its 64-year history, where the presentations center around controlling unwanted weeds like horseweed, morningglory and Johnsongrass — not pot.

Horne was invited to speak on marijuana cultivation as the tentacles of these illegal operations pervade the rural, agricultural areas of the state. Marijuana cultivation has grown to the point where it is making it dangerous for government employees like University of California Cooperative Extension farm advisors to do their jobs.

Michelle Le Strange, UCCE farm advisor in Tulare County and immediate past president of CWSS, said she has been warned by county officials and law enforcement officers that she should be alert in driving a county vehicle in rural areas because marijuana plantation tenders might think she is a law enforcement officer, and she could be in danger.

Horne said Le Strange and any government officials driving vehicles with government plates should be concerned because these marijuana plantations are operated by Mexican drug cartels, the same lawless gangs who are responsible for thousands of murders each year in Mexico. These cartels actually scour the U.S. Forrest Service lands in search of ideal growing sites, often adjacent to running streams. The cartels stock these plantations with people, drip irrigation tubing and chemicals to farm the illegal weed.

Horne showed a video and photos of what his men have uncovered in the national forests. As expected, there were neatly planted marijuana rows with drip irrigation tubing, the same as used by farmers. More chilling to the CWSS audience were the photos of not only automatic weapons confiscated in a raid, but pictures of chemicals and fertilizers used in these growing operations. The logos of many very prominent agchem and fertilizer companies were clearly visible. There were also photos of agchem products manufactured in Mexico, brought in by the cartels. Horne said many of those chemicals are not legal in the U.S.

Le Strange pointed out that chemicals and fertilizers used in these growing operations could well find their way in to streams and lakes. The unsuspecting public is likely to put the blame on agriculture for any contamination from these illegal chemicals or misuse of U.S. registered products.

Marijuana flourishing in California

The national forest marijuana problem is not new, but it is growing, becoming more sophisticated and more dangerous with the cartel involvement. Workers in these plantations are armed with automatic assault rifles.

In recent years, marijuana growing has flourished in California’s rich agricultural valleys. This has been precipitated by California’s new medical marijuana laws. Illegal drug dealers are operating under the guise of growing medical marijuana. One large-scale growing operation raided by county sheriff’s officials just east of Fresno was in an area of small vegetable farms. On the fence surrounding the pot farm letters were posted professing that it was a medical marijuana operation. Many of the letters were duplicated and tacked on the fence of the raided farm. Sheriff’s deputies had traced the marijuana grown there to illegal drug sales on the East Coast.

Horne said Asian gangs are leasing agricultural land for these marijuana operations.

Horne cited official statements that only 15 percent of marijuana growing operations on federal land are detected and destroyed each year. He disagrees with that, at least in his county, where he said his task force takes out 50 percent to 70 percent of the operations.

What he did not dispute is the size of the problem statewide. Horne said it has been estimated that there are 71,000 acres of marijuana under cultivation each year in California. That represents 121 square miles or an area equivalent to the size of Sacramento.

Horne said they are so plentiful, it is common for hunters and hikers to stumble across marijuana plantations.

These operations have also been linked to wildlife deaths from drinking polluted water and several have been linked to starting forest fires.