Tom Ramstack

Mexico's president congratulated his military leaders Friday for finding what appears to be the largest marijuana field in the country's history.

The crop stretches over 296 acres, or more than 100 football fields, in a remote area of Baja California.

"Congratulations, general, for the big blow yesterday to organized crime in Baja California," Mexican President Felipe Calderon said in a message to his defense secretary.

Mexican authorities estimate the value of the marijuana found about 200 miles south of San Diego at $160 million.

It evaded detection previously because it was covered with a dark netting typically used to protect tomato plants. In fact, numerous tomato plants were interspersed with the marijuana to help conceal them.

They were irrigated with a sophisticated system of pipes that drew water from underground wells. Some of the marijuana plants were reported to be two meters high.

They were discovered by soldiers patrolling the area as part of Mexico's war with drug cartels.

Sixteen workers who tended the crop were arrested as they tried to flee, according to General Alfonso Duarte Mujica, the Mexican military's regional commander.

He estimated that 60 people worked at the site, which is located less than two miles from a major highway that extends to the U.S. border.

An investigation is continuing to discover which drug cartel operated the plantation. However, police said all of the people arrested came from the state of Sinaloa.

Sinaloa is the headquarters of the Sinaloa Cartel, which operates out of the states of Baja California, Sinaloa, Durango, Sonora and Chihuahua. The region is known for its production of marijuana and poppies, which are used to make heroin.

The U.S. Attorney General has said the Sinaloa Cartel is responsible for importing nearly 200 tons of cocaine and large amounts of heroin into the United States between 1990 and 2008.

Typically, the Mexican military burns the drugs it discovers as part of an effort to destroy the income source for the cartels.

Directly north of the plantation in Baja California, U.S. border agents have discovered about 40 tunnels used by drug smugglers to carry marijuana, cocaine and heroin into the United States in recent years.

The United Nations lists Mexico as the world's largest producer of marijuana, followed closely by the United States. Mexican drug cartels are suspected of reaping billions of dollars in revenue every year, although the exact amount is not known.

More than 40,000 people have been killed in the war between the cartels and Mexican government that started in December 2006, when Calderon ordered troops to help police crack down on the gangs.

Debate continued Friday about whether the Baja California plantation was really the largest illegal marijuana field ever discovered in Mexico, or merely speculation by the military to shore up morale among the troops.

In 1984, Mexican police found marijuana crops spread over 1,344 acres of a ranch in northern Chihuahua state called "El Bufalo," or "The Buffalo."

Some security experts being quoted in the Mexican news media say El Bufalo was much bigger than the crop found in Baja California.

However, El Bufalo consisted of 13 different fields. None of them alone was bigger than the plantation discovered this week, Mexican officials said.

The drug dealer who owned the El Bufalo property, Rafael Caro Quintero, later was charged with torturing and murdering U.S. Drug Enforcement Administration agent Enrique Camarena and his pilot, Alfredo Zavala. They are credited with discovering the El Bufalo plantation.