Agriculture had another booming year in Marin, with the gross value of products in the county reaching its highest value for the second year in a row. The annual crop report released on Tuesday pegged gross values for 2015 at over $111 million, a 10 percent increase from 2014, with organic milk having the single largest increase in value.

Some sectors fared better than others, however, and pending rules on weeds are also worrying some agriculturalists.

“You guys do a lot to support agriculture,” Stefan Parnay, the deputy agricultural commissioner, told supervisors during a presentation on Tuesday. “I think this report really reflects your commitment.” Yet he said that agriculture is a tough industry facing “challenging times,” including lawsuits, regulations and climate change.

The value of milk, Marin’s most valuable agricultural commodity, shows the dichotomy of success and struggle. Overall production for both organic and conventional milk remained relatively stable, but values diverged significantly. Organic milk had a banner year last year, with the gross value in Marin jumping from $33.6 million in 2014 to $41.1 million in 2015—a 22 percent increase. 

But the gross value of conventional milk in Marin plunged 26 percent, down to just $4 million, due to falling prices.

“This transformation of the dairy industry in Marin County into organic…is both a commitment to sustainability in a broad sense, but also survivability in a business sense,” Supervisor Steve Kinsey remarked.

Other growing sectors include chicken eggs and meat, whose combined gross value shot up 44 percent, to $17 million. The gross value of cattle meat went up about 9 percent. Wool values also rose; production was up 32 percent, though overall value was only up 8 percent, as the price per pound dropped.

Other areas didn’t fare so well. Aquaculture values dropped 40 percent, from $10.6 million to $6.4 million, because of the closure of Drakes Bay Oyster Company at the end of 2014, Mr. Parnay said. 

Wine grape growers also fell on hard times, which he attributed to “unfavorable conditions” for grapes. Wine grape yield plummeted by 68 percent, according to the report, to 108 tons. So though the total value of wine grapes in the county is a pretty small portion of the total gross value of agricultural products, it became even smaller, falling from $703,000 in 2014 to $347,000 last year, a 51 percent drop. There was also a 22 percent decline in the value of sheep meat, largely due to a drop in price per head for the animal.

One problem the crop report didn’t mention—but which Supervisor Kinsey brought up near the end of the discussion—was invasive weeds on agricultural lands, which eat up space for crops and pose fire hazards.

“We have work to do on the invasive weeds that are really a very serious threat to our productivity,” Supervisor Kinsey said, mentioning hearing about “rumblings of ordinances or other means” to help control them.

Mr. Parnay agreed that weeds were a serious concern. “There may be 10,000 to 15,000 acres of land that are really unusable because of invasive weeds,” he said.

The agricultural department is trying to work on solutions. In the short-term, Mr. Parnay said it is working on updating a weed ordinance that hasn’t been changed since 1959. “The goal is to update that to reflect current information and to really lay the groundwork for moving forward on invasive weeds,” he said. He did not get into specifics at the meeting, but the ordinance may require landowners to actively manage invasive weeds.

In the long term, the department would like to revisit a 10-year invasive weed management plan it proposed in 2013, which got public support from about two dozen groups but also drew concerns. That plan is a multipronged approach that includes some herbicide use, education, mapping and help for landowners to pay for weed management. As of now, Mr. Parnay said there is “no timeline” for renewing a discussion on the matter.