In what may be a promising sign that the housing market is picking up steam, but a troubling sign for the Central Valley's most vital industry -- agriculture -- farmland loss is again emerging as a concern for the region's future.

A report by the American Farmland Trust has found that despite making pledges to protect farmland from urban encroachment, the region is on track to lose half a million acres of the most fertile, water-secure farmland by 2050. In economic terms, that's a drain of between $100 billion and $200 billion from the local economy in the coming decades.

This gloomy prediction comes despite the fact that farmland loss is a well-recognized peril for the region's growth and many cities throughout the valley adopted policies years ago to address those issues. The problem, according to the study, is that those policies aren't working.

The report found that 61 percent of all development in the valley is taking place on high-quality farmland, mainly along the Highway 99 corridor. Because of the abundance of land around valley cities, development has consumed an acre of land for every 6.4 new residents, an incredibly low density.

The report urges valley communities to consider new ways to protect farmland before development again reaches pre-recession levels. There are a number of ways to do this.

While many valley communities have policies that aim to preserve farmland, few monitor whether growth reflects those policies or have tools in place to ensure those policies are enacted. One example is a Kings County incentive that provides a 25 percent reduction in development application fees for infill development in areas where water and sewer are already available. The report also suggests that cities review the size of their spheres of influence to determine if they allow for more capacity that can realistically be used.

Another option -- and a worthy one -- is the use of conservation easements. Ag easements are voluntary, legally recorded deed restrictions designed to keep agricultural land in production by removing the development pressure from the land. The farmer cashes in by selling his development rights, usually to a trust, which keeps the land available for farming by restricting nonfarm development.

For reasons that remain unclear, agriculture easements have not caught on in the Central Valley. Only 10,770 acres of valley farmland are held under easement, according to the report. More needs to be done. This is an area where Central Valley cities and counties, and their various farm bureaus and trade groups, could work together to explore how to encourage more protection of land using easements.

As the report notes, now is the time to act. With development slowed to a halt in recent years, farmland loss has not been top-of-mind for many valley leaders. But with the housing market suddenly on the rebound, it's the ideal time to strengthen policies that will prevent the future erosion of this invaluable regional asset.