WASHINGTON - A new report reinforces what most everyone in U.S. food production already knows: Development is irreversibly diminishing the limited supply of U.S. farmland, raising serious food-production, economic and environmental concerns.

But the report from American Farmland Trust also finds that the loss of farmland is much greater than was generally known. Almost 31 million acres, double the amount previously documented, were lost to development from 1992 to 2012, according to "Farms Under Threat: The State of America's Farmland."

The 31 million acres nationwide are nearly the equivalent of all farmland in Iowa or the entire land mass of New York State, the report noted.

"Farmland is critical infrastructure, akin to roads and bridges," said John Piotti, AFT's president and CEO. "Without farms, there's not only no food, but there's no future. We need farmland to feed us and sustain our economy - but also to help restore our planet."

Agweek received an advance copy of the the report, officially released Wednesday, May 9. Other key findings include:

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• About 11 million of the 31 million lost acres of U.S. farmland are "the best farmland in the nation" or land "where the soils, microclimates, growing seasons and water availability combine to allow intensive production with the fewest environmental impacts."

• Expanding urban areas accounted for 59 percent of the lost farmland. Low-level residential development, or houses built on 1- to 20-acre plots, accounted for the other 41 percent.

• Farmland is affected disproportionately by development. Seventy percent of urban development and 62 percent of all development occurred on ag land.

American farmers and ranchers now use more than 1 billion acres, or 55 percent of the land in the continental United States.

The importance of U.S. agriculture - and of protecting farmland - shouldn't be overlooked or minimized, American Farmland Trust said.

Agriculture accounts for more than $1 trillion of the U.S. Gross Domestic Product and provides many environmental and recreational benefits, all of which are threatened by the loss of farmland, the report said.

Soaring global food demand - the world's food and fiber needs are expected to rise 50 to 70 percent by 2050 - increase the importance of protecting farmland, the report noted.

Federal policymakers, farmers, landowners, local and state planning agencies and the general public all need to do more to stem future loss of farmland loss, the report said.

American Farmland Trust recommends "a bold and comprehensive national strategy" to protect farmland. Its three key recommendations are:

• Double funding in the 2018 farm bill protect farmland through the U.S. Department of Agriculture's Agricultural Conservation Easement Program, which provides financial and technical assistance to help conserve agricultural lands and wetlands and their related benefits.

• Supporting and fully funding USDA programs that "provide unbiased information to help monitor changes in U.S. agricultural resources." That includes funding for a new 50-state Tenure, Ownership and Transfer of Agricultural Land survey.

• "Enacting a 21st century agricultural land protection platform," which includes "a new level of federal commitment." One example of what American Farmland Trust wants to see: enacting federal tax code changes that encourage keeping ag land in production and transferring it from one generation of farmers and ranchers to the next.

'We can be smarter'

AFT worked with Conservation Science Partners, a nonprofit conservation organization, on the report. USDA's National Resource Conservation Service, or NRCS, provided technical and financial support. A National Advisory Committee provided additional guidance; one of the committee members was Mary Podoll, North Dakota state conservationist with the NRCS.

Podoll told Agweek she served on the committee while working as deputy chief for soil survey and resource assessment at NRCS.

The new report utilized, among other sources of data, the NRCS's Natural Resource Inventory, which observes trends in land use and natural resource conditions.

Collecting and analyzing data is crucial to protecting farmland, Podoll said.

"We can be smarter (about development), and data collection is the key," she said.

The new report doesn't include state-level data. But a separate study released later this year will examine farmland loss state by state and look at the effectiveness of state farmland protection policies, American Farmland Trust said.

Podoll said the state-level data also will be interesting and useful.

The full report released Wednesday is available at www.farmland.org/FarmsUnderThreat.