Even as the residential real estate market founders, U.S. farmland values are at an all-time high, with record-high crop prices pushing up agricultural real estate value, Bloomberg.com reported.

The value of farmland averaged $2,350 an acre at the start of this year, which was up more than 8 percent from a year earlier, the U.S. Department of Agriculture (USDA) said Monday in its annual report.

The boom reflects increases in commodity prices that raised net farm income to $92.3 billion this year from $88.7 billion last year, according to the USDA.

The most expensive farmland was found in Massachusetts at $12,200 an acre, followed by Rhode Island and Connecticut. The least expensive land was in New Mexico, where prices averaged $630 an acre.

The USDA’s report also tracked rates for land that is rented for farming. Rental prices for cropland rose 13 percent last year to $96 an acre, and pasture fees rose 8.3 percent to $13 an acre.

But because of increasing demand for additional farmland and high buying costs, farm-rental prices may rise 20 to 30 percent in 2009, said Murray Wise, chief executive office of Illinois-based Westchester Group Inc.