WASHINGTON — Up to 8.7 million acres of what the U.S. Department of Agriculture considers “prime farmland” is tied up from production under contracts with a 10- to 15-year duration under the Conservation Reserve Program, according to a report issued June 12.

The National Grain and Feed Association, which sponsored the study, is calling for this land to be excluded from the C.R.P. in the 2012 farm bill currently under consideration by Congress.

The study, “ReGaining ground – a Conservation Reserve Program right-sized for the times,” was prepared by Strategic Conservation Solutions L.L.C. The group’s founder and principal, Bruce Knight, earlier was chief of the U.S. Department of Agriculture Natural Resources Conservation Group.

The N.G.F.A. study recognized not all of the prime farmland was suited for removal from the program. Some of this land serves as filter strips, grassed waterways and other sensitive acreage.

“But with C.R.P., contracts that include more than 70% of acreage enrolled — 21.2 million acres — set to expire over the next five years, there is an urgent need to manage the program so that the most productive land from the reserve is returned to production,” the study said.

The study suggested a faster reduction in C.R.P. acreage than would be called for in a Senate Agriculture Committee plan, which would reduce the C.R.P. area to 25 million acres from 35 million by the end of fiscal 2017. Removing most of the prime farmland from the C.R.P. would equate to a program cap of about 21 million acres, the N.G.F.A. said.

The study supported continued use of C.R.P. for areas that are “truly environmentally sensitive.” With budgetary pressures, rising demand for feed, feed and biofuels worldwide, the need is crucial to remove land in the C.R.P. that is suitable for production, the group said.