OMAHA, Neb. (AP) – U.S. Agriculture Secretary Tom Vilsack said he hopes landowners will commit 4 million acres of land this year to a federal program that pays farmers not to farm fragile acres.

But the agriculture secretary also said the Conservation Reserve Program may need to be changed when lawmakers write the 2012 farm bill.

Vilsack said Friday during a visit to Omaha that allowing landowners to grow biofuel crops like switch grass on land in the program might improve the habitat for wildlife while making the CRP more economical.

Vilsack said all the farm bill programs will have to be examined closely for effectiveness because of the growing federal deficit.

The Conservation Reserve Program now keeps about 31 million acres of environmentally sensitive land from being farmed.