BIG U.S. CONSERVATION ENROLLMENT EXPECTED Enrollment in the U.S. Agriculture Department's fourth conservation signup is expected to be announced tomorrow, and USDA officials said the figure may be higher than total enrollment for the first three signups. Enrollment will be in the range of seven to 12 mln acres, USDA conservation specialists said. Total enrollment so far in the 10-year conservation program is 8.9 mln acres. Producers submitted bids to enter 11 to 12 mln acres into the program, Milton Hertz, administrator for USDA's Agricultural Stabilization and Conservation Service said at a congressional hearing yesterday. Not all the bids will be accepted, Hertz said, but enrollment is expected to be high. As in the first three signups, the Great Plains area is expected to attract the greatest enrollment. "The Great Plains area will be the predominate area which we'll get signup in," a USDA conservation specialist said. Marginal corn acreage will likely be the bulk of the acreage pulled from that area, he said. Fringe soybean acres in the southeast and some bean acreage in the midwest are also expected to be taken out of production, but the USDA source said this would be a relatively small percent of the total. A special two dlr bonus to corn producers who enroll part of their corn base acreage into the program has sparked more interest in this latest signup, USDA officials said. Under the program, USDA pays farmers annual rents to take land out of production for 10 years. The average rent payment accepted in the first three signups was 43.50 dlrs per acre.