WASHINGTON — The Senate turned back an effort by Sen. Tom Coburn to keep parcels of land proposed for federal ownership open for renewable energy exploration. Senators also rejected two other amendments by Coburn in his long-running battle over a massive public lands bill. Coburn, R-Muskogee, has tried for more than a year to make some major changes to a package that includes more than 160 different bills, many of which will add to the federal government’s large inventory of land. One of the amendments rejected on Wednesday would have required the National Park Service to make needed repairs to its current sites before undertaking any new construction projects. Another Coburn amendment that was killed would have prohibited the government from using eminent domain for land acquisitions authorized in the bill. Coburn said the bill would establish new wilderness areas and make other designations that would restrict access for developing renewable energy. He offered an amendment to nullify any provisions that would prohibit alternative energy development, but the Senate overwhelmingly voted it down.