After vastly expanding on an already proposed special rule dealing with the conservation of the lesser prairie chicken, the U.S. Fish and Wildlife Service once again will be taking comments.

Provisions within the special rule could serve as a de facto anti-sodbuster rule within the prairie chicken's range as well as attempting to mandate impractical, and likely unenforceable, harvesting methods to prevent the birds from being inadvertently trapped and killed by combines.

The rule, published Wednesday in the Federal Register, reopens the comment period, the fourth offered by the federal wildlife agency that now appears to be headed for what likely is a certain listing of the bird as a threatened species.

Failing to do so would undermine its latest proposal under what is known as a 4(d) provision that offers protection from "incidental take" of the bird if it's listed.

The comment period will end Jan. 10.

The FWS in May issued the first of what is now several 4(d) rules offering protection to developers, provided they participate in a conservation program that at the time still was under development. The rule also opened the possibility of continuing hunting of the birds, but only in an area of west-central Kansas it shares with the greater prairie chicken.

FWS already has endorsed the conservation plan developed by the five states with the birds -- Kansas, Colorado, Oklahoma, Texas and New Mexico.

But it endorsed, and continues to endorse a September version, one that was submitted and already has been modified at the insistence of the federal agency.

The latest additions to the 4(d) rule extend protection to conservation activities under a lesser prairie chicken initiative offered through the Natural Resources Conservation Service, an arm of the U.S. Department of Agriculture.

Only a handful of agreements have been made between NRCS and farmers under that program.

The new 4(d) rule also would offer protection for "the continuation of routine agricultural practices ... on cultivated land that are in row crop, hay or forage production."

But only on land that has been worked in the past five years.

"Thus, this provision does not include take coverage for any new conversion of grassland into agriculture," according to the Federal Register notice.

That could prove to effectively serve as an anti-sodbuster rule that could be put in place in the historic range of the bird.

The FWS considers routine agricultural activities as "plowing, drilling, disking, mowing or other mechanical manipulation and management of lands in cultivation ... ."

But in something of a bizarre twist, the agency went on to include a caveat: "... provided that the harvest of cultivated lands is conducted by methods that allow wildlife to flush and escape, such as starting operations in the middle of the field and working outward, or by modifying equipment to include flush bar attachments."

Small game biologist Jim Pittman, on the science committee of the five-state group developing the conservation plan, marveled at portions of the latest proposal.

He called the harvest directions "unenforceable."

Gove County farmer Mahlon Tuttle, on the executive board of the Kansas Natural Resource Coalition, which opposes the listing, offered a conciliatory note, but didn't think much of it.

"They obviously never farmed very much terraced ground," he said.

While he said the suggestion to start in the middle could be followed, he's not sure anyone would be willing to do so.

"I don't think they're going to want to be told to do it that way," he said of farmers in his county.

While Pitman agreed the rule covering routine farming practices could serve as a de facto sodbuster rule, he's worried it might cause some farmers to dump Conservation Reserve Program contracts early.

CRP has been the driving force behind a long-term boost in prairie chicken numbers.