Optimism flickers among conservationists that the massive conversion of grasslands and wetlands to row crops in recent years — and the subsequent loss of wildlife habitat — might be slowed or stemmed by a Farm Bill now being considered in Congress.

Additionally, the first general sign-up in a year for the federal Conservation Reserve Program, which pays landowners to idle sensitive lands, begins Monday, boosting conservationists' hopes.

But the reality is this: Hunters and wildlife lovers in the Upper Midwest might never again see the abundance of habitat they witnessed in the past decade. And the future, even of wildlife-rich states such as South Dakota and North Dakota, looks increasingly grim.

South Dakota's claim to be the "Pheasant Capital of the World" could ring hollow in the not-too-distant future.

"The long-term trends are very, very sobering," said Dave Nomsen, Pheasant Forever's vice president of governmental affairs, who has been intimately involved in the Farm Bill for decades. "We're turning the eastern Dakotas into northern Iowa every day. I've never seen anything like it in my lifetime."

A downward spiral

A recent study on the state of the prairie pothole region concluded: "All scientific papers and data we reviewed indicate conversion of grasslands and drainage of wetlands will continue ..."

That same study noted that the acreage planted to soybeans since 1970 increased by 2,000 percent in North Dakota and by 1,600 percent in South Dakota.

Sky-high corn and soybean prices — though now tempered — and escalating land values are driving the conversion.

The loss of CRP acreage underscores the dwindling wildlife habitat. Soil erosion and water pollution also could rise with the loss of associated grassland buffers. Since 2007, South Dakota has lost more than a half-million acres — or 875 square miles — of CRP lands. Fewer than 1 million acres are currently enrolled, and more likely will be removed as those contracts expire.

Minnesota currently has about 1.4 million acres enrolled in CRP, a loss of 400,000 acres — or 625 square miles of grasslands — since 2007. (Some good news for pheasant hunters: CRP acreage within the state's pheasant range has remained fairly constant at around 700,000 acres.) North Dakota has lost an incredible 1.6 million acres of CRP, or 2,500 square miles, since 2007.

"It's a downward spiral right now," Nomsen said.

Nationwide, about 27 million acres are enrolled in CRP, a reduction of some 10 million acres from the peak. And an additional 3.3 million acres are set to expire Oct. 1.

Some good news?

Nomsen is a glass-half-full guy. This week, a Senate committee OK'd a new five-year Farm Bill authorizing $56.8 billion for conservation programs over 10 years. Importantly, the bill includes a provision requiring farmers who buy crop insurance to also comply with conservation measures to protect highly erodible lands and sensitive wetlands.

"It's not some new burden, it was in place before 1996," Nomsen said. "If you want to qualify for federally subsidized crop insurance, you need to address conservation on your farm."

But even if that provision is included in the new Farm Bill, versions in the Senate and House call for capping CRP at 24 million to 25 million acres.

"We'll have to be as efficient as we can possibly be to get the best-of-the-best 25 million acres," Nomsen said. That means better managing CRP acres with prescribed burns and re-establishing forbs so those grasslands are more productive wildlife habitat.

A big question that will be answered starting next week is whether CRP will pay enough to entice landowners to enroll in the program.

"Even with $7 [a bushel] corn, there's still a place on every farm for conservation and CRP," Nomsen said. "We'll see what happens."

He pointed to a recent report that this year's corn harvest could be 30 percent above last year's, which could drive corn prices down sharply, prompting some landowners to enroll in CRP.

So far, Nomsen said, there has been little discussion about the social impacts over the loss of so much land and water protection and wildlife habitat. In South Dakota, hunting is a $250 million-a-year industry, and thousands of Minnesotans flock there each fall to chase ringnecks.

But they may stay home if pheasants become as scarce as they are in Iowa, where the pheasant harvest fell from 1 million in 2003 to 100,000 in 2011.

Meanwhile, Nomsen said conservation-minded people and groups like Pheasants Forever must continue to fight for wildlife habitat.

"We have to be more proactive, creative and aggressive," he said. "We can't just sit back and let this happen."

Doug Smith • dsmith@startribune.com