General Mills has made its largest contribution to help save pollinators, announcing a $2 million commitment that will add more than 100,000 acres of bee and butterfly habitat on or near existing crop lands.

The five-year agreement with the U.S. Department of Agriculture's Natural Resources Conservation Service and the Xerces Society, the world's oldest and largest pollinator conservation group, will focus its efforts in Minnesota, North Dakota, California, Nebraska, Iowa and Maine. The USDA and Xerces will match this donation with another $2 million toward the project.

Gaining support from large corporations is a key step, conservationists say, in reversing the decline of pollinators that are needed to reproduce food crops and plants.

The investment will support six new field biologists in these regions who will work with General Mills' suppliers to implement a pollinator habitat plan. With private landowners managing more than 70 percent of all land on the United States mainland, the USDA and nonprofit organizations must rely on corporate and other private partners if they are to stop the decline of pollinators, said Jason Weller, conservation service chief of the federal department.

"Partnerships are vital. If we really want to conserve wildlife and help the environment, we have to work with private landowners," said Scott Black, executive director of the Xerces Society.

Over the past several years, Black said, U.S. beekeepers have lost between 35 and 40 percent of their hives. A recent United Nations report found that 40 percent of the world's invertebrate pollinators are facing extinction. While bees and butterflies are the most common, birds, moths, beetles and bats also are pollinators, according to the USDA.

Both the World Wildlife Fund, or WWF, and the Xerces Society say pollinators help produce one-third of all human food.

For General Mills, there are two obvious benefits to this effort: long-term protection of its food supply through the work done by pollinators and brand loyalty from its environmentally concerned consumers.

"At General Mills, we take a lot of care to the ingredients that are in our food. And that includes how the ingredients are grown, the impact they have on the environment and the lives of the people who grow them," said Jerry Lynch, chief sustainability officer for General Mills. "Our consumers care a lot about how our food is grown."

Some of the General Mills brands particularly close to this work, Lynch said, are Annie's, Cascadian Farm, Honey Nut Cheerios and Muir Glen.

A WWF study published last month found agriculture is quickly replacing the grasslands of America's Great Plains, leading to the destruction of pollinator habitat. Since 2009, more than 53 million acres of grassland — an area the size of Kansas — have been converted to crop lands, according to the WWF study.

General Mills, which Black calls an "early adopter" among corporations on pollinator issues, also is promising to revisit about 300,000 acres of existing pollinator habitat on its suppliers' farms and ranches to explore possible improvements. The agreement makes the Golden Valley-based company the largest private partner of Xerces, based in Portland, Ore.

Farmers and ranchers will opt-in to the new program and receive a science-based plan from these field researchers tailored to their individual situations. Lynch said they have found "a great willingness to experiment" among their suppliers.

"Farmers are very open to putting habitat into their farming operations because they care a lot about the land that produces the food," Lynch said.

These habitats will vary from farm to farm, but will seek to address three core issues contributing to the decline in pollinator populations: flowers to eat, places to nest and refuge from pesticides. Some may be changes in processes while others will be the addition of plants and grasses in buffer zones of fields, areas that are not being used to grow crops.

Weller said these field biologists can work with livestock operators on better seed mixtures that are good for the animals and that offer "high-quality forage possibilities for honeybees and monarch [butterflies]."

The partners say such habitats also can reduce soil erosion and improve water quality.