Editor’s note: Though potatoes and other root and tuber crops don’t necessarily need the help of pollinators to produce a healthy crop, these insects have proven to be a boon to a wide range of U.S. agricultural interests. In the January 2015 issue of Potato Grower, National Potato Council executive vice president John Keeling wrote, “The NPC recognizes the importance of pollinator health to all of agriculture and will continue to work … to further improve the health of bees, butterflies and other beneficial insects.”
Insects and plants have a pact: Hungry bees, butterflies and bumble bees can help themselves to a plant’s sweet nectar in return for spreading its pollen. And pollination has advantages, especially for humans: Many plants we eat either benefit from it or, like almonds, pumpkins and melons, are largely dependent on it. A lot of flowering plants also need insects to pollinate them, such as many types of meadow flowers and the wildflowers that grow near farmers’ fields. And plants like these supply other animals with seeds and fruit to eat.
But, often, agricultural land is not a very nice place for the hardworking insects. This is because agriculture has intensified over the years. While this has the advantage of being able to feed a growing world population, monocultures with no natural field boundaries make it impossible for insects to find enough food and shelter.
“Germany is one of many countries where huge swathes of agricultural landscape are effectively an ecological no-man’s land,” says Dr. Rainer Oppermann. “We’re all just used to it now,” he adds. Oppermann, an engineer and agricultural environment expert, heads the Institute for Agroecology and Biodiversity (IFAB) in Mannheim, Germany. His team is working on renewing the ties between agriculture and nature.
Even very simple measures can bring about big changes. Allowing wildflowers to grow in areas next to fields is one way of ensuring that pollinators have a good supply of pollen and nectar. Nesting aids that provide bees with shelter are another good option. “At the moment, though, we don’t have many quantitative, comparative long-term studies on how these kinds of targeted measures affect insect diversity,” says Dr. Christian Maus, global pollinator safety manager at the Bayer Bee Care Center. He is now aiming to close that knowledge gap with researchers from the IFAB and the Institute of Landscape Ecology and Nature Protection in Bühl, Germany. They have sown flowering plants and created a home for wild bees on two farms in the Upper Rhine Valley of southwestern Germany.
The researchers return every year to observe how the insect world has changed. Over the four years of the project, the number of pollinator species has increased. In addition, the ecologists have also seen a rise in the number of insects of each species.
Things looked very different in 2010 when the project began. That year, the researchers set up one area employing the new measures and one control area on each farm—a total of four areas, each spanning 50 hectares (124 acres). The project areas were designed to be insect-friendly, while the control areas remained unchanged. Before the experiment began, the team made an inventory of the wild bees and butterfly species present on each farm. They then started sowing wildflowers in between the maize and cereal fields. Ten percent of the agricultural land was turned into “insect restaurants,” where pollinators can now fill up on nutrients from field poppies, sunflowers and cornflowers.
The project has also tested bee shelters, such as soil banks where wild bees can breed. Conventional fields don’t give the bees much shelter. “The ground is too densely vegetated, too shady and too cold,” says Oppermann. “The eggs need to be kept warm if they are to develop properly.” Beneficial insects like wild bees can also nest in chunks of wood with holes drilled in them, which the research team also distributed in the study areas for experimental reasons.
The insects appreciate the offerings: “The situation has improved immensely over the past four years,” says Maus. “At first it went quite slowly, but now the difference is very clear.” In the first year, very few species of bumble bee were seen above the stretches of wildflowers. But that changed over the next few years. The number of wild bee species on one farm grew from 31 to 58, while on the other it more than doubled, rising from 34 to 74.
“We’ve also seen more endangered species take up residence here,” adds Oppermann. Meanwhile, in the unaltered control areas, the number of species stagnated. The researchers observed the same thing with butterflies.
“The entire ecological food web benefits when there are more species,” says Oppermann. “Birds, for instance, will have more insects to eat.” And even farmers stand to benefit from the measures, as areas of wildflowers also attract predatory insects that can kill off agricultural pests like aphids.
The project is now being extended. “We want to examine if we can transfer this model to large-scale farms in eastern Germany,” says Belinda Giesen-Druse, who will be coordinating the project at Bayer CropScience. “We’ll soon be sowing flowering plants on two farms there.” The measures will be combined with ecological focus areas—sections of fields that are not treated with fertilizers or crop protection products, for instance. These will be obligatory for all EU farmers starting in 2015. “We want to work with farmers to investigate how to best set up flowered areas and, possibly, other measures in order to achieve the most promising results,” says Giesen-Druse.
Oppermann is especially happy about this: “It’s an important step, and the right one,” he says. “After all, for the measures to be implemented, they must be convincing and produce results.”
More Space for Nature
Europe’s Common Agricultural Policy aims to narrow the gap between agriculture and nature. Ecological focus areas are among the measures designed to do this. These will apply starting in 2015. One example will require farmers to keep sections of land between fields free from crop protection products and fertilizers. The areas could take any number of forms. They might be strips of land where flowers are allowed to grow, fallow land, or wooded sections planted with trees and bushes. Farmers who own over 15 hectares of agricultural land will have to dedicate 5 percent of it to ecological focus areas.