Stories tagged agriculture

Large scale study shows 540% net energy gain when ethanol is produced from switchgrass

Panicum Vergatum: Switchgrass
Courtesy U S Govt
Kenneth Vogel, a geneticist with the U.S. Department of Agriculture in Lincoln, Nebraska, and his colleagues, found that ethanol produced from switchgrass yields 540% of the energy used to grow, harvest, and process it into ethanol.

Their results, published online in Proceedings of the National Academy of Sciences, shows that switchgrass, farmed using conventional agricultural practices on less-than-prime cropland yields only slightly less ethanol per hectare on average than corn.

Farmers planted switchgrass on 10 farms, each of which was between 3 and 9 hectares. They then tracked the inputs they used--diesel for farm equipment and transporting the harvested grasses, for example--as well as the amount of grass they raised over a 5-year period. ScienceNOW Daily News

Switchgrass monoculture or mixed prairie grasses?

Anyone remember our Buzz post "Chalk one up for diversity"? David Tilman in that post is quoted saying, "diverse prairie grasslands are 240 percent more productive than grasslands with a single prairie species"
Now I read:

... Vogel says, is that yields on farms using fertilizer and other inputs, such as herbicides and diesel fuel for farm machinery, were as much as six times higher than yields on farms that used little or no fertilizer, herbicides, or other inputs to grow a mixture of native prairie grasses. ScienceNOW Daily News

Who is right? Can anyone explain why two reputable researchers are getting such different results?

Tags : energy, ethanol, David Tilman, greenhouse gas, biomass, agriculture, switchgrass, bioenergy, biomass energy, cellulosic, Ken Vogel, PNAS, Panicum virgatum

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Bye, bye bees?: The mysterious disappearance of large portions of honey bee populations in 22 states have scientists trying to figure out where they're going. (Photo courtesy BugMan50)It’s not a very good time to be a honey bee.

Beekeepers in 22 states across the country have reported huge disappearances of their bees. And it’s a total mystery as to where they’ve gone.

I saw a report about this on the CBS Evening News a few weeks ago and have since seen more press accounts of the situation. And no one seems to know what’s really going on.

"Colonies are going down. The bees aren't dead in the box or aren't out front," said Jerry Bromenshenk, a bee researcher at the University of Montana in the CBS report. "They've just disappeared. Just vanished."

While parasites and disease have depleted bee populations in the past, there were traces of the dead bees left behind for scientists to analyze and figure out what’s happened. In these cases, huge numbers of bees kept by beekeepers, hundreds of hives and thousands of bees, within just a few days.

The loss of so many bees could have a huge impact on our human food chain. One of every three food items we chuck into our mouths each day is the direct result of the work of honey bees.

They’re hard work of popping from flower to flower pollinates the plants that give us vegetables and fruits we eat each day. Without the bees, and that pollinating action, those plants won’t bear their fruits.

Star-Tribune columnist Nick Coleman looked a the situation a couple days ago. Talking to a researcher at the University of Minnesota, he discovered that some of our large-scale agricultural practices may be “burning out” bees on their vital work.

Dr. Marla Spivak says that monoculture farming – the practice of planting one time of crop in a huge field for years and years – has led to a reduction in the amount of honey a bee colony produces. Over the past few years, that average has dipped from 100 pounds a year to 80.

On top of that, he points to the large-scale commercial beekeeping colonies where bees are trucked around the country to do pollination work around the country. They’re maybe being stretched too far in their work.
Also, the problems don’t seem to be impacting hobby beekeepers here in Minnesota. I didn’t know it, but Minnesota is one of the top five honey-producing states in the country, and the vast majority of those bees are tended by amateur keepers.

Tags : insects, honeybee, beekeeping, agriculture, bees

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It's time for the annual wild rice harvest.

The traditional harvesting technique requires one person to pole a canoe and one or two other people to gather grain. They beat the stalks with paddles, sweeping about half the rice into the boat. The rest of the grain falls to the bottom of the lake, where it sprouts the next spring.

But wild rice in Minnesota is threatened in many ways, and many lakes have produced a poor crop.

Wild rice, or Zizania palustris, is actually an aquatic grass. To grow, it needs shallow water and a mucky bottom. Drainage and damming of wetlands or lakes for farming or reservoirs have destroyed wild rice habitat. (Wild rice once grew throughout Minnesota and the eastern United States. In Minnesota alone, there are 70 Rice Lakes and 25 other lakes with "Rice" in their names, even though wild rice may no longer grow there.) And runoff of herbicides and nutrients from farm fields kills rice, too.

Fluctuating water levels are tough on the plants. When wild rice sprouts in the spring, a tiny root anchors the seed in place. When the stalk reaches the surface, long leaves form, floating on the surface of the water. If the water level rises, the weakly rooted stalk is pulled up and the plant dies. If the water level drops, the weak stalk collapses, killing the plant.

Carp often kill wild rice seedlings. They're bottom-feeders, digging up and disturbing young plants as the fish search for food. (These fish are not native.)

But there's another threat: for decades, the University of Minnesota has been researching wild rice, aiding in the development of 25,000 acres of machine-harvested, cultivated paddy rice in Minnesota. See, the seed head of the wild grain shatters easily. That allows the plant to seed itself, but makes it tough to farm commercially. Many fear it's just a matter of time until scientists genetically modify the wild rice genome, and contamination by genetically modified rice might decrease the economic and cultural value of the wild grain.

"We consider the wild rice to be a sacred gift from the Creator and it's always been here for us. Now, if the rice is altered genetically, it may be a strain that will take over the wild rice, and we will lose what was given to us by the Creator."

(Not everyone agrees that the genetic research is a problem.)

Bills banning genetically modified wild rice in Minnesota (supported by White Earth Band members) didn't make it through the last legislative session, but will be reintroduced next year.

But here's the good news. At Lower Rice Lake on the White Earth Indian Reservation (north of Detroit Lakes), where lakefront development is prohibited and the White Earth Land Recovery Project manages the watershed, 200 people participate in the traditional harvest, gathering 11,000 to 15,000 pounds of rice a day, or 200,000 to 300,000 pounds each year. The rice is processed locally and sells for about $8.50 a pound. The grain itself feeds many White Earth families, and the proceeds from the rice harvest are a significant chunk of the annual income of many families.

Tags : phenology, rice, White Earth Indian Reservation, agriculture, restoration, wild rice, food

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