The earlier post Twirling Ethanol claimed that:

When you decode the buzz words - bio-fuel, bio-mass, oil-free, foreign oil, etc. - you end up with proposals to revert to an earlier time in history when plants and dung were all the fuel we had. Food was scarce enough that gloomy predictions of impending doom were made while beasts of burden consumed large quantities of crops. For a few decades food production increased greatly while at the same time beasts of burden were replaced by fossil fueled engines. It desn't seem to make sense to have our engines replace beasts as competitors for food even if our technologies are very much more advanced than they were in the past since there are also lots more of us.

So how much stuff did those draft animals eat? [via Knowledge Problem]

At the turn of the last century, America's transportation system was fueled by biomass: 30 million horses and mules, give or take a few million, pulled buggies, hauled wagons, dragged plows. According to Ken Vogel, a U.S. Department of Agriculture forage geneticist helping develop and test switchgrass for the BFDP, replacing animal power with machine power freed up 80 million acres of U.S. land—land that had been used to grow grass and other feed for these millions of animals.

One of the anecdotes often told among grass farmers is about the farms of Ohio that literally shipped thier soil, as hay and oats etc., down the Erie canal to New York. While the streets of New York grew knee deep in dung, the farms of Ohio strip mined a foot of their topsoil. Farmers that didn't enter the commodity trade, who ran general farms with livestock as well as crops, and only shipped out higher value produce, meat and dairy prodcuts, kept their soil. The difference is stark when you stand at the fence line and gaze down into the fields a foot below on the farm across the fence.

Why would we want to return to that?

Annual cultivation of many agricultural crops depletes the soil's organic matter, steadily reducing fertility. But switchgrass adds organic matter—the plants extend nearly as far below ground as above. And with its network of stems and roots, switchgrass holds onto soil even in winter to prevent erosion.

Besides helping slow runoff and anchor soil, switchgrass can also filter runoff from fields planted with traditional row crops. Buffer strips of switchgrass, planted along streambanks and around wetlands, could remove soil particles, pesticides, and fertilizer residues from surface water before it reaches groundwater or streams—and could also provide energy.

And because switchgrass removes carbon dioxide (CO2 ) from the air as it grows, it has the potential to slow the buildup of this greenhouse gas in Earth's atmosphere. Unlike fossil fuels, which simply release more and more of the CO2 that's been in geologic storage for millions of years, energy crops of switchgrass "recycle" CO2 over and over again, with each year's cycle of growth and use. . .

Now, at the dawn of the next century, the wheel could begin to turn full circle. On millions of acres of farm land not needed for food crops, fast-growing energy crops of switchgrass—harvested and converted efficiently to clean-burning, affordable ethanol, methanol, or diesel—could once again supply vast amounts of horsepower.

In short, biomass could bring back a 21st-century version of the prairie. And along with the prairie, it could bring a new crop to America's farms, a boost to U.S. energy independence, and brighter prospects for a clean, sustainable future. According to BFDP and its research partners across the country, that's a future worth cultivating.

A better 21st-century version of the prairie would grow more palatable, digestible and nutritious deep rooted perennial grasses than panic grass, and graze livestock on it. It would have all the environmental benefits, including increased biodiversity, unlike panic grass swards that are mono-cultures, and produce more healthful foods as well.

A great deal of the land in cultivation produces field corn for livestock feed. The hogs and chickens need such grain but cattle, sheep and goats don't. They are ruminants and do just fine on grass and weeds. Good grass and nutritious weeds are best of course. If the "millions of acres of farm land not needed for food crops" cited by the gov, and the millions of acres of farm land used for field corn were all converted to permanent pastures we would have all the environmental benefits of the prairie, including soil improvement and GHG sequestration, a slightly brighter planetary albedo to reflect more sunlight away to space, more healthful and nutritious food high in omega-3 fatty acids that promote heart and brain health as well as reducing some of inflamatory diseases of aging joints, less soil erosion, less chemical pollution and better water management.

We need better energy sources than fossil fuels. They did their job in an earlier era but enough is enough. But we need more energy - lots more energy - to continue development, and lots more food - over twice as much world wide. Other parts of the world have the same needs, but more so since they are at a lower level of development now, and have faster growing populations. Using biomass for energy won't get us there. It's a Luddite fantasy about the good old days that ignores the need for huge increases in both energy and food needed in the near future.

Nuclear, solar, gravitational (tides) and even wind (a special case of solar) are better sources of energy than biomass. There are a few cases, such as wood slash from forest clean-up or high oil algae grown in waste treatment ponds, where biological sources of chemicals for energy conversion make sense. But the idea doesn't scale up to provide an energy answer for the world.