A question about growing switchgrass for ethanol on "marginal land".

[GliderGuider]

I understand the attractions of switchgrass as a fuel crop - low fertilizer requirements and the ability to grow it on marginal land that's not being used for food crops. My question is, "Isn't one of the reasons land is considered marginal that it's hard to run mechanical harvesting equipment over it?"

I have visions of ten million hectares of switchgrass being harvested by men on foot with scythes...

[mqbush]

1. marginal land

You don't have to grow all of it on marginal land.
Marginal land includes flat land that doesn't have much fertile loam, but is fine for switchgrass.

[cloudythescribbler]

2. I guess it boils down to a cost/benefit analysis ...

with of course the old chestnut problem of how do you get the benefit to society/humanity as a WHOLE to be reflected in reality, rather than just capitalist/market dynamics....

[XemaSab]

3. Marginal lands are often used for grazing

Depends on which crop brings in more scrilla, I suppose. :shrug:

[OKIsItJustMe]

4. "Marginal Land"

http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0036949.html

Marginal Land

In farming, poor-quality land that is likely to yield a poor return. It is the last land to be brought into production and the first land to be abandoned. Examples are desert fringes in Africa and mountain areas in the UK.

[malakai2]

5. Some is also land that is difficult to harvest

As suggested in the OP, or perhaps to put it a bit more clearly, land on which the cost of growing and harvesting the crop approach the market return.

I'm concerned that although some land in the united states certainly does fall under the "difficult to plow" category, such as the Flint Hills in Kansas, the Sandhills in Nebraska, and the Missouri Coteau in the Dakotas, much of what is classified as "marginal" is the sort of stuff between the Rockies and the mixed grass prairie. Go ahead and harvest the bulk of the aboveground biomass from those systems, but be sure not to excrete any of those nutrients back onto the landscape. See what happens after a few years. "Marginal" farmland (i.e., places where intensive agriculture is a poor fit) will give way to totally unproductive wasteland.

[OKIsItJustMe]

6. Any agricultural land can be mismanaged

My (maternal) grandfather was a farmer. He practiced "crop rotation" back when it was a revolutionary new idea. He planted clover in the fields to regenerate them. Switchgrass can be used in a similar fashion.

http://www.ag.auburn.edu/aaes/communications/highlights/spring96/rotations.htm

...

Advocates of sustainable agriculture propose the incorporation of forage grasses in cropping patterns since this often results in reduced chemical use and soil erosion, which help reduce water quality degradation. Switchgrass, a native warm season forage grass, can be found from the U.S.Canadian border to South Florida and Texas. This grass has low fertilizer requirements, is widely adapted to different soil types, has soil conservation properties, a deep root system, and provides an excellent wildlife habitat. Switchgrass may be a good rotation crop in peanut fields to reduce the infestation of nematodes and diseases, such as southern stem rot and cercospora leaf spot. If switchgrass is adopted in a peanut rotation system it may create a cropping system that reduces a farmer's dependence on chemicals.

...

[malakai2]

9. But there are some big issues there

If legume crops like peanuts and soybeans in productive landscapes (the OP was about marginal lands) make farmers a lot of money, why would they bother with the expense and time required to establish a grass crop? Native grass seed is expensive, native forb seed more expensive, and good emergent growth can be two or three years down the road. Cutting the grass down when the sugar storage in the stems is highest means removing any wildlife habitat it creates. Years of zapping the soil with all manner of pesticides and fertilizers intended to grow monocultures of target crops can so alter the microflora and microfauna of the soil as to render it difficult to convert to native plants without much amendment.

I think all that pretty much limits this to areas currently used for dryland crops or cattle ranching, because that's the only place I see that would fit the definition of marginal and maybe offer the chance for landowners to break even. Of course, those farmers wouldn't be growing legumes, so unless the mix they planted included native legumes, after a few seasons of harvest their marginal agricultural land would become poor agricultural land.

I really don't see how this will work.

[OKIsItJustMe]

11. My point (different from the OP)

Was that crop rotation is a good thing (as I'm sure you would agree) and that switchgrass is actually a good candidate for rebuilding topsoil.

So, convincing peanut farmers (for example) to rotate their fields between peanuts and switchgrass might actually result in ecological benefits.

[Fledermaus]

7. Highly diverse mixtures of native prairie plant species have emerged as a leader in the quest

Recent research has proven that fields that have gone wild and have many types of grasses are more productive than a monoculture of switch grass.

Literally, doing nothing is the most productive way to produce biomass from grasses

A new study led by David Tilman, Regents Professor of Ecology in the University of Minnesota's College of Biological Sciences, shows that mixtures of native perennial grasses and other flowering plants provide more usable energy per acre than corn grain ethanol or soybean biodiesel and are far better for the environment.

"Biofuels made from high-diversity mixtures of prairie plants can reduce global warming by removing carbon dioxide from the atmosphere. Even when grown on infertile soils, they can provide a substantial portion of global energy needs, and leave fertile land for food production," Tilman said.

The findings are published in the Dec. 8 issue of the journal Science and featured on the cover.

Based on 10 years of research at Cedar Creek Natural History Area, the study shows that degraded agricultural land planted with highly diverse mixtures of prairie grasses and other flowering plants produces 238 percent more bioenergy on average, than the same land planted with various single prairie plant species, including monocultures of switchgrass.



http://www.sciencedaily.com/releases/2006/12/061207161136.htm

[GliderGuider]

12. OK, you can grow it.

How economic is the harvesting process?

[losthills]

8. "Marginal Land....."

would be land that hasn't already been developed because it's steep, arid, rocky, inaccessable or all four. Also some of the last land that still has wildlife and native plants.

[NNadir]

10. This reminds me of the "cover Arizona with solar cells" theory of the universe.

One man or woman's "desert" is another man or woman's "ecosystem."

In any case, switchgrass, which has been the topic of many thousands of threads on this website in the last 5 or 6 years, has thus far proved unable to produce one afternoon's worth of a traffic jam in LA.

It's all just another car culture fantasy and I wouldn't spent more than 5 minutes worrying about the big switchgrass harvest for GM's ethanol Hummer or Ferrari's ethanol sports car.

If you really believe in switchgrass, you can always invest in Iogen. Last I looked, the company wasn't causing a crash in ethanol prices because of its huge suppy.

[phantom power]

13. What NNadir said.