Food and fuel: A model for bioenergy feedstock/vegetable double-cropping systems

[OKIsItJustMe]

http://news.aces.illinois.edu/news/food-and-fuel-model-bioenergy-feedstockvegetable-double-cropping-systems

[font face=Serif][font size=5]Food and fuel: A model for bioenergy feedstock/vegetable double-cropping systems[/font]

Published May 7, 2015

[font size=3] URBANA, Ill. – Much attention has been given to dedicated, perennial bioenergy crops to meet the revised Renewable Fuel Standard mandating production of 36 billion gallons of biofuel by the year 2022. Even so, concern remains over the impending need to convert as much as 30 million acres of U.S. crop land, which would include food crops, to land for perennial energy crops in order to meet that demand.

Researchers realize that biomass feedstocks will need to come from many different sources, including crop residues, forest residues, and municipal waste, for example, said Marty Williams, a University of Illinois crop scientist and ecologist with the USDA-Agricultural Research Service. The use of double-cropping systems—a winter annual biomass crop is grown then harvested in the spring, followed by a summer annual crop—has been suggested as an additional option.

...

Interestingly, the researchers saw pumpkin yields in the double-cropping system were comparable to conventional pumpkin production. However, the biomass feedstock also yielded an average of 4.4 tons per acre of dry biomass prior to pumpkin planting. “We saw a theoretical yield of 349 gallons of ethanol per acre, and a higher farm gate value than typical pumpkin production,” Williams said.

“It looks promising,” he added. “The biomass yield wasn’t as high as something like Miscanthus, but we’re producing feedstock and not taking land away from food production. Moreover, the cropping systems were not optimized, such as for soil fertility, so our economic estimates are likely conservative.”

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[Sherman A1]

1. Interesting

Thanks for posting.

[OKIsItJustMe]

2. You’re welcome! (no text)

[mackdaddy]

3. When all of the biomass is removed from the field,

How much is the fields soil depleted of nutrients?

[quadrature]

4. trace nutrients do not show-up in the ethanol,

and can be returned to the field.

[NickB79]

5. And the macronutrients are primarily returned via synthetic (ie fossil-fuel-derived) fertilizers

Just like the rest of our unsustainable industrial farming industry.

Keep removing the biomass, and trying to maintain soil fertility with mostly synthetic fertilizers, and eventually you'll end up with sand and gravel once the humus is destroyed.

Think soils of the Mediterranean, eroded and rocky and good for only olive groves and goat grazing. They used to be rich, deep wheat fields in Roman days.

[kristopher]

6. This study is related to first paragraph of OP

Cropland expansion outpaces agricultural and biofuel policies in the United States

Cultivation of corn and soybeans in the United States reached record high levels following the biofuels boom of the late 2000s. Debate exists about whether the expansion of these crops caused conversion of grasslands and other carbon-rich ecosystems to cropland or instead replaced other crops on existing agricultural land. We tracked crop-specific expansion pathways across the conterminous US and identified the types, amount, and locations of all land converted to and from cropland, 2008?2012. We found that crop expansion resulted in substantial transformation of the landscape, including conversion of long-term unimproved grasslands and land that had not been previously used for agriculture (cropland or pasture) dating back to at least the early 1970s. Corn was the most common crop planted directly on new land, as well as the largest indirect contributor to change through its displacement of other crops. Cropland expansion occurred most rapidly on land that is less suitable for cultivation, raising concerns about adverse environmental and economic costs of conversion. Our results reveal opportunities to increase the efficacy of current federal policy conservation measures by modifying coverage of the 2014 US Farm Bill Sodsaver provision and improving enforcement of the US Renewable Fuels Standard.

Open Access http://iopscience.iop.org/1748-9326/10/4/044003

There could be a stronger motive for the double cropping if Romm is reading the cards correctly. His take is here:
Is Corn Ethanol Breaking The Law?
BY JOE ROMM
http://thinkprogress.org/climate/2015/05/07/3654392/corn-ethanol-illegal/