His decision came as an investigation into sexual harassment allegations against him was ongoing.
The inclusion of soil nutrient fluxes is critical for more-accurately assessing the societal value of ethanol biofuel vs. corn feed.
June 30, 2017|
PIXABAY, KIRAHOFFMANNIn the search for ways to diminish human impact on the earth by reducing emissions and promoting sustainable resources, researchers and engineers have introduced alternative energy sources such as biofuels, or fuel created from plant matter. The demand for biofuel from corn competes with the supply of corn for food. This requires us to assess the energy efficiency and actual environmental impacts of using corn for biofuel as compared to feed or other secondary food sources such as cornstarch or corn meal.
In our recent study in Earth’s Future, we use a life cycle assessment method to account for all processes in the production of corn feed and corn-based ethanol. This method computes the energy from all processes first, and then finds the associated environmental impacts. Using a life cycle assessment to compare the energy efficiency of biofuel production is not new. However, our environmental assessment is unique in quantifying soil nutrient fluxes, in addition to greenhouse gases, in terms of U.S. dollars.
We are part of a greater network of scientists studying the Critical Zone, the permeable layer of the earth’s surface from the top of the tree canopy to the bottom of the groundwater table, in which most terrestrial organisms interact with the Earth. We quantify Critical Zone services, that is, the value of functions that support and sustain life. Critical Zone services pertaining to specific products or processes are measured by the affected changes in the Critical Zone’s ability to perform such functions. We account for costs and benefits for energy used and the environmental impact both upstream and downstream of agriculture production. This includes fertilizer, herbicide and insecticide production, machinery, labor, and direct energy used on the field. It also includes nitrate leaching, carbon storage in the soil, and carbon dioxide and nitrous oxide escaping into the atmosphere.
The services relevant to ethanol and corn feed production are atmospheric stabilization that considers related greenhouse gas emission, water quality—particularly, nitrate leaching out of the soil—and primary productivity, in our case, corn. Each of these categories was quantified monetarily.
We incorporated models to track the flow of carbon and nitrogen throughout the soil system of a cornfield. The change in services (a.k.a. environmental impacts) due to the flow of nutrients in the soil consisted of almost 80 percent of the total amount for the production system. This means that the soil is an extremely important factor of environmental impacts of both agriculture and biofuel. Critical Zone services include both emissions to the atmosphere and impact on the landscape and water bodies.
After harvest, the corn can either be sold for consumption or for conversion into ethanol. At this point the corn has a value, taken as the price of the corn. This value, representing the society’s current value of the crop based on consumers’ willingness to pay, more than makes up for the costs of emissions and water quality impacts during the agricultural phase, we find. However, once the corn is converted into ethanol, this value is lost and additional emissions associated with ethanol production in the refinery are added. After the grain has been converted into ethanol, the new value of the product is taken as the fossil fuel emissions avoided by using ethanol instead of conventional gasoline. This value does not make up for the total cost of emissions and water quality impacts associated with the ethanol’s entire production cycle.
Our research presents values of the net benefits for the U.S. as, on average, $1,492 and -$10 per hectare of corn used for feed and energy, respectively. These values do not include the soil fluxes, which make up almost 80 percent of the total environmental cost from production. Alternatively, the benefits of a hectare of corn production turn out to be $1,098 and -$942 for corn feed and ethanol, respectively, when we include the soil nutrient fluxes modeled through the soil system and provide a more-accurate account of the environmental impacts due to the agricultural phase of production.
For this research, when we are talking about costs, we are referring to the estimated costs of environmental benefits or impacts rather than physical production costs. We find that the net benefits derived from producing corn for food are much larger than producing corn for biofuel. This is because the perceived benefit we derive from corn for food is greater than that for biofuel, meaning that the cost we are willing to pay for corn for food is much larger than the estimated cost of emissions from conventional gasoline, which are avoided when biofuel is used for transportation.
This study does not advocate for one use of corn over another. Rather, it provides information of the net energy and services derived from each intended use. Based on our findings, we aim for scientists and the public to be more aware of the role of soil when conducting environmental studies and for the public to understand that what seems “greener” may not always be the case.
Meredith Richardson is a PhD student and Praveen Kumar a professor in the Department of Civil and Environmental Engineering at the University of Illinois, Urbana-Champaign. The study was funded by the National Science Foundation.
July 3, 2017
There seems to be a large gap in this study. Corn used in ethanol production is not removed from animal feed. Only the carbohydrate portion is used. The resulting feed product is much higher in protien, and takes one third the energy to deliver to the feed market compared with the original feed corn. If that was missed, as this brief article seems to indicate, then other parts of the equation are probably incorrect as well. Modern ethanol production requires less water, uses far less energy, and is far more efficient in yield. A recent USDA study can provide some dated information. Most ethanol production also includes capture of a portion of the corn oil, which is either used as livestock feed (primarily poultry) or feedstock for the production of biodiesel.
July 3, 2017
I have always wondered how the emission of a pound of carbon dioxide for pound of ethanol fermented was ever deemed justifiable. Then you have to include the energy involved in distillation and drying of the product, mixing, analysis and transport to destinations. This whole thing seems to be deeply involved in polical crony-ism. It reminds me of the farmland reserve program which was nothing more than an occult form of welfare for the very rich who were paid federal dollars not to grow on viable farmland. Do the other savings (if they are such) balance out the environmental negatives? Leftover retrieval takes energy also.
Algal oil production was proposed in a viable manner years ago that could produce an estimated 10,000 gallons or more of oil per acre, far more than corn fuel. Such systems, since they can be adapted to enclosed systems, could produce pre-refined fuels for various uses. They could also be coupled with water containing farm runoff, etc. to feed the algae and in the process purify the water systems and the product could even conceivably be used to produce hydrogen while feeding back the resultant carbon dioxide into the system and producing cattle feed with the leftovers, or composting them for farm use.
July 3, 2017
One bushel of corn is no longer 54 Lb but 52 Lb. The difference is the decreased uptake of minerals that are blocked by glyphosate A.K.A RoundUp that is sprayed on genetically modified corn (GMO-corn) that is "RoundUp Ready"
What glyphosate does is, among other things, block the uptake of minerals when the corn is sprayed two weeks before harvest for the corn to "ripe" prematurely.
The glyphosate also mimics the amino acid glycin in the production of proteins in the bodt and creates havoc in the body when enzymed containing glyphosate instead of glycin. The glyphosate containing enzymes are misformed and thus nonfunctional giving rise to many diseases due to malfunktioning enzymes. When too many enzyme molecules are nonfunctioning the person dies.
So please include the cost of glyphosate, insecticides in your calculations and also the amount of minerals taken off every field with the crop.
Remember that it took several thousand years for the cattle including buffalos to make the 2 m layer of soil on the prairies of North America. Now farming with crops and wind has removed about a meter of soil in a hundred years.
July 3, 2017
Corn oil is containing too much omega-6 polyunsaturated fat to be used for feed as the livestock is having too much inflammation driving omega-6 för human (and animal!) consumption.
so the corn oil is just good for biodiesel. But diesel engines are producing too much nitrous gasses and too much nano particles to be healthy.
Conclusion: Corn is not a viable crop for the survival of the Earth.
July 5, 2017
The entire premise of this study is flawed. Garbage in, garbage out. The authors suggest that there are different corn production practices and different environmental impacts based on the different end uses of the corn. In other words, they say corn that is ultimately used for ethanol is produced using more energy intensive and more disruptive practices than corn that is used for "food." That's utterly ridiculous for several reasons. 1) Farmers don't grow corn for ethanol or for livestock feed or for exports; they grow corn for the MARKET, and it is the marketplace that ultiamtely allocates how and where corn is used. Corn production practices are the same regardless of the end use. 2) The corn used for ethanol is NOT edible by humans. It isn't sweet corn. There is no direct competition for corn for "food or fuel." Yes, a fair amount of corn ultiamtely becomes food, but only after it is fed to livestock and poultry, or processed by a mill into chips, sweetener, cereals, etc. 3) As Urged points out, the feed value of the corn that IS processed by ethanol plants is maintained because ethanol uses only the starch; the protein, fiber, and other nutrients from the corn kernel end up in "distillers grains" that are sold by ethanol plants to livestock and poultry feeders around the world. 4) If ethanol was really causing a "food or fuel" conundrum, we'd see that relfected in corn prices. But the truth is, corn prices today are LOWER than they were when Congress passed the bill esablishing the renewable fuel blending requirements.
"The Scientist" should be a little more discerning in what opinion pieces it chooses to publish...otherwise you'll soon be called "The Junk Scientist."
July 5, 2017
Uh, Bjorn, you are mistaken. At least half of the corn oil produced by ethanol plants is going into the feed industry, mostly into poultry rations. Just ask Tyson or Perdue or anyone else producing poultry. Tyson is on record saying: "Corn oil is an excellent source of energy in livestock and poultry diets."
July 6, 2017
I understand the poultry producers as corn is cheap feed for producers. The imflammation takes time, longer than the life before slaughter. So you don't see any inflammation.
But thatt feed is bad for us predators eating those corn fed poultry. We eat those omega-6 fats and more than 20 grams per day gives e.g. increased risk for breast cancer according to reserach published in 2002.
And Purdue does not give the poultry anything but vegetables which means they might be deficient in some essentials amino acids
July 31, 2017
That was missed in this study. It assumes that the entire kernal is used for ethanol. I read the actual paper and wrote the authors emails requesting information as to why this was excluded from the study and got not response. In my mind. Also, it makes no sense that the CZ should be affected dependant upon what happens to a product after it is grown. Whether it is grown for food or for industiral uses the impact of its growth on the CZ is the same.
July 31, 2017
I'm not sure where you're getting your numbers, but the test weight of a bushel of corn is more depent upon the growing season than anything. Just two years ago we had corn that was 58 lbs per bushel. And that corn was Round up Ready. But most of that test weight is determined by the weather in the corn belt during kernal fill, after it has been pollinated.