Fueling our Future with Weeds

Instead of using beneficial crops to produce biofuel, Steven Apfelbaum, ecologist at Applied Ecological Services, suggests using invasive weeds as a biofuel alternative.

| October 8, 2010

Russian olive tree

Russian olive trees are an invasive "weed."

iStockPhoto/Donald Erickson

Looking down from an airplane window on a flight from San Jose to Minneapolis, I took note of the very large numbers of tamarisk and Russian olive trees growing along a river in Utah. I’ve seen the same weedy plants up close while flying low in a small plane, and while driving dusty back roads and hiking.

These fast-growing, aggressive invasive species, once colonized, wreak havoc on native, soil-stabilizing grasses, sedges, and wildflowers. By weeds, I don’t mean just dandelions. Think European buckthorn, Russian olive tree, Tree of Heaven (not really very heavenly), and so many other invasive plants. They form dense thickets and stands, and beneath these, produce eroding, nearly bare soils.

The problem is serious, both in ecological and economic terms. For Western cattle ranchers, this colonization reduces their economic returns by curtailing the growth of natural grasses. In the corn belt, these same plants colonize ditch and stream banks, increasing erosion and the flooding of crops. The resulting erosion washes additional sediments and fertilizers into rivers, lakes, wetlands and coastal estuaries, creating algae blooms and dead zones.

But there’s a silver lining in the billions of tons of weedy plants that have colonized our farmlands, ranchlands, floodplain and even urban yards.

Many of these weeds are potentially good sources of biofuel. Biofuel doesn’t have to come from valuable farmland and compete with crop production for feeding our nation and the world. It doesn’t have to come from prime agricultural lands now being used to grow corn to produce biofuels such as ethanol. There are important co-benefits to using weeds, as well: by removing them for biofuel use and replacing them with native species, we can reduce flooding and improve soils, which sequester carbon, mitigating global warming.

The answer to our question appears to be yes. In many locations where dense growths of invasive species are found, it is economically feasible to harvest, process and transport the materials to power plants. In locations where these other conditions can’t be met, the answer can still be yes — with the help of landowners, landscapers and eco-restoration firms.

erich j. knight
10/17/2010 9:16:58 PM

Recent NATURE STUDY; Sustainable bio char to mitigate global climate change http://www.nature.com/ncomms/journal/v1/n5/full/ncomms1053.html Not talked about in this otherwise comprehensive study are the climate and whole ecological implications of new , higher value, applications of chars. First, the in situ remediation of a vast variety of toxic agents in soils and sediments. Biochar Sorption of Contaminants; http://www.biorenew.iastate.edu/events/biochar2010/conference-agenda/agenda-overview/breakout-session-5/agriculture-forestry-soil-science-and-environment.html Dr. Lima's work; Specialized Characterization Methods for Biochar http://www.biorenew.iastate.edu/events/biochar2010/conference-agenda/agenda-overview/breakout-session-4/production-and-characterization.html And at USDA; The Ultimate Trash To Treasure: *ARS Research Turns Poultry Waste into Toxin-grabbing Char http://www.ars.usda.gov/IS/AR/archive/jul05/char0705.htm Second, the uses as a feed ration for livestock to reduce GHG emissions and increase disease resistance. Third, Recent work by C. Steiner showing a 52% reduction of NH3 loss when char is used as a composting accelerator. This will have profound value added consequences for the commercial composting industry by reduction of their GHG emissions and the sale of compost as a nitrogen fertilizer. Since we have filled the air , filling the seas to full, Soil is the Only Beneficial place left.

kathleen meyer
10/17/2010 10:55:47 AM

In defense of the russian olive trees, and some noxious weeds (mans definition). I would remind us that they provide habitat, and food for many birds, bees, honey bees especially(very critical). Whenever man tries to overdue something, we make it worse. I live in Idaho and grew up on a cattle ranch on Silver Creek. Human activity has changed the area for the worse. I remember my dad planting russian olive trees purposely for a wind break.

erich j. knight
10/16/2010 11:31:52 AM

Dear Abbey, Modern reactors are closed-Loop with no significant emissions, small scale pyrolitic cook stoves emit no incomplete products of combustion. Several hundred peer reviewed studies! "Plants get all of the Carbon they need from air" Absolutely! the beauty is that microbes can't eat char, but love to live in it. Agriculture allowed our cultural accent and Agriculture will now prevent our descent. Wise Land management; Organic farming and afforestation can build back our soil carbon, Biochar allows the soil food web to build much more recalcitrant organic carbon, ( living biomass & Glomalins) in addition to the carbon in the biochar. Every 1 ton of Biomass yields 1/3 ton Charcoal for soil Sequestration (= to 1 Ton CO2e) + Bio-Gas & Bio-oil fuels = to 1MWh exported electricity, so is a totally virtuous, carbon negative energy cycle. Biochar viewed as soil Infrastructure; The old saw; "Feed the Soil Not the Plants" becomes; "Feed, Cloth and House the Soil, utilities included !". Water,nutrients & Internet comunication via Fungi Networks Free Carbon Condominiums with carboxyl group fats in the pantry and hydroxyl alcohol in the mini bar Build it and the Wee-Beasties will come Microbes like to sit down when they eat By setting this table we expand husbandry to whole new orders & Kingdoms of life. Since we have filled the air , filling the seas to full, Soil is the Only Beneficial place left. Carbon to the Soil, the only ubiquitous and economic place to put it

10/16/2010 8:49:20 AM

I have investigated hemp as a means in which to arrest corrosion also has over 25,000 uses, requires no herbicide or pesticide and Canada is in the process of economic recovery due to hemp production. the reason that hemp is on the schedule 1 list is because dupont and monsanto consider it a threat to their bottom line. these big corporations continue to pollute land and sea, pushing their rape and pillage agenda unabated. killing our host like the cancer. when is enough, enough? !!! Let us make a different choice. today?

w. a. mackay
10/15/2010 11:15:58 PM

In Willamette Valey and elsewhere, we have more than an abundance of scotchbroom. lets make that into biofuels.

john duffy_3
10/15/2010 9:06:26 PM

I nominate the multiflora rose bushes in Indiana as a test fuel. These buggers redefine prolific.

abbey bend
10/15/2010 10:20:51 AM

When you look at the expense of attempting to take weeds and turn them into ethanol versus the calories of energy you can get out, this makes no sense! The problems with converting cellulose to ethanol fuel have not been figured out yet and do not get me started about bio-char. Making charcoal is not an environmentally friendly thing to do, has not been, see no reason the think it will be in the future. Has not been proven in any manner that would be called scientific. Plants get all of the Carbon they need out of the atmosphere, not through their roots. The idea of removing invasive plants from large areas is a good one, but it is extremely expensive to do and I would love to see some real numbers about the calories of energy involved to harvest, convert and replant an area before I get too excited about this idea.

cate anderson
10/15/2010 9:05:30 AM

This sounds like a viable option and I am very interested in the results of your investigation. The main point that you fail to make obvious is how these weeds are to be made into fuel. I assume you mean to be burnt? In which case my first reaction is, the heat they produce won't be worth the effort of harvest. I believe most of the weeds listed tend to be fast growing soft woods, which do not to burn hot. Again this is just a first impression and could be wrong. I await the report from your investigation. I hope I am wrong.

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