A new review in the Agronomy Journal suggests that crop residue removal from corn, wheat, and grain sorghum may not be the most earth-friendly source of biomass for cellulosic ethanol production.
The review found that removal of more than 50% of crop residue can have negative consequences on soil structure, reduce soil organic carbon sequestration, increase water erosion, and reduce nutrient cycling and crop production, particularly in erodible and sloping soils.
While most research is focused on the conversion of cellulosic feeedstocks into ethanol and increasing production of biomass, the impacts of growing energy crops and the removal of crop residue on soil and environmental quality have received less attention.
"Crop residue removal can make no-till soils a source rather than a sink of atmospheric carbon," says Kansas State University researcher Humberto Blanco, even at rates less than 50%.
Residue removal at rates of less than 25% can cause loss of sediment in runoff relative to soils without residue removal. To avoid the negative impacts on soil, perhaps only a small fraction of residue might be available for removal. This small amount of crop residues is not economically feasible nor logistically possible.
An alternative to crop residue removal is growing warm season grasses and short-rotation woody crops as dedicated energy crops. These crops can provide a wide of range of ecosystems services over crop residue removal. Available data indicate that herbaceous and woody plants can improve soil characteristics, reduce soil water and wind erosion, filter pollutants in runoff, sequester soil organic carbon, reduce net emissions of greenhouse gases, and improve wildlife habitat and diversity.
Whereas crop residue removal reduces carbon concentration, dedicated energy crops can increase soil organic carbon concentration while providing biofuel feedstock. Because of their deep root systems, warm season grasses also promote long-term carbon sequestration in deeper soil profile unlike row crops.
Growing dedicated energy crops in marginal and abandoned lands instead of prime agricultural fields will further benefit the soil and environment. Warm season grasses can grow in nutrient-depleted, compacted, poorly drained, acid, and eroded soils.
Herbaceous and woody energy crops cannot replace natural forest and native prairie lands, but well-managed dedicated energy crops may provide a myriad of benefits to soil and environment while supplying much needed feedstocks for cellulosic ethanol production. Developing the next generation of biofuels will not only require new technologies to transform it into fuel, but new agricultural methods for growing it.
Citation: Humberto Blanco-Canqui, 'Energy Crops and Their Implications on Soil and Environment', Agronomy Journal, March-April 2010, 102:403-419; doi: 10.2134/agronj2009.0333
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- How A Former Naturopath Can Help Unravel The Trickery of Alternative Medicine
- Swarm Bots Kill Mass Shooter
- Can A New Rule Trigger A Second EU Referendum? Petition 4 Millon Signatures, Nearly 12% Of Total Votes Cast
- Nanotech: The Most Dangerous Science Least Carefully Done
- A Billion Years Ago, What Did Earth's Ancient Magnetic Field Look Like?
- Finding All-Hadronic Top - Again
- Did Controversy Over Statins Influence Their Use In The UK?
- "Sorry, but even using the term allopath shows your bias. That is a term invented by the creator..."
- "Lets make something clear- most of you are arguing past each other on topics that are too broad..."
- "Hi Anlain, it explains on the page itself. It's a post vote survey - not a poll, so more accurate..."
- "If british elections and referenda are supposed to be secret ballots,how can statistics like those..."
- "If you really wanted to know the truth you could find many researched and peer reviewed articles..."
- Why Some Sounds Make Us Cringe
- Over 100 Nobel Laureates Condemn Greenpeace for Opposing Golden Rice
- New Team Member: Dr. Alex Berezow
- DIY Biohacking: Unethical, Fringe and Probably Necessary to Advance Science
- Summer Camp Means Fun for Kids, But Panic for Some Parents
- Swayed By Lunch Money: A Grotesque Insult to Doctors
- Cannabinoids remove plaque-forming Alzheimer's proteins from brain cells
- NIH-supported study pinpoints origin of 2009 H1N1 influenza pandemic
- The July 2016 issue of Geology is now online
- At the droplet of a hat: Capturing mixable liquid interaction
- Triple external quantum efficiencies -- a new material TADF was developed