Something Old, Something New: Corn Stover
Doesn't it just amaze you sometimes how much our everyday vocabulary has changed in, say, the past 30 years?
I'm not claiming that absolutely no one used any of these terms in the mid-1970s, but I don't think they were a common part of daily conversation: "greenhouse gases," "DNA fingerprinting," "online" or "biofuels," to name a few. Our world has definitely changed since the days when Elvis' "Aloha from Hawaii" concert being broadcast live via satellite was the big buzz!
As we head into a future that features more bio-based energy, here's another vocabulary word for you: stover.
That's the name for the corn stalks, leaves and cobs that are left in the field after the grain's been harvested. If left to decay, stover can do a lot of good by building up soil organic matter and reducing the erosion that can occur when bare soil is exposed to wind and rain.
Stover also helps "sequester" carbon in the soil. Maybe you've heard that farmers' crops are helping to counter greenhouses gases through something called "carbon sequestration." Here's how that works: Plants use photosynthesis to capture the atmospheric carbon dioxide (CO2) emissions that result from the burning of fossil fuels, and tuck that carbon safely away in the soil. In fact, ordinary turfgrass can store nearly a ton of carbon per acre per year.
The latest interest in corn stover comes from its potential as an abundant feedstock for making ethanol. But a big question that the scientists of the Agricultural Research Service (ARS) are trying to answer is, how much stover can we harvest to make ethanol without losing out on those other environmental benefits?
That's exactly what ARS scientists in Morris, Minn., are focused on these days. They're measuring the carbon in the soil and the amount of carbon dioxide and other greenhouse gases returned to the air, depending on the amount of stover on the fields. They also want to know how using different tillage methods — from plowing the soil bare to planting directly into the residue of previous crops — affects the amount of stover that needs to stay on the land.
The ARS scientists in Morris are part of a nationwide team with a five-year project to answer those and similar bioenergy-related questions. Others on the team include researchers from state universities and the Department of Energy's Idaho National Laboratory.
For example, in St. Paul, Minn., ARS scientists are experimenting with whether winter cover crops and living mulches such as kura clover, which is grown right in the cornfield, could provide the biomass we need for biofuel without jeopardizing soil health or productivity. At Fort Collins, Colo., other ARS researchers are figuring out how different farm management techniques and factors (such as plant types or frequency of fertilization) affect biofuel crops' potential to sequester carbon.
In Lincoln, Neb., ARS scientists are working with two brothers who run a family farm to study cropland with high-, medium- and low-productivity soils. That study, which covers 100 acres of corn and uses field-scale equipment, will give us a real-world chance to look at stover harvesting's effect on organic matter, grain yields and carbon sequestration in the western Corn Belt.
Of course, stover isn't the only game in town. Cotton farmers who practice conservation tillage often plant cover crops such as rye and wheat to control erosion and weeds during the winter months. ARS scientists in Auburn, Ala., are studying the potential of harvesting that winter cover biomass in the spring, before the farmers plant their cash crops, and how that biomass harvest would affect the cash crop's productivity and profitability.
There are so many directions that science can go to meet our needs. ARS researchers are also looking at whether there's some way to increase plants' ability to make the most of solar radiation. This could be as simple as changing planting dates or crop row widths, or as complicated as developing plants that have an enhanced ability to take sunlight, carbon dioxide and water and make oxygen and sugar.
As the saying goes, there really are many paths to the summit of a mountain!
"Everybody's
Science" is written by Sandy Miller Hays, Director of Information for
the Agricultural Research Service, the chief scientific research agency
of the U.S. Department of Agriculture. Hays is a native of Fort Smith,
Ark. From the late 1970s until early 1988, Hays was a reporter, editor
and columnist at the Arkansas Democrat (now the Arkansas Democrat-Gazette),
a Little Rock-based daily newspaper. She joined the ARS Information
Staff in 1988, and became Director of Information in April 1998.
Doesn't it just amaze you sometimes how much our everyday vocabulary has changed in, say, the past 30 years?
I'm not claiming that absolutely no one used any of these terms in the mid-1970s, but I don't think they were a common part of daily conversation: "greenhouse gases," "DNA fingerprinting," "online" or "biofuels," to name a few. Our world has definitely changed since the days when Elvis' "Aloha from Hawaii" concert being broadcast live via satellite was the big buzz!
As we head into a future that features more bio-based energy, here's another vocabulary word for you: stover.
Bales of corn stover collected from a REAP experiment near York, Nebraska. Stover is often left in place to protect soil, but it also has potential as a feedstock for cellulosic ethanol production. (Photo by Wally Wilhelm)
Stover also helps "sequester" carbon in the soil. Maybe you've heard that farmers' crops are helping to counter greenhouses gases through something called "carbon sequestration." Here's how that works: Plants use photosynthesis to capture the atmospheric carbon dioxide (CO2) emissions that result from the burning of fossil fuels, and tuck that carbon safely away in the soil. In fact, ordinary turfgrass can store nearly a ton of carbon per acre per year.
The latest interest in corn stover comes from its potential as an abundant feedstock for making ethanol. But a big question that the scientists of the Agricultural Research Service (ARS) are trying to answer is, how much stover can we harvest to make ethanol without losing out on those other environmental benefits?
That's exactly what ARS scientists in Morris, Minn., are focused on these days. They're measuring the carbon in the soil and the amount of carbon dioxide and other greenhouse gases returned to the air, depending on the amount of stover on the fields. They also want to know how using different tillage methods — from plowing the soil bare to planting directly into the residue of previous crops — affects the amount of stover that needs to stay on the land.
The ARS scientists in Morris are part of a nationwide team with a five-year project to answer those and similar bioenergy-related questions. Others on the team include researchers from state universities and the Department of Energy's Idaho National Laboratory.
For example, in St. Paul, Minn., ARS scientists are experimenting with whether winter cover crops and living mulches such as kura clover, which is grown right in the cornfield, could provide the biomass we need for biofuel without jeopardizing soil health or productivity. At Fort Collins, Colo., other ARS researchers are figuring out how different farm management techniques and factors (such as plant types or frequency of fertilization) affect biofuel crops' potential to sequester carbon.
In Lincoln, Neb., ARS scientists are working with two brothers who run a family farm to study cropland with high-, medium- and low-productivity soils. That study, which covers 100 acres of corn and uses field-scale equipment, will give us a real-world chance to look at stover harvesting's effect on organic matter, grain yields and carbon sequestration in the western Corn Belt.
Of course, stover isn't the only game in town. Cotton farmers who practice conservation tillage often plant cover crops such as rye and wheat to control erosion and weeds during the winter months. ARS scientists in Auburn, Ala., are studying the potential of harvesting that winter cover biomass in the spring, before the farmers plant their cash crops, and how that biomass harvest would affect the cash crop's productivity and profitability.
There are so many directions that science can go to meet our needs. ARS researchers are also looking at whether there's some way to increase plants' ability to make the most of solar radiation. This could be as simple as changing planting dates or crop row widths, or as complicated as developing plants that have an enhanced ability to take sunlight, carbon dioxide and water and make oxygen and sugar.
As the saying goes, there really are many paths to the summit of a mountain!
The Agricultural Research Service is the chief in-house scientific
research agency of the U.S. Department of Agriculture. You can read
more about ARS discoveries at http://www.ars.usda.gov/news/.
About the author
"Everybody's
Science" is written by Sandy Miller Hays, Director of Information for
the Agricultural Research Service, the chief scientific research agency
of the U.S. Department of Agriculture. Hays is a native of Fort Smith,
Ark. From the late 1970s until early 1988, Hays was a reporter, editor
and columnist at the Arkansas Democrat (now the Arkansas Democrat-Gazette),
a Little Rock-based daily newspaper. She joined the ARS Information
Staff in 1988, and became Director of Information in April 1998.