Grasslands in the Conservation Reserve Program (CRP) in the United States may be increasingly converted to growing bioenergy grain crops.
Questions abound regarding the fate of carbon sequestered in the soil during the CRP program by perennial grasses if the land is converted to grain crop production and the potential effectiveness of no-till production systems to conserve the sequestered soil organic carbon (SOC). The effect of no-till conversion of land that had been in smooth bromegrass for 13 years to no-till corn production on soil organic carbon in eastern Nebraska was observed for 6 years by USDA scientists.
The bromegrass was killed with herbicides in late fall of 1998 and corn was planted directly into the killed sod in the spring of 1999. No plowing or cultivation was conducted during the entire period of the study. Weeds were controlled with herbicides. Soil samples were collected at three different depths at the beginning and several times during the study and were analyzed for soil organic carbon. Carbon isotope ratio analyses made it possible to determine the amount of soil organic carbon that originated from bromegrass or corn.
The results of this study were reported at the October 5th to 9th meeting of the Soil Science Society of America in Houston, TX, and are published in the March-April 2009 issue of Agronomy Journal.
During the 6 years of the study, the origin of the soil carbon in the two upper soil layers (0- to 5-, and 5- to 10-cm depths) changed with the soil carbon from bromegrass gradually replaced by that from corn. Total soil organic carbon, however, did not change significantly at any depth during the 6 years of the study. There was no loss of sequestered soil carbon during 6 years of continuous no-till corn production.
Ronald Follett, who led this study, states, “If Conservation Reserve Program grasslands are converted to grain crop production, data from this study strongly supports the use of no-till farming practices. The use of no-till was observed to conserve both previously sequestered SOC while also enhancing sequestration of SOC by the bioenergy crops.”
Coauthors Gary Varvel and Ken Vogel indicate that no-till conversion of CRP grasslands into grain crops or perennial biomass crops such as switchgrass is significantly less expensive than using extensive tillage including plowing. No-till conversion of grasslands is feasible because of effective herbicides and improved no-till planting equipment that has been developed. In addition, associated and effective management procedures for no-till conversion of grasslands have been developed and validated.
There are modeling studies reported in the literature that indicate massive amounts of soil carbon will be released to the atmosphere if grasslands such as the CRP grasslands are converted to energy crops and that these releases would then negate the greenhouse gas benefits of the energy crops. These modeling studies are based on the assumption that the grasslands will be plowed followed by extensive tillage to prepare seed beds for the following crops. This study demonstrates that such predicted negative outcomes are likely erroneous.
The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://agron.scijournals.org/cgi/content/full/101/2/261.
A peer-reviewed international journal of agriculture and natural resource sciences, Agronomy Journal is published six times a year by the American Society of Agronomy, with articles relating to original research in soil science, crop science, agroclimatology and agronomic modeling, production agriculture, and software.
The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.
New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Fighting a destructive crop disease with mathematics
21.06.2017 | University of Cambridge
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
24.07.2017 | Power and Electrical Engineering
24.07.2017 | Materials Sciences
24.07.2017 | Materials Sciences