One of the most significant developments in agricultural growth in modern times has been the continuous and substantial increase in corn yield over the past 80 years in the U.S. Corn Belt.
This extraordinary yield advance has been associated with both breeding of improved hybrids and the ability to grow them at increased density. In a new study, published in the January-February issue of Crop Science, researchers have investigated the importance of the effects of leaves and roots on this dramatic increase in yield in the U.S. Corn Belt, and have found that the root structure may be the key to understanding how these crops have grown so efficient.
One associated change in the traits of these corn crops has been a more erect leaf angle, which is known to create greater efficiency in converting incident light to biomass. Over the years, detailed studies have shown that the increase in total biomass accumulated through sustained photosynthesis is one of the key factors explaining the yield increase.
However, some studies have also shown that changes in the root system also have an effect, as newer hybrids appear more effective at extracting soil water from deep in the soil profile. There is some evidence suggesting that hybrids with narrower root angle have this capability. It is also plausible that decrease in root angle combined with growing plants at higher density could cause the increase in biomass accumulation. Root systems with improved occupancy of the soil at depth can extract more water to sustain biomass increase.
A team of scientists from Australia and the U.S.A., led by Professor Graeme Hammer of The University of Queensland (UQ), conducted this study on the leaves and roots of corn as part of an Australian Research Council linkage project with Pioneer Hi-Bred International. The project included scientists from UQ, Queensland Department of Primary Industries, and Pioneer.
Their approach involved the use of virtual plant computer simulation technologies. They modified an advanced crop model to take account of known effects on crop growth associated with varying leaf erectness and/or root system architecture. They then simulated consequences on yield for representative sites in the U.S. Corn Belt for a set of “hypothetical hybrids” varying in leaf and root characteristics.
The study revealed that the historical corn yield trend and its association with higher plant density was more likely related to change in root system architecture than to change in leaf erectness. While more erect leaf types could contribute to the effect in some high-yielding situations, changes in root systems to enhance capture of soil water at depth had the dominating effect. Results for simulations conducted for hypothetical hybrids that varied in root system characteristics were found to be consistent with a set of field experiments that reported yield response to density for hybrids released over the past 20 years.
“The use of dynamic crop models helped us to look beyond the clearly visible differences among hybrids in this time series of yield advance,” says Hammer. “It enabled us to focus on the driving processes of crop growth that must be responsible for these effects. It is clear that as we move forward we need to look much harder at root systems and how they capture water.”
In the study, the extra amount of water required for the 6t/ha historical yield increase was estimated as about 270mm. Further research is required to determine whether this has now positioned the corn crop near the limit of water resource availability or whether there remains opportunity for yield advance by further improvement in water capture.
Crop Science is the flagship journal of the Crop Science Society of America. Original research is peer-reviewed and published in this highly cited journal. It also contains invited review and interpretation articles and perspectives that offer insight and commentary on recent advances in crop science. For more information, visit http://crop.scijournals.org
The Crop Science Society of America (CSSA), founded in 1955, is an international scientific society comprised of 6,000+ members with its headquarters in Madison, WI. Members advance the discipline of crop science by acquiring and disseminating information about crop breeding and genetics; crop physiology; crop ecology, management, and quality; seed physiology, production, and technology; turfgrass science; forage and grazinglands; genomics, molecular genetics, and biotechnology; and biomedical and enhanced plants.
CSSA fosters the transfer of knowledge through an array of programs and services, including publications, meetings, career services, and science policy initiatives.
Sara Uttech | Newswise Science News
Energy crop production on conservation lands may not boost greenhouse gases
13.03.2017 | Penn State
How nature creates forest diversity
07.03.2017 | International Institute for Applied Systems Analysis (IIASA)
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
22.03.2017 | Materials Sciences
22.03.2017 | Physics and Astronomy
22.03.2017 | Materials Sciences