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
New data unearths pesticide peril in beehives
21.04.2017 | Cornell University
New rice fights off drought
04.04.2017 | RIKEN
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Physics and Astronomy
25.04.2017 | Materials Sciences
25.04.2017 | Life Sciences