“The labile fraction is small – usually less than 20 or even 10 percent, depending on how you define it,” explains Steve Culman, lead author of a study published online Feb. 8 in Agronomy Journal. “But it is where a lot of the action happens. It’s where soil nutrients are rapidly cycled and are interacting with microbial communities.”
The size of the labile pool, then, can be an important predictor of corn agronomic performance. But the tests used up to this point to measure those pools, such as microbial biomass and particulate organic matter, were labor intensive and expensive. Culman, in Sieg Snapp’s lab at the W.K. Kellogg Biological Station, decided to use other measurements of the labile fractions – including nitrogen mineralization and carbon mineralization – to see what information these inexpensive tests might give them. Their results suggest that simple measures of labile organic matter can reflect long-term management and short-term seasonal changes as well as predict corn performance.
To better understand labile soil organic measurements and what they could tell farmers, the researchers measured soils managed in a variety of conditions. Fields were maintained with three different management practices (conventional, integrated, and compost) and two different crop rotations (continuous corn with no cover crops and corn-soybean-wheat with cover crops). After collecting soil from the different fields, the scientists then measured carbon and nitrogen mineralization.
“What’s nice about carbon and nitrogen mineralization is they’re based on actual biological activity,” says Culman. “You take into account the soil microbes and environment for these tests.”
A long-term cropping system trial provided the perfect opportunity to test the extent to which carbon and nitrogen mineralization measurements were affected by both management practice and crop rotation. These tests, then, could be used to identify the best practices, such as fertilizer application, for a given field. This would be especially useful for nitrogen – a nutrient that is incredibly important for crop growth but is rarely measured by farmers.
“Most farmers don’t test their soils for nitrogen,” explains Culman. “They just basically apply a rate based on their yield goals, and excess nitrogen may be applied. The long-term goal would be to offer these as predictive tests for farmers so they can say, ‘Given my soil type, management, and these measures, I should apply this amount of nitrogen.’ That’s the ultimate goal.”
The predictive power of such tests for best management practices goes hand-in-hand with crop performance. The researchers also found that carbon mineralization was a better predictor of corn agronomic performance than other measures that are currently used (pre-sidress nitrate test and leaf chlorophyll). With these tests, Culman and his coauthors hope to provide farmers with better tools to manage their fields and increase crop yields.
Says Culman, “This could have tremendous impacts, locally, regionally, and nationally, in terms of having tools that better predict our cropping system performance based on soil properties.”
The full article is available for no charge for 30 days following the date of this summary. View the abstract at https://dl.sciencesocieties.org/publications/aj/abstracts/0/0/agronj2012.0382.
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. For more information visit: www.agronomy.org/publications/aj
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.
Caroline Schneider | Source: Newswise
Further information: www.sciencesocieties.org
Further Reports about: Agronomy > Corn > corn-soybean-wheat > Crop rotation > crop yield > cropping system > leaf chlorophyll > management practices > microbial communities > organic farms > Performance Measurement-Systems
More articles from Agricultural and Forestry Science:
Biodegradable or not?
10.12.2013 | Helmholtz Centre for Environmental Research (UFZ)
Sustainable recultivation of abandoned agricultural land in Russia, Ukraine and Belarus
04.12.2013 | Leibniz-Institut für Agrarentwicklung in Mittel- und Osteuropa
Researchers from Brown University and the University of Hawaii have found some mineralogical surprises in the Moon's largest impact crater.
Data from the Moon Mineralogy Mapper that flew aboard India's Chandrayaan-1 lunar orbiter shows a diverse mineralogy in the subsurface of the giant South Pole Aitken basin.
The differing mineral signatures could be reflective of the minerals dredged up at the time of the giant impact 4 billion years ago, ...
In power electronics systems bonded connections create the central electrical connections between adjoining surfaces.
The quality of these bonded connections is one of the main factors that determines the reliability and availability of drive systems in electric vehicles, and hence constitutes a major design challenge for German auto manufacturers aiming to electrify their vehicles.
Now the partners participating in the RoBE (Robust Bonds in ...
International team of scientists develops new feedback method for optimizing the laser pulse shapes used in the control of chemical reactions
In many ways, traditional chemical synthesis is similar to cooking. To alter the final product, you can change the ingredients or their ratio, change the method of mixing ingredients, or change the temperature or pressure of the environment of the ingredients.
Like an accomplished chef, chemists have become very skilled ...
A genetic defect protects mice from infection with influenza viruses
A new study published in the scientific journal PLOS Pathogens points out that mice lacking a protein called Tmprss2 are no longer affected by certain flu viruses.
The discovery was made by researchers from the Helmholtz Centre for Infection Research (HZI) in Braunschweig in collaboration with colleagues from Göttingen and ...
The Light: Global study gets underway with online user survey
Light has a fundamental impact on our sense of well-being and performance. In cooperation with Zumtobel, a supplier of lighting solutions, Fraunhofer IAO has launched a global user survey of lighting quality in offices. The objective is to identify the best lighting conditions for a variety of spaces and lighting ...
10.12.2013 | Physics and Astronomy
10.12.2013 | Agricultural and Forestry Science
10.12.2013 | Power and Electrical Engineering
10.12.2013 | Event News
05.12.2013 | Event News
04.12.2013 | Event News