Soil variation occurs across multiple geographic scales ranging from vast climatic regions of the Earth to a 50 acre farm field to the molecular world of soil nano-particles in a pinch of soil.
For example, in a forest or an agricultural field, soil properties vary from the summit of a hill down to the base. Within a single soil aggregate that may be less than a quarter inch in diameter, there is a variable distribution of open spaces (soil pores), solids (soil particles), and water and gas molecules, and within each of the elements themselves there is variation, such as different pore shapes and different elemental solids.
Many approaches have been used to examine soil variation at these diverse scales, but there is a common difficulty among methods in separating out random variations from systematic variations. Some of the variation observed in, say, a desert community or a handful of soil is random, but other variation is predictable (systematic) based on variables such as landscape position, climate, or time of the year.
New methodological developments better enable us to separate out these different sources of variation by examining soil variability over a range of scales, which is important for linking soil properties with soil processes. These linkages have important predictive capacities, such as forecasting corn yields based on soil characteristics, or understanding where microorganisms live in soil and how human alteration to certain soil properties affects their livelihood.
Scientists from USDA-ARS-NSTL in Iowa, The University of Tennessee, and E.T.S. Ingenieros Agrónomos in Spain have assembled a collection of 12 papers covering a range of original approaches for assessing soil variability across multiple scales. The papers are published in a special section of the May 2008 issue of Vadose Zone Journal.
A variety of multi-scale methods are described and some authors compared the performance of different approaches. The methodologies employed include a variety of sophisticated mathematical approaches including geostatistics (variance of a property depends upon its position in space) and fractals and multi-fractals (similar patterns at different scales), to name a few. The authors then applied these different multi-scale methods to diverse data sets including soil pore shapes, soil aggregates, water content, rate of water movement, gas fluxes, corn yields, geochemical data, and remote sensing data.
“Understanding the interrelationships between physical, chemical, and biological factors at different scales is essential for research in agriculture, engineering, hydrology, and the environment,” says researcher Dr. Sally Logsdon of the USDA-ARS, National Soil Tilth Laboratory, Ames, IA. “Future research should examine how to better mesh together soil data and predictions across landscape position and time scales.”
The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://vzj.scijournals.org/cgi/content/full/7/2/453.
Vadose Zone Journal, http://www.vadosezonejournal.org/ is a unique publication outlet for interdisciplinary research and assessment of the biosphere, with a focus on the vadose zone, the mostly unsaturated zone between the soil surface and the permanent groundwater table. VZJ is a peer-reviewed, international, online journal publishing reviews, original research, and special sections across a wide range of disciplines that involve the vadose zone, including those that address broad scientific and societal issues. VZJ is published by Soil Science Society of America, with Geological Society of America as a cooperator.
The Soil Science Society of America (SSSA) is a progressive, international scientific society that fosters the transfer of knowledge and practices to sustain global soils. Based in Madison, WI, and founded in 1936, SSSA is the professional home for 6,000+ members dedicated to advancing the field of soil science. It provides information about soils in relation to crop production, environmental quality, ecosystem sustainability, bioremediation, waste management, recycling, and wise land use.
SSSA supports its members by providing quality research-based publications, educational programs, certifications, and science policy initiatives via a Washington, DC, office. For more information, visit http://www.soils.org.
SSSA is the founding sponsor of an approximately 5,000-square foot exhibition, Dig It! The Secrets of Soil, opening July 19, 2008 at the Smithsonian's National Museum of Natural History in Washington, DC.
Sara Uttech | newswise
Huge stores of Arctic sea ice likely contributed to past climate cooling
21.02.2020 | University of Massachusetts Amherst
First research results on the "spectacular meteorite fall" of Flensburg
18.02.2020 | Westfälische Wilhelms-Universität Münster
The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.
Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...
Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.
Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...
Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices
The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...
Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.
Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.
After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.
"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.
12.02.2020 | Event News
16.01.2020 | Event News
15.01.2020 | Event News
21.02.2020 | Medical Engineering
21.02.2020 | Health and Medicine
21.02.2020 | Physics and Astronomy