Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Earthworms can survive and recover after 3-week drought stress

19.09.2013
Earthworms are a welcomed sight in many gardens and yards since they can improve soil structure and mixing.

But they are hard to find in the drier soils of eastern Colorado where water and organic matter is limited. Adding earthworms to fields where they are not currently found could help enhance the health and productivity of the soil. In areas where droughts are common, though, can earthworms survive? A new study suggests that they can.


This is an earthworm in estivation.

Credit: Photo courtesy of Jacob McDaniel

Earthworms use water for many things – for respiration, to keep their bodies from drying out, and to make the mucus that helps them slide through the soil. When soils get dry, earthworms go into estivation.

"During estivation, earthworms wrap their bodies into a tight knot to reduce the amount of surface area exposed to the soil," explains Jacob McDaniel, lead author of the study published today in the September-October issue of Soil Science Society of America Journal. "Then they'll seal themselves up in a chamber lined with their mucus. Inside that chamber, the humidity is higher so they don't dry out as the soil dries."

The ability of earthworms to go into estivation suggests they can survive dry periods in the soil. The aim of the current study was to find out how long they could survive and whether they would recover after an extended drought. To answer those questions, researchers from Colorado State University recreated drought conditions in pots containing soil and worms.

Earthworms live in Colorado soils, but their distribution is limited. They are mostly found in areas close to water or with higher levels of precipitation or irrigation. Earthworms for the current study were gathered near an irrigated alfalfa field close to Fort Collins. If these worms can survive periods of drought, they could be established in no-till, dryland agricultural soils of eastern Colorado to improve and mix soils.

Four different levels of drought stress were created for the study: constant water and one, two, or three weeks without added water. These conditions were based on rainfall patterns in the area where the soil for the study – a sandy loam from a dryland agricultural field – was collected.

Before the start of the study, the earthworms were gathered, allowed to acclimate to the soil for four days, and weighed. Each pot containing the soil and earthworms was then watered. Pots were again watered at the end of each one-, two-, or three-week drought period. At 21, 42, and 63 days, the earthworms were found within the soil and classified as active, in estivation, or dead. The alive and estivating earthworms were then rewetted and weighed.

McDaniel and his co-authors found that the length of drought stress affected the number of earthworms that died or went into estivation. More earthworms went into estivation as the drought stress period got longer. Fourteen percent of earthworms died in the three-week drought, significantly more than in the other treatments. Still, the earthworms that survived drought, even for three weeks, were able to recover after rewetting.

"If the soil did get rewetted, their weight didn't change," says McDaniel. "They should be able to survive through and recover after a drought that matches our conditions."

The results of the study suggest that by going into estivation, earthworms could survive in drought-prone soils, such as those in eastern Colorado. But further work will be done to pinpoint strategies to increase their survival and understand their drought response. McDaniel explains that an important step will be to see what happens out in a field.

"The stress in the pots could be very different than what we would see in the field," he says. "Future work needs to be done in the field setting with actual droughts instead of set time periods."

Also, researchers want to find out whether the amount of time earthworms are allowed to acclimate to soils before encountering drought stress affects their survival. If an ideal length of time for acclimation can be found, efforts to establish earthworms may be more successful. Then even drought-prone, dryland soils could reap the benefits that worms provide to other soils throughout the world.

For more information, contact Jacob McDaniel at jacob.mcdaniel@colostate.edu.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://dx.doi.org/doi:10.2136/sssaj2013.02.0064.

Soil Science Society of America Journal, http://www.soils.org/publications/sssaj, is a peer-reviewed international journal published six times a year by the Soil Science Society of America. Its contents focus on research relating to physics; chemistry; biology and biochemistry; fertility and plant nutrition; genesis, morphology, and classification; water management and conservation; forest, range, and wildland soils; nutrient management and soil and plant analysis; mineralogy; and wetland soils.

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, 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. Founded in 1936, SSSA proudly celebrated its 75th Anniversary in 2011. For more information, visit http://www.soils.org or follow @SSSA_soils on Twitter.

Jacob McDaniel | EurekAlert!
Further information:
http://www.soils.org

More articles from Life Sciences:

nachricht A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>