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Posts tagged ‘lysimeters’

Jan 16

German Researchers Directly Measure Climate Change Effects Using Lysimeter Network (part 2)

In Germany, scientists are measuring the effects of tomorrow’s climate change with a vast network of 144 large lysimeters (see part 1).  This week, read about the intense precision required to move the soil-filled lysimeters, how problems are prevented, and how the data is used by scientists worldwide.

Image of truck moving the Lysimeters

Moving the lysimeters

Moving the Lysimeters is not Easy

As noted previously, one TERENO lysimeter weighs between 2.5 and 3.5 tons depending on the soil and the water saturation, so the problem of transporting it without compacting the soil or causing cracks in the soil column caused Georg many sleepless nights.   He explains, “We found a truck with an air venting system, which could prevent vibrations in a wide range. We made a wooden support structure, bought 100 car springs, and loaded the lysimeter on this frame.  After some careful preparation and design adjustments, I told the truck driver, ‘take care, I’m recording the entire drive with my acceleration sensor and data logger so I can see if you are driving faster than I allow.”  Each lysimeter soil surface level was marked to check if the lysimeter was rendered useless due to transport, and the truck was not allowed to go over a railway or a bump in the road faster than 2 km per hour to avoid the consequences of compaction and cracking.

Image of a Tensiometer sticking out of the ground

Tensiometers and soil moisture sensors monitor the hydraulic conditions inside the lysimeters.

Preventing Problems

Understanding the water potential inside the intact lysimeter core is not trivial. Georg and his team use maintenance-free tensiometers, which overcome the typical problem of cavitation in dry conditions as they don’t need to be refilled. Still, this parameter is so critical they installed 3 of them and took the median, which can be weighed in case one of the sensors is not working. Georg says, “There is a robust algorithm behind measuring the true field situation with tensiometers.”

What Happens With the Data?

Georg hopes that many researchers will take advantage of the TERENO lysimeter network data (about 4,000 parameters stored near-continuously on a web server). He says, “Researchers have free access to the data and can publish it. It’s wonderful because it’s not only the biggest project of its kind, each site is well-maintained, and all measurements are made with the same equipment, so you can compare all the data.”  (Contact Dr. Thomas Puetz for access). Right now, over 400 researchers are working with those data, which has been used in over 200 papers.

Picture depicting a Lysimeter plant in a garden with a CO2 fumigation facility located in Austria

Lysimeter plant with CO2 fumigation facility in Austria.

What’s the Future?

Georg thinks 40,000 data points arriving every minute will give scientists plenty of information to work on for years to come. Each year, more TERENO standard lysimeters are installed to enlarge the database. The ones in TERENO have a 1 m2 surface area, which is fine for smaller plants like wheat or grass, but is not a good dimension for big plants like trees and shrubs. Georg points out that you have to take into account effort versus good data. Larger lysimeters present exponentially larger challenges. He admits that, “With the TERENO project, they had to make a compromise. All the lysimeters are cut at a depth of 1.5 m. If there is a mistake, it is the same with all the lysimeters, so we can compare on climate change effects.”  He adds, “After six years, we now have a standard TERENO lysimeter design installed over 200 times around the world, where data can be compared through a database, enhancing our understanding of water in an era of climate change.”

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Read about 12 large Ecotron weighing lysimeters measuring climate change at the University of Hasselt.

Download the “Researcher’s complete guide to soil moisture”—>

Download the “Researcher’s complete guide to water potential”—>

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Jan 9

German Researchers Directly Measure Climate Change Effects Using TERENO Lysimeters

In Germany, scientists are measuring the effects of tomorrow’s climate change with a vast network of 144 large lysimeters.

Image of Lysimeters in there installation site

The goal of these lysimeters is to measure energy balance, water flux and nutrition transport, emission of greenhouse gases, biodiversity, and solute leaching into the groundwater.

In 2008, the Karlsruhe Institute of Technology began to develop a climate feedback monitoring strategy at the Ammer catchment in Southern Bavaria. In 2009, the Research Centre Juelich Institute of Agrosphere, in partnership with the Helmholtz-Network TERENO (Terrestrial Environmental Observatories) began conducting experiments in an expanded approach.  

Throughout Germany, they set up a network of 144 large lysimeters with soil columns from various climatic conditions at sites where climate change may have the largest impact.  In order to directly observe the effects of simulated climate change, soil columns were taken from higher altitudes with lower temperatures to sites at a lower altitude with higher temperatures and vice versa. Extreme events such as heavy rain or intense drought were also experimentally simulated.

Image of Lysimeter locations in Germany

Lysimeter locations in Germany

Georg von Unold, whose company (formerly UMS, now METER) built and installed the lysimeters comments on why the project is so important. “From a scientific perspective, we accept changes for whatever reason they may happen, but it is our responsibility to carefully monitor and predict how these changes cause floods, droughts, and disease. We need to be prepared to react if and before they affect us.”

How Big Are the Lysimeters?

Georg says that each lysimeter holds approximately 3,000 kilograms of soil and has to be moved under compaction control with specialized truck techniques.  He adds, “The goal of these lysimeters is to measure energy balance, water flux and nutrition transport, emission of greenhouse gases, biodiversity, and solute leaching into the groundwater. Researchers measure the conditions of water balance in the natural soil surrounding the lysimeters, and then apply those same conditions inside the lysimeters with suction ceramic cups that lay across the bottom of the lysimeter.  These cups both inject and take out water to mimic natural or artificial conditions.”

Image of Lysimeters in a field and a diagram of whats inside the Lysimeters

Researchers use water content sensors and tensiometers to monitor hydraulic conditions inside the lysimeters.

Researchers monitor the new climate situation with microenvironment monitors and count the various grass species to see which types become dominant and which might disappear. They use water content sensors and tensiometers to monitor hydraulic conditions inside the lysimeters. The systems also use a newly-designed system to inject CO2 into the atmosphere around the plants and soil to study increased carbon effects.  Georg says, “We developed, in cooperation with the HBLFA Raumberg Gumpenstein, a new, fast-responding CO2 enrichment system to study CO2 from plants and soil respiration. We analyze gases like CO2, oxygen, and methane. The chambers are rotated from one lysimeter to another, working 24 hours, 7 days a week.  Each lysimeter is exposed only for a few minutes so as not to change the natural environment.”

Next week:  Read about the intense precision required to move the soil-filled lysimeters, how problems are prevented, and how the data is used by scientists worldwide.

Download the “Researcher’s complete guide to soil moisture”—>

Get more information on applied environmental research in our

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Jun 24

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Lysimeters Determine If Human Waste Composting Can Be More Efficient (Part 2)

In Haiti, untreated human waste contaminating urban areas and water sources has led to widespread waterborne illness.  

Hospital rooms in Haiti with patients infected with cholera

Waterborne disease is the leading cause of death for children under 5. Currently, Haiti is battling the largest cholera outbreak in recent history. Over 1/6 of the population is sickened to date.

Sustainable Organic Integrated Livelihoods (SOIL) has been working to turn human waste into a resource for nutrient management by turning solid waste into compost.  (See part 1).  

Water ways infected with waste and trash

Contaminants making their way into the waterways.

The organization plans on performing experiments with lysimeters, to determine if human waste will contaminate Haitian soil during the composting process.

A river infected with waste right below a huge forest

Even in places where there are toilets, they are often poorly designed or poorly placed. This latrine is located just above a river, where people are getting their bathing and drinking water.

Lysimeters Help Assess Health Hazards

SOIL will use G3 passive capillary lysimeters in an experiment to determine if composting human waste without a barrier between the waste and the soil will result in ecological and/or health hazards.  Why? The problem is “jikaka,” or “poo juice.”  The compost facility currently redistributes it onto the compost and finishing piles, but they would rather not have to manage it. They believe if they remove the concrete slab and allow composting to occur in contact with soil, the composting process will be easier and faster.

Mounds of dirt behind a tree

SOIL’s agricultural team conducts studies on the use of compost to improve farming practices and maximize economic benefits of targeted compost application.

The Experiment

The organization will test their idea as they expand their facility. New compost bins and staging areas for finishing have been built absent concrete pads. G3 passive capillary lysimeters have been installed, three beneath the compost bin, and four beneath the first staging area for finishing. They will be used to monitor the amount of moisture (jikaka) that travels through the soil as well as check for anything harmful that travels with it.

Children holding soil in their hands

SOIL’s human waste compost was found to increase sorghum yields by 400%.

What’s the Future for Konpòs Lakay?

SOIL’s agricultural team studies the use of their compost (Konpòs Lakay) in order to optimize farming practices and the economic benefits of targeted compost application. The data they collect will help them expand the market for Konpòs Lakay, which in turn will support the sustainability of SOIL’s sanitation programs.

For more information on SOIL’s waste treatment efforts, visit their website, or watch the video below, a TEDx talk given by SOIL co-founder, Sasha Kramer.

Discover G3 Drain Gauge passive capillary lysimeters→

Download the “Researcher’s complete guide to soil moisture”—>

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Jun 17

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Lysimeters Determine If Human Waste Composting Can Be More Efficient

In Haiti, untreated human waste contaminating urban areas and water sources has led to widespread waterborne illnesses such as typhoid, cholera, and chronic diarrhea.

Human wastes are making their way into Haiti’s waterways.

Human wastes are making their way into Haiti’s waterways.

Sustainable Organic Integrated Livelihoods (SOIL) has been working since 2006 to shift human waste as a threat to public health and source of pollution to being a resource for nutrient management by turning solid waste into compost.  This effort has been critical to sustainable agriculture and reforestation efforts, as topsoil in Haiti has severely eroded over time, contributing to Haiti’s extreme poverty and malnutrition.

Border between Haiti and the Dominican Republic from an aerial view

This is a very famous image of the border between Haiti and the Dominican Republic. It’s often used to demonstrate how badly off Haiti is relative to their neighbors. What you’re actually seeing is the environmental scars of a very different post-colonial history.

Why Compost?  

Topsoil erosion in Haiti was estimated to be 36.6 million metric tons annually in 1990, and it is estimated that only one sixth of the land currently cultivated in Haiti is suitable for agriculture. SOIL combats desertification by producing over 100,000 gallons of agricultural-grade compost made from human waste annually.  SOIL research has shown that this compost can increase crop yields by up to 400%.  The organization has sold over 60,000 gallons of this compost to local farmers and organizations, increasing soil organic matter and nutrients throughout the country.

Waste covers the urban area infecting people and causing problems

Today in Haiti, only 25% of people have access to a toilet – meaning people are forced to go to the bathroom outside or in urban areas, in a plastic bag, which often times gets disposed of in a canal or an empty lot.

How Do They Do It?

SOIL distributes specially constructed toilets throughout Haiti that separate urine from solid waste.  Odors are reduced by covering the solid waste with organic cover material.  The toilet utilizes a five gallon bucket to collect solid waste that can be swapped out when full.

Toilet in Haiti

Instead of flushing nutrients away with fresh water, people use a dry carbon material to cover it up so that it doesn’t smell, and it doesn’t attract flies. This material also provides food for the microbes that will ultimately transform the poop.

The five gallon buckets are collected weekly and taken to the composting facility, where they are dumped into large composting bins.  It takes about 1500 buckets (3-4 days worth) to fill each bin. Bins are required to reach 122°F and left for 2.5 months in order to kill all pathogens.

Waste water transformation chart

Wastes are safely transformed into nutrient-rich compost in a carefully monitored composting treatment process that exceeds the World Heath Organization’s standards for the safe treatment of human waste.

The compost is then removed from the bin and turned by hand. There are three concrete slabs used to manage the finishing process.  Compost is turned horizontally and then moved forward to the next slab, allowing multiple batches to be finishing at the same time, each at a different stage.  After processing, the compost is sifted, bagged, and sold, reinvigorating the agriculturally-based Haitian economy.  

Students study plants sold for agriculture

The compost SOIL produces is bagged under the Haitian Creole brand name “Konpòs Lakay” and then sold for agricultural application, improving both the fertility and water retention of soil. With over four billion people worldwide currently lacking access to waste treatment services, finding ways to provide waste treatment services profitability through the private sector has the potential to dramatically improve public health and agricultural outputs globally.

Continue reading part 2→

Understand the Impact

Watch this 5 minute video filmed by independent parties to see how SOIL is impacting Haitian citizens and the environment.

Read how experiments using lysimeters will help SOIL make the composting process more efficient.  

Download the “Researcher’s complete guide to soil moisture”—>

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May 27

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Are Biodegradable Mulches Actually Better for the Environment?

Henry Sintim, PhD student at Washington State University, is investigating whether biodegradable mulches are, in fact, what they claim to be.

Plant row farm with dirt between each row

Application of plastic mulches conserves water, and helps in weed, pest, and disease control.

He and his research team want to understand what leaches into the soil as the mulches degrade and which ones perform as well as polyethylene-made plastic mulches (PEs) at weed, pest, and disease control.

Plastic Mulch

Application of plastic mulches in agriculture is a common practice by specialty crop producers worldwide. It conserves water, and helps in weed, pest, and disease control, subsequently improving crop yield and quality. Because PE is durable and does not degrade in the soil, you cannot leave it in the field, which ultimately leads to the question of disposal.  When PE is buried in the field, it becomes contaminated with soil and can’t be recycled but instead requires transport to a landfill, increasing production costs. Another problem arises when landfill facilities are not available. When this is the case, growers stockpile PE on their farm, where the rain can wash the mulch down to streams and water bodies. Henry Sintim and his team are investigating whether or not biodegradable plastic mulches (BDMs) could be a viable alternative.

Researchers digging a site up for installation

The team installs a lysimeter beneath the mulches.

Biodegradable Alternatives

Substituting PE with BDM could alleviate the need for disposal. However, Sintim says the potential impact on agricultural soil ecosystems needs to be assessed before adopting biodegradable mulch for field use. For instance, do biodegradable mulches really degrade?  Sintim explains, “By BDM, we mean it is plastic mulch, but it has been made from pure or partial biobased materials. Though there are plastic mulches advertised as biodegradable, none have actually been proven to biodegrade, so the team is examining degradation of different commercial BDM types over time. They have also included an experimental BDM, in which the constituents were specified by the team.”

Sintim is monitoring the degradation of BDM by assessing the material properties and measuring the particle size and surface area via photography: digitizing and analyzing them using Image J software.

Researchers standing at an installation getting data

There are indications that some of the BDMs are performing well.

How Well Do the Mulches Compare?

Sintim also wants to find out how well BDMs maintain microclimate in comparison to PE. Since soil temperature and moisture content are important parameters that govern chemical reaction rates and microbial activity, and are likely to vary among the different BDM treatments, he is monitoring soil moisture dynamics using soil moisture and temperature sensors installed at 10 cm and 20 cm depths. In addition, the team has installed sensors directly underneath the mulches to measure surface temperature and light penetration. Reduction of light penetration is the attribute that helps plastic mulches to control weeds. The team is also assessing soil quality using the USDA Soil Quality Test Kit.  

Sintim says so far one of the commercial BDMs and the experimental BDM had the same yield performance as PE.  He adds, “We don’t have final results yet, and there are a lot of variables that could come into the picture. But I will say there is an indication that some of the BDMs are performing well.”

Next week:  Find out how Sintim will determine what’s leaching into the soil and another alternative for polyethylene plastic mulch.

Download the “Researcher’s complete guide to water potential”—>

Get more information on applied environmental research in our

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