When faced with a reluctant spring thaw, dryland wheat growers know they have only two weeks to remove the snow from their fields, or large sections of their crop will die off from snow mold. Melting the snow artificially can be an expensive process, but one southern Idaho wheat grower has found a unique solution that could save both money and the environment (see part 1). He covers the snow with displaced topsoil, which speeds up the warming process and is less expensive than using traditional fly ash. This week, find out which techniques Campbell uses to save time and money while redistributing his soil.
Campbell says the number of passes he has to make with his tractor makes a difference.
Soil Application
Campbell says the number of passes he has to make with his tractor makes a difference, so he spreads the soil in patches, rather than evenly, in order to save time and money. “What we’ve found is, if you can get the soil deposited every 40 feet (9 m), you start changing the temperature in the whole area, and not just where the soil was dropped. The breeze will spread the warmth, and the snow in between the patches of soil will melt a lot faster. We do adjust our spacing depending on the amount of snow. If there’s more snow, that means we’ve got less time, and it’s got to melt faster, so we’ll place the patches of soil closer together for more even coverage.
Using a tractor to spread the soil in patches, rather than evenly, saves time and money.
Campbell adds that he is selective on which field he spreads the soil. If the weather conditions are not looking good, and they have deep snow, then they may skip a field they think they can’t save. Or if the fields further south have less snow, and the weather looks warm, they may also skip that field because the snow may melt on it’s own. There are challenges in trying to make those predictions, however. He says, “It’s hard to make those guesses based on the weather forecast because the predictions just aren’t very accurate a couple of weeks out. One year the forecast was sunny, so we applied fly ash to the fields. But the next day it snowed a foot, and it was two weeks before that snow melted so the sun could get to the ash. We lost quite a bit of grain that year.”
Campbell is selective on which field he spreads the soil.
Future Plans
Next year Campbell will try mixing the soil with some fly ash, to take advantage of the ash’s darker color. He says, “We’re going to keep putting the soil back on the field. It’s less expensive, and we don’t have to haul it. Next year we’ll try mixing the soil with about ⅓ ash so we can get it a little blacker. It will be a nice middle ground where the dark color will melt the snow, yet it won’t cost too much. And we can redistribute the eroded, nutrient-rich topsoil.”
Each year in early spring, dryland wheat farmers battle for their crop’s survival. As temperatures climb to 0 degrees C, the dark, wet microclimate underneath the snow begins to propagate snow mold.
Wheat spikes in a wheat field.
Soil scientist, Dr. Colin Campbell says, “Soil under a blanket of snow can warm as spring temperatures rise, despite their icy covering. Temperatures above freezing and the water from snowmelt are a perfect environment for mold to grow.“
When faced with these weather conditions, wheat growers know they have only a couple of weeks to remove the snow, or large sections of their crop will die off. Melting the snow artificially can be an expensive process, but one southern Idaho wheat grower has found a unique solution that could save both money and the environment.
Temperatures above freezing and the water from snowmelt are a perfect environment for mold to grow.
The Old Method
Traditionally, wheat growers have spread fly ash (ash from coal) on the spring snow to try and speed the melting process. The black fly ash creates a warmer microclimate by absorbing more solar radiation rather than reflecting it. To demonstrate its effectiveness, the USDA performed studies using fly ash to speed snow melt, with positive results. However, growers say the challenge is using the method in a way that is economical on dryland wheat where the profit margin is narrow. Bryce Campbell, a dryland wheat farmer near Burley, ID, says, “Some people use fly ash to get in the field faster or to get the water flowing into the soil, butour primary goal is to prevent snow mold from killing the winter wheat. If that happens, we have to replant the crop to a spring crop which yields a lot less. Our goal is to try and keep our crop alive.”
During heavy rain events, topsoil washed down to the edges of the field, collecting in dikes Campbell constructed.
An Inexpensive New Method
Campbell has used fly ash in the past, but last year, he had a better idea. He noticed that during heavy rain events, some of his topsoil washed down to the edges of the field, collecting in dikes he constructed and eventually becoming dried and powdery. He wondered if he could use that soil as an economical replacement for fly ash. In the fall, he collected some in a truck and left it to dry completely in the back of his shed; then this season, he spread it over the spring snow. Seeing the results, he decided it was worth the effort, both economically and environmentally. Campbell estimated the fly ash melt to be approximately 30% faster than the powdered soil because of its darker color, but the soil was free, which made a difference in his bottom line.
If snow mold kills the wheat crop, growers have to replant the crop to a spring crop which yields less.
He adds, “Some of the wheat farmers down the road are using a finely ground coal dust product to melt their snow. It’s a great product, and it works really well for melting snow, but their cost is about $20/acre. When you spread that on a thousand acres, that’s $20,000. I can put my soil on a thousand acres, and my only cost is two hours of gathering up the soil plus a day and a half in the tractor for application.”
Next week: Find out which techniques Campbell uses to save time and money redistributing his displaced soil.
Scientists often evaluate Low Impact Development (LID) design by quantifying how much stormwater rain garden systems (cells) can divert from the sewer system. But Dr. Amanda Cording and her research team want to understand what’s happening inside the cell in order to improve the effectiveness of rain garden design (see part 1). Below are the results of their research.
Deep rooted systems were found to have a much better ability to hold the soil in place and remove nutrients.
Key Findings
Cording says that some of her key findings were that the soil media and vegetation selection is absolutely crucial to the performance of these systems. Cording’s team looked at the root layering perspective in three dimensions and found that deep rooted systems were found to have a much better ability to hold the soil in place and remove nutrients throughout the life cycle of the cell. The more surface area the roots covered, the more pollutants the cell would remove. She adds, “Cells with deep-rooted plants were found to be resilient during increased precipitation due to climate change, did well at retaining peak flow rates, and performed well at removing total suspended solids and nutrients predominantly associated with particulates.” Labile nutrients, Cording says, were a completely different story. She says the bioretention systems have to be specifically designed to remove those nutrients through sorption (P) and denitrification (N).
Compost was found to have a negative effect on water quality.
Compost, which is often used as an organic amendment in the soil media to help remove heavy metals and provide nutrients for the plants, was found to have a negative effect on water quality overall, due to the high pre-existing labile N and P content. She says, “It’s intuitive, but at the same time, a lot of these systems are designed based on bloom time and color, and not necessarily on the physical and chemical pollutant removal mechanisms at work.”
Green algal bloom in a small freshwater lake in New Zealand. (Image: Massey University)
What Lies Ahead?
Cording also tested a proprietary bioengineered media in two of her cells which was designed to remove the phosphorous that causes algal blooms in the rivers and streams. She says, “It did a phenomenal job. There was very little phosphorous coming out compared to the traditionally-designed retention cells. Cording, who is now based in Honolulu and works for an ecological engineering company called EcoSolutions, is looking at how to use natural, highly-leached iron rich soils, to get a similar amount of phosphorous removal, and how bioretention can be designed with anoxic storage zones to remove nitrate via denitrification. She says, “These nutrients can be easily removed from stormwater with a little conscious design effort and a splash of chemistry.”
Low Impact Development (LID) is an approach to development (or re-development) that mimics pre-development hydrology and uses ecological engineering to remove pollutants in stormwater and wastewater so it can be reused or replenish groundwater supplies. Examples of LID features include porous pavement, constructed wetlands, green roofs, and rain gardens. LID stormwater bioretention systems such as rain gardens have been proven to work, but are they designed as effectively as they could be? Dr. Amanda Cording (formerly at the University of Vermont) and her team wanted to understand which design factors would make rain gardens more resilient, increase phosphorus adsorption, and reduce nitrates.
Cording and her team wanted to understand what was happening inside bioretention cells.
What’s Happening Inside?
Scientists often evaluate LID design by quantifying how much stormwater the systems (cells) can divert from the sewer system. But Cording and her team wanted to understand what was happening inside the cell. They wondered which types of soil media and infrastructure would optimize a stormwater bioretention system’s ability to improve water quality. She says, “We wanted to gather water quality information coming in and going out of the system. I designed inflow and outflow monitoring infrastructure to measure nutrient and sediment pollution.” The system monitored pollution by sampling stormwater runoff from a paved road surface before and after it went through bioretention cells. Each cell was constructed with different features to test the influence of vegetation and soil media on pollutant removal capabilities.
Bioretention cells at the newly constructed Bioretention Laboratory at the University of Vermont.
Methods Used
To understand what was happening within eight bioretention cells at the newly constructed Bioretention Laboratory at the University of Vermont, Dr. Cording and her team investigated the mechanisms influencing greenhouse gas emissions and nutrient transformations at various depths in engineered soil media. In addition to using her own monitoring infrastructure, Dr. Cording used soil moisture sensors to measure water content within the soil media. She says, “I was comparing different vegetation treatments while simulating increased precipitation due to climate change in the Northeast. I put the soil probes in at 5 cm and 61cm, one on top of the other. Then I looked at the way the EC and the volumetric water content (VWC) changed prior to a storm event, during a storm event, and after a storm event.”
One of the team’s bioretention cells at the University of Vermont.
Cording says the EC and VWC sensors allowed them to get a general sense of what was happening inside the cell over time. She adds, “I used the data when I needed to know more of the story, such as how the conductivity at the surface compared to other depths so we could see if the nutrients in the soil were migrating, and how much was moving down. We were also able to use the sensors to compare the VWC around the roots of different vegetation types. It provided a lot of insight into the dynamic world that exists below the soil surface.”
Next Week: Read about the team’s key findings and what lies ahead for this research.
Limited water availability is a significant issue threatening the agricultural productivity of soybean, reducing yields by as much as 40 percent. Due to climate change, varieties with improved drought tolerance are needed, but phenotyping drought tolerance in the field is challenging, mainly because field drought conditions are unpredictable both spatially and temporally. This has led to the genetic mechanisms governing drought tolerance traits to be poorly understood. Researcher Clinton Steketee at the University of Georgia is trying to improve soybean drought tolerance by using improved screening techniques for drought tolerance traits, identifying new drought tolerant soybean germplasm, and clarifying which genomic regions are responsible for traits that help soybeans cope with water deficit.
Researchers are trying to improve soybean drought tolerance by using better screening techniques for drought tolerance traits.
Which Traits Are Important?
Clinton and his colleagues are evaluating a genetically diverse panel of 211 soybean lines in two different states, Kansas and Georgia, for over two years to help him accomplish his research objectives. These 211 lines come from 30 countries and were selected from geographical areas with low annual precipitation and newly developed soybean lines with enhanced drought-related traits, along with drought susceptible checks. The researchers are looking at traits such as canopy wilting. Some plants will take a few days longer to wilt, allowing these plants to continue their photosynthetic ability to produce biomass for seed production. Other traits that he is interested in evaluating are stomatal conductance, canopy temperature with thermal imaging, relative water content, and carbon isotope discrimination.
The scientists want to monitor traits such as canopy wilting.
Use of Microclimate Stations to Monitor Environmental Conditions
Clinton says to make selection of drought-tolerant lines easier and more predictable, knowledge of field environmental conditions is critical. He says, “You can phenotype all you want, but you need the true phenotype of the plant to be observed under real drought conditions so you can discover the genes for drought tolerance and improve resistance down the line in a breeding program.”
In addition to soil moisture sensors, the team used microclimate weather stations to help monitor water inputs at their two field research sites and determine ideal time periods for phenotyping drought-related traits. Steketee says, “We put microenvironment monitors in the field next to where we were growing our experimental materials. Both locations use those monitors to keep an eye on weather conditions throughout the growing season, measuring temperature, humidity, and precipitation. Since we could access the data remotely, we used that information to help us determine when it was time to go out to the field and look at the plots. We wanted to see big differences between soybean plants if possible, especially in drought conditions. By monitoring the conditions we could just go back to our weather data to show we didn’t get rain for 3 weeks before we took this measurement, proving that we were actually experiencing drought conditions.”
The team identified some lines that performed well.
Results So Far
Though 2015 wasn’t a great year for drought in Georgia, Clinton says there was a period in late July when he was able to measure canopy wilting, and they identified some lines that performed well. He says, “We compared our data to the data collected by our collaborator in Kansas, and there are a few lines that did well in both locations. Hopefully, another year of data will confirm that these plants have advantageous drought tolerance traits, and we’ll be able to probe the advantageous traits out of those lines and integrate them into our breeding program.”
Future Plans
The team will use what’s called a genome-wide association study approach to identify genomic regions responsible for drought tolerance traits of interest. This approach uses phenotypic information collected from the field experiments along with DNA markers throughout the soybean genome to see if that marker is associated with the trait they are interested in. If the scientists find the spot in the genome that is associated with the desired trait, they will then develop genomic tools to be used for selection, integrate that trait into elite germplasm, and ultimately improve the drought tolerance of soybeans.
See weather sensor performance data for the ATMOS 41 weather station.
What can you do when you need data from all over the world in a short amount of time? Many scientists, including ones at JPL/NASA, are crowdsourcing their data collection.
Projects range from ground truthing NASA satellite data, to spotting migration patterns, to collecting microbes.
Darlene Cavalier, Professor of Practice at Arizona State University is the founder of SciStarter, a website where scientists make data collection requests to a community of volunteers who are interested in collecting and analyzing data for scientific research.
Who Collects the Data?
SciStarter was an outgrowth of Cavalier’s University of Pennsylvania graduate school project where she sought to connect people who didn’t have formal science degrees with scientists who needed their help. She says, “We know from various National Science Foundation reports that many people without science degrees are interested in participating in and learning about science. The challenge was that there was no easy way to find those opportunities.”
One project invites UK citizens to find and take pictures of orchids.
Cavalier started SciStarter, in part, to create a “one-stop shop” resource where people could easily search and find projects best suited to their locations and interests. She says, “We have over 1,600 projects and events. Projects range from ground truthingNASA satellite data, to spotting migration patterns, to collecting microbes.” One project,sponsored by the National History Museum in London, invites UK citizens to find and take pictures of orchids with their smartphones, so scientists can study the effect of climate change on UK flowering times.
How Are Volunteers Recruited?
Volunteers are recruited through SciStarter’s partnerships with the National Science Teachers Association, Discover Magazine, the United Nations, PBS and more. One of the most visible ways that volunteers are enlisted is through an organization Cavalier started called Science Cheerleader. The organization consists of 300 current and former NFL and NBA cheerleaders who are scientists and engineers. These role models visit youth sports groups, go to science festivals, and talk in schools. During their appearances they engage people of all ages in actual citizen science projects. Darlene says, “This is our way of casting a wide net and making new audiences aware of these opportunities.”
Science cheerleader consists of 300 current and former NFL and NBA cheerleaders who are now scientists and engineers.
What’s the Ultimate Goal?
Cavalier is determined to create pathways between citizen science and citizen science policy. She says, “The hope is after people engage in citizen science projects, they will want to participate in deliberations around related science policy. Or perhaps policy decision makers will want to be part of the discovery process by contributing or analyzing scientific data.” Darlene has partnered with Arizona State University and other organizers to form a very active network called Expert and Citizen Assessment of Science and Technology (ECAST). This group seeks to unite citizens, scientific experts, and government decision makers in discussions evaluating science policy. Cavaliers says, “The process allows us to discover ethical and societal issues that may not come up if there were only scientists and policy makers in a room. It’s a network which allows us to take these conversations out of Washington D.C. The conversations may originate and ultimately circle back there, but the actual public deliberations are held across the country, so we get a cross-section of input from different Americans.” ECAST has been contracted by NASA, NOAA, the Department of Energy, and others to explore specific policy questions that would benefit from the public’s input.
ECAST is a network which allows us to take science policy conversations out of Washington D.C.
Overcoming Obstacles
Cavalier says the SciStarter team constantly works to remove challenges and impediments to public participation. She explains, “We’ve found it can be difficult to articulate the geographic bounds of a project because when a researcher says, “this project can be done in a watershed,” it doesn’t mean anything to most people. So SciStarter spent time developing a system of “Open Streetmap and USGS databases that show land-type coverage.”
Another obstacle to some types of research is access to instrumentation. Darlene comments, “The NASA Soil Moisture Active Passive (SMAP) project really opened our eyes to how many obstacles can exist between the spectrum of recruiting, training, equipping, and fully engaging a participant.” This year, SciStarter is building a database of citizen science tools and instruments and will begin to create the digital infrastructure to map tools to people and projects through a “Build, Borrow, Buy” function on project pages.
“The NASA Soil Moisture Active Passive (SMAP) project really opened our eyes to how many obstacles can exist to full engagement.”
What’s Next?
Darlene says that sometimes scientists who want accurate data without knowing about or identifying a particular sensor for participants to use often create room for data errors. To address this problem, SciStarter and Arizona State University will be hosting a summit this fall where scientists, citizen scientists, and commercial developers of instrumentation will meet to determine if it’s possible to fill gaps to develop and scale access to inexpensive, modular instruments that could be used in different types of research. You can learn more about crowdsourcing your data collection with SciStarter here.
In Haiti, untreated human waste contaminating urban areas and water sources has led to widespread waterborne illness.
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).
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.
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.
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.
SOIL’s human waste compost was found to increase sorghum yields by 400%.
What’s the Futurefor 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.
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.
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.
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.
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.
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.
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.
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.
We interviewed Gaylon Campbell, Ph.D. about his association with one of the founders of environmental biophysics, Champ Tanner.
Who was Champ Tanner?
Champ Tanner was a dominant scientist in his time and a giant among his colleagues. He was the first soil scientist to be elected a member of the National Academy of Sciences: the highest honor a scientist can achieve in the United States. Some may not realize that throughout a career filled with achievements and awards, he battled the challenges of a debilitating illness. He didn’t let that limit his passion for science, however. His efforts to understand and improve measurements generally went beyond those of his fellow scientists. One of his colleagues once said of him, “Champ’s life exemplified goal-oriented determination and optimism regardless of physical or financial impediment.”
Dr. Tanner was one of the pioneers in applying micrometeorology to agriculture.
What were his scientific contributions?
Champ was an extremely careful experimentalist who was gifted at developing instrumentation. He started out making significant contributions in soil physics such as improved methods for measuring water retention, particle size distribution, air-filled porosity, and permeability. He was one of the pioneers in applying micrometeorology to agriculture and was passionate about finding ways to improve the precision and reliability of measurements. No measurement was too difficult. He designed and built his own precise weighing lysimeters which provided measurements of evapotranspiration in as little as 15 minutes. Later, he switched to plant physiology, reading almost every published paper on the subject and then building his own thermocouple psychrometer and plant pressure chambers, making important contributions in that field.
His largest contribution, however, was the measure of excellence he inspired in the students that he trained. I don’t know of anybody, anywhere in the world, that produced a crop of students that has attained the levels that his have. They’ve all made enormous contributions in many different fields. Perhaps it was because he was a pretty hard taskmaster. He expected the students to meet a standard, and the ones that struggled with that had a hard time. In fact, to this day one former student complains, “About once a year, I have a nightmare in which Champ appears.”
I don’t know of anybody, anywhere in the world, that produced a crop of students that has attained the levels that his have.
Champ wanted his students to measure up, but he also cared about them. His fellow scientist, Wilford Gardner, described him this way, “There was a transcendent integrity to his personality that permeated everything he did. He could be blunt, candid and forthright, but he was never lacking in compassion and concern for students, colleagues, and friends.”
What was your association with him?
I had a wonderful relationship with Champ, although I wasn’t one of his students. One of his former students came to WSU as a visiting scientist and told him about what I was working on. As a result, he brought me into his inner circle of associates and played a vital role in the success of my research. This association even extended to my family who were with me on one of my many trips to Madison. Despite my numerous and occasionally unruly progeny, he and his wife welcomed us like long lost relatives and made each of the children feel special. That’s who they were: the most caring and outgoing people.
Champ also had a sense of humor. He used to call me up to have long discussions about science, and because he was two time zones ahead, it would get pretty late for him. We’d be having an intense discussion about experimentation, and all of a sudden he’d stop and say, “Oh, I’d better cut this off, or I’ll get home to a cold supper and a hot wife.”
What kind of a person was he?
If you worked in his lab, you needed to tow the mark. You didn’t leave tools around, and you didn’t mess them up. If you left out a screwdriver, you’d find it on your desk the next morning with a terse note. And if you took the diagonal pliers, cut some hard wire with it and left some nicks, those would be on your desk too. It was a sort of tough love, but he used it to train his students to the highest possible level.
He taught his students to be rigorous in their measurement protocols
He wanted his students to stand up and argue for their point. If you were the kind of person that could stand your ground and put up a good defense, he loved that. Gardner described Champ in this way, “His work hours were legendary. His standards of science and personal integrity were almost unrealistically high. The stories his students now pass on to their students may sound apocryphal to those who did not know Champ. But it was impossible to exaggerate where Champ was concerned.”
What do you think scientists today can learn from him?
What we can learn from Champ Tanner is not to fool ourselves. He thought you should try to come to an answer in a few different ways, to be sure that it really was the answer. He taught his students to be rigorous in their measurement protocols in order to get the noise out of their experiments. He wanted them to dig to the bottom of problems and understand the details. In his mind, you couldn’t be a scientist and rely on somebody else to figure out heat transfer or radiation. He thought you should understand it well enough that you could defend it yourself.
You can read more about Champ Tanner’s life and scientific contributions in this biographical sketch, written for the National Academy of Sciences when he died.
In a continuation of last week’s post, Henry Sintim, PhD student at Washington State University is investigating whether biodegradable mulches are, in fact, what they claim to be (see part I).
Sintim and his team want to understand what’s leaching through the soil as the mulches degrade. He installed passive capillary lysimeters at a 55 cm depth to collect leachate samples for analysis of BDM particulates. He was surprised when the lysimeter readings revealed higher EC measurements.However, the EC in the PE, paper mulch, and no-mulch treatments were also high, hence that could be due to the leaching of accumulated salts in the soil surface. He says, “We have yet to examine the leachate samples for the presence of particulates.”
Installing lysimeters
Composting Alternatives
If the team finds that some of the BDMs do not biodegrade very well in the field, the alternative could be on-farm composting, which would be more viable than having to deal with polyethylene plastic. Sintim and his research team have set up a composting study where they have been digitizing the images of the mulches degrading. He adds, “We buried the mulches in a mesh bag, and periodically we retrieve the bags to study the mulch. There was some black staining on the mesh bag, which we suspect is a nanoparticle called, “carbon black,” used as reinforcing filler in tires and other rubber products.
The team buried the mulches in compost, and periodically they retrieve the mesh bags to study the mulch.
Sintim says the manufacturers do not disclose the actual constituents of their mulches, so he has arranged to examine the mesh bags with WSU’s scanning electron microscope in order to confirm that the stains were due to the presence of particulates. Sintim confirmed that carbon black was used in their experimental BDM, but they don’t know whether the carbon black was made from petroleum products, as there is non-petroleum-based carbon black. He is going to determine whether these particles leach through soil by examining leachate samples from the lysimeter. He will also perform more tests to make sure that these nanoparticles are not going to have any adverse effects on the agro-ecosystem.
What’s in the Future?
While Sintim and his colleagues have made important discoveries, there is still work to be done. He and his team are going to collect three more years’ worth of data to see if there really is a BDM that delivers on its promises and if leaching particles pose a threat to the groundwater.