Navel orangeworm can be devastating for almond and pistachio growers and knowing when and where to spray can often depend on weather. Researchers have been working with state weather services to collect data and determine the best spraying times. Washington State entomologist Dave Crowder discussed these efforts recently with Matthew Malcolm from California Ag Network. Watch this quick video and read more in Pacific Nut Producer Magazine.
Tag: Washington State University
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Federal Funds Awarded on Behalf of West Coast Dairy Businesses
Over $11 million in grant funding has been released by the U.S. Department of Agriculture through the Agricultural Marketing Service (USDA AMS) to support dairy producers and businesses through the Dairy Business Innovation Initiatives (DBI) initiative. The allocation of $690,000 will strengthen small and mid-sized dairy businesses and university pilot plants in California, Oregon, and Washington – all served by the Pacific Coast Coalition – Dairy Business Innovation Initiative (PCC-DBII).
“We anticipate a quick turnaround in distributing these funds so the awardees can see results,” said PCC Director Carmen Licon Ph.D. “Based on applications submitted in the recent Fall 2025 cycle, these resources will help dairy processors in the development, production, marketing, and distribution of dairy products,”
According to Project Co-Director and “Cowkeeper” Susan Pheasant, PhD., many generational farms and new innovators will now be able to better produce cheese, ice cream, and additional higher value dairy products.
Hosted by California State University, Fresno, The PCC-DBII is funded through the USDA Agricultural Marketing Service and is a collaboration with Cal Poly San Luis Obispo, Chapman University, Oregon State University, Oregon Dairy Council, Washington State University, and the California Dairy Innovation Center. For more information: https://www.dairypcc.net or nancyvanleuven@gmail.com.
PCC grantee Cottage Hill Creamery goat milk products (Beavercreek, OR) -
American Pistachio Growers Awarded $1 Million for Regional Pest Management Collaboration
American Pistachio Growers (APG), in collaboration with Washington State University, University of California – Riverside, UC Cooperative Extension, the USDA Agricultural Research Service and regional nut industry partners, has been awarded a $1 million grant through the California Department of Food and Agriculture’s Biologically Integrated Farming Systems (BIFS) Program to develop a Regional Integrated Pest Management (IPM) network for Navel Orangeworm (NOW) — the most damaging pest in California’s tree nut industry.
The project, led by Dr. Houston Wilson (UC Riverside), Dr. David Crowder (WSU), Dr. Jhalendra Rijal (UC IPM), and Dr. Charles Burks (USDA ARS) will pilot a groundbreaking Decision Aid System (DAS) that integrates real-time trap data, weather models, and crop phenology into a single communication platform. The goal is to improve the timing and precision of pest control decisions while fostering regional cooperation among almond, pistachio, and walnut growers.
“This project moves us beyond the farm gate,” said Joe Coelho, APG’s Director of Sustainability and Member Outreach, who serves as Technical Agronomist and PCA on the project. “For the first time, growers across commodities will have access to shared regional data and communication tools that allow them to anticipate pest pressure before it hits their fields and ultimately make precise, timely treatment decisions. The outcome is fewer sprays, lower costs, and higher quality nuts.”
Through field-level data acquisition, the system’s meta-analytics will identify regional flight trends coupled with crop-specific phenological development and enhance forecasting of NOW flights — critical steps in breaking the pest’s lifecycle across neighboring farms. Ultimately, the program is expected to help reduce pesticide use, improve nut quality, and lower aflatoxin risk associated with pest damage.
APG will serve as the grower administration partner, coordinating grower participation and outreach. Carlee Branco, APG Grant Programs Administrator, will conduct on-farm grower coordination, engagement and data collection. “This is a major milestone for sustainable pest management,” said Coelho, “and it demonstrates APG’s leadership in advancing research that directly benefits growers.”
The Regional IPM for Navel Orangeworm Project represents a pivotal step toward the state’s Sustainable Pest Management (SPM) Roadmap by providing a scalable, data-driven framework that can be expanded statewide.
“This is exactly the kind of innovation California agriculture needs,” said Dr. Wilson. “Regional coordination is essential to long-term pest reduction, especially for highly mobile insects like the navel orangeworm, and this project will now put those ideas into practice at scale.”
The program launches in early 2026, with pilot regions in West Fresno County and Modesto, serving as the foundation for a future statewide expansion. Growers within these territories who are interested should contact Carlee Branco for more information at cbranco@americanpistachios.org.
American Pistachio Growers (APG) is a non-profit trade association representing more than 800 growers and processors across California, Arizona, and New Mexico. APG’s mission is to enhance grower profitability through global marketing, industry research, and sustainability initiatives that promote economically viable and environmentally responsible pistachio production.
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Environmental and Social Benefits from Diversified Ag Found in Global Study
Food security and biodiversity are both helped by diversified farming techniques, with little negative impact, according to a new study, published in the journal Science, involving 58 co-authors located at institutions on five continents.
“The results are overwhelmingly strong for all diversification strategies,” said David Crowder, a professor in Washington State University’s (WSU) Department of Entomology. “The working theory is that diversity is good in agriculture, but I was surprised that the benefits were so strong.”
Crowder and his colleague Jeb Owen, an WSU associate professor in entomology, both contributed data to the paper, which was a meta-analysis of 28 global studies. In fact, neither Owen nor Crowder knew the other was involved in the paper until it was nearly published.
Owen’s contribution centered on wild birds and their impact on organic farms. His lab conducted surveys at 30 different locations in four states, including Washington, to look at costs and benefits from wild birds as well as each farm’s crop diversification.
“We found that the more complex and diverse a farm, the wider the diversity of wild birds it supported, and that the birds were a net positive for the farms,” Owen said.
Owen’s former graduate student, Olivia Smith, led his wild bird research and was another co-author on the new paper.
Wild, native birds fed on insect pests that damage crops, decreasing the need for pest-control measures, while not increasing pathogen spread or destroying crops, he said.
Crowder’s contribution included his lab’s research on canola and different tillage processes used by growers.
“There’s a lot of research at WSU looking at diversified farming and ways we can improve the sustainability of farms,” Crowder said. “This paper shows that WSU is plugged into global issues, and I hope we see more of this out of the university.”
Laura Vang Rasmussen of the University of Copenhagen is lead author on the new study and worked for nearly four years to coordinate and synthesize data from around the world.
“Our results from this comprehensive study are surprisingly clear,” Vang Rasmussen said. “While we see very few negative effects from agricultural diversification, there are many significant benefits. This is particularly the case when two, three, or more measures are combined. The more, the better, especially when it comes to biodiversity and food security.”
The researchers saw the greatest positive effects on food security, followed closely by biodiversity. Furthermore, social outcomes in the form of well-being also improved significantly.
Among the many strategies adopted, livestock diversification and soil conservation had the most positive outcomes.
Yields not hampered — with clearly improved food security
According to the researchers, previous studies investigated either the socioeconomic or environmental effects of agricultural diversification. This study investigates effects across the board, with surprisingly positive results.
“Agricultural diversification has been accused of perhaps being good for biodiversity, but having a few negative aspects too — especially with regards to not being able to achieve sufficiently high yields,” said Ingo Grass of the University of Hohenheim. “What we actually see is that there is no reduction in yield from diversified agriculture — not even when we include data from large-scale European agriculture.”
In fact, the figures demonstrate that in the case of small farms and farms surrounded by lots of cultivated land, more diversified agriculture can significantly promote food security. This, according to the researchers, could be due to a number of factors.
“One example is fruit trees planted in maize fields in Malawi, which can help farming families improve their food security through improved diet and nutrition,” Vang Rasmussen said. “Partly because they eat the fruits themselves, and also because the trees generate extra income when their fruits are sold at market — income that provides small-scale farmers with purchasing power for other foods.”
All 58 of the study’s authors participated actively in its design to attempt a robust and credible interweaving of the many data sets spread across the world — from maize production in Malawi, to rubber trees in Indonesia, to silvopastoral cattle farming in Colombia and winter wheat in Germany.
“The study unites many different situations from the many data sets that we used,” Vang Rasmussen said. “In Malawi, we have data on food security expressed, for example, in the number of hungry months for small-scale farmers where they have been short of food. Such metrics are not used for, for example, large European farms, where we have yield data instead, such as winter-wheat yields in Germany.
“But the point is that when we look across all data sets, our results show that applying more diversification strategies improved both biodiversity and food security, and didn’t have a negative effect on yields,” she added.
The researchers also investigated which diversification strategies result in “pairs” of favorable “win-win” outcomes. Their data showed that strategies beneficial for biodiversity also improved food security.
They also witnessed win-wins for biodiversity and people’s well-being.
“It’s a simple message to be able to pass on to different types of farms — whether it is small farms in South America or Africa or advanced European agriculture, there are lots of positive effects to be gained by introducing these various strategies — and very little to fear,” Grass said. “It is very positive that so many different things can be addressed, and that, in general, positive biodiversity outcomes seem to go hand in hand with well-being and food security.” — By Scott Weybright, Washington State University
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High Winds can Worsen Pathogen Spread on Outdoor Chicken Farms
Farmers who keep their chickens outdoors may want to watch the weather. A study of chicken farms in the West found that high winds increased the prevalence of Campylobacter in outdoor flocks, a bacterial pathogen in poultry that is the largest single cause of foodborne illness in the U.S.
Researchers found that about 26% of individual chickens had the pathogen at the “open environment” farms in the study, which included organic and free-range chicken farms. High winds the week prior to sampling and the farms’ location in more intensive agricultural settings were linked to a greater prevalence of Campylobacter.
“Farmers need to be aware of the risk,” said co-lead author Olivia Smith, a recent Washington State University Ph.D. graduate in the School of Biological Sciences. “These environmental factors are influencing if the poultry are going to have foodborne pathogens, so farmers need to be aware of what’s around them. If there’s a lot of wind and if they’re in really agricultural areas, that’s a problem.”
To help reduce Campylobacter exposure, the researchers suggested farmers consider installing windbreaks and watch weather patterns, so they can bring chickens inside during periods of high winds that could be blowing the bacteria onto their farms from nearby fields and livestock areas.
For the study, published in the journal Animals, researchers tested chicken feces taken from 27 farms in California, Oregon, Washington and Idaho. They took samples at most of the farms once a year for three years. They found that the majority of the flocks at these farms, 69.4%, had some instance of campylobacter.
Researchers also interviewed the farmers about their management practices as well as types, breeds and ages of their chickens. Only 11 of the farms in the study were officially certified organic producers, but all of the farmers avoided using chemicals in their flocks, including antibiotics, vaccines or medications that kill parasites.
This is almost the exact opposite of commercial poultry producers who typically raise birds indoors in enclosed barns and treat them with medicines. These producers also select chicken breeds for efficiency, such as “broiler” chickens that can grow fast and big providing a lot of meat, or “layer” breeds that can produce the most eggs, with the least amount of feed.
The growing market in local, organically minded food production has a different set of values, said Jeb Owen, a WSU entomologist and senior author on the paper. These farmers reduce or fully eliminate chemicals, keep a wide range of chicken breeds and allow their flocks to roam outside because they believe it is better for the animal and the environment. It is also what many consumers want, Owen said. But it doesn’t come without risks.
“We’ve spent a century raising birds indoors and forgotten about all of these parasites and pathogens that chickens used to be afflicted with, but they didn’t go away,” he said. “Now you have this rapidly exploding market of producers who want to raise their birds outside, but they have no background knowledge of the disease risk.”
Being outside means chickens are exposed to disease from wild birds and simply from contact with the ground, where they can pick up pathogens spread by feces of other infected birds.
Owen’s lab has taken on a range of research to better understand the disease risk that faces open environment chicken farms, including a study on enteric parasites like worms that live in the birds’ digestive systems and another on ectoparasites, those that are found on the skin and feathers. His team is also undertaking a study to better understand the disease resilience of the many different breeds raised on these types of farms. The overall goal is to help farmers mitigate the risk.
“If they aren’t doing it already, farmers should set up a professional relationship with a veterinarian to get their flocks checked and monitored on a regular basis,” he said. “Whether for productivity or for animal welfare, you don’t want your animals to be sick.” — By Sara Zaske, Washington State University
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Studying Plant Systems to Increase Understanding of Oil Production
Oil is a necessary source of energy and materials for the modern world, but petroleum won’t last forever. Replacing it with plant oil is currently the best solution, but we need a large amount, and can’t replace agricultural land to grow it.
Washington State University scientists are spearheading a new project, funded by a National Science Foundation (NSF) grant, to figure out how to make plants produce more oil and produce oils of different fatty acid compositions. It’s a complex process.
“Most plants we eat have five or six kinds of fatty acids,” said Phil Bates, an associate professor in WSU’s Institute of Biological Chemistry (IBC). “But there are over 450 fatty acid structures in the various uses of industrial oil. We need to figure out how to get more of those structures out of plants in a large scale.”
Industries and products requiring oil include plastics, lubricants, and glues.
The new NSF grant, funded at $1.2 million over three years, will allow researchers to look at the incredibly complex chemical reactions plants use to make oil and how to control the fatty acid composition of the oil.
The project is a continuation of research Bates and his colleagues have been working on for over a decade. One new aspect of this grant is the addition of a cell biology expert to help figure out the cellular organization of plants’ oil production processes.
“Traditionally, cells were seen as mostly bags filled with enzymes,” said Andrei Smertenko, a cell biologist and fellow IBC associate professor. “That’s not correct. Different enzymes have specific locations, and we’re trying to figure out how changing those locations impacts oil production. The localization of enzymes in cells can contribute to oil production and which types of oils are produced.”
The NSF project is more focused on understanding basic science than finding an immediate application for the findings, Bates said. But understanding is often the first step to making a discovery that can have tremendous impact.
“We want to produce plants that make more oil,” Bates said. “But to do that, you must understand the systems plants use to make it. Once we figure that out, we can get more oil and control its fatty acid composition.”
The NSF is investing in that discovery. And the grant came about in large part because of an investment made by the state of Washington. This project wouldn’t have happened before the Plant Sciences Building, funded by the state legislature, was built on the WSU Pullman campus.
“Collaboration is one of the new building’s perks,” Smertenko said. “Phil and I bump into each other regularly while getting coffee and we kept talking about the idea of working together. This project is an outcome of having the new building.”
Bates agreed with that assessment.
“We didn’t see each other in our old building; it was full of individual labs that we rarely left,” Bates said. “It’s unusual for a biochemist like me to work on a project with a cellular biologist, but this project meets at the cutting edge of both fields. The open labs allowed for this collaboration.”
In addition to each other, Bates and Smertenko are also working with three other collaborators: two researchers with the U.S. Department of Agriculture and one at the University of Missouri. — By Scott Weybright, Washington State University
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Self-Teaching Web App Improves Speed, Accuracy of Classifying Cereal DNA Variations
Agricultural Research Service and Washington State University scientists have developed an innovative web app called BRIDGEcereal that can quickly and accurately analyze the vast amount of genomic data now available for cereal crops and organize the material into intuitive charts that identify patterns locating genes of interest.
With the rapid advancements in the field of genomics the past 25 years, a game-changer for crop improvement has emerged referred to as the pan-genome, defined as the assembled genome sequences from multiple varieties within a species. But understanding and enhancing crops based on the huge amount of data that have been generated also has created a challenge for researchers due to the lack of efficient and user-friendly bioinformatic tools, particularly ones designed to handle large volume DNA variations in a species.
Take wheat, for example. The standard reference wheat genome — which was done for the wheat variety Chinese Spring — is five times larger than the human genome. In addition, researchers have long struggled with the wide variation in the locations of genes that control essential agronomic traits across wheat’s 21 chromosomes. Right now, a dozen wheat genomes are publicly available.
This adds up to a huge amount of data, making analysis of it a tedious process even for researchers with advanced bioinformatic skills. It is particularly challenging to sort through all of the data to identify similar stretches of DNA that may control the same trait no matter where they are located on a chromosome.
“Researchers will find BRIDGEcereal to be an invaluable tool for selecting and prioritizing candidate genes that control specific traits in cereal crops,” said Bosen Zhang, a WSU postdoctoral research associate and co-developer of the web app.
BRIDGEcereal is designed to transform the process of identifying large DNA variation from tedious to efficient.
“By simply providing BRIDGEcereal with the sequence of DNA you are interested in, it will complete the search process in less than one minute.” explained ARS research biologist Xianran Li, the leader of the BRIDGEcereal project. Li is with the ARS Wheat Health, Genetics, and Quality Research Unit in Pullman, Wash., and is an adjunct professor at WSU.
“And BRIDGEcereal will organize the data it finds and present it to you in easily understood charts that highlight any patterns of where that DNA is,” Li added.
It only took a minute for BRIDGEcereal to identify a promising candidate gene as the controller of a wheat mutation that reduces the length of awns, the bristle-like extensions from the wheat grain head. It had been known since the 1940s that a gene on wheat chromosome 4A controls awn development, which is an iconic wheat trait. But the exact gene controlling that trait has remained unknown.
“By searching dozens of potential genes through BRIDGEcereal, we were able to quickly identify a gene with a large DNA variation as the one that has been eluding researchers,” Li said.
The scientists also designed BRIDGEcereal to be self-teaching — also called unsupervised machine-learning — meaning BRIDGEcereal can autonomously learn to recognize new patterns without the need for explicit instructions to follow.
“So what we’ve developed is a one-stop gateway to efficiently mine publicly accessible cereal pan-genomes that will only get more efficient as the data continues to mount up,” Li said.
BRIDGEcereal was first developed to work with wheat. It has already been adapted to analyze similar data from barley, maize, sorghum, and rice.
This research was published in the journal Molecular Plant.
The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.
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Hackathon Aims to Solve Agricultural Challenges
Almost 200 students from around the U.S. had the chance to work on two challenges for the agricultural industry as part of the NSF/USDA-NIFA-funded AgAID Institute’s Digital Agathon. The event was held on the Washington State University Pullman campus as well as in Corvallis, Oregon and Merced, California.
A total of 32 teams from WSU, Oregon State University, University of Virginia, Virginia Tech and University of California, Merced participated in the event, which was sponsored by the AgAID Institute, and held in partnership with Microsoft and innov8.ag.
“Our hackathon is experiential learning, providing a deep dive into areas of agriculture where artificial intelligence (AI) can help,” said Ananth Kalyanaraman, Boeing Centennial Chair in the School of Electrical Engineering and Computer Science and director of the AgAID Institute. “The hackathon gives our students a chance to creatively and collaboratively solve problems in interdisciplinary settings, and in the process learn and apply new.”
The students were given one of two agricultural challenges and had 48 hours to come up with solutions. In one challenge, students were asked to develop computer vision, using AI methods to measure and count apples grown in an apple orchard. The information is important for farmers because they would like to know how their decisions about orchard organization, pruning strategies, watering, fertilization, and harvest scheduling impact their crop yield.
“Estimating the number of apples grown in farms can be a time-consuming and error-prone process during the fast-paced harvest season,” said Kalyanaraman.
Another challenge had the students develop and apply computer models to forecast winter precipitation in the Sacramento Basin of California. Researchers would like to improve seasonal forecasting to reduce risks to water systems and help water managers manage supplies.
A WSU team including students Gabriel Compton, John Hadish, Josh Oliver, Michael Oliver, and Shlok Tomar took first prize for the labor challenge competition, while WSU students Nicholas Kraabel, Bhupinderjeet Singh, Krishu Thapa, and Sejal Welanakar took second prize for the water challenge competition. Muluh Muluh, Meijing Liang, Srikanth Gorthi, and Grant Erickson took fourth prize in the labor challenge.
The AgAID Institute began in 2021 with a $20 million federal grant. The multi-institutional research institute aims to develop artificial intelligence solutions and workforce to tackle critical agricultural challenges related to labor, water, weather, and climate change. The institute aims to build and foster partnerships between the AI and agriculture communities and create a transdisciplinary ecosystem for technology innovation and knowledge transfer. — By Tina Hilding, Voiland College of Engineering & Architecture, Washington State University
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New Nanoparticle-Based Sensors to Measure Residual Herbicides in Food
Two newly developed, low-cost tests that use nanoparticles to detect chemicals can accurately measure tiny amounts of two potentially harmful herbicides in fruits, vegetables and their products.
Reporting in the journal Food Chemistry, a Washington State University research team used two testing methods to measure the levels of two herbicides, namely atrazine and acetochlor, in samples of apples, strawberries, cabbage, corn and fruit juices. The work shows the real-world viability of their easy-to-use and inexpensive methods of testing.
“We applied this technology for real sample detection – which is an important step in moving towards commercialization,” said Annie Du, research professor in WSU’s School of Mechanical and Materials Engineering and the principle investigator of the project.
Annie Du The Food and Drug Administration (FDA) regularly tests a broad range of commodities for approximately 800 pesticide residues, and producers are required to keep the chemical residues on food below a certain level that is considered safe. The two herbicides the researchers measured are widely used in crop production in the U.S. At high exposures, they are potentially toxic for people and have been linked to a range of maladies from allergies to hormone disruption to cancer.
Doing the testing, however, currently requires sophisticated and expensive instruments as well as a trained technician.
“We want to come up with a low-cost method that can be used in the field or in the laboratory,” said Bernie Van Wie, corresponding author on the paper and a professor in WSU’s Gene and Linda Voiland School of Chemical Engineering and Bioengineering.
Bernie Van Wie In the past few years, the researchers have developed and patented their idea that uses nanoparticles of palladium and platinum to amplify the signal of molecules. The nanoparticles attach to an antibody, which recognizes the chemical, and then stimulate the production of a signal. The amplification allows the researchers to know that tiny amounts of the chemicals are present and at what level.
In this latest work, the researchers used the nanoparticles in two types of tests to measure two chemicals simultaneously. The chemicals were spiked into fruit and vegetable samples that were pureed in a blender.
One of the tests uses the palladium-platinum nanoparticles to catalyze a reaction that causes a color change in a sample when the herbicide is present. The test can be done using a small unit that can be carried into the field. The other test the researchers developed uses the nanoparticle in a low-cost paper strip that looks like a COVID-19 or pregnancy test and can be read with a smartphone reader.
The tests were sensitive enough to measure the chemicals down to the maximum acceptable levels and were validated using traditional testing methods.
“We’re actually able to detect below the maximum concentration limits. If there’s any pesticide or herbicide in the sample,” said Van Wie. “That’s good because while this can be done by other methods, this method is low-cost and portable in the field.”
Du has recently started a company that is negotiating with WSU’s Office of Commercialization to license the technology for additional applications. The work was supported by the USDA/National Institute of Food and Agriculture (NIFA) Agriculture and Food Research Initiative (AFRI) program (grant number 2018-67021-27970). —
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Measuring Electric Current in Soil Could Provide Answers on Soil Health
Washington State University researchers have developed a way to assess soil health by measuring the electric current produced by its tiniest microbes.
The team used a probe originally developed to measure the electrochemical signal of microbes in aquatic environments and tested it on healthy and unhealthy soil samples to measure microbial metabolism and other indicators of soil health. This proof-of-concept research, published in Journal of Electrochemical Society, could someday lead to a simple, real-time test for farmers to determine whether soil is productive.
“Soil underpins all the food we eat, and most of it is degraded worldwide,” said Maren Friesen, an associate professor in the Departments of Plant Pathology and Crop and Soil Sciences and a co-author on the study. “One of the biggest barriers to improving soils is not being able to have rapid, real-time measurement to develop appropriate management strategies for them. This sensor has the potential to be able to do real-time measurements not just of the structure of the soil, but how it’s actually functioning. It would be a huge advance in the field.”
“I believe this is one of our most significant works and will have a high impact on soil health determination,” said Haluk Beyenal, professor in the Gene and Linda Voiland School of Chemical Engineering and Bioengineering and corresponding author on the paper.
Other co-authors on the study include postdoctoral research fellow, Abdelrhman Mohamed, and graduate students Eduardo Sanchez and Natalie Sanchez.
Soil health is critically important to agriculture and crop success worldwide, but measuring it is not straightforward. Farmers and researchers use soil chemistry, nutrient analysis, texture and pH measurements to gain understanding of soil’s physical and chemical properties. While that information can be valuable, it doesn’t always reflect how productive the soil actually is.
That’s because a key to soil productivity is how microbes function, said Friesen. Billions of bacteria, fungi and other organisms play critical roles in nutrient mobilization and provisioning, defense against pathogens and plant growth. But, until now, there has been no simple, real-time way to measure the microbial activity.
“What makes a soil beneficial for a plant is that it is alive and contains all these bacteria and fungi,” she said.
In the new paper, the WSU research team was able to measure current through the soil to determine microbial activity and distinguish healthy and unhealthy soils.
The researchers used a probe that they developed a few years ago to measure the electrochemical signal of microbes in aquatic environments. Similar to how humans eat and breathe, microorganisms take in food and then use electrons liberated during metabolism for their energy. Finally, microbes give these electrons to an acceptor molecule such as oxygen. The probe the team developed replaces these acceptor molecules with an electrode. Using this electrode, they can then measure the electric current and get an idea of the magnitude of microbial activity.
“We are able to measure metabolic rate of the microbes by capturing electrons that are released as a part of metabolism,” said Mohamed, a postdoctoral researcher in the Voiland School. “We’re watching the microbes breathe in the soil.”
The two soil samples the researchers used were collected from the R.J. Cook Agronomy Farm and looked nearly identical to each other in terms of their soil composition. They were both collected from plots that had not been tilled, were relatively high in organic matter, and had the same pH and soil type. But, the researchers had data showing that one of the soils had been significantly more productive in its wheat yield than the other.
The researchers found that the more productive soil produced an electric current while the less productive soil produced almost no current – about 1% of the more productive soil.
“There was a really dramatic difference in the amount of current generated,” said Friesen.
They also found another difference between the two soils in the open circuit potential measured in the soil. When they added sugar to stimulate metabolic activity, the researchers also observed the electrochemical signals change in the healthy and unhealthy soil samples converging, which suggests that the sugar addition stimulated the microbial activity in both soil types.
“We could see that in a couple of days, the microbes in the soil started to respire,” Mohamed said.
With just the two soil samples compared initially, the researchers say their idea is still just a proof of concept. They have many additional questions, such as what the creatures are doing to generate current and what specific microorganisms might be in the samples to create productive soil.
“We have two different signals, but what do they really tell in terms of the fundamental parameters of the soil?” said Mohamed. “Both parameters tell slightly different things, and we need to work on their interpretation.”
They also want to test a lot more soils, including in actual farm fields rather than in the controlled setting of a laboratory. They hope to eventually develop a portable probe that could be inserted directly into the soil to provide real-time information.
“In terms of working towards a just society with sustainable global food production, I feel this has the potential to be a game-changing technology,” Friesen said. — By Tina Hilding, Voiland College of Engineering & Architecture, Washington State University