Interview with Professor Joann K. Whalen

September 21, 2020
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Joann K. Whalen is a Professor and William Dawson Scholar at McGill University, Adjunct Professor with the Northeast Institute of Geography and Agroecology Chinese Academy of Sciences.

She received her Ph.D. from Ohio State University (USA) and prior to joining the faculty at McGill, she worked as a research scientist for Agriculture and Agri-Food Canada.

Dr. Whalen is a professional agronomist in Quebec, Canada. Her research focuses on soil fertility and soil ecological health of agroecosystems. She has published more than 160 peer-reviewed scientific publications and supervised more than 50 students at the M.Sc. and Ph.D. levels.

She teaches courses in soil fertility, nutrient management planning and soil ecology. Dr. Whalen is senior author of the textbook “Soil Ecology and Management”, published in 2010, by CABI Publishers. She’s the editor of “Soil Fertility Improvement and Integrated Nutrient Management: A Global Perspective”, which is an open-access e-book published in 2012, presenting 15 written chapters by leading soil fertility experts spanning more than 20 countries. In 2016, Dr. Whalen served as President of the Canadian Society of Soil Science.

SFH – What fascinated you to become a professor in soil ecology?

JW – Ok, so I never really dreamed I would get in soil ecology because my first interest was in food sciences, and food chemistry. One semester I was taking 2 courses.  At the same time, I was taking a food chemistry course and a soil chemistry course. I was really fascinated by how it overlapped so well. I really enjoyed my soil chemistry teacher because he explained things well and he pushed us to dig deeper into the research aspects, to dive into the literature, so it was an eye-opening experience. Then with the same professor, I later did my master’s degree.  I enjoyed his approach to things, and his openness that soil is more than just a bunch of chemicals.  There I learned that soil is more than chemical reactions, it has physical and biological component to it.  Then I went off to do a doctoral research.  I got in a lab in the US that specialized on soil Ecology, top notch. I learned much with them and that put me on the path to becoming a professor in soil ecology.

SFH – You’ve written extensively in soil health and management; do you think as a society we will become greater soil stewards? 

JW – I think that the public has a better appreciation of soil, and soil health.  This has become a hot topic. People have talked about soil conservation or issues about soil erosion and protecting the soil surface needs; and integrity of it. But then comes a point in time they say – but there’s creatures in the soil. The idea there is a lot of biology in the soil, it becomes a living organism, it becomes a living soil, and so I think that appeals to people. The concept of soil health is that it resonates well with the general public.  People know when they feel healthy, and when they don’t feel very well.  You can imagine the analogy, you can look at the soil and measure things in the soil, is the soil healthy or not?  From a practical stand point, we have certain tools we can take measurements with, and we can determine it fairly quickly; whether the soil has the capacity to support sustainable agriculture, or are there interventions that should be made, to have the soil regain its potential?

  • The public has a better appreciation of soil health today – it is a hot topic.
  • People appreciate that there are living organisms in soil and that it is a tangible animate breathing thing.
  • Soil health resonates with people because they see the connection with their health.
  • We have better soil measurements today to help guide us care appropriately for our soil.

 SFH – Farming practices aside, one of the greatest challenges I think for farmers and growers is the lack of organic matter in the soil.  Can you explain what organic matter represents and its role in farming?

JW – Organic matter is one of the components of the soil. Many people think of the soil as granular particulate parts.  The sand silt and clay. That’s one of the parts of it but, organic matter is what helps to hold those mineral particles together. It provides a cohesion in the soil and it forms the aggregates that are  little aggregation of soil particles together. All those millions of little aggregates have got little homes inside them, where microorganism live, that have little compartments where animals live.

They also allow the water to move through the soil. They leave particles and space for water to move in and infiltrate the soil. The organic matter helps to hold water and retain it like a sponge. Another aspect of organic matter is its capacity to hold and retain some of that water so that it stays available for the plans when they need it.

This organic matter is also extremely rich in nutrients. It is a reservoir of nutrients, that has come in the form of plant residues, animal residues, any types of organic material.  Anything that comes back into the soil, even the remains of the dead soil animals, the bacteria, and the fungus, are another component of the organic matter. They can be living, or they can be dead.

To recapitulate, organic matter is holding the soil together, retaining the water, providing structure, allowing water infiltration, providing nutrients, and lastly it just makes the soil have a texture that is easy for us to manipulate. To till, or to allow plants, little seedlings to grow their root systems, to germinate, in soil. There are so many reasons to focus on the organic matter. One of the things I always say is, a little bit of a joke to my Soil Fertility undergraduate students is: “We have soil “X”, what you do?”  we all laugh and say: – “add organic matter!” But it’s really is true, by adding organic matter really does solve a lot of problems we find in soils.

  • Organic matter holds the soil together provides structure, cohesion maintaining the soil aggregates.
  • Retains the moisture in the soil, permitting water permeability.
  • The organic matter facilitates workability of the soil, offering a malleable texture.
  • Organic matter provides the bed necessary for the seedlings and the plant roots to comfortably establish and grow healthy.
  • Organic matter is the habitat for beneficial living organisms.

 SFH – At this point, we’ve ended up with a situation where soil has really been lacking in organic matter, so perhaps can you explain how we got here?

JW – There is soil that we find to have a low organic matter content. One of the reasons they have low organic content is because they inherently do not have the capacity to hold onto organic matter. The sandy soils will have less organic matter. There is not much you can do about it. It’s the actual situation of those soils. The organic matter tends to bind to the clay, so, you have soil that’s very sandy which won’t tend to hold a lot of organic matter in it, and because it doesn’t get held, it gets stuck into the soil and attached to the clay.

The decomposition rate is faster than the rate of residue coming back to replenish that organic matter.  Then the trend over time is a declining trend. You will see the organic matter level going down. A person farming on sandy loam soil, with a clay content, of let’s say, 10% to 15%, will have to be quite attentive and regularly put organic inputs back into the soil.

Crop residue that they have, should be left in the soil. That helps quite a bit, but it still may not be quite enough. So, we would recommend to this person that they look for other sources of organic matter to help boost up the soil. Those could be in the form of compost, it could be a municipal solid waste, it could be an animal manure. It could also be some type of bacteria that are able to grow and to provide more carbon fixation, which grow in soil as well.

There’s a lot of other resources out there, and we would recommend that people farming very sandy soil try to make use of those resources. At least try to stabilize, if not build the organic matter in the soil for better performance.

  • Some soils lack the capacity to hold organic matter, like sandy soil; while others have a greater capacity to hold organic matter like clay.
  • For some soils, if organic matter is not replenished quickly enough, the rate of decomposition is faster than the rate of organic matter replenishment.
  • Crop residue needs to be left for the soil to consume; however, sometimes it is not enough and more needs to be done.
  • Organic matter needs to be added to soil to gain its favorable consistency and capacity.
  • There are more resources out there today to build soil, investigate the many options available for better soil performance.

SFH – Is organic matter something that is currently being followed, or is it measured as something apart from farming?

JW – I believe so, because on all our standard soil test reports when you go and send your soil into analysis, it’s one of the tests they do on a very routine basis.

The soil testing labs will normally test the pH of your soil.   They’ll test the nutrient levels in the soil, and then evaluate the Cationic Exchange levels.  They will do the texture if you ask them to, but the other very important thing they do, is assess the organic matter level.  A lot of people that I know who are farming, will take the reports year after year, and they’ll look at the organic matter levels in the soil.  Along with the pH, it will let them know if their practices are kind of building practices or if they’re depleting practices.

If you’re coming into a piece of land, for the very first time, and you’re not certain:  what’s the actual status, how do I compare this, am I low, or where am I? There are soil survey reports for every place in North America.  You can get the standard full survey report, that tells you if you can expect to add organic content, and you can then compare your numbers to see how you’re doing.

  • Soil organic matter can be followed today by means of soil testing.
  • These types of analysis should help indicate if your practices are building or depleting practices.

 SFH- Over the last years, if not more, greater attention has been given to the biological approach to farming.  The care for the soil microbiome. Could you tell us a bit more about that? And it’s effect on farming?

JW – Sure, what we have now in soil science is what can allow us to identify all the organisms in soil from just a couple of grams in the soil. To extract the DNA, and using high throughput sequencing we can determine who are the fungi, the bacteria, and archaea living in your soil.

This is amazing because not only do we know who’s there. We also have another way of using metagenomics to know what they’re doing. The genes they are possessing which allow them to produce enzymes that do various functions, like help the plants, or provide a nitrogen fixing capacity, to independently do decompositions and nutrient cycling in the soil.

So, it’s a pretty exciting time for researchers. From a practical perspective, it’s a little difficult for a producer to understand exactly what this means. For example, to have bacillus in the soil.  It’s hard to understand this, so generally right now, the farmers are looking to soil test laboratories to do biological soil tests which provides information on nitrogen mineralization capacity of the soil, and soil respiration. These measurements give a lot of insight into the activity of the microbial community living in your soil, which turns out to be quite useful.

  • Biological tests give insight to the soil’s microbial DNA.
  • We can see what the microorganisms are, and what they do.
  • Farmers are relying a lot on the soil test laboratories to provide them with answers.

SFH – So how may we compare this introduction of this new practice of the biological aspect to what’s going on with the conventional, or synthetic approach?

JW – Now we can measure different types of elements in the soil. These test on respiration; the nitrogen mineralization is complimentary and actually provide us new information that are not available from conventional soil testing at all.

Our conventional methods would tell us if you are low in phosphorus, potassium, etc.  So, you need to add those fertilizers.  With the biological approach, we now know there’s some capacity of the soil to supply nutrients to the plants. We’re able to have a more measured approach to fertilization because we are not having to over apply nutrients.  We’re accounting more correctly and properly for the capacity of the soil to help grow the plants.  Which we were not able to do with our older testing methods.

So, I think there’s a real advantage from asking the labs to do these extra measurements and paying attention to those results. You’ll be a lot more targeted on what you will actually add to the soil and going to be building using the resources that are already there from the biological perspective.

It also helps you to understand some other things when we start to get into pathogens. The new techniques will help with the identification of such organisms like the disease-causing organisms and what they are? You can have a very targeted approach to control it, rather than just understanding what something out there is causing this problem. When I don’t know what it exactly is?  But then what to do?  Maybe by fumigation or harsh sprays or something like that we can be a lot more targeted, more careful and measured about what we’re doing now, when we know what the problem organism is?

  • Biological testing approaches are now available and give much more valuable information than conventional soil testing.
  • Conventional methods measure NPK, which are helpful to understand what fertilizers to immediately apply.
  • Biological tests offer a more targeted approach to dealing with soil management.
  • New techniques offer a window into recognizing soil pathogens.

 SFH – How can we increase the rate of the adoption to such practices into the current industry?

JW – I think a lot of people in the industry would like to hold back on using agrochemicals. They don’t necessarily want to use a lot of fumigants because they’re expensive. From an environmental and health perspective, they cause concerns.  People would really like to get away from that, but of course, they’re afraid of the economic repercussions. If I don’t control for this abnormality than what’s going to happen to my yield? If I don’t put enough fertilizer in, am I going to get the economic return at the end of the season?

I think we need to give enough demonstration and from the research perspective, we can explain the reasons why certain products work while some other products are less effective, or work under certain conditions.  Then we can give a lot more confidence to the industry to say: well I can decide to use this product because it’s been shown to be effective under these sets of conditions, which are similar to mine.

There is a goal for companies to go forward and try new products.  The role for research is to come up and support that. Not only confirm that products might work, but also to explain the reasons why and under what conditions those products will be effective.

  • Many prefer not to use harsh chemical additives in soil.
  • There are concerns on what products to use that will maintain their yield.
  • Wise product choices can be made by growers by giving greater guidance as to which product is most effective for set conditions.

SFHWith Soil for Humanity, our goal is to bring awareness to the depleting quality of soil and make it a part of our daily conversations, what advice do you have for us?

JW – So how to make soil a part of our daily conversations?  I think it’s just about connecting people to the soil.  Just make an awareness that where did your food come from? Sometimes people get sidetracked from the actual origin of food, and they just start to think food comes from the supermarket.

Bring it back to where did this food come from? We can encourage people to go to the source to get food.  That they have more interaction with people who produce food.  When they start to ask questions and start to be more interested, they will see where their source is.

At the base, the source of your food is not just the seeds, but it’s the environment in which those little seeds must grow up in. If you don’t have a suitable soil environment, your just not going to grow anything

All the things that you are doing with education, outreach, and sensitizing people, by reminding them:  where did your food really come from? What gave all those nutrients that grew all that food?  The water comes from the sky, but water drains away, so how did it stay someplace so that it was useful and gets absorbed by the plant.  It must stay and be absorbed with the organic matter in the soil.  So, there is a sense to say that soil is really life.

  • Make soil a part of our daily conversations.
  • Have people connect with the soil.
  • Awareness on where their food directly comes from.
  • To educate and provide an outreach to sensitize people to healthy living from soil.

 SFH – Can you share with us some of the future endeavours where you will be exploring?

JW – We’re interested in the biological functions of the soil. We have on-going projects that deals with specific types of organisms like mycorrhizal fungi, and their ability to help plants retrieve nutrients from the soil.  We’re also looking at them in the sense of how much water can a mycorrhizal network, associated with your plant roots, provide to the plant.  Particularly as we get into the situations, when we have a long dry period, when we have more types of droughts, looking at how those organisms become important?

We’ve also been thinking at other types of stress events. Water stress is important, but heat stress is important as well, because it really impacts plants severely. Sometimes you don’t know what’s the matter with the plant.  It’s wilted, and you put water on it.  They are not responding, they’re overheating. It’s like having a fever. So, there’s organisms that live in the soil that can produce plant hormones to help control the senses.  There are stressors out there to help the plant take control through hormone levels.  Through physiological adaptations it can tolerate and survive through very dry or either very hot events, so that the plant can continue to survive. It’s in the interest of the microbes, they want the plant to live.  They live with it, they are in a symbiosis or live in a very close association with the microbial environment created by the plant, and the roots exudates that the plant shares are very important for the life of those microbes. The microbes have an invested interest that the plant stays healthy and strong.

The second thing that we’re interested in, is accounting for the contribution of soil organisms to the nutrients supply that gets to the plant. To do it on a very site specific and careful basis, in which we want to be able to target parts of the field that have higher, inherent fertility and differentiate those from other parts that have lower fertility. If we’re making choices about where to apply fertilizer, or other types of soil amendments that we target them specifically where they are needed.

In terms of supplying nutrients to the plants, we tend to use a spoon-feeding approach where we are very careful about using measured, judicious amounts of nutrients and not giving too much. Or not over doing it per say. I think you can produce crops very well without over applying any type of chemical, or any type of fertilizer or pesticide. If you are carefully accounting for what the soils’ biological activity brings to that crop, you can reduce your dependence on some of these other inputs.

  • Biological functions of soil.
  • The specific organisms in the soil and what their role is to soil health.
  • What stressor provoke soil behaviour with plant interaction: supporting microbes in soil and plant fertility.
  • Nutrient supply to the plants that mimic nature as opposed to the modern spoon-feeding techniques.

SFH -Would you agree with the saying: “It is better to farm soil rather than to farm crops because if you take care of soil it will take care of the rest?’’

JW – It’s a very apt quotation, it seems very relevant, and it’s very consistent with the approach that we’ve taken.  To look after the soil and other things will follow along.

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