SOIL CONSERVATION, ORGANIC MATTER AND SOIL LIFE

Invited Presentation to the Senate Committee on Soil Degradation in Canada

- Surveys main groups occurring in soil and notes their importance.

SENATE OF CANADA

Proceedings of the Standing Senate Committee on Agriculture, Fisheries and Forestry
Chairman: The Honourable HERBERT O. SPARROW
Thursday, May 3, 1984 Montreal, Quebec
Issue No. 13
Thirteenth proceedings on:

The examination of the subject-matter of soil and water conservation throughout Canada pp. 46 - 55.

The Acting Chairman: The meeting will come to order. I will ask Professor Hill to take the floor, and remind him that we are increasingly pressed for time. I would ask him to limit himself to about 15 minutes, as the list of speakers is quite long. You have the floor, Professor.

Professor Stuart Hill, Department of Entomology, Macdonald College, McGill University: Thank you Mr. Chairman. Honourable senators, ladies and gentlemen, I have read with interest the proceedings of this committee and I commend honourable senators for tackling this problem, which is one of the most important problems that face us today in Canada. You have heard that the situation has reached a critical level in most regions of Canada. While the presentations to date adequately describe the problem, few examine its fundamental causes and none deal with the nature of soil in any more than a superficial way. Rather than repeat what has already been said, I will use my time to introduce you to the life in the soil and to the holistic, ecological approach to its management.

I come to honourable senators from Macdonald College, more particularly,from the Entomology Department, of which I am a professor, and from Ecological Agriculture Projects, which was established in 1974 to provide a resource center where people from around the world could find information onhow to design sustainable, nourishing food systems; that is, systems, for example, in which soil fertility and productivity are maintained and enhanced rather than degraded. Ecological Agriculture Projects came into being as a result of the foresight and concern for problems such as soil degradation of Dr. and Mrs. David Stewart of the Macdonald-Stewart Foundation. As honourable senators may know, Dr. Stewart died last Friday, so I would like to dedicate my remarks today to his memory and to acknowledge that it is largely because of his support that I am here today, able to provide you with a rather different perspective than you have been exposed to up to now.

First of all, I would like to start by stating my initial assumption, and that is that the collective wisdom and intelligence in this room is capable of solving the problem of soil degradation. Otherwise, I would not be here.

However, I would add that we need to take a very different view from that which we have taken up to this point. What is often not realized is that soil is not a dead system but is very much a living system. In fact, when you look out on the landscape there is more life below the surface of the soil than above it. Most presentations to this committee have been delivered as though we were dealing with something dead. I want to emphasize that we are dealing with a living system.

I also want to point out that, when we look at subjects such as soil degradation, we often move through this series--and think we have seen this to some extent this morning--whereby we start off with a problem that seems relatively straightforward, soil degradation, we think that there must be a solution, and then, as we listen to presentations such as your committee has heard, we start to find that it is complex--in fact, paralyzingly complex--and we feel very confused. The state we need to reach is the third stage, which is profound simplicity where the truths of the situation emerge. Rather than introduce this idea to you with more data initially, I would like to introduce it to you by quoting a poem, because poetry often conveys meaning more clearly than data. It is a poem by Elizabeth Odell and it goes like this:

Flat outstretched upon a mound of earth I lie; I press my ear against its surface and I hear, far off and deep, the measured sound of heart that beats within the grounds. And with it pounds in harmony the swift, familiar heart in me. They pulse as one, together swell, together fall. I cannot tell my sound from earth's, for I am part of rhythmic, universal heart. Those words convey, essentially, a philosophy relating to the soil. The problems we have with the soil exist because we have separated ourselves from the soil. The profound simplicity, in a sense, is that we have to close that separation, or, as Sitting Bull stated much more simply, "The earth and I are of one mind." That is the point we have to reach if we are to generate a way of managing soil that is not going to lead to degradation. To look at it another way, we have to study the problem much as your committee is doing. More than that, however, we have to spend time with the environment we are talking about. It is very difficult to understand these problems and to understand how the soil functions when we are sitting in a city in an air-conditioned room.

Thirdly, we need to imitate the way the system works and to work with the natural processes. To understand that simple system, we need to see that agriculture is a production-consumption-recycle process. All of our emphasis in agriculture has been on production and we have taken attention away from recycling. The soil, however, is the recycle part of that system, and, if we want it to function, we must pay attention to providing it with the things it needs to keep working.

As I said earlier, removing the separation between us and the soil is really a matter of integrating our life-style with the way the soil works. In that way, we create a balance between us and the soil, paying attention to the feedback when the soil is being washed away and recognizing what that means and what we must do about it.

I would now like to move from studying the soil to spending time with it, ma sense, to take you down into the world of the soil. People often think that soil is just a pile of dirt, but it is more likened to something like the hotel where we are right now. Soil has different things going on in different levels. It is a stratified material. When we come along and jumble it up, we initially create problems. We therefore have to recognize the layered nature of the soil, the litter, the humus and the mineral layers, for example. If you look at it in terms of space, about half of the soil is solid material, while the other half is space. Half of that space is filled with water. The life in the soil is divided up into a number of organisms that are swimming around. They are basically aquatic and swim in the water around the particles of soil. It is these organisms that are in the soil which maintain the soil's fertility. It is not so much the farmer putting on fertilizer, which is an indirect way of dealing with fertility. If we want to maintain the fertility of the soil, it is those organisms that we have got to cater to. There is a whole range of such organisms. In an average acre or so of fertile soil, there can be as many as a thousand different species. We can turn that organic matter into the surface of the soil with equipment. When we do that we are providing these organisms with food. We can also grow green manure crops and turn those into soil. In this way we provide food for the organisms in the soil. When this material is provided to the organisms they start to break down and it begins to look like this. It is the by-product of this breakdown which maintains the structure and health of the soil. When a dead animal falls to the ground maggots and beetles soon arrive on the scene and break it down. Not long after that process starts we are left with some bones, the flesh of the animal is gone. If it were not for these organisms in the soil we would be up to our necks in waste.

So the production of healthy soil is a decomposition process--it is the breaking down of dead organic matter into humus and the breakdown of the parent rock to minerals. The combination of these two results in mineralorgano complexes. It is from these complexes in the humus that nutrients are taken up to plants and the system is maintained. If we want to have healthy soil we must do what we can to promote this decomposition process, since that is how soil is formed. What I am saying is that if we cater to the needs of the organisms in the soil they will maintain the soil and the soil will maintain us. This is why it is very important to be familiar with the organisms I am showing you now.

This slide depicts some of the organisms in the soil. I believe I have passed around a sheet which is the same as this picture. There are bacteria, moulds, or fungii and protozoa, which are one-celled animals swimming around in the water film feeding on the bacteria. This next slide shows more protozoa and some other exotic animals which swim around in the water film.

This next slide depicts nematodes, most of which are beneficial and not harmful at all. There is a tendency to think that all worms are harmful. Some of these organisms have very intricate relationships with other animals in the soil. For example, these nematodes take rides on this mite, which is how they get around in the soil. This is a picture of some mites, which are most beneficial. In fact, less than I per cent of arthropods, which includes insects and mites, do any harm. Again, there is a tendency to believe that insects and mites are harmful. This slide depicts some of these other organisms. In order to illustrate the intricacy involved, this next slide shows a little white dot on the left, which is a mite taking a ride on another mite. The next slide depicts mites taking a ride on a dung beetle. You can imagine the scene. If these mites happen to be the type of mites associated with animal dung, their legs are very short and they would have quite a long walk to get from one cow cake to the next. So they have tuned into the dung beetles which have wings. When the dung beetle is about to take off it gives off an odour which says, in effect, "the bus is leaving". The mites jump on the back of the beetle and are transported to the next pile of dung. These are just some of the wonders which are taking place down there. When we think in our arrogance that we are running the system it is important to remember this type of relationship.

There are other mites which are attracted by flies and use these flies to transport themselves from one location to another. There are small insects with feather-like wings, as shown in this slide. Then we have ants, white worms, or pot worms as they are sometimes called. In fact, much of the fertility in soil is really a result of the waste materials of these organisms, that is, the fecal packages which they deposit. The next slide shows earthworms--the intestines of the soil, as Aristotle called them. In a square metre of fertile soil there may be over 300 earth worms. If there are no earthworms the soil is in poor condition. There are other types of nematodes which are not beneficial. Actually, some of them can cause problems. Fortunately, the soil has its own way of dealing with these types of organism. The next slide depicts fungi which will actually trap nematodes by giving off an odour which causes the nematode to swim into the little nooses formed by the fungi. The noose tightens and the fungi digest the nematode. By providing the soil with organic matter we provide an environment where the fungus can grow, which then catches the nematodes. We do not need to put out nematocides or different types of poisons on the soil to deal with these harmful organisms; rather, we need to maintain the fertility of the soil. As a doctor friend of mine once said, "We do not suffer from a headache because of a deficiency of aspirin in the blood." Likewise, we do not suffer from nematodes because of a deficiency of nematocidcs, but, rather, because the soil is not functioning. In a way, the nematode, which is a pest, is telling us that we are not running the soil properly. Rather than kill the nematode, we should take notice of the problem and deal with it at its causal level. There are other pests such as grass grubs; but even these provide methods of control. Most of them are attacked and killed by at least half a dozen insects. By providing the environment with these organisms we can control the pests. There arc a great many predators which feed on these organisms, such as centipedes and ground beetles, both depicted in this slide. The general tendency we have is to get out onto the fields and spray. However, that spraying kills most of the beneficial organisms in the soil. It will also kill this person depicted in the slide, if he continues to spray without protective clothing. This photograph is from a pamphlet which sets out methods on how to spray, which completely disregards the need for protective clothing. The following slide depicts the Italian model; and this one an upside down model. At one time a great deal of spraying was done by airplanes, which causes incredible damage to the life in the soil. idespread overuse of chemical fertilizers, particularly nitrogen fertilizers, has led to the acidification of soil, already heard in other presentations.

Basically, we are in the type of situation where we are destroying the soil and then enriching it with a few nutrients. A plant which grows takes a dozen or so nutrients out of the soil. We then put two or three nutrients back in and call it "enriched". We do exactly the same thing with food by processing the nutrients out, putting a few back in and calling it "enriched". We take the same sort of approach with respect to people through the use of toximolecular approaches. The soil is really the foundation on which our society stands. If we do not learn how to manage the soil properly, we will not only be witnessing a degeneration of the soil but a degeneration of our society. What we have to do is feed these organisms in the soil by returning the wastes to the soil, for example, as manure, and even through the composting of manure. People sometimes say that composting is a backyard activity. I show you the following slide which depicts a man putting compost on a quarter of a million acres of land in the United States. He calls himself a used hay salesman. Composting is a good way to deal with wastes which otherwise would not be used. The following slide depicts woodchips combined with chicken manure which, six weeks later, results in nice rich black humus as a result of decomposition in a managed way. Composting is a way to build up humus and return valuable organic matter to the soil.