Thursday, May 9, 2013

Science as Dialogue: What My Garden and I Are Discussing in 2013

Another cloudy, wet spring day in St. Louis. The mulched bed is my herb garden.

In the last post I brought up my use of the scientific method in my gardening practice. Now I’d like to talk more about how ordinary folks (and as far as gardening goes, I’m as ordinary as any of you) can use the scientific method to solve problems that come up with the materials of everyday life. What I hope to do is de-mystify the method and also separate it from any negative associations you may have picked up about it from prior experiences, so that you can turn to it when the question you have in mind is amenable to its use.

In my previous post I quoted Wikipedia’s definition of the scientific method: “the process of systemic observation, measurement, and experimentation and the formulation, testing, and modification of hypotheses.” It’s an accurate enough description, but I suspect rather forbidding for ordinary people to apply to everyday problems in the material world. This may have something to do with schooling and its tendency to separate knowledge into fields that seem to have nothing to do with each other. The scientific method gets classified as something you do in science class and nowhere else. If you didn’t like or do well in science, you may not realize how useful the method can be.

So let me suggest a more informal and friendlier description of the method so that anyone who is curious about a problem in the material world can use it fruitfully. Think of the scientific method as a dialogue with the material world, a process by which you can ask questions about aspects of the material world that puzzle you and obtain information that may help you to answer those questions, or modify them, or ask new ones, or any combination of these things. The questioning part corresponds to the hypotheses mentioned in Wikipedia’s definition. Obtaining information corresponds to the systematic observation, measurement, and experimentation portion of the definition. The questioning and information-gathering process continues for as long as you find the dialogue useful to maintain.

Suppose we want to find out why a friend holds a particular position. We might have an idea about how our friend came to that position and start by asking questions to see if our idea is in fact important to our friend’s thought process. Our friend’s answers to these questions would provide information that we would consider in deciding whether or not our idea has merit. If it doesn’t, we might have gained enough information from our friend’s answers to change our idea about how she came to that position, or perhaps we are now thoroughly confused about why she holds that position. Maybe we’d ask some more questions, especially in the latter case, as we attempt to understand her position from her viewpoint. Perhaps she’s changing her own ideas as she listens to and responds to our questioning; she may ask some questions of her own about our position and why we hold it. Eventually the process, done well, results in a clear understanding of each person’s position and the reasons for it. It may lead to changes in one or both peoples’ positions due to the new information that comes to light. This sort of extended dialogue is what I’m doing in my garden. I can’t do it through talk because of the language differences between me and the plants, animals, and other materials and processes that constitute the garden system. The scientific method, or scientific dialogue, offers me a language in which to ask and receive answers to questions that I have about the garden system and change the way in which I garden to interact more fruitfully with it. In the process, I’m likely to be changing the garden itself ... and it changes me in turn.

In the scientific dialogue that I am having with my garden, the major question that I’ve been asking since I first learned of Ecology Action’s work in the middle to late 1990s is the one that I mentioned in my last post: can a person grow all of his or her own diet in a small backyard garden in the St. Louis region without making it difficult or impossible for someone else to do the same thing in a similar sized garden elsewhere? At the time Mike and I were living on a 1/8 acre lot, of which I had less than 150 square feet in vegetables. I obtained One Circle by David Duhon no later than the 1999 three day Ecology Action workshop in Fairfield, Iowa that I attended. Duhon’s claim that it was possible to grow a complete diet in about 700 square feet of gardening space suggested to me that the answer to my question could be yes, at least in principle. If we chose to remove the trees, ornamental plantings, and patio from the back yard and planted the flattest portion completely to vegetables, and if I put some of the prettier edibles in the front yard, I could have installed close to 1000 square feet of garden space into that excessively sloped and paved-over (a 100 foot long driveway!) lot, enough space to provide two adults with most of a complete diet according to the book. That lot was similar in size to many urban lots in St. Louis. Most suburban lots in the region are closer to 1/4 acre in size; a sizable fraction, including our current lot, are larger than that.

Since the availability of sufficient gardening space didn’t appear to be an issue for most people in the region, the next question became whether or not I could obtain a high enough yield (measured as pounds of food harvested per 100 square feet of growing space) of the crops discussed in One Circle to grow the complete diet worked out there. The tricky part of working out a complete diet is that the usual crops grown in a backyard garden -- largely salad crops like lettuce and tomatoes along with fresh vegetables like snap beans and peas -- provide vitamins and minerals but not many calories for their weight. One Circle has an extensive discussion of human dietary needs, the first among them being calories, or food energy. Most backyard gardeners haven’t concerned themselves with growing crops dense with calories, primarily root and seed crops, because these are widely available at low cost from agribusiness and its distributors and retailers. Backyard gardeners prefer to grow the more perishable vegetables that do well in small spaces, often taste better grown and consumed fresh than do the multiple-day-old versions available through the agribusiness chain, and cost more to purchase fresh from a local farmer than they do to grow oneself. In addition, the seed crops such as wheat, corn, and rice that constitute a high proportion of the calories in my diet and that of most people in the U. S. take a lot of space to grow per calorie obtained, more than is available in a small backyard garden, and also require considerable processing to use. Root crops like potatoes and sweet potatoes, in contrast, do provide a lot of calories for the garden space they take up and don’t need special processing to use but do require a lot of storage space in living quarters. Potatoes are harvested in the height of summer and require a cool, dry storage space, something St. Louis conditions don’t provide at that time of year. Sweet potatoes may be better suited to our climate and storage conditions but still require a lot of storage space. Both crops are cheap and readily available in grocery stores however so most gardeners do not bother with them. All that being the case, One Circle puts forth a convincing argument that a backyard gardener who wishes to grow most of what she eats should concentrate on growing calorie-dense root and seed crops along with some highly nutritious greens. As jobs and income continue to erode and food costs continue to rise, the economic argument for raising a higher proportion of calorie-dense crops in backyard gardens gains merit as well, for me and Mike as well as many other people.

For this reason I started including most of the One Circle crops (potatoes, sweet potatoes, soybeans, sunflower seeds, onions, garlic, leeks, wheat, parsnips, parsley, collards, and turnips) in my garden once we moved to our current lot, where we have enough space for a 1500 square foot vegetable and grain garden. For the past several years, therefore, the form of the major question that I have been asking my garden to answer has been can I obtain high enough yields of the crops profiled in One Circle that we could grow almost all of our diet from them in the 1500 square feet I now have available for those crops? So far for all of these crops except parsley, the answer has been no.

I’ve been trying to understand why my garden keeps telling me no. As I noted before, it could be my gardening techniques are not optimal for this climate and I continue to pursue information that could help me to improve them. However, I think two other factors have a larger effect. One is an unbalanced soil mineral base as discussed a few posts back. That’s what has prompted the particular question that I am asking my garden to help me understand in 2013: what effect does proper soil mineralization have on the yields that I am able to obtain under my particular growing conditions and at the skill level I now have? As the year proceeds and I harvest my crops, I’ll be reporting on the yields I obtain and other garden observations I make so you can follow the dialogue as it proceeds. That may help you learn how a scientific dialogue could aid you with questions you have about your material world.

The second factor is one I mentioned briefly in the last post: it may be that growing conditions in the St. Louis region will not allow for high yields of some of these crops because our growing conditions do not match well to the requirements of the crops. I suspect this is the case for many if not most of the crops on the list. If after proper soil re-mineralization and attention to garden technique (planting the crops at the right time and in the proper spacing, for instance) I still cannot achieve the yields needed for the set of crops advocated by One Circle, then I’ll need to use the information in that book and a later Ecology Action publication, Designing a Grow Biointensive Sustainable Mini-Farm, to work out the space requirements for a complete diet specific to the St. Louis region and the yields I have been able to obtain. Then I’ll have to try growing that diet and eating it to see what modifications it may require. That means lots of good scientific work to be done in upcoming years and reported on in this blog!

As for how to conduct my dialogue with my garden, I rely on another of my favorite garden writers, Carol Deppe. She includes in her excellent book Breed Your Own Vegetable Varieties: The Gardener’s and Farmer’s Guide to Plant Breeding and Seed Saving a description of how to conduct the dialogue (which she calls gardening research) as it pertains to variety trials. She points out that variety trials are central to answering gardening questions. I’ve used her work as a guide to my own.

Observations, data gathering, and record-keeping are essential to any scientific dialogue. Your partner in the dialogue -- in this case, my garden -- offers its answers in the form of things you can sense by sight, hearing, touch, smell, and taste. So you won’t forget these things after you sense them, you need to write them down someplace where you can refer to them later as needed. These pieces of sensory information are what scientists call observations and data. An observation is usually something qualitative: the lettuce leaves have some kind of insect on them, for instance. Data is more often quantitative: on May 8 I harvested 13 ounces of asparagus. You want a place where you can record both kinds of information. The Bountiful Gardens website has a downloadable pdf (Crop Record Keeping) form with spaces for both qualitative information (called Observations) and quantitative information such as weight harvested (and number if it’s something like heads of lettuce or cabbage) and the date, as well as information on what variety was planted, when it was planted and in how much space, how the bed was prepared and how the crop was spaced, and other important information to help you figure out what your garden is telling you. You can use this form or devise a similar form more suited to your own garden. I keep records the old-fashioned way, using paper and pen, but there is nothing to stop you from keeping the information on your computer if that makes more sense to you. I use a separate sheet of paper similar to the form linked to above for each variety of each different crop I grow each year. I keep all the current year’s sheets in one binder, arranged alphabetically by crop and then alphabetically by variety within each crop, because that binder is small enough to carry with me to wherever I need it. After each variety is completely harvested and I’ve calculated the yield and written down anything else I want to remember about it, I file its data sheet into master binders also arranged alphabetically by crop and variety. Within each variety that I grow for more than one year, I arrange the sheets chronologically by year. I find this arrangement is the best for answering questions on yield and how it changes from year to year. You may prefer a different system depending on the questions you most want to answer. As for the information you might want to record, see Deppe’s book as she has a thorough list that you can choose from according to the questions you are asking.

In order to get answers to the questions you are asking, you have to know how to set up a gardening plan or design that will allow the garden to answer those questions for you. Scientists call this design an experiment. Deppe calls it a garden trial. Whatever you call it, you have to make sure you can obtain the answer you want from the way in which you garden. Since one of the questions I want to answer has to do with how many pounds of, say, ‘German Butterball’ potatoes I grow so I can compare it directly to the yield for potatoes in How to Grow More Vegetables, I need to know the number of square feet of those potatoes that I have planted and I need to weigh all the potatoes that I harvest from that area. The square feet of garden space devoted to these potatoes is noted on my garden plan for 2013 and on that potato’s data sheet. I weigh all the produce I harvest, and I also record the date it’s harvested. At the end of the season, I add up the total pounds harvested for these potatoes, convert that to pounds per 100 square feet using the actual bed space for the crop, and check that against what I’ve obtained for this and other varieties I’ve grown over the years. I’d like to see the yield increase in 2013; at least it should not decrease, or if it does, another factor like taste should increase enough to compensate for that. But I think it will take a few years for me to obtain a definitive answer to the yield question, for reasons I’ll explore farther down.

One of the claims for Ecology Action’s method is that when the soil has been properly fertilized, the compost that the garden produces maintains garden fertility without further importation of fertilizer. Steve Solomon makes a similar claim in The Intelligent Gardener: a garden with a proper mineral balance should maintain that balance for at least a period of some years and should require over time fewer mineral imports. A quantitative method to assess both of these claims is to test soil mineral levels each spring. If my garden is moving closer to a balanced, self-maintaining fertility, those minerals that are currently deficient or in excess should become less so over time. Each March I plan to repeat the same soil testing I did in April of this year to see if this pattern is observed. If anything is deficient, the 2014 garden prescription will be based on the March 2014 soil test. I expect it will take at least a few years to learn how the garden answers this question as well.

Besides these two quantitative tests, I will be evaluating some qualitative properties as well. One of Solomon’s claims is that produce grown on well-balanced soil tastes better. Since I have been running garden trials of different varieties of crops against current favorite varieties for many years, I will be checking for any obvious taste differences between, say, this year’s ‘Bronze Arrow’ lettuce and my memory of its taste from previous years. Obviously this sort of test is highly subjective and can’t make subtle distinctions, but that does not mean it’s useless. If it turns out that most of my favorite varieties seem to taste better this year, I’d consider that a major point in favor of soil re-mineralization even if nothing else changes. The other qualitative testing I’ll be doing is watching for any pest or disease pressure among the various crops. The major pest problems I have are squash bugs on the squash-family crops and harlequin bugs on the cabbage-family crops. A common disease issue, especially in wet years (and so far 2013 has been a wet year) occurs on many to most pepper plants and sometimes tomato plants as well. I’m not sure of its identity but I do know the symptoms so I will be watching for it. Again, properly balanced soil is supposed to grow crops that are less susceptible to pests and diseases, so this is my guess for what I’ll observe. And again, I suspect it will be a few years before I can say for sure how the garden answers this question.

I might be able to get quicker answers to some of my questions if I were more careful about using controls in my gardening dialogue. A control could be planting some of the ‘Bronze Arrow’ lettuce in a bed that was fertilized the same way I have fertilized that bed in past years, which in this case would be not at all. Using a control would correct for problems like unfavorable or especially favorable weather conditions or an unusual pest or disease problem or lack thereof that might happen in any particular year. This year, my lettuce crop is going in very late, probably next week in fact when I would prefer to plant it by April 20. If it gets and stays hot rapidly, none of my lettuces might do well. But if the lettuce in the re-mineralized part of the garden yielded better than the same variety in the control area, I’d be pretty certain that the reason was because of the re-mineralized soil.

The problem with running controls has to do with the large numbers of different crops I grow in most beds and the consequent small space devoted to most varieties of most crops. It would be quite difficult to get uniform yet different fertilization schemes into two 8 square foot areas next to each other, the amount of ‘Bronze Arrow’ lettuce that I grow each year. The only one of my crops that I will grow enough square feet of in different beds that I can use a control is corn. For corn I might in fact fertilize one bed (100 square feet) with the original fertilizer formula and the other two beds (200 square feet total) with the 2013 formula. As long as I segregate the ears from the differently-treated beds and weigh them separately, I will have a good control for that one crop. However, for most of the other crops I grow I do have at least one variety that I have grown from anywhere from 5 to 15 years, in a variety of different weather conditions. It shouldn’t be too difficult for me to determine if the yield I get for ‘Bronze Arrow’ lettuce is about what I would expect for whatever conditions it has to grow under, or much better or much worse. I can always change gardening patterns in succeeding years if it seems necessary to the quality of the dialogue that my garden and I practice.

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