Sir Albert Howard and the scientific method

In describing the origins of organic agriculture, Pollan leans heavily on Sir Albert Howard’s An Agricultural Testament, which he calls “the movement’s bible” (145). Pollan explains that Howard’s work is the story of “a Fall” in which the “serpent” is Baron Justus von Liebig, who showed that plants need only nitrogen, phosphorous, and potassium to grow.  Howard called this the “NPK mentality” after the chemical symbols for those three elements.

After explaining that humus-rich soil does much more for plants than provide those three nutrients, Pollan writes,

To reduce such a vast biological complexity to NPK represented the scientific method at its reductionist worst. Complex qualities are reduced to simple quantities; biology gives way to chemistry. As Howard was not the first to point out, that method can only deal with one or two variables at a time. The problem is that once science has reduced a complex phenomenon to couple of variables, however important they may be, the natural tendency is to overlook everything else, to assume that what you can measure is all there is, or at least all that really matters. When we mistake what we can know for all there is to know, a healthy appreciation of one’s ignorance in the face of a mystery like soil fertility gives way to the hubris that we can treat nature as a machine. (147)

Though Pollan doesn’t say so directly, one might guess from reading his account that Howard’s work was some sort of anti-science treatise. The complete text of An Agricultural Testament is available online, and Howard does indeed devote a full chapter (Chapter 13) to criticizing agricultural science. This chapter criticizes many aspects of agricultural science as it was practiced in his day, such as the tendency to fit agricultural problems into existing branches of science, the insistence on quantitative results, the role of economics in research, and the failure of scientists to adequately communicate their results to farmers. Notably absent, however, is any criticism of the scientific method.

To clarify this distinction, I think it’s worth discussing what is meant by the scientific method. This refers to a very general method for gathering and organizing knowledge. Loosely speaking, it’s a sort of systematization of the trial-and-error process. It involves seeking the answer to a question by using observations to make a hypothesis, using the hypothesis to make a prediction, testing the hypothesis experimentally, and using the results to form a new hypothesis.

If the NPK mentality led agriculture astray, I would argue that it’s not because the scientific method is inherently reductionist but because science was applied badly. The NPK mentality confuses the question of what plants need, at minimum, to grow (answer: nitrogen, phosphorous, potassium) with the question of how we should grow crops. It’s absolutely a reductive mindset, but that’s the fault of the scientists, not the scientific method.

To see that better science is possible, one need look no further than Howard’s An Agricultural Testament. The twelfth chapter is titled “Soil Fertility and National Health” and sets out to address a general question: “How does the produce of an impoverished soil affect the men and women who have to consume it?” It’s a much broader question than the one that guides the NPK mentality.

I would be remiss if I didn’t mention that the age of Howard’s work shows through in this chapter. After suggesting the idea of experimenting on subjects in concentration camps, convict prisons, and asylums, Howard simply writes, “Objections…would almost certainly be raised,” and he later tells us that the people of northern India include “some of the finest races of mankind.” Nonetheless, the chapter does present ideas about how the scientific method might be applied to agriculture to produce better results.

Although Howard does acknowledge the impracticality of experimenting on humans, he also relays some observations on relationships between various groups of people in India and the health of their soils. This isn’t a controlled experiment like the ones that Liebig and his followers used to justify the NPK mentality, but it is an example of what is called a “natural experiment,” an experiment in which the controls are assigned by nature (rather than by researchers). Howard also presents limited scientific evidence from studies in Britain and writes that more work is needed. Notable also is his proposal,

The agricultural colleges with their farms should devote some of their resources to feeding themselves, and so demonstrating what the products of well-farmed land can accomplish.

In doing so, he proposes to have the agricultural researchers address a question more useful than the one that led them to NPK. He proposes that they should address the question of which agricultural methods are best for human health and also that they should test their hypotheses on themselves.

Pollan’s retelling of Howard’s work seems to be guided by an overly simplistic notion of the nature of scientific inquiry. Reading Pollan’s work, one might think that science refers only to work done in laboratories. He writes,

Howard’s concept of organic agriculture is premodern, arguably even antiscientific: He’s telling us we don’t need to understand how humus works or what compost does in order to make good use of it.

But there’s nothing antiscientific about this idea. Indeed, Howard presents scientific evidence that humus does work, including the fact that it works in nature. To say that we shouldn’t try to find out why humus works would be antiscientific, but to say that we can reap its benefits without understanding how it works is not.

Contrast this with a claim that Howard makes in his eleventh chapter:

The policy of protecting crops from pests by means of sprays, powders, and so forth is unscientific and unsound as, even when successful, such procedure merely preserves the unfit and obscures the real problem — how to grow healthy crops.

To Howard, it is conventional — rather than organic — agriculture that is unscientific. To him, the problem with conventional agriculture isn’t that it’s scientific but that it isn’t. Whereas Pollan believes that conventional agriculture is driven by “the scientific method at its reductionist worst,” Howard considers reductionism to be unscientific, a consequence of researchers focusing on the wrong problem.

Howard reaffirms his belief in science in his concluding chapter, where he writes,

[T]he investigator of the future will only differ from the farmer in the possession of an extra implement — science — and in the wider experience which travel confers.The future standing of the research worker will depend on success: on ability to show how good farming can be made still better.

There should be no doubt that Sir Albert Howard believed the scientific method to be an important tool for agricultural research. Sadly, Pollan relays Howard’s work in a way that not only fails to make this clear but also promotes overly simplistic ideas about what science is.

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2 Comments »

  1. […] also receives unfair treatment in the agricultural context. Pollan attempts to summarize parts of Sir Albert Howard’s An Agricultural Testament, which he calls the organic […]

  2. John Paul Trask said

    Good critique. Pollan had put me in something of a dilemma about the relationship between science and farming – whether explicitly or implicitly. Howard, it seems, is not wanting to throw science out, as you say, but he is disgusted with the manifestations of scientific agricultural research (which can be seen on page 23 “these mustroom ideas of agriculture are
    failing”). On the other hand, he is searching for ways to employ his own professional knowledge in the field – as he himself was a scientist of an agricultural sort. He was looking for ways that science had truly helped and could truly help agriculture. This can be seen on page 23 also: “Is it possible to preserve the first freshness of food? If so then science will have made a very real contribution.”

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