Welcome. My name is Paul Small and I teach agronomy at a land-grant university in the upper Midwest. Agronomy, for those who didn't take it, is the science of field crops and the soil they grow in: wheat, corn, soybeans, oats, alfalfa, and how to grow more of them with less trouble. I have spent most of my adult life walking through fields with a clipboard, so when people found out I had opinions about crop circles, they told me to put them on the Internet. So here they are.

Let me say up front what this page is and isn't. I am not here to make fun of anyone. Some of the nicest people I have met this year believe that circles in wheat fields are messages from somewhere else, and I had a fine afternoon with several of them (see the account of my July visit below). I am here to tell you what the plants themselves have to say, because plants are what I know. What you conclude from that is your business.

If you would rather read about the lights in the sky, my neighbor in this neighborhood keeps a good page at Kevin's UFO Sighting Reports. We disagree cheerfully. Go say hello.

Flattened patches in grain fields are nothing new. Wind and heavy rain have been knocking down wheat for as long as there has been wheat, and farmers have a word for it: lodging. What is new, more or less, is the neat geometric circle with a sharp edge, and those began turning up in the news in southern England in the late 1970s and through the 1980s, mostly in the chalk country of Wiltshire and Hampshire. By the end of the 1980s there were books, societies, a magazine or two, and a lively summer trade in people driving out to look at them.

Then, in September 1991, two men from Southampton named Doug Bower and Dave Chorley told a British newspaper that they had been making circles since the late 1970s, at night, with a plank, a length of rope and a great deal of patience. They demonstrated the technique for reporters. Their sighting device for keeping a straight line was a loop of wire fixed to the brim of a cap. They said it started as a joke, and that they kept going because people kept taking it seriously.

That admission did not end the subject, as you might have expected. Some folks said the two men could not possibly have made all the circles (which is true; there have been a great many, and other groups of people have since come forward or been caught at it). Others said the "real" circles are different from the man-made ones in ways you can see in the plants, and that brings me to the part I actually know something about.

The plank-and-rope method is simple enough that I have done it myself, in a corner of a university plot, with permission, at nine o'clock on a summer evening with two graduate students and a tape measure. Here is the general procedure as it has been described publicly many times:

1. Walk into the field along a tramline. Those are the parallel bare tracks the sprayer wheels leave, spaced evenly across every modern wheat field. They mean you can reach the center of a field without leaving a trail of crushed stalks, which is one reason circles so often sit right beside a tramline.
2. Drive a stake or have someone stand at the center holding the end of a rope.
3. Walk the rope around in a circle, holding a plank (or a short board with a rope loop for your foot) against the stalks and pressing them down ahead of you, one step at a time.
4. Work outward from the center in overlapping rings, always laying the stalks in the same direction. The rope keeps the radius, so the edge comes out surprisingly clean.

Two of us laid a circle about 30 feet across in a little under an hour, and we were not in any hurry. The edge was sharp. The stalks lay in a swirl. It was, if I say so myself, a pretty thing, and I understand now why people do it. A crew of four or five with a plan drawn up on graph paper could make something a good deal more complicated in a short summer night, and evidently they do.

This is the part I get asked about most, so I will go slowly.

A wheat stalk (the culm) is a hollow tube with solid joints along it called nodes. If you push a green stalk over, it bends but it usually does not break; grasses are built to spring back from wind. Now here is the interesting bit. A grass plant that has been knocked flat "knows" which way is up. The nodes are able to grow on one side faster than the other, and over a few days the stalk curves back toward the vertical. Botanists call this gravitropism. Any farmer who has seen a field lodged by a thunderstorm in June and then watched it partly straighten out over the next week or two has seen the same thing.

So when someone shows me a circle and says, "look, the stalks are bent at the nodes and turning upward, no human could do that," my honest answer is: that is what wheat does when it has been lying down for a few days. A plank does it. A hailstorm does it. A cow does it. The plant does not care how it got knocked over; it just starts growing back toward the light.

A few more plant facts that come up:

• "The stalks aren't broken." Green wheat in June or early July bends rather than snaps. Ripe, dry wheat in August is brittle and does break. If you see a circle in green wheat with unbroken stalks, that tells you it was green wheat.
• "The plants inside the circle kept growing." Yes. Flattening a wheat plant does not kill it. The head still fills. A lodged field is a nuisance to harvest, not a dead one.
• "The stalks are laid in a swirl, in layers." That is what you get when you press outward in overlapping rings, and it is also roughly what you get when a swirl of wind (a dust devil, say) drops into standing grain. It is not, by itself, evidence of anything.
• "The nodes are swollen or blown out." I have read the claims and looked at a good many nodes under a hand lens this summer. Nodes on lodged plants are frequently enlarged on the side doing the growing; that is the plant doing its job. I have not seen anything I could not account for, but I am one man with a hand lens, and I say that with appropriate modesty.

Here is a thing the books rarely mention: farmers do not like crop circles, and it has nothing to do with what made them. Consider it from the farmer's side:

• The flattened grain in the circle itself is mostly lost. The combine header cannot pick up what is lying flat in a swirl, and what it does pick up is dirty and may be sprouting.
• Far worse is what happens next: the visitors. Word gets around, cars line up on the road, and a few hundred people walk out through the standing crop to have a look, each one making a new path. I have seen fields where the damage from sightseers was ten times the circle.
• Somebody always leaves a gate open. Somebody always parks in the field entrance.
• If a visitor twists an ankle in a tramline at midnight, guess whose insurance agent gets the phone call.

So please, if you go looking at one: ask at the farmhouse first, walk in on the tramlines only, take nothing, and leave the way you came. The people who make circles at night are, whatever else you think of them, trespassing on somebody's livelihood, and the people who visit by day can do just as much harm without meaning to.

On the morning of July 10th my neighbor down the road called to say there was "one of those things" in his winter wheat, about a quarter mile from the county road, and would I come look at it before the whole township did. I brought the tape measure, the hand lens, a notebook, and my daughter's camera (the film is still at the drugstore, I'm sorry to say, so no photos yet).

It was a plain circle, 52 feet across by my tape, with a smaller ring about eight feet wide around it and a gap of standing wheat between the two. Very tidy. The stalks lay clockwise in the big circle and counter-clockwise in the ring. It sat directly against a tramline. The wheat was still green with the heads filling; a few stalks near the edge had been stepped on rather than laid down, and those were bent sharply, not swirled.

By noon there were eleven cars on the road shoulder. I met a retired schoolteacher with a dowsing rod, a family from two counties over, a young man with a camcorder who was certain it had been done by "plasma vortices," and a fellow who wanted my professional opinion on whether the wheat would be safe to eat. (Yes.) Everyone was polite. Everyone walked in on the tramlines once I explained why. My neighbor sat on his tailgate and sold lemonade, which I thought was a sensible response.

What did the plants say? Green, unbroken stalks, already starting to lift at the nodes after what I would guess was two or three nights on the ground. Some stalks along the outer edge of the ring were creased at exactly the height a board would hit them. No scorching, no dead spots, no anything in the soil that a spade could find. In other words: a very nicely made circle, and I mean that as a compliment to whoever laid it out. I did not find out who. Neither did the sheriff, who did not try very hard.

By the following Saturday the stalks in the middle were half upright and the whole thing looked like an ordinary patch of storm damage. Two weeks after that my neighbor combined the field and got a fair yield except for the circle itself. He said next year he might plant soybeans.

I think crop circles are made by people, with planks and rope and a little geometry, and I think the plants agree with me. I have not seen one that needed any other explanation. I also think the people who make them are, some of them, genuinely talented, and that a summer night spent laying out a perfect ring in a wheat field is a more harmless hobby than most, provided you ask the farmer first. (They never do. That is my real complaint.)

Could I be wrong? Certainly. If somebody shows me a circle in which the stalks are laid down in a way a plank cannot manage, or plants that are doing something plants do not do, I will say so here, and I will be delighted. Until then, the wheat bends because something pushed it over, and it straightens up because that is what wheat does.

Questions, arguments and invitations to look at circles are all welcome. I answer e-mail in the evenings after the fall planting.