THE SOIL
The following winter The Chief gave Friday afternoon talks to his boys and girls. These meetings did not in any way interfere with the boys' regular Saturday evening club.
Immediately after school each Friday afternoon they all trooped round to The Chief's little house, which had become a centre of village interest. Finally the men came too, for they had found out that this man knew of what he spoke.
But we are wandering away from those Friday afternoons.
There was the strangest collection of stools and benches in The Chief's side entry, all belonging to the boys and girls. "You must each one bring your own seat, because you all know that I haven't chairs enough to go around." And this called forth the collection.
It was an odd sight that first Friday in early November. A long straggly line of boys and girls, each one with a seat of some kind, wound its way up to The Chief's hospitable door, where he stood waiting, laughing aloud at the sight. In they came, and made a semi-circle about the big fireplace.
"I just love this room," said Albert, voicing the feelings of them all.
"I have thought," began The Chief, "that since our really successful first year of gardening, we ought to be in a position to undertake and to desire to know more about certain subjects which I shall discuss. Each Friday I am going to take up a topic such as I should if I were teaching you in school."
"You do not mean that we'll have to remember and answer questions just like school? You surely do not mean that, Big Chief," broke in Albert.
"No," replied the man laughing, "no, you may forget it all if you like. Remember it, if it seems to you useful. But if it's a strain on you, Albert, make it your business to forget."
They all laughed at this, but none so heartily as Albert himself. "That's one on this old head of mine," he said, banging that member up against the side of the chimney.
"My first talk I have given you in part, but I have more I wish to add. I believe even Albert can stand it. The subject is the soil.
"Soil primarily had its beginning from rock together with animal and vegetable decay, if you can imagine long stretches or periods of time when great rock masses were crumbling and breaking up. Heat, water action, and friction were largely responsible for this. By friction here is meant the rubbing and grinding of rock mass against rock mass. Think of the huge rocks, a perfect chaos of them, bumping, scraping, settling against one another. What would be the result? Well, I am sure you all could work that out. This is what happened: bits of rock were worn off, a great deal of heat was produced, pieces of rock were pressed together to form new rock masses, some portions becoming dissolved in water. Why, I myself, almost feel the stress and strain of it all. Can you?
"Then, too, there were great changes in temperature. First everything was heated to a high temperature, then gradually became cool. Just think of the cracking, the crumbling, the upheavals, that such changes must have caused! You know some of the effects in winter of sudden freezes and thaws. But the little examples of bursting water pipes and broken pitchers are as nothing to what was happening in the world during those days. The water and the gases in the atmosphere helped along this crumbling work.
"From all this action of rubbing, which action we call mechanical, it is easy enough to understand how sand was formed. This represents one of the great divisions of soil—sandy soil. The sea shores are great masses of pure sand. If soil were nothing but broken rock masses then indeed it would be very poor and unproductive. But the early forms of animal and vegetable life decaying became a part of the rock mass and a better soil resulted. So the soils we speak of as sandy soils have mixed with the sand other matter, sometimes clay, sometimes vegetable matter or humus, and often animal waste.
Constant Cultivation of the Soil Saved George's Cabbages
Photograph by Karl W. Helmer
"Clay brings us right to another class of soils—clayey soils. It happens that certain portions of rock masses became dissolved when water trickled over them and heat was plenty and abundant. This dissolution took place largely because there is in the air a certain gas called carbon dioxide or carbonic acid gas. This gas attacks and changes certain substances in rocks. Sometimes you see great rocks with portions sticking up looking as if they had been eaten away. Carbonic acid did this. It changed this eaten part into something else which we call clay. A change like this is not mechanical but chemical. The difference in the two kinds of change is just this: in the one case of sand, where a mechanical change went on, you still have just what you started with, save that the size of the mass is smaller. You started with a big rock, and ended with little particles of sand. But you had no different kind of rock in the end. Mechanical action might be illustrated with a piece of lump sugar. Let the sugar represent a big mass of rock. Break up the sugar, and even the smallest bit is sugar. It is just so with the rock mass; but in the case of a chemical change you start with one thing and end with another. You started with a big mass of rock which had in it a portion that became changed by the acid acting on it. It ended in being an entirely different thing which we call clay. So in the case of chemical change a certain something is started with and in the end we have an entirely different thing. The clay soils are often called mud soils because of the amount of water used in their formation. The slate that Myron brought for road making belongs to the clay family, and so does shale.
"The third sort of soil which we farm people have to deal with is lime soil. Remember we are thinking of soils from the farm point of view. This soil of course ordinarily was formed from limestone. Just as soon as one thing is mentioned about which we know nothing, another comes up of which we are just as ignorant. And so a whole chain of questions follows. Now you are probably saying within yourselves, how was limestone first formed?
"At one time ages ago the lower animal and plant forms picked from the water particles of lime. With the lime they formed skeletons or houses about themselves as protection from larger animals. Coral is representative of this class of skeleton-forming animal.
"As the animal died the skeleton remained. Great masses of this living matter pressed all together, after ages, formed limestone. Some limestones are still in such shape that the shelly formation is still visible. Marble, another limestone, is somewhat crystalline in character. Another well-known limestone is chalk. Perhaps you'd like to know a way of always being able to tell limestone. I'll drop a little of this acid on some lime. See how it bubbles and fizzles. Now Albert will drop some on this chalk and on the marble, too. The same bubbling takes place. So lime must be in these three structures. One does not have to buy a special acid for this work, for even the household acids like vinegar will cause the same result. Albert will prove this to you.
"Then these are the three types of soil with which the farmer has to deal, and which we wish to understand. For one may learn to know his garden soil by studying it, just as one learns a lesson by study.
"I believe the boys from their last winter's work feel fairly familiar with soils, I have in these three tumblers the three types of soil. As I pour water on them just see what happens. Observe how little water it takes to saturate sand. The limy soil holds more water and the clayey an amazing quantity.
"I do not know whether you are much acquainted with the sea shore, I doubt it."
"I am," broke in Katharine, "for each summer, except this last one, I have spent a month at the beach."
"Then possibly you can tell us, Katharine, whether, or not, the sand takes in, or absorbs, much heat during the day."
"Indeed it does absorb heat; why some days we used to go barefooted on the beach right after dinner. I can tell you there were times when we couldn't stand the heat of the sand."
"That is quite true," continued The Chief, "sand absorbs heat to a remarkable degree. This heat is, to be sure, in the upper layers of the sand. Had Katharine burrowed down with her toes below those upper layers she would have found moist, cool sands. But an upper layer of soil, made up of particles which fall apart easily because of the loose make-up, a layer which has absorbed little water and much heat—well, to me that sort of soil doesn't sound quite right for good gardening. Add to such a soil, humus in the shape of stable manure in large quantities and this same poor soil becomes very good.
"Now here is the lime soil tumbler. This soil has taken up rather more water than the sand took. But it, too, surely needs to develop greater power to take in and hold water. So the same sort of medicine which we gave the sandy soil may be dealt out to the lime soil. Lime is a pretty good substance to have in soil. Lime is a kind of fertilizer in itself; it's a soil sweetener; it helps to put plant food in shape for use, and causes desirable bacteria to grow. This sounds a bit staggering but all of these things I am going to talk over with you. So just at present forget it, Albert, if it is a heavy burden.
"The clay soil, you observe, has taken in quite a quantity of water. That seems like a good thing. It is. But clay has a mean little habit of squeezing tightly its particles together with the aid of water so that air is excluded from the mass. It forms huge lumps; it bakes out and cracks badly; and it is also very damp, cold and soggy in early spring.
"As the problem with sand is to add something so that more water may be held in the soil, so the problem with clay is to overcome that bothersome habit of baking and caking and cracking. To do this we might add sand or ashes. But perhaps it would be better yet to add manure with a lot of straw in it. This is the easiest kind of thing for country boys and girls to get, because the bedding swept out of horses' stalls is just the thing.
"When I speak of clay's horrid habit of tight squeezing, I always have to stop and talk about the two great needs of all soils. One is the need for water; the other, for air. A soil cannot exist without these two things any more than we can. Without these, or poorly supplied with them, a soil is as if it were half-starved.
"That trouble always comes from a lack of one or the other is quite sufficient to prove to us that these are essential. Just see how sand lacks water, as does lime soil too! But there is plenty of air space, unless these soils are too finely powdered. Now look at clay! plenty of water, but how about the air? When clay begins its packing, then air is excluded.
"So one of the questions to be asked in soil improvement concerns the water and air problem. We must have air spaces, and we must have water-holding capacity.
"Before we go home I must just speak of soil and subsoil. When you strike your spade down into the earth and lay bare a section of the soil this is what you see: on top is the plant growth, the soil beneath this, dark in texture and about our locality of a depth of from six to eight inches. This layer is called the topsoil. In sections of the West it is several feet in depth. Now below the topsoil is a lighter coloured, less fertile, more rocky layer, the subsoil. Beneath comes a layer of rock.
"And finally you may be a bit confused by the word loam. It is often given as one of the classes of soils. By loam we mean clay, sand and humus. You will often hear people speaking of a sandy loam or a clayey loam according as there is a greater percentage of sand or clay in the soil.
"Next Friday I shall talk about soil fertility. So trot home lively now!"