THE GENESIS OF SOIL.
Soil primarily had its beginning from rock along side animal and vegetable decay, if you'll imagine long stretches or periods of your time when great rock masses were crumbling and ending . Heat, water action, and friction were largely liable for this. By friction here is supposed the rubbing and grinding of rock mass against rock mass. consider the large rocks, an ideal chaos of them, bumping, scraping, settling against each other . What would be the result? Well, i'm sure you all could work that out. this is often what happened: bits of rock were worn off, an excellent deal of warmth was produced, pieces of rock were pressed together to make new rock masses, some portions becoming dissolved in water. Why, I myself, almost feel the strain and strain of it all. Can you?
Then, too, there have been great changes in temperature. First everything was heated to a heat , then gradually became cool. Just consider the cracking, the crumbling, the upheavals, that such changes must have caused! you recognize a number of the consequences in winter of sudden freezes and thaws. But the small samples of bursting water pipes and broken pitchers are as nothing to what was happening within the world during those days. The water and therefore the gases within the atmosphere helped along this crumbling work.
From all this action of rubbing, which action we call mechanical, it's easy enough to know how sand was formed. This represents one among the good divisions of soil sandy soil. the ocean shores are great masses of pure sand. If soil were nothing but broken rock masses then indeed it might be very poor and unproductive. But the first sorts of animal and vegetable life decaying became a neighborhood of the rock mass and a far better soil resulted. therefore the soils we speak of as sandy soils have mixed with the sand other matter, sometimes clay, sometimes substance or humus, and sometimes animal waste.
Clay brings us right to a different class of soils clayey soils. It happens that certain portions of rock masses became dissolved when water trickled over them and warmth was plenty and abundant. This dissolution happened largely because there's within the air a particular gas called CO2 or acid gas. This gas attacks and changes certain substances in rocks. Sometimes you see great rocks with portions sticking up looking as if that they had been eaten away. acid did this. It changed this eaten part into something else which we call clay. A change like this is often not mechanical but chemical. The difference within the two sorts of change is simply this: within the one case of sand, where a mechanical change went on, you continue to have just what you started with, save that the dimensions of the mass is smaller. You started with an enormous rock, and ended with little particles of sand. But you had no different quite rock within the end. Mechanical action could be illustrated with a bit of sugar . Let the sugar represent an enormous mass of rock. hack the sugar, and even the littlest bit is sugar. it's with great care with the rock mass; but within the case of a chemical process you begin with one thing and end with another. You started with an enormous mass of rock which had in it some that became changed by the acid working on it. It led to being a completely different thing which we call clay. So within the case of chemical process a particular something is started with and within the end we've a completely different thing. The clay soils are often called mud soils due to the quantity of water utilized in their formation.
The third kind of soil which we farm people need to affect is lime soil. Remember we are thinking of soils from the farm point of view. This soil in fact ordinarily was formed from limestone. even as soon together thing is mentioned about which we all know nothing, another comes from which we are even as ignorant. then an entire chain of questions follows. Now you're probably saying within yourselves, how was limestone first formed?
At just one occasion 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 at once , after ages, formed limestone. Some limestones are still in such shape that the shelly formation remains visible. Marble, another limestone, is somewhat crystalline in character. Another well-known limestone is chalk. Perhaps you want to understand how of always having the ability to inform limestone. Drop a touch of this acid on some lime. See how it bubbles and fizzles. Then drop some on this chalk and on the marble, too. an equivalent bubbling takes place. So lime must be in these three structures. One doesn't need to buy a special acid for this work, for even the household acids like vinegar will cause an equivalent result.
Then these are the three sorts of soil with which the farmer has got to deal, and which we wish to know . For one may learn to understand his garden soil by studying it, even as one learns a lesson by study.
ليست هناك تعليقات: