the soil lec ( 2 )

 TILLAGE OF THE SOIL

A good many years ago a man hv the name of Jethro Tull lived in England. He was a farmer and a most successful man in every way. He first taught the English people and the world the value of thorough tillage of the soil. Before and during his time farmers did not till the soil veiy intelligently. They simply prepared the seed-bed in a careless manner, as a great many farmers do to-day, and when the crops were gathered the fields were not large.
Jethro Tull centered attention on the important fact that careful and thorough tillage increases the available plant food in the soil. He did not know why his crops were better
when the ground was frequently and thoroughly tilled, but he knew that such tillage did increase his yield. He explained the fact by saying, " Tillage is manure." We have
since learned the reason for the truth that Tull taught, and, while his explanation was incorrect, the practice that he was following was excellent. The stirring of the soil enables the air to circulate through it freely, and permits a breaking down of the compounds that contain the elements necessar}' to plant growth. You have seen how the air helps to crumble the stone and brick in old buildings. It does the same with soil if permitted
to circulate freely through it. The agent of the air that chiefly performs this work is called carbonic acid gas, and this gas . is one of the greatest helpers the farmer has in cariy-ing on his work. We must not forget that in soil preparation the air is just as important as any of the tools and implements used in cultivation. If the soil is fertile and if deep plowing has always been done, good crops will result, other conditions being favorable.If, however, the tillage is poor, scanty har\'ests will always result. For most soils a two-horse plow is necessary to break up and pulverize the land. A shallow soil can always be improved by properlv deepening it. The principle of greatest importance in soil-preparation is the gradual deepening of the soO in order that plant-roots mav have more comfortable homes. If tlie farmer has been accustomed to plow but four inches deep, he should adjust
the plow so as to turn live inches at the next plowing, then sLx, and so on until the seed-bed is nine or ten inches deep. This gradual deepening \\ill not injure the soil but will put it quickly in good condition. If to good tillage rotation of crops be added, tlie soil will become more fertile each succeeding year. The plow, harrow, and roller are all necessary to good tillage and to a proper preparation of the seed-bed. The soil must be made compact and clods of all sizes must be crushed. Then the air circulates freely, and pa>ing crops are the rule and not the exception. Tillage does these things: it increases the plant-food
supplv, destroys weeds, and influences the moisture content of the soil.

THE MOISTURE OF THE SOIL

Did any one ever explain to you how important water is to the soil, or tell you why it is so important .'' Often, as you know, crops entirely fail because there is not enough water
in the soil for the plants to drink. How necessar}' is it, then, that the soil be kept in the best possible condition to catch and hold enough water to carr\' the plant through dr}-, hot
spells ! Perhaps you are ready to ask, " How does the mouthless plant drink its stored-up water ? "
The plant gets all its water through its roots. You have seen the tiny thread-like roots of a plant spreading all about in fine soil; they are down in the ground taking up plant food and water for the stalk and leaves above. The water, carrying plant food with it, rises in a simple but peculiar way through the roots and stems. The plants use the food for building new tissue, that is, for growth. The water passes out through the leaves into the air. When the summers are dry and hot and there is but little water in the soil, the leaves shrink up. This is
simpU' a method they have of keeping the water from passing too rapidly off into the air. I am sure you have seen the corn blades all shriveled on ver\- hot days. This shrinkage
is nature's way of diminishing the current of water that is steadily passing through the plant.
A thrifty farmer will tr)- to keep his soil in such good condition that it will have a supply of water in it for growing crops when dr)- and hot weather comes. He can do this by
deep plowing, by subsoiling, by adding any kind of decaying vegetable matter to the soil, and by growing crops that can be tilled frequently. The soil is a great storehouse for
moisture. After the clouds have emptied their waters into this storehouse, the water of the soil comes to the surface, where it is evaporated into the air. The water comes to the
surface in just the same way that oil rises in a lamp-wick. This rising of the water is called capillarity. It is necessar)- to understand what is meant by this big word. If into a pan of water you dip a glass tube, the water inside the tube rises above the level of the water in the pan. The smaller the tube the higher will the water rise. The greater rise inside is perhaps due to the fact that the glass attracts the particles of water more than the particles of water attract one another. Now apply this principle to the soil. The soil particles have small spaces between them, and the spaces act just as the tube does. When the water at the surface is carried away by drying winds and warmth, the water deeper in the soil rises through the soil spaces. In this way water is brought from its soil storehouse as plants need it. Of course when the underground water reaches the surface it evaporates. If we want to keep it for our crops, we must prepare a trap to hold it. Nature has shown us how this
can be done. Pick up a plank as it lies on the ground. Under the plank the soil is wet, while the soil not covered by the plank is dr}-. Why ? Capillarit}- brought the water to the surface,
and the plank, b\- keeping away wind and warmth, acted as a trap to hold the moisture. Now of course a farmer cannot set a trap of planks over his fields, but he can make a
trap of dry earth, and that will do just as well. When a crop like corn or cotton or potatoes is cultivated, the fine, loose dirt stirred by the cultivating-plow will make a mulch that ser\-es to keep water in the soil in the same way that the plank kept moisture under it. The mulch also helps to absorb the rains and prevents the water from running off the surface. Frequent  cultivation, then, is one of the best possible ways of saving moisture. Hence the farmer who most frequently stirs his soil in the growing season, and especially in seasons of drought, reaps, other things being equal, a more abundant harvest than if tillage were neglected.