There are many treatises available that deal with the soil, its composition and its treatment. No attempt will be made here to go exhaustively into that subject. There are a few fundamental factors, however, which the potential owner should know regarding soil treatment, for that is the base upon which he will build his income-producing operations.

The particles of soil have had their genesis in rock. The rock has become disintegrated and decomposed through natural processes. The action of the weather is the most important factor in creating soil. Water falling on rock not only wears it away mechanically, but through certain mild acid elements which it acquires, disintegrates the binding materials that hold rock segments together. In addition, there is the action of frost and freezing, too, making the moisture in rock expand and contract and thereby causing the breaking down of the segments. With this action is coupled that of hot suns which cause expansion and breaking up of the rock as it becomes heated and cooled under atmospheric influence.

A great deal of the soil surface in many sections of the country is the result of glacial action. These glaciers not only eroded the surface, thereby creating millions of rock particles, but they also carried large deposits of the rock particles to more distant areas and deposited them over a subsoil that may be totally different in character from the surface soil thus deposited.

How Tillable Soil Is Made.—The action of plants themselves has a great effect in adding to our supply of tillable soil. Seeds of plants or seeds of trees become established in some slightly weathered rock areas and begin to grow. The roots penetrate wherever there is any loose soil, and partly by their pressure and partly through the acidity accompanying decomposing plant tissue, complete a further breaking down of the rock. There is a continuous process of destruction of rocks and leveling off of mountains and hills to fill the valleys below.

Many groups of deep-rooted plants tend to increase the depth of the surface soil by growth of the roots in the subsoil and by creating therein a condition approaching that which already exists on the surface. The action of earth worms and similar forms of life in bringing subsoil to the top and in opening channels through which water and surface air can penetrate constitutes another continually operating force in the creation of a productive soil. A deeper layer of productive soil can also be created through a plan of consistently deeper plowing, bringing up with each annual plowing operation a small portion of subsoil which, when mixed with the surface soil, tends to become like it.

(Courtesy New Jersey Department of Conservation and Development)
Soil is created from rock by nature’s weathering processes and by plant growth.
At the bottom may be seen solid rock; just above are disintegrating rock fragments, and at the top, the soil.

Every type of real soil contains all the elements of plant growth. This plant food results from a breaking down of soil particles and the setting free of chemical elements which, either singly or in combination, serve as food for plants.

Whatever the type of soil may be, it will be found that certain crops will make better growth in it than others. As a general rule, it may be said that the only way to determine which plants will grow best on a given soil is by the trial-and-error method. However, by observation of the growth on similar types of soil we can learn something of a soil’s crop adaptability. There are some crops that will grow in almost any soil and there are others that need an exactness of texture, moisture and plant food which makes them highly specialized products. The operator must learn how to work in harmony with the peculiarities of his own soil before he can hope to get the best results.In acquiring a tract for the growing of plants of any kind it is desirable to get a soil type that will meet the requirements of most plants. As a general rule, this type contains enough clay to be retentive of moisture, enough sand to be easily worked and is generally suitable for bacterial growth. In other words, what is commonly called a loam is the ideal type for general agricultural and horticultural purposes. This may be a heavy loam, in which clay predominates, or a so-called light loam, in which sand particles predominate. An examination of a handful of soil by a person experienced in farming will indicate its nature and its adaptability to ordinary crop production.

Essential Elements of Plant Food.—Countless scientific experiments in plant growth show that potassium, lime, phosphorus, magnesium, iron, sulphur, nitrogen, carbon, oxygen and hydrogen are essential to normal development. The carbon, hydrogen and oxygen elements make up nearly 99 per cent of the entire composition of the plant and are derived from the atmosphere. All of the other elements are derived from the soil except in the case of peas, beans, clovers and other legumes which secure most of their nitrogen from the air.

The mineral elements are not needed in large amounts but well-balanced plant growth is strictly dependent upon their presence in available form. Of these elements, those most likely to be deficient either in total amount or in availability are nitrogen, phosphorus, potassium and calcium. It is entirely feasible and economical to apply concentrated chemical fertilizers containing the first three elements so that their lack will not constitute a limit to size of crops harvested. In many cases it is necessary to apply chemical fertilizers to get satisfactory yields, even where natural manures are available and can be applied as well.

In addition to supplying essential plant food, nitrogen, phosphorus and potassium perform specific functions in plant growth. The application of nitrogen in one of its readily available forms (e.g., nitrate of soda and sulphate of ammonia) will stimulate vegetative growth. If too much of this one element is applied, leaf and branch development may occur at the expense of the crop. Good results follow the use of nitrogen on grass sods and on leafy vegetables like spinach. On the other hand, corn, peas, beans and other seed-forming crops need to have the nitrogen balanced with phosphorus. Potatoes, in common with other tuber and root crops, will utilize plenty of potassium in the development of starch.

Sources of Plant Food.—Chemical fertilizers can be purchased at supply stores in ready mixed condition and of analyses that will meet general crop needs. A good formula for such a general purpose fertilizer is 4 to 5 per cent nitrogen, 7 to 9 per cent phosphoric acid and 7 to 10 per cent potash to the ton. It is known that such a mixture will supply the food needs of a large variety of plants in balanced amounts. Highly concentrated mixtures are now on the market providing double the amount of plant food in the example quoted, costing nearly twice as much but effecting a saving by cutting in half the material handled to get the same result. Care should be taken, in using these highly concentrated fertilizers, to avoid contact with tender roots. A mixture for general farm and garden purposes may contain the following ingredients:

This mixture will have a formula of 4-9-7 (4 per cent nitrogen, 9 per cent phosphoric acid and 7 per cent potassium). The individual who wishes to mix his own fertilizer may do so by purchasing the finely ground ingredients separately, and by means of a shovel, integrate them all into a mixture. Home mixing will not be found profitable where small amounts of fertilizer are used. Those who practice home mixing for the first time should realize that most combinations of ingredients will “set” or harden if not used immediately, necessitating the breaking up and pulverizing of the mass. When it is broken up after curing, no further difficulty should be experienced with “setting” if the mixture is kept in a dry place. The advantages of home mixing for the large user lie in lower cost per ton of plant food as a rule; confidence in the quality of the ingredients which he should purchase on the basis of guaranteed analysis; and the setting up of a mixture which study of his soil and the plant requirements has convinced him is best suited for his individual case.

Chemical Soil Analysis Not Helpful.—There is a mistaken notion that it is necessary to analyze soils chemically in order to fertilize them intelligently. Such an analysis of a reasonably fertile soil will show the presence of the essential elements of plant food, though perhaps not all in sufficient amounts, to produce ordinary crops for centuries to come. Only a small amount of the elements become available for root absorption each year and a chemical analysis will not bring out this most important factor—availability. The use of a few simple tests, mainly of a physical nature by a competent soils specialist, will prove of some assistance in the treatment of the soil. Such tests will show the presence of adequate amounts of humus, and indicate the acidity content. The soil texture will give some index of its crop adaptability and thereby serve as a basis for fertilizing treatment that will meet the needs of both soil and crop. The practical man will not expect any considerable aid from a highly technical and costly chemical analysis of his soil.

Another factor that militates against worth-while benefits of chemical soil analysis is the great variation in soil types frequently occurring in the same field. To attempt to draw a representative sample by mixing soil from several areas might result in a specimen that would not be really typical of any area. For the purpose of ordinary physical examination and testing for acidity, representative soil samples should be taken from several parts of the same soil type, mixed together and a composite sample for testing drawn from the mixture, weighing not less than a pound in each case. If the soil is quite apparently variable it may be necessary to draw two or more composite samples from the same area. Very helpful service in intelligent soil treatment may be secured from the county agricultural agent and the state college of agriculture in the county or state of residence.

Legumes as Soil Improvers.—A means of soil improvement that is well understood by progressive farmers is the use of legumes to improve the soil. The legumes include a large family of plants of which the bean, the pea and the clovers are outstanding examples. Such plants have on their roots nodules which house nitrogen-gathering bacteria. These bacteria absorb nitrogen from the air in the soil and, in the ordinary process of growth, death and decay, make this nitrogen available to the host plants, leaving a residue in the soil for the roots of plants that are to follow. Thus this group of plants, known as legumes, have been used for generations as a method of increasing the nitrogen content of soils. Nitrogen, incidentally, is the most costly element to buy in commercial fertilizers. The soil-improving benefits of legumes may be secured by growing them either for harvest as a source of animal food or for plowing under as a means of utilizing them entirely for the development of soil fertility.

In reading of the studies of soil fertility that were made by George Washington at Mount Vernon, we learn of the improvement that he made in the relatively poor soils of that area by growing plants of the legume family. The actual reason why such improvement was brought about was not known in Washington’s time, but the results were apparent. Today, the value of legumes as soil builders is well recognized and we understand much more definitely than Washington did the reasons for their being so helpful in increasing crop production.

Many soil areas do not contain the particular type of bacteria necessary to the fixation of atmospheric nitrogen by legumes. This is frequently the cause of failure in growing alfalfa, soybeans, cowpeas and less well known members of the legume family. Each legume has its own type of nodule-forming bacteria. In order to assure the presence of the proper bacterial family, means often must be employed to add them to the soil where the specific crop is to be grown. This may be accomplished by adding soil from an area where the legume does well to the new area, or the seed may be inoculated with commercial cultures before seeding. Either method is effective. If soil is used it should be drilled in or spread on a cloudy day to prevent the destructive action of the sun’s rays on the exposed minute forms of plant life we call bacteria.

If it is not known that the legume to be planted has been grown successfully in a given field within the previous several years, the precaution of adding the proper bacteria should be taken. In some sections, such legumes as red, alsike, crimson and white clovers have been grown for many years and the bacteria for these plants are well distributed. There, inoculation is not necessary for these crops, but it probably should be practiced if other legumes such as alfalfa, cowpeas or soybeans are to be grown on land for the first time.

The Value of Humus.—In addition to the chemical elements of plant food, all productive soils contain decaying vegetable matter, generally classified under the term “humus.” Humus serves as a source of acid-generating material which further breaks down soil particles and, most important of all, serves as a food for millions of microscopic plants which develop and die quite beyond the scope of human vision. These constitute a type of bacteria which are distinctly beneficial and essential to human life since they make possible the growth of larger plants that serve as human food.

Green plants, straw or leaves, when plowed under or spaded in the soil, are attacked by bacterial agencies which gradually turn these products into humus. The same process occurs when a “compost” is set up. This is made of leaves, manure, soil, straw and other materials thrown into a heap and allowed to decay. Such compost is excellent for placing around plants when setting them out, since it holds moisture, supplies fertility and creates optimum conditions for young root growth. Under practical field conditions, humus may be added to soils by spreading animal manures, followed by plowing them down, or by the growing of heavy green crops such as wheat, rye, cowpeas or vetch and turning the entire mass under with the plow when they are at their height.

Lime and Its Application.—Reference has been made to the fact that calcium is an essential plant food and is frequently deficient in soils. As a matter of fact, the great majority of soils are deficient in calcium and their productiveness is inhibited thereby. Lime supplies calcium and also magnesium as food for plants. Its application accomplishes many other desirable things such as correcting soil acidity. The growth of beneficial bacteria is greatly stimulated in a soil that has had its acidity neutralized by the application of lime. This product, therefore, creates a more congenial condition for the growth of bacteria, which, in turn, make for better crop production. Lime is also beneficial through furnishing the element calcium with which other plant foods combine chemically and thereby become soluble in the soil water. Unless plant foods are in a state of solution, they cannot be absorbed by plant roots. Lime is a potent force in creating chemical reactions in the soil, resulting in the stimulation of growth through increased absorption of essential elements in solution.

Lime also benefits soils of a clayey nature through its ability to cement together the fine clay particles and in that way create air spaces so greatly needed in tight clay soils. Lime is beneficial, too, in the case of soils which have a large proportion of sand or large particles, and serves as an agent in creating a better condition of tilth and of moisture retention.

It makes little difference in what form lime is applied. It may be purchased and applied in the form of ground limestone, a rock rich in calcium which has been mechanically ground to a very great degree of fineness. It can also be applied in the form of hydrated lime. This is obtained by heating ground limestone and slaking it by adding water. A common example of this is the slaking of lime for whitewashing purposes. Another good source of lime is finely ground shells of oysters or other forms of sea life which collect the calcium from sea water and deposit it in their shells.

Adjusting the Water Content of Soils.—Aside from the supplying of water by irrigation, a rather costly process under most conditions, the water resources of most soils can be greatly increased by adding to their humus content. Humus, which, it has been pointed out, is decaying vegetable matter, serves as a sponge for the absorption of soil water and for underground water supplies. Therefore, the more humus that can be plowed into the soil, other conditions being equal, the greater is the ability of the plants growing in that soil to withstand drouth. As soils are cultivated, the tendency is for the humus to become “burned out” and to have a reduced moisture-holding capacity. To overcome this tendency, it is necessary to add vegetable matter to the soil whenever it is possible. Incidentally, the incorporation of large quantities of humus in the soil creates a condition of acidity which may call for the application of lime as a corrective.

There are many acres of land which contain too much water in the area that roots should penetrate to permit of optimum plant growth. Roots of most plants will not penetrate where there is an excess of water, and air cannot circulate where moisture is superabundant. Usually these conditions exist where the soil is of a clayey nature. The abundance of water may be caused by the inability of surface water to percolate through the soil. It may take so long, due to the nature of the soil, for this water to pass through the lower depths of subsoil that the roots of plants are destroyed by lack of oxygen. In such cases the application of lime, increasing the humus content, and deeper plowing will be found helpful. Occasionally, the discharge of dynamite or blasting powder in the area, if it appears to be in the form of a pocket, will break up the hard pan subsoil and permit the water to escape. Less dependence is now being placed on this means of correcting a wet condition of the soil than was the case some years ago.

A similar condition of overabundant water in soil may be due to the presence of springs or to a high water table. Little can be done to correct a condition where the water table itself is so close to the surface as to inhibit plant growth and this is assuredly one of the factors to be looked into before a tract is purchased. Where the surplus water is evidently being supplied by a spring, an underdrain made of tile pipe, 3 or 4 inches in diameter, can be laid as a means of conducting the water into a ditch or adjoining drain. In laying such a drain, it should be placed above the area where the wet soil surface is most evident. If such a drain is laid 18 inches to 3 feet deep above the wet area, it will cut off the water seeping down underground and carry it away. Good results cannot be secured if the drain is laid directly in the area of extreme wetness or if it does not cut off the flow of water before it reaches the area that is consistently too wet for plant growth.

From what has been said in this brief description of soil treatment and soil improvement, it is evident that one must live with his soil for some time in order to understand it and to be able intelligently to correct its deficiencies, overcome its weaknesses and make it capable of supporting plants which are desirable from the owner’s point of view. In the great majority of cases, the improvement process, while a slow one, is far from hopeless and almost any soil that is not extremely sandy or clayey can be so intelligently treated as to make it productive.

Cultivation.—Any discussion of soil treatment is not complete without mention of cultivation. Intelligent cultivation is an essential factor in securing adequate crops. It is interesting to recall that the word “manure,” which has come to mean fertilization or fertilizer, is derived from the Latin word “manus” meaning “hand” and implying “manipulation” of the soil, which we now call cultivation. Cultivation has been most frequently practiced as a method of destroying weeds, thereby making all of the available plant food subject to absorption by the roots of the desired plants and not by the intruders we call weeds. Cultivation does more than destroy weeds, however. It opens up the soil so that air containing atmospheric nitrogen can penetrate it and so that the bacteria requiring air for their best growth may have it available. Furthermore, cultivation conserves moisture and is more essential during dry periods in the growing season than at any other time.

We know that in entering the soil the rain water follows certain channels in and around the soil particles on its way to the subsoil. When the rain has ceased and the top layer of soil becomes dry, the tendency is for the water to work up through these same channels to the surface, where it evaporates. Cultivation, by breaking up these channels, or capillary tubes, checks the escape of moisture into the air. It creates a blanket of dry surface soil which insulates the soil moisture from the air above. The tendency of soil moisture to reestablish capillary methods of escape makes recultivation necessary from time to time in dry weather. Care must, of course, be taken that the cultivation is not harmful to roots of growing plants. If these roots are disturbed or destroyed through cultivation, more harm than good may result because of the damage to the root systems.Farm Power and Equipment.—Where the land area to be cultivated is larger than the family garden some type of equipment for working the land, propelled by horse or motor, will be found desirable and in larger areas essential. One or more horses may be used where there are stabling facilities and where arrangements can be made for the daily care and feeding that these animals require. A horse suitable for work purposes may be obtained for less than $200. The price will, of course, depend upon the age and physical soundness of the animal, but should not exceed $150 for a physically sound animal under ten years old. A person unskilled in the assessing of animal values should obtain the services of a veterinarian or an experienced horseman in making a selection. A horse for this purpose should be of quiet, tractable disposition, bred and broken for work purposes. The cost of caring for a horse for one year will approximate $125, including feed and bedding, but without labor charge.

Leather harness costing $25 to $50 will be required and in addition tools, including a plow, a harrow, and a cultivator costing about $15 each. Other special equipment such as a mower will cost considerably more, depending upon the type used.If the members of the family are fond of animals and willing to assume the responsibility for their daily care, the horse will be found an efficient and useful source of power for tilling the land. In this connection it should be pointed out that flies breed with great rapidity in the strawy manure of the stable, and such wastes should be spread upon the land almost daily or treated to prevent fly-breeding.

Tractor Power.—Just as large tractors have supplanted horses and horse-drawn equipment on thousands of farms in the United States, the so-called garden tractor has become increasingly popular for the tilling of small acreages. The tractor requires “feed” only when it is working, is not subject to the ills that beset animals, and may be used for twenty-four hours a day if necessary. It makes an appeal to the mechanically minded members of the household and, if properly cared for, will give economical and lasting service.

The usual type of garden tractor consists of two large wheels with lugs on them to give traction and is driven by a one- or two-cylinder motor. A plow, a cultivator, or mower may be attached to the drawbar, the operator walking behind and regulating the speed and guiding the outfit by handles provided for the purpose. Earlier types of these machines were not always satisfactory owing to construction weaknesses and occasionally balky motors. Those now on the market, however, are greatly improved, require less attention, and rival their big brothers, the powerful farm tractors, in dependability.

There are a number of types and makes of garden tractors now on the market, ranging in price from $175 or less to $400, the cost depending largely upon the size and capacity of the motor. In selecting a satisfactory garden tractor attention should be directed to the simplicity and power of the motor, the type of bearings, the method of lubrication of all moving parts, the working speed and the economy of fuel. Bearings ought to be of standard, long-wearing type since these are subject to hard service. Two speeds are desirable, a slow one for heavy duty and a faster one for lighter work. The tractor should operate all day on about 2 gallons of gasoline and a quart of oil. In addition to power applied at the drawbar where special tools are attached, a pulley will be found a desirable accessory for operating belt machinery such as small feed mills, pumps, and cream separators. The rating of the motor should be not less than 3 horsepower at the drawbar for the ordinary tasks it will be called upon to perform.

All types of attachments are available for the garden tractor. These include plows, disks, harrows, cultivators, mowers, fertilizer distributors, planters, sowers and seeding accessories. The prices of these vary according to make and quality. Levers are provided for adjusting the depth of plowing, cultivating and seeding. Some of the large type garden tractors are equipped with a seat on a sulky attached to the machine so that the operator can ride and have complete control over speed and the type of work he wishes to do. A modern garden tractor will be found very useful in taking care of a lawn or garden. In the case of larger areas under cultivation, but not of field size, this type of machine is rapidly gaining popularity for performing efficiently and economically the numerous jobs that are to be done on every small farm.