Читать книгу War Gardens, A Pocket Guide for Home Vegetable Growers - Montague Free - Страница 7

Table of Contents

Practically all of the vegetable crops require sunshine, and plenty of it, in order to attain their full development. Therefore, in selecting the location of your vegetable-garden (if it is possible to have any choice) choose one open to sunshine and not hemmed in by tall buildings which shut out the air. A location near big trees should be avoided, for the trees not only shade the crops, but their wide-spreading roots also rob the ground of food and moisture which the vegetables need. The ideal location for a vegetable-garden is one open to the south and sheltered from the north and west winds, but always with this provision—the soil must be of a suitable nature.

This brings us to a consideration of one of the most important factors in successful vegetable culture—that of the soil.

Soils vary a great deal in their physical characters and also in their chemical composition.

Sandy soils quickly dry out and warm up in the spring, and in consequence it is possible to prepare them for planting and produce crops much earlier than is the case with heavier soils. For this reason sandy soils are usually preferred by market gardeners, whose object is to get their crops on the market as soon as possible. One great objection to sandy soils is the rapidity with which they lose their moisture by drainage and evaporation. They are frequently not naturally fertile and it is necessary to apply large quantities of manure to make them profitable. They are also subject to loss of fertility by leaching. The way in which these disadvantages can be corrected will be told later.

At the other end of the scale, almost exactly opposite in every particular, are those soils in which clay predominates. Soils of this type are cold, they dry out very slowly, and as a result it is late before they can be fitted for planting. In dry seasons, because of their water-holding capacity, they are greatly to be preferred, and plants growing on them are less liable to suffer from drought. Clay soils, because of their stickiness, are very difficult to work, and although they may be well supplied with plant food, it is sometimes unavailable because of the sticky, tenacious character of the clay which does not provide a good medium in which the roots may ramify in search of food.

Peat soils and muck lands are made up largely of decayed organic matter. They are usually deficient in minerals, but by correct management can be made to produce good crops of certain kinds of vegetables. Enormous quantities of celery and onions are successfully grown on muck soils.

The kind of soil most desired by the gardener is the happy medium that is called loam. This consists of a mixture of clay and sand in nearly equal proportions, combined with a considerable quantity of decayed organic matter. Such soils are fertile, easy to work, retentive of moisture, but sufficiently porous so that the moisture is not retained in excess. Air can penetrate such soils, a prime necessity for healthy root growth, and also necessary for the existence of bacteria which do so much in making inert plant foods soluble and available for the use of plants.

The extreme types of soil previously mentioned can be greatly improved by judicious treatment. It will be remembered that one of the great drawbacks to sandy soils was the readiness with which they lose their moisture. The proper treatment for this type is to add organic matter. This decays and forms humus, which binds the coarse particles together to a certain extent and increases the absorbtive and retentive properties of the soil. This organic matter is best applied in the form of decayed, or partially decayed, barn-yard or stable manure. If manure is not available a good substitute can be found in leaves. These may be gathered in the fall and piled in a heap to decay. Very little decomposition will take place during the winter months in the Northern states, and for this reason leaves that have been piled in heaps for twelve months or more are to be preferred. Decay may be hastened by forking over the leaves two or three times during the summer. Although decayed leaves are better than fresh ones for mixing in with the soil, fresh leaves are better than none at all.

The owners of city gardens frequently neglect an opportunity of adding humus to their soil when they allow the leaves of street trees to be burned or carted away. The city street-cleaning department is usually only too glad to be relieved of this duty.

When it is impossible to add humus to the soil through the medium of organic manures, as is often the case in city back yards, recourse may be had to one of the many brands of prepared humus obtainable from seedsmen.

Liming is also considered to be good for sandy soils, as the lime exercises a binding influence on the coarse particles. Of course when clay is available it is good to add it, and mix thoroughly with the sand, but it is seldom that clay is present in near enough proximity to make this practice a paying proposition. Compacting sandy soils, by means of a roller on large areas, or by means of the feet in the case of small plots, is good horticultural practice.

Clay soils, like the preceding, are greatly improved by the addition of organic matter. It should be applied in the fall, in the form of strawy stable manure, and buried deeply. Leaves also are a valuable addition. Liming is good, as this causes the flocculation of the clay particles and renders the soil more open and permeable by air and water. The addition of sand, sifted coal ashes, or wood ashes serves the same purpose. Clay soils are benefited by being plowed or spaded in the fall and left rough over the winter. This allows the frost to penetrate more readily, resulting in the breaking up and disintegration of the clods. Another advantage of fall plowing in the case of land of this type is that by so doing it dries out more rapidly in the spring and it is possible to get your crops planted earlier.

Muck and swamp soils are frequently waterlogged, and before they will support a crop it is necessary to underdrain them; but as this is an operation that is scarcely practicable for those for whom this book is written, it will not be dealt with here. As there is always a lack of basic salts in this type of soil, liming is practised, usually to good advantage.

Those who contemplate taking over a piece of land for the purpose of growing vegetables should, if the land has not previously produced a crop, obtain the opinion of a competent gardener as to its possibilities from a gardening standpoint. Such men are usually available in every community, and as a rule are glad to help. If expert opinion is not available, the novice can form an approximate idea of its value by making careful observations in the following manner. Take notice of the vegetation growing on the plot. If it is luxuriant and consists mostly of grasses it will probably be all right for growing vegetables. Dig holes here and there with a spade or trowel and examine the soil. If you find, an inch or two below the surface, nothing but tin cans and broken bottles it is not a safe gardening proposition. Neither should you go ahead if you find only a thin layer of topsoil, two or three inches, above the subsoil. It is usually easy to tell the difference between what is known as topsoil and subsoil. The topsoil is darker in color, due to the presence of humus, and of a finer texture. This topsoil should be at least eight inches deep to get good results. Soils which contain too many large stones should be avoided, also those which consist of only a thin layer overlying a rock ledge.

Most vegetables succeed best in a soil that is slightly alkaline, and land intended for garden use should be tested with litmus paper to discover if acid is present in excess. Take a piece of blue litmus paper and press it upon a handful of moist soil. If it turns red it indicates the presence of acid and the advisability of liming. Lime is a valuable element in the soil, as it assists in making plant foods soluble. It is best applied in the fall, spreading it over the surface and digging or plowing it in. It can also be applied in the spring, but in no case should it be put on so that it comes in direct contact with manure. Lime applied with manure causes ammonia to be liberated too rapidly in the form of gas, which escapes into the air, and thus much of the fertility of the manure is lost. When it is necessary to apply lime in the spring, the manure should first be dug or plowed under, and the lime then spread on the surface, and raked or harrowed in. Use about 20 pounds of air-slaked lime or 30 to 40 pounds of ground limestone to 400 square feet.

Thorough preparation of the soil is essential if best results are to be obtained. This means that the soil must be broken up and pulverized as deeply as possible. There are several reasons for this. Breaking up the soil to a good depth increases the water-holding capacity of the soil—a very important point because of the fact that plants have to take all of the food substances that they obtain from the soil in solution. It provides a greater bulk of soil in which the plant roots may ramify in search of food. The less fertile the soil the greater is the necessity for breaking it deeply to increase the area from which the roots may draw nourishment. Deep tillage encourages the roots to penetrate downward, and plants whose roots go down deeply in the soil are less likely to suffer during dry spells.

It is well to remember, however, that although it is desirable to have the soil broken up deeply it is not a good practice to bring too much of the subsoil up to the surface in digging or plowing. In farming operations a greater depth of soil is obtained by using what is known as a subsoil plow. This implement frequently is used after the field has been plowed in the usual way and penetrates below the topsoil and breaks up the subsoil, but without disturbing their relative positions. In gardens the same result is obtained by what is called bastard trenching, of which more will be said later.

In preparing a piece of ground that has not previously been cultivated the first thing to do is to remove all large stones and rubbish that may be on the surface. If it is a large area, the work of breaking it will, of course, be done with a plow. Supposing the land is covered with a growth of sod, it is a good plan to go over it several times with a disk harrow before plowing. This will cut up the sods, cause them to decay more rapidly when they are turned under, and insure the soil being pulverized throughout its whole depth. After plowing, harrowing is necessary to break the lumps and to compact the soil somewhat. The fining process can then be completed by hand, using a rake for the purpose.

Small areas can be prepared for planting by digging with a spade or spading-fork. A trench should first be dug a foot or eighteen inches wide and a foot deep, provided that the topsoil extends that far. The soil from this trench should be placed on one side so as to be available for filling in the last trench when digging is finished. Having opened the first trench, proceed with the digging, turning each spadeful of soil bottom up in the trench. The soil can be turned over with greater ease and more efficiently by always maintaining a trench when digging. It is the only way by which sods, manure, and weeds may be properly buried so that they may decay and form plant food.

Bastard trenching is carried out in the same way as digging except that the trench is made at least two feet wide and the subsoil thus exposed is broken up with a spading-fork before the topsoil from the next trench is turned over upon it.

When digging, the soil should be broken up as finely as possible with the spade or fork, so as to leave no lumps, and all large stones should be thrown out.

Digging or plowing should never be attempted when the ground is frozen or when it is so wet that the soil sticks to the tools used.

After the soil has been turned over and broken up the rake should come into operation and the surface fined so as to fit it for seed-sowing.