Almost every garden journal during the year contains several articles on soil, stressing the importance of fertility, texture, heat retention, water-holding capacity, and other factors essential to good plant growth.
Important as the soil is to plant life, it is amazing to the average gardener to discover how little of the actual soil enters the plant body and how relatively minute quantities of it can support good plant growth.
They Grow In Strange Places
Our native Eastern columbine (aquilegia) likes good soil but frequently grows for years on almost bare rock, its roots limited to small soil accumulations in cracks or depressions.
The dwarf sweet blueberry inhabits exposed rocky ridges in the Adirondacks, often with the roots partially exposed because their diameter is greater than the depth of the soil on the rocks.
Florida moss clings to posts, telephone wires, and branches of trees, growing so vigorously that it becomes a nuisance even though it is probably dependent for its mineral requirements on dust.
It is not an unusual sight to find large raspberry bushes growing and bearing fruit in crotches of elms and sugar maples, where the soil is limited to accumulations of dust and decayed leaves.
Except for anchorage, the quantity of soil for the natural growth of many green plants is less important than the quality and content of the soil.
In its simplest form, the soil is part of the earth’s crust made up of decomposed rock, but such soil is sterile.
Essential Factors To Support Plant Growth
To support plant growth, organic and inorganic materials and a minimum amount of free water and air are essential. The necessary organic and inorganic substances must be soluble to be taken up by plant roots.
But only minute quantities of the soluble substances will become a part of any plant body, probably less than 5 percent in most instances. Nevertheless, these materials are necessary for the welfare of plants.
Some become a part of the plant structure; others serve to activate vital processes. The justification for using commercial fertilizers is to add the essential elements to the soil order that they may become available to plants through the roots.
Use Fertilizer Intelligently
Fertilizers are frequently spoken of and advertised as plant foods. However, the mineral elements supplied by fertilizers are not foods but materials essential to various plant processes, including the food-making process known as photosynthesis.
Plants use the same foods, namely carbohydrates, fats, and proteins, as other living organisms, but only green plants can synthesize these foods.
Since all life depends upon food, and since food can be produced by green plants only when essential mineral salts are available, the minute quantities of soil used by plants become of extreme importance to the welfare of man.
Consequently, it behooves gardeners, arborists, horticulturists, and all plant growers to use fertilizers intelligently.
Too much fertilizer can be as detrimental to plant growth as too little. Major changes in soil acidity may cause some essential elements to become unavailable to plants.
Compacted soil may adversely affect plant growth by reducing oxygen diffusion, retaining harmful amounts of carbon dioxide, and causing water runoff that may result in drought. Thus, the content, texture, and condition of soil can be beneficial or harmful to plant life.
Success With Potted Plants
Potted house plants can thrive indoors under suitable environments and add many grams to their weight during the winter months, even though the soil in the pots is not measurably reduced.
Good growth occurs, however, only when the potting soil is properly prepared and when ample moisture is supplied.
Gardeners know that some plants can be grown successfully in nutrient solutions without soil.
Such nutrient solutions, however, supply those essential elements that would normally occur in rich soil. In addition, the nutrient solutions are highly soluble fertilizers that many indoor gardeners add to their potted plants.
Whereas soil in quantity is advantageous to most plants for anchorage, plant growth requires only relatively minor amounts of soil to supply the required mineral elements.
Plant growth results in no visible reduction in the amount of soil; under natural conditions, plants serve as soil builders.
44659 by Na