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CHAPTER I.

GENERAL PRINCIPLES.

The rapid growth of science, and the development of the mechanic arts which have made possible the unprecedented activity in the industries during the past quarter of a century, have brought about economic changes in methods of production, which must be taken into consideration in attempts to improve the practice and increase the profits of agriculture.

From the intense competition in farm products of all kinds, arising from the extraordinary development of facilities for cheap transportation, the farmers of the United States are directly interested in every means of diminishing the cost of production, to enable them to hold a commanding position in the world's markets, and obtain remunerative returns for their labor, without impairing the value of their invested capital. The business methods that have been found necessary to insure success in other pursuits must be adopted, and attention must be given to every available means of increasing the productiveness of the soil and making the labor expended on it more effective, while the losses resulting from bad seasons must be reduced to a minimum by the intelligent direction and control of the forces of nature.

One of the first steps in the direction of improved methods of farm practice is to put the soil in a condition to yield the best net returns from the elements of plant food which it naturally contains, or that may be applied to it in the home supplies of manure. The questions that may arise in regard to artificial, or purchased fertility,

are of secondary importance to the majority of American farmers, and the leading problem for them to solve is to obtain the best returns from the elements of production already within their control.

Among the available agencies for bringing about this desirable conservation and utilization of the elements of profitable crop-growing on a large proportion of the farms of this country, thorough drainage is the most important, as upon it will depend the successful application of other means of increasing productiveness, including thorough tillage and manures, which are relied upon to increase the net income that may be derived from the aggregate of farm operations.

In order to lay a foundation for the intelligent discussion of the advantages of thorough drainage it will be necessary to briefly review some of the conditions that are essential to the health and well-being of the crops. grown on the farm. The results of scientific investigations are suggestive, and the knowledge that has been gained of the laws and processes of vegetable nutrition and growth must be recognized as of great practical value in farm economy, when their relations to details of practice are clearly understood.

The uniform certainty of results obtained in all operations in other industries can only be realized in agriculture when the practice of the art is based on consistent principles, in harmony with those natural laws which it is the mission of science to discover and investigate. In dealing with the different forms of life with which the farmer is chiefly concerned, the best results can only be obtained by a strict conformity to physiological laws, the practical significance of which may readily be learned and appreciated, without any profound knowledge of the science of physiology.

Clear and consistent notions of the philosophy of farm drainage can only be secured by an examination

of the known facts relating to the nutritive activities of plants and their relations to the soil and its contained. moisture, to ascertain what special conditions are likely to interfere with their normal processes of growth. The intelligent farmer will not be satisfied with the simple. statement that the draining of retentive soils makes them more productive, but he will inquire how this result is brought about, and the knowledge he may acquire in tracing to their source the conditions that favor the vigorous growth of his crops, will be of value to him in suggesting many details of practice that may be profitably adopted in his general system of farm management.

We cannot, of course, in this connection, attempt a full discussion of the physiology of plants, and attention will only be directed to some of the leading facts in this · department of science, that have a direct relation to the principles of farm drainage.

Physiologists tell us that a very large proportion of the dry substance of plants is derived from the atmosphere, but it is well understood that the atmospheric supplies of plant food are only made available when their roots are enabled to take from the soil, under favorable conditions, the comparatively limited amount of nutritive materials it is their function to furnish.

From a practical standpoint it is, therefore, a matter of the first importance to provide suitable soil conditions to promote the functional activities of the roots of plants, as they have direct relations with the part performed by the leaves in appropriating from the atmosphere materials that constitute the great bulk of the dry substance of the plant.

Dr. Gilbert makes the statement that in the Rothamsted experiments, "by the application of nitrogen to the soil, for mangels, there was, in many cases, an increased assimilation of about one ton of carbon per

acre, from the atmosphere," and that one pound of nitrogen as manure for mangels gave an increase of over twenty-two pounds of sugar, derived almost exclusively from the atmosphere. With wheat and barley for twenty years there was an increase of from fourteen to twenty-two pounds of carbon in the crop for each one pound of nitrogen in the manure. The results here presented are in strict accordance with other known facts in vegetable physiology, which it is unnecessary to notice, and we cannot avoid the conclusion that soil conditions have a direct influence on all of the nutritive processes of plants, and that their chemical composition furnishes no index of their requirements in regard to the food constituents that may be profitably applied in the form of manures.

In the growing of crops, as well as in the care of his animals, the farmer is dealing with living organisms, and it is not sufficient to furnish the food elements required in building tissues, but he must also provide conditions that are in every way favorable for the exercise of their vital activities, on which the appropriation and assimilation of their food directly depends.

CONDITIONS OF PLANT GROWTH.

In common with other living organisms, our farm crops require certain conditions of environment for their active growth and perfect development, and among those which the farmer can, to a greater or less extent, control, may be enumerated as essential-a favorable temperature, a proper supply of moisture, and a supply of appropriate food. In the absence of, or any marked deficiency in, either of these conditions, the plants cannot thrive. These conditions must be studied in detail, as they have a direct relation to the subject of farm drainage.

Temperature. Plants do not grow in the spring, and seeds do not germinate until the soil is sufficiently

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