Soil, and its relation to the welfare of whole nations, has recently assumed a new importance. It is significant that this new interest is directed toward soil, not simply land. Land is real estate. Land 'values' depend upon transitory economic conditions as well as upon soil. When these conditions change, land changes, but soil remains the fundamental material basis for a civilization.
Soil is productive for plants and furnishes homes for people when correctly managed. Successful agriculture is thus a result of soil and husbandry: a failure of either leads to soil deterioration, human distress, or both. For countless ages and in different places man has struggled to reach an adjustment with the soil and establish a secure agriculture — one that returns the greatest production of the things he wants from the soil, with a satisfactory labor income and on a permanent basis. Thus conservation for the maintenance of the soil is the handmaiden of secure production. Since human relationships are always changing, such an adjustment in an absolute sense, never has been completely attained, and probably never will be. Some people have approached it very closely for a long time. Many have nearly reached it, only to lose it because of an alien invasion or as a result of internal difficulties.
Poor farm homes, soil erosion, and unhealthy rural folk are evidences that the people on the land are not in adjustment with their soil. This may be their own fault; perhaps an exploitive type of agriculture has been followed from choice, and the people have taken little thought of the future security of their homes. Frequently a lack of knowledge, either as to what was taking place under their feet or what to do about it, has been responsible.
Again, it may not be their own fault as individuals or even as a social group within a broader social group. More often social and economic conditions and institutions are so out of adjustment with the soil that individuals simply cannot adapt their techniques to the soil and manage the land in a way to achieve the ends of secure production. Exploited people pass their suffering to the land. Portions of Northern China have already suffered from this sequence. Soil erosion, one of the more obvious evidences of a serious maladjustment between people and soil, has already appeared in parts of the United States, Canada, Australia, South Africa, East Africa, Northern India, and elsewhere in the world. Although soil deterioration may not be an important cause of the decline of civilizations, it has often accompanied or followed these declines. People now realize that soil depletion and other evidences of a declining agriculture have national significance. Cities themselves cannot thrive in the midst of a decadent agriculture.
Soil Deterioration Not Inevitable.
Soils are not necessarily injured by using them; quite the contrary. Careful husbandry has made the soils of much of Western Europe and even parts of the United States more productive than they were naturally. There are, for example, lands in Puerto Rico that have produced sugar-cane almost continuously for over 300 years — and with improved varieties and better husbandry, yields are higher today than ever before, even though they have by no means attained their probable maximum.
In nature, the soil represents the combined effect of all the natural forces in the landscape working together — the rocks, the vegetation, the slope, and the climate, acting in time. Indeed, it is impossible to see the influence of any one of these alone. Of these, the vegetation itself is the most important. Each combination of forces produces a different soil. Some soils differ from one another in only a few particulars, whereas others differ in every respect and have no common characteristics. They are adapted to different crops and require entirely different systems of management.
It may be said that each soil represents the total effect of its past history and environment. Each has certain capabilities and limitations for use. When man uses the soil he may either destroy or intensify these capabilities. He may, through the proper sequence of crops and with proper tillage and fertilization build up its fertility and improve its structure; or he may, by careless husbandry, impair these qualities. There are many examples where farmers have worked both 'with and against the grain.' One may travel, for example, through the Shenandoah Valley in Eastern United States and see soils devoted to corn, oats, wheat, and clover under a diversified system of farming such that they are more productive now than when they were in the hands of the Indians. Other soils have been used almost continuously for growing intertilled crops like corn, under a restricted system of management that has reduced their fertility, encouraged erosion, and sent them on the down-hill road.
Extent of the Soil Erosion Problem in the United States.
According to the most recent estimates of the United States Department of Agriculture, of the 415 million acres of land in Continental United States listed as crop land by the 1935 census, 76 million acres or 18 per cent of the total, is unsuited for cultivation under price levels that have prevailed since 1920. A portion of this land is unsuitable because of the high susceptibility to erosion,* and other portions because of other unsatisfactory soil characteristics. Of the remaining 339 million acres, 178 million acres, or 52 per cent, is now eroding to some extent even though such erosion could be controlled by practices demonstrated to be practical for owner-operators. The remaining 48 per cent can be cultivated indefinitely under current practices without serious erosion losses, although it may be subject to a serious decline in productivity with losses in fertility or destruction of structure if improperly managed. In addition, it is estimated that about 51 million acres of land not now used for crops could be added to that which can be used safely under current practices without erosion; while if the best practices were followed this figure could be increased to well over 100 million acres.
* In addition, there is serious erosion on some of the western range lands.
From the point of view of meeting the need for agricultural products there seems to be no danger of the United States running out of land in the predictable future. But what of the people on the 76 million acres that are unfit for cultivation? And what about those on the additional acres that are now eroding because of poor husbandry? These questions get at the real heart of the problem. It is on the welfare of the people that attention must be focused primarily; and their welfare is intimately bound up with that of the whole country. The most serious erosion is taking place largely in areas of increasing population. The sons and daughters of these people will make up a large percentage of the citizens of tomorrow. Certainly the whole nation has a vital interest in the welfare of these future citizens.
The Remedies.
From the strictly physical point of view it is possible to suggest changes in husbandry that will tend to reverse these trends of soil depletion and bring about soil conservation. More must be learned about many soils before positive recommendations may be safely made. A great deal of further experimentation is necessary. It is known that practices must vary greatly on different soils. What may be a good practice on one soil may be ruinous on another.
Social and economic adjustment are frequently essential to changes in husbandry and must precede or accompany changes in cropping systems, the use of fertilizers, and other physical improvements in farm practices. As the farmer has become more dependent upon cities for many of his goods and services, his welfare has been related more intimately to fluctuations in prices than was true in previous generations. It is not possible for farmers as a whole to follow soil conservation practices with the instability of farm prices that has obtained in the United States during the past 25 years. When farm prices go down to extreme levels there is a natural tendency to use exploitive methods of farming in order to reduce costs and increase output. Even though such emergency practices may be injurious to the soil, the farmer frequently has no other choice except immediate bankruptcy. In the end such practices may simply delay this alternative, and at the same time deplete the land.
Credit facilities in agriculture have a real bearing upon the adoption of conservation practices. Thus farmers attempting to change from exploitive systems of cash crops, let us say, to a more permanent system, including the legumes and grasses for livestock, must be financed during the period of change. With such a change there is a considerable period before normal farm income is again realized. Many farmers will absolutely require credit at low cost if they adopt conservation practices suited to their soil.
Security of tenure through ownership or favorable leasing arrangements is generally, if not universally, essential for the adoption of good management practices. Unless the farmer is reasonably confident of continuity of tenure of the land he is using, there is little or no incentive for him to adopt practices which will lower his immediate income (or raise his immediate costs of production) even though such practices would return a greater income over a period of several years and at the same time improve the soil. The simple fact is that the wide adoption of conservation practices by one-year tenants cannot be expected even though the effectiveness of such practices is ever so well demonstrated.
The development and distribution of cheap electric power to the farm is another important factor bearing upon land-use practices. Quite apart from the desirable social implications in the home life on the farm, it offers the farmer greater opportunity for diversification. Particularly in the warmer sections of the world, cheap electric power means cheap refrigeration, an important factor in the production of livestock products; and livestock farming has an important bearing on soil conservation. At the present time the electrification of farms in both Europe and the United States is proceeding rapidly and may in the future be recognized as the most important single physical improvement made available to the farmer in this century.
Conservation for Production.
To the agriculturist soil conservation does not mean abandonment of soil. It means rather the use of soil for production in a way that will achieve maximum secure returns to the operator. This may imply the use of certain soils for pasture grasses or for forests, rather than crops; but in a program for soil conservation such determinations are made positively in the interest of secure production, not negatively.
Desirable practices vary so greatly among the different soils that it is extremely difficult to generalize and specify that certain practices are good. There is no practice that is everywhere good. Some of the more important ones can be summarized as follows:
(1) The wider use of close-growing grasses and legumes such as alfalfa, lespedeza, and the clovers, is likely of first importance. Except for certain soils in the tropics and many of the alluvial soils, most soils must be periodically devoted to close-growing grasses and legumes if they are to maintain their fertility and structure. Some soils need to be devoted almost entirely to these crops if the soil is to be maintained; others can be used for intertilled crops grown in long rotations with the grasses. With relatively few exceptions, the productivity of soils in the United States cannot be maintained if intertilled crops are grown continuously. The plowing under of leguminous crops and other devices for the maintenance of soil organic matter frequently are necessary as supplements to crop rotations.
(2) In the United States there will need to be a wider use of fertilizers, especially phosphatic fertilizers, lime, and other amendments in order to maintain a vigorous plant cover, the fundamental and most important protection of the land. A large proportion of the present erosion is occurring on lands that have lost their fertility and consequently do not support a thrifty vegetative cover. The first step in the control of erosion on these lands is proper fertilization.
(3) There is needed a better adaptation of tillage methods to particular soil conditions looking to the preservation of soil structure and the encouragement of water infiltration into the soil. Much of the existing agricultural machinery does good work on one or more groups of soils but is not suitable on others. Further, a good deal of this machinery has been developed with the single thought of cost of operation without regard to its influence upon the structure of the soil.
(4) The wider use of devices for water control on the land must be expected. Such devices include various types of terraces and dams, designed to increase the amount of water entering the soil and to prevent erosion. In addition much can frequently be accomplished in this direction through the arrangement of fields so as to accomplish tillage operations on the contour and arrange the crops in strips along the contour. Many sloping areas cannot be terraced effectively, but the land can be properly managed through strip cropping and contour furrowing.
This simple enumeration must not lead the reader to oversimplify the problem. There are numerous other practices that have a direct or indirect bearing upon soil conservation and there are wide differences within those listed above as they are applied to different soil conditions.
Zoning Ordinances and Land Use Regulations.
Throughout the world agriculturists have been giving an increasing amount of attention to legal and cooperative devices for the regulation of land-use in the public interest. As a result a great variety of laws have been developed in the various countries. Laws looking toward the prevention of forest fires are an obvious example. Where streams are used for navigation, irrigation, or hydro-electric power, it has been necessary in many instances to adopt stringent protective regulations within the watershed. In some states rural areas are zoned so as to prevent the development of farms on land unsuited to farming in order to obviate the necessity for the use of public funds for roads and schools in areas that cannot give any appreciable support toward such services themselves.
Within the past two years public interest in the control of soil erosion has become so great that many states have passed laws permitting the establishment of soil conservation districts where citizens cooperate in the development of a plan for controlled land-use in cooperation with the Government. By Aug. 15, 1938, over 80 such districts, involving a combined area of about 40 million acres, had received certificates of organization in the United States.
On the whole a good deal of useful legislation has been enacted in the United States and in other countries in order to safeguard the nation's interest in the land and to enable farmers to adopt better husbandry. Some of this legislation is definitely experimental and as the result of experience much more will likely be done in the years that lie ahead. Different countries and different states will need different laws and regulations adapted to their own peculiar soils and unique problems.
Recently the United States has taken more definite steps toward the control of soil erosion than most other countries although active interest is beginning to awaken elsewhere. Even though soil erosion is not an important problem in very much of Western Europe, its soil problems have been acute and most of the countries have developed laws designed to require occupiers of the land to protect it. The United States Department of Agriculture has increased its efforts in the fields of education, research, and demonstration in respect to this problem and has developed a system of subsidies for farmers using good soil management practices. Many other Federal and state agencies, especially the Agricultural Experiment Stations, have increased their work directed toward the solution of this problem. One special Federal agency, the Tennessee Valley Authority, in cooperation with the Department of Agriculture and the State Experiment Stations, is developing an elaborate program for water and soil conservation for a great river watershed.
Fortunately the people of the United States have come to realize the national significance of their soil resources. A great deal more needs to be done, especially in the fields of research and education. The progress which has been made during the past ten years permits optimism for the future.
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