Soil Science and Geography

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  • SOIL SCIENCE AND GEOGRAPHY

    W. Elmer EkblawClark University

    Soil science, the study of soilsand their relationships, involves in agoodly number of its aspects, the applica-tion of geographic principles and disci-pline to the solution of certain problemsof soil genesis, soil character, and soildistribution. Most of such problems aredirectly related to place and its attrib-utes, the essential concept about whichthe science of geography is crystallized.Insofar as soil science relates to the at-tributes of place it is distinctly geo-graphic in its discipline, that is, thesame criteria must be applied to its prin-ciples as to the principles of geography.

    For, in its essence, geography isthe science of place and its attributes.Facts and principles and relationshipswhich include in their composition the con-cept of place, or which depend upon attrib-utes of place, are geographic. Just astime and time sequence constitute the fun-damental concept of history, or rocks androck relationships constitute the essenceof geology, or plants and their functionsform the core of botany, so place, and theattributes of place,constitute the essen-tial concept of geography. All controversyand dogma, all definitions and classifica-tions to the contrary notwithstanding,place, with its attributes, has, through-out history, remained, the popular and con-tinuous criterion by which geography hasbeen defined as a science.

    By this definition, the content ofgeography is logically and reasonably de-termined. Whenever the place relation-ships of any set of facts or principlesare under consideration, they are amenableto geographic discipline, and the geographyof man, the geography of land forms, orclimate or soils, the geography of bananas,or grasshoppers, or even of telephonepoles, becomes equally reasonable and logi-cal. The three essentials in every mate-rial drama are the time, the place, and

    the thingand place implies geography!The geography of soils, their

    place attributes and relationships, thusbecomes a very real and definite phase ofsoil science, with broad implications andprofound significances. The genesis ofsoils, the character of soils, the dis-tribution of soils, the productivity ofsoils, are all in considerable measure, afunction of place and place relationships,that is, of geography.

    Soil occupies a most importantplace in the environmental complex whichforms such a large factor in geographic de-scription and geographic interpretation.It is peculiarly a product of the environ-ment, and more fully expresses the wholeenvironment at any given place than doesany other phenomenon. However closely itsparent material may be related to the long,well-nigh infinite processes of geology,the soil itself is relatively dissociatedfrom that geologic history. Land form,drainage, and relief are all much moreclosely related to geologic history than isthe soil.

    Climate, upon which soil genesisand the genetic classification of soils de-pend, is ultimately determined by factorsquite extraneous to the earth, the quantity,and distribution of radiant energy receivedfrom the sun by the earthj and consequent-ly, the climatic factor is either directlyor indirectly consequent upon solar condi-tions in which our little earth plays-buta negligible part.

    Vegetation and the plants whichcomprise it possess the innate or inherentpower of adaptation within themselves. Thevital response of plants and all organiclife to the elements of the environment isreflected in the power of adaptation whichthey all possess in greater or lesser de-gree, which is not a fixed, but decidedlyvariable factor, and which shapes theplants and vegetation to a definite form

  • SOIL SCIENCE SOCIETY PROCEEDINGS 1936

    and character.In addition to the power of adapta-

    tion, animals possess in marked degree,the quality of mobility, not entirely, butalmost entirely, denied to plants. Whileanimals as groups possess as much geneticadaptation to the -factors of environmentas do plants, individual animals representrather fixed forms and size, quite in con-trast to the exceeding variability of sizeand form in individual plants. Because oftheir power of moving from place to place,they can, generally, or in some measure,escape an environment that might provelethal or injurious. They modify theirresponse to one environment, by their re-sponse to another to which they move. Thequality of mobility thus lends confusionto the study of an animal's relation toits environment.

    Man is most difficult of allthings to relate scientifically to his en-vironment because he possesses as wide adegree of adaptability as plants and ani-mals, greater mobility as a genus thaneither plants or animals, and, in addition,has his peculiar power of volition, ofchoosing for himself his own course; ofnot only choosing for himself the environ-ment which enables him to live and actmost satisfactorily, but of modifying byhis own efforts to a very large degree,the character or attributes of the placewhere he finds himself. Plants can veryslightly do this, and only without voli-tion; animals can change their environmentto a considerable degree, but more or lessintelligently. By exercise of his wit,man can, and does, modify his environmentprofoundly within variable but definitelimits. He thus obscures so effectivelythe effect of his environment as. almost toobliterate it, no matter how profoundly hemay, or does, ultimately respond to itsinfluences.

    Soils are more expressive of theirenvironment in toto than are any otherfactors of the environmental complex. Theyare relatively independent of the longtime sequence and all its incidents whichso profoundly affect their parent materialand the land forms upon which they develop;they escape, in large part, the direct in-fluence of the sun, which so closely con-trols climate in all its phases; they haveno power within themselves of adjusting

    themselves to the environment, either ge-netically or specifically, as have allliving organisms; they are not mobile asare animals including man; and they haveno power of volition, or of consciouslymodifying their environment, as has man.

    Thus the soil at any place is thebest manifestation of the effects of near-ly all the factors of environment whichconstitute the attributes of that placethe character of the rocks, the form ofthe land surface, the location of thewater table, the character and extent ofthe plant cover, the number and characterof animal life, and the effects of man'sactivities. Certain attributes of theplace are not obviously expressed in thesoil. Seasonality of light, temperature,and moisture is in most cases exceedinglyhard to differentiate; the effect of lightas a factor may not be determined from theattributes of the soil at any place;storms, or extremes of place attributes,are similarly not expressed. But, in gen-eral, soils may be said to reflect moreclosely than any other attribute of place,the complex of factors in any given en-vironment.

    It is because of this close corre-spondence, or adjustment, to the attributesof a given place, that the geography ofsoils becomes so interpretative, that theother attributes of place become of suchvital importance and significance to thesoil scientist. He is concerned withsoil in all its relationships, whether itbe genetically to the parent material, theland form, or the drainage; to temperature,to rainfall, to length of frost-free sea-son; to natural vegetation and to animallife; to man in his need for food, forclothing, and for raw materials and re-sources for his industry. Whether he beconcerned with the classification and no-menclature of soil, with its form and com-position, or with its productivity or itsfertility, he must explore its place rela-tionships and place attributes.

    While students of soil yet weregroping for the fundamental concept whichshould distinguish soils as a distinctentity, as a distinct natural body neces-sitating a distinct philosophy and a dis-tinct discipline, they investigated manyof the relationships of soils to other at-tributes of place. The early farmers and

  • SOIL SCIENCE AND GEOGRAPHY

    rulers of Mesopotamia and. Egypt, of Judeaand Phoenicia, of Minos and Greece andRome, delved deep into the problems of soilfertility and productivity, and understoodwell how the quality of the soil affectedthe character of land use, the welfare ofthe people, and the policies of the state.Much later, the geologists, the mineralo-gists, the chemists, the botanists relatedsoils to geologic processes and elements;to the composition of its constituent ma-terials- to its chemical reaction; or tothe kind of plants it supported.

    The Russians who finally gave formto soil as a distinct, natural body, andwho rebelled against the philosophy andsystem of soil knowledge and classifica-tion that their predecessors had set up,at first related soil-genesis and soilcharacter wholly to climate, and impatient-ly ignored the significance of all otherrelationships, though Dokuchaev, Glinka,and Sibirtzev were probably less guilty ofthis neglect of the whole composite, en-vironmental complex than were most of theirdisciples and successors. Joffe, in his"Pedology," states that Kossovitch finallypointed out the fallacy of such simple andnaive interpretation, and today soil scien-tists everywhere, Russia included, are en-gaged in a much broader field of investiga-tion. Every attribute of place as it af-fects soils is under survey and explora-tion. The geologic and mineral signifi-cance of the parent material; the impor-tance of slope, drainage, and land form;the role of all the elements of the cli-mate; the influence of forest and savannaand grassland, of rodent and worm and bac-teria, of man and all his worksall thesetoday form the legitimate grist of thesoil scientist's mill; they all fall un-der the province of his investigations.

    The soil scientist, like the ge-ographer who would understand the full im-port of his science, must be acquaintedfully, not merely superficially, with amultiplicity of facts, and must be thor-oughly trained in the disciplines of well-nigh a score of sciences. He must under-stand the variable attributes of place.Like the geographer, he must know the es-sentials of geology, physiography, clima-tology, botany and zoology, particularlyin their ecologic phases; history, eco-nomics, and sociology as they relate to

    land; of agriculture and its several divi-sions, not only as they comprise the at-tributes of place, but as they touch uponhis science in any vital way.

    If, instead of surveying his wholefield, he specializes in some particularphase of his science, he must entrust tothe geographer the task of exploring theplace attributes and relationships of soils,and profit by the results of the geog-rapher's studies. For land form attri-butes relating to soils, he would turn tothe physiographer; for temperature or rain-fall attributes relating to soils, he wouldturn to the climatologist; for plant coverattributes relating to the soils, he wouldturn to the botanist. Similarly, theywould all turn to the specialist in soilscience for the soil attributes of anyplace as they relate to physiography, cli-matology, or botany. The relationship be-tween soil attributes of any place andother attributes of that place form abroad borderland for mutual exploration.

    It is in the field of distributionof soils, their classification and genesis,that the geographer and his geographic dis-cipline can render the soil scientist thegreatest service, though in the applica-tion of soil science to the fields ofland utilization, land planning, and agron-omy, the geographer can likewise be of ap-preciable help, particularly in guiding ordirecting a program of investigation or acourse of action or procedure, and in cor-relating the factors that should determinepolicies or plans.

    Just as the geographer must includein his studies the part that mineral com-position plays in weathering and decomposi-tion of rocks to shape land forms that af-fect man's movements and other activities,so must the soil scientist investigatethat same subject to determine how somemineral constituent in the parent materialaffects the growth of some cropmanganesefor buckwheat, zinc for the tung oil tree,copper for Everglades string beans. Justas the geographer studies the character ofhuman occupancy on plain or terrace orslope, so does the soil scientist studythe character of his soil profile on cor-responding land forms. Just as the geog-rapher must take into account the effectupon man's economy, of the character andextent of the plant cover, so must the

  • SOIL SCIENCE SOCIETY PROCEEDINGS 1936

    soil scientist consider it with regard toits effect upon the composition and agro-nomic quality of the soil. The geographerstudies the distribution of animal lifewith regard to its effect upon man's cul-ture or activities or welfare; the soilscientist studies it in relation to theproductivity of the soil, or to its effectupon some of the soil attributes. Thestudies of the soil scientist and the ge-ographer thus include a great deal of com-mon material, involve a great deal of thesame field and method of research, and di-rect themselves in part to the same end.It is in that part of their sciences whichoverlaps, or points in the same direction,that the soil scientist and the geogra-pher can, and should, join forces for mu-tual aid and interest toward their commongoal. Both have vast fields, as yet rela-tively unexplored, that are distinctivelytheir own; but where their fields merge,where one -may be of substantial help tothe other, they might well agree upon acommon program.

    The utilitarian policy of manymodern states to translate the knowledge,the principles, which all science is at-tempting to assemble and classify, intopractical application toward a so-calledricher and more abundant life, a so-calledhigher standard of living, impels us allto integrate our knowledge and research asnever before, not only that it may be moreeffectively employed for practical pur-poses, but that it may be so well delimit-ed that it will not be employed for il-legitimate purpose or extended beyond itsproper significance. Both geography andsoil science, as well as their relatedsciences, face the hazard of being con-sidered much more possible of concrete ap-plication than their present stage of de-velopment Justifies. Unless both groupsare careful that their body of knowledgebe not overestimated or overvalued in itspractical significance, they are likely tofind it overtaxed or injudiciously applied,and to suffer serious loss of usefulnessand confidence as a result. They must notclaim more for their sciences than theiraccumulated knowledge justifies, or doubtand criticism will surely accrue to them.'In the widespread programs for land utili-zation, conservation of resources, reset-tlement of populations, revisions of farm

    methods and.types of management, it be-hooves us all to insist upon sharp andhonest distinction between hypothesis andtheory, and proved fact.

    On the assumption that we know...

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