wi.gif (GIF Image, 863x704 pixels) - Scaled (96%) http://www.ocs.orst.edu/pub/maps/Precipitation/Total/States/WI/wi.gif1 of 1 8/24/2004 10:58 AMThis guide cov ers modern soil mapping in its vari ous forms, ex plaining both thetechnical methods of this type of map pingas well as typi cal uses of mapped soil in -for ma tion.The mod ern de tailed county soil sur -vey is our pri mary fo cus here. An in-depth as sessment of soil sur veying is be -yond the scope of this guide; rather, wecon cen trate our at ten tion on tech niques ofcre at ing and meth ods of evalu at ing soilmaps.Mapping the earth’s soils is a tech ni-cal and sci entific chal lenge. Yet the re -sults can help us un derstand the ca pabilityand limitation of the land to sup port ag ri-cul ture, hous ing, trans por ta tion, and manyother uses. The his tory of soil mappinghas been one of con tinual in novation, in -creasing pre cision, and ever wider- ranging ap pli ca tions.In or der to fully grasp the importanceof soil mapping, a ba sic un derstanding ofthe soil it self, its vari ability, and char ac-teristics is nec essary. This is cov ered inthe first sec tion of this guide.Wis con sin is em pha sized through outin or der to pro vide the reader with a rele -vant un derstanding of the lo cal “state- of-the-art”. The status of soil in formationacross the state at the time of this guide’spublication is pre sented in the form ofstatus maps, with the ac companying nar -rative pro viding a con text for the maps.More cur rent in for ma tion is avail able viathe Inter net.With es tab lish ment of the Wis con sinLand In for ma tion Pro gram (WLIP), the is sue of land in for ma tion in te gra tion hasbecome more and more a part of the daily dialogue be tween state and lo cal agen cies.Soil mapping is des ignated as one of thefoun da tional ele ments of the WLIP.This pub lication will be use ful tothose in volved in modernizing land rec -ords, as well as to those simply seek ing abet ter un der stand ing of currently- available soil in for ma tion, its limi ta tions,and its pos si bili ties.Soil Char ac ter is ticsThe soil hosts much of the re cycling ofresources criti cal to plane tary life, includ-ing en ergy, wa ter, gases, and nu trients.The soil is also the an chorage and sup -plier of nu trients for vege tation. Simi -larly, the soil pro vides a ba sis for mosthu man en deavor, in clud ing ag ri cul tureand food pro duc tion, tim ber har vest ing,con struc tion and en gi neer ing proj ects,waste dis posal, and recreation. Indeed,the soil is essential to life.Although soils ex tend in a vir tuallyunbroken ve neer over the land sur face,they are di verse and vari able. Soils arecomposed of a wide va riety of con stitu-ents. Most soils origi nate from the samebasic materials, the solid rocks of theearth’s crust (which vary from one placeto an other). These rocks are weathered,transported by wind, wa ter or gla cialmove ment, de pos ited, and com pactedthrough a se ries of pro cesses which areunique to each soil.Once in place, these build ing blocksof the soil, known as par ent ma te rial, arechanged through a se ries of pro cessesover time into the soils we ob serve at theearth’s sur face. These pro cesses varyfrom place to place due to the in fluencesof liv ing organisms (plants and ani mals),cli mate, and to pog ra phy.In other words, each soil has a uniquehistory and a unique set of char acteristics.As a re sult, dif ferent soils have dif ferentcon stitu ent min er als, or ganic mat ter, andstruc ture, as well as dif ferent prop erties(such as soil mois ture ca pac ity and load- bearing ca pac ity). These prop erties af-fect each soil’s ca pacity to sup port natu -ral, ag ricultural, and other hu man uses.The his tory of a soil may best be seenthrough its pro file, a ver tical slice fromthe sur face down into the un weatheredmaterial be low. A soil pro file will con -Soil Map ping 1 May 1997State Car tog ra pher’s Of ficeGuide 4, 2nd edition May 1997One of a se ries ofguides cov er ingvari ous map pingtop ics in Wis con sinWis con sinSOILMAP PINGHighlights of this guide....· Soil Char ac ter is tics........................1· Soil Sur veys ....................................2· Uses and Mis uses of Soil Sur veys ..4· Methods of Soil Map ping ...............7· Wis con sin Soil Sur veys...................8· Other Ac tivities Re lated to Soils ....9· Digital Soil Data ...........................12· Current Is sues and Trends ............13· How to Ob tain Soil Maps..............15tain sev eral soil ho ri zons, lay ers in thesoil rep re sent ing the com bined ef fects ofdif fer ent sources of par ent ma te ri als, withmany hun dreds of years of wa ter mov ingcertain materials down (or up), andchemi cal and bio logi cal ac tiv ity.A pri mary prop erty of a soil is its tex-ture. Soil tex ture is an ex pression of themix of the different-sized mineral par ti-cles in the soil. The three soil particle- size com po nents used in de ter min ing tex-ture are sand, silt, and clay. The soil tex -tural tri angle is used to de termine soil tex -ture based on the rela tive amounts ofthese three components (see Fig ure 1).Soil clas si fi ca tionInformation about soils is or ganized in the Gen eral Soil Clas si fi ca tion Sys tem in tro -duced by the U.S. De partment of Ag ricul-ture (USDA) in 1960 and re vised everyfew years. This clas sification sys tem ar -ranges the soils of the world into broadgroups called or ders, of which there are11 in the United States. Each or der isthen sub di vided into cate go ries basedupon more spe cific char ac ter is tics. The pri mary clas si fi ca tion unit is thesoil series. There are over 10,500 differ-ent soil series in the United States alone,although only about 650 are mapped inWis con sin.A soil se ries des ignation is based upon many soil prop er ties, in clud ing ho ri zonthick ness, tex ture, and po si tion; par entma te rial; or ganic mat ter con tent; and thesoil depth. A soil se ries is usually namedfor a town or geo graphical lo cation nearwhere it was first identified.Phases are subsets of soil series usedin the mapping of soils, while as so cia -tions are combinations of soil se ries usedto de scribe soils over larger ar eas, usu allyon county- wide soil maps.The ac tual de lineations on soil mapsare called soil map units, which are based on but not al ways equiva lent to soilphases. Map