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_---~ $eC. 1~: 12 LAND CAPABILITY CLASSIFICATION j¢~ <br />- Engineers and hydrologists also use sod survey information in a practical <br />__- way. Prospective roadbeds can be selected from soil survey maps. Estimates <br />-- ofwater runoffand infiltration can be made on the basis ofsod characteristics <br />enumerated in soil survey bulletins. Predictions can be made of hydrologic <br />chances in relation to modifications in land-use patterns. <br />The soil survey in a practical way is perhaps of greatest value in land classi- <br />- - fication for agricultural and other uses. The classification of greatest im- <br />- portance to aerictilturisrs is that.m use by the U. S. Soil Conservation Service <br />because of its widespread application. <br />~• - 12:12. LAND CAPABILITY CLASSIFICATION <br />_ At this point it may be well to point out the di13'erence between soil and <br />land. Soil is the more restrictive term, referring to a collection of natural <br />r>. bodies with d~th as well as breadth whose charact_eristits may be only in- <br />;~,: directly related to their current vegetation and use. Land is a broader term <br />which includes among its characteristics not only the soil but other physical <br />~,_ attributes, such_as wafer supply, exisiing plant covey_and location with <br />~: respect to cities, means o~ransportation, etc. Thus, we_hav~oresr land, <br />~• : borrom land, and.grass ands, which may include a v_arietY of ~oi1s. <br />Soil survey maps and reports have become two of the bases for a system <br />:~` of land capability classification. This system requires that every acre of land <br />.~r; ; be used in accordance with its_capability_and limitarions. Land is classified <br />=~' according to the most_suitable sustained use that-can be made of it while <br />providin¢ for adequate protection from erosion or other means of deterjora- <br />tion. Thus, an area where the soils are deep, well drained, and have a stable <br />surface structure, and where the slope is only I to 2 percent may be cropped <br />intensively almost indefinitely with little danger of erasion or loss in produc- <br />tivity. Such an area has great capabilities and few limitations in the use to <br />which it can be put. In contrast, an area on which shallow or poorly drained <br />soils are found or wherein steep slopes are prevalent has limited capabilities <br />aad many limitations as to its use. It can easily be seen how the characteristics <br />of soils are one of the criteria for identifying [he best land use. <br />cAPABtcrrv cLASSFS. Under the system se[ up by the U. S. Soil Conserva- <br />tion Service, eight land capability classes are recognized (j). These classes <br />are numbered from I to VIII. Soils having greatest capabilities for response <br />to manaeemen[ and least limitations in the ways they can be used are in <br />class 1. Those with least capabilities and greatest limitations are found in <br />class VIII (see Figs. 12:16 and 12:17). A brief description of the charac- <br />knstics and safe use of soils in each class follows. <br />ctASS t. Soils found in this land class have few limitations that res ct t eir ~ : i,Ml <br />ese. --- - -- - -- ~ ~~ <br />-They can be cropped intensively, used for pasture, range. woodlands. <.~- <br />~L <br />~~ <br />.~ible the delineation of soil bounaei ~° <br />iap shown in Fig. 12:13. The soil le e[ <br />ope (second capital lever) and the de <br />ood silt loam 1 Osl that has a r9 P°~ <br />courresv Sod Swvey Division, U. S. S~ <br />