118 SOIL PHYSICS AND MANAGEMENT 



of the soils, very little of real value is accomplished, as the soil 

 survey is only preliminary to a more complete investigation. If, 

 however, the soils are analyzed, field experiments carried on, reports 

 published giving the results of the work, and recommendations for 

 improvement and management made, the farmer may avail himself 

 of all this information for improving his soil and his farm manage- 

 ment generally. 



2. Methods of the Survey. For the application of this infor- 

 mation to the individual farm, it is necessary that the maps showing 

 the soils of the farm should he accurate in all details. To accom- 

 plish this, three things at least are necessary: first, careful, well- 

 trained men to do the work; second, an accurate hase map upon 

 which to show the results of their work ; and third, the means nec- 

 essary to enable the men to place the soil type boundaries, streams, 

 etc., accurately upon the map. 



For work in the field each man must be familiar with the soil 

 types and their variations in the area he is surveying; he carries 

 an auger for examining the soil to a depth of 40 inches, a map of 

 the area made to the proper scale mounted upon a small, smooth, 

 light board. Where a satisfactory base map is not available, one 

 must be made before the mapping is begun or as the work pro- 

 gresses. A compass is carried to enable him to keep his directions, 

 and he should be an expert at pacing distances and keeping his lo- 

 cation. The mapper should have pencils for drawing in soil boun- 

 daries and other features, and coloring soil areas. A traverse plane 

 table should be within easy reach to be used for getting the direc- 

 tion of roads and railroads. If buggies are employed the odometer 

 may be used for measuring distances along roads or the revolutions 

 of the wheel may be counted. 



The party consists of two men who work side by side. It has 

 been found necessary, in order to get the detail with sufficient ac- 

 curacy, that all areas must be traversed and every ten acres in- 

 spected. To facilitate this, each section on the map used is divided 

 into 40-acre plots and these form the most convenient unit area for 

 work. 



Certain lines are selected that form the center of the work, such 

 as a section line in one case and a half section line in the other, and 

 each man works an area one-half mile in width, inspecting the soil, 

 locating r.nd indicating on his map the soil boundaries, roads, 

 streams, railroads and any other features that should be shown. 



