738 SOILS: PROPERTIES AND MANAGEMENT 



Illinois has given special prominence to color, and, in ad- 

 dition to the general description of the soil types, includes 

 data derived from chemical analyses to show the itore o! 

 plant-food in the surface layers. The Indiana and Mis- 

 souri surveys have combined a purely geological scheme of 

 classification on the basis of origin, with certain properties 

 of practical importance, such as texture, color, and content 

 of humus, but without observing a systematic order. 

 The New Jersey survey includes rather full data <>n the 

 chemical composition of the soil types, in addition to the 

 usual discussion of their properties and relationships. 



634. Surveys in other countries. — Several countries 

 have undertaken some type of soil or agrogeological sur- 

 vev. These surveys, which have been undertaken in 

 Germany, France, Italy, Russia, Great Britain, and Japan, 

 have aimed at a broad practical classification of soils 

 based on their agricultural values and tillage properties. 

 Several thousand square miles have been covered by the 

 surveys in each of these countries. Colored charts are 

 published to accompany the descriptive reports. In these 

 surveys the classification is largely genetic, in combina- 

 tion with a consideration of the more evident physical 

 and chemical properties, which are recognized and grouped 

 in the field in much the same manner as in the American 

 surveys. The details, of course, are considerably differ- 

 ent in the reports of the different countries. In Germany 

 the maps are geological-agronomic in character; that is, 

 prominence is given to both the geological and the crop 

 relations of the soils. Their physical and chemical proper- 

 ties are pointed out and are used in the classification. 

 Similar methods are followed in France and Japan. 



In England the areas of soil are determined, first, by 

 means of their texture ; secondly, by means of their con- 



