TABLE OF CONTENTS XXI 



PAGES 



associated with dry farming, 615 Extent of dry farm- 

 ing, 616. 



CHAPTER XXXI 



THE SOIL SURVEY 718-740 



The classification of soils by survey, 617 Factors 

 employed in classification, 618 Texture, the soil class, 

 619 Special properties, the soil series,. 620 Source of 

 material, the soil group, 621 Agency of formation, the 

 soil province, 622 Climate, 623 The practical classi- 

 fication of soils in the United States, 624 The soil type 

 and soil series, 625 The equipment for survey work, 

 626 Procedure in the field, 627 Collection of soil 

 samples, 628 The accuracy and detail of the soil sur- 

 vey, 629 The soil survey report, 630 The soil map, 



631 The extent of soil surveys in the United States, 



632 Surveys by state institutions, 633 Surveys in 

 other countries, 634 Use of the soil survey, 635. 



