376 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



The demand for the Soil Survey reports and for maps and reports 

 covering special areas shows not only that an increasing number of 

 scientific investigators are using information of this kind but also 

 that more men engaged in various lines of business are interested 

 in the results of the work. 



Cooperative work with the Forest Service was continued during 

 the year. Special attention was given to the relationship between 

 certain soil types and the character of the forest growth. Informa- 

 tion of this kind is of great practical value in the reforestation of cut- 

 over lands. 



At the request of the Reclamation Service, Interior Department, 

 this bureau continued the classification of the soils in a number of 

 areas. The information secured will be used mainly in determining 

 the agricultural value of the land in proposed irrigation projects. 



The usual cooperative work with other departments of the Govern- 

 ment and with experiment stations was carried on during the year. 



Numerous inquiries regarding the identification of soil types and 

 the treatment and improvement of soils were answered, and much 

 advice and information was given by correspondence or in person 

 to callers. Exhibits of the work of the Soil Survey were prepared, 

 and a representative from the bureau, accompanied by representa- 

 tives of other bureaus of the department, visited a number of impor- 

 tant fairs for the purpose of presenting and exhibiting the work of 

 the Soil Survey and giving advice on the treatment of soils. 



It has been recognized for several years that much valuable work 

 in soils has been done abroad with which the soil investigators in this 

 country were not in close touch, and that many processes of soil 

 development are more clearly shown under the climatic conditions 

 prevailing in parts of Europe than in this country. The behavior 

 of soils under centuries of continued cultivation had also become a 

 subject of interest to soil investigators in this country. The bureau 

 was fortunate during the fiscal year ending June 30, 1922, in being 

 able to send a representative abroad for three months to confer with 

 the soil investigators of other countries and to examine the soils of 

 certain regions in order that they might be compared with the soils 

 of the United States. During this journey Czechoslovakia, Hun- 

 gary, Rumania, Yugoslavia, Italy, Greece, Germany, and England 

 were visited, and a large number of samples of the typical soils were 

 collected, and as far as time permitted a study was made of the soils 

 m the field with reference to their history and treatment. Especial 

 attention was given to the effect of continual cropping for centuries 

 in these long-cultivated regions. An account of this journey and 

 observations on the soils and agriculture of the countries visited 

 has been prepared and presented to the public in papers and addresses. 

 The samples collected have been compared with the soils of similar 

 regions m this country and turned over to the laboratories of the 

 bureau, which are engaged in an investigation of their chemical and 

 physical properties. 



CHEMICAL DIVISION. 



Investigations of the Chemical Division, as in the previous year, 

 were concerned chiefly with colloidal soil material. By modifying 

 the treatment adopted for isolatmg the colloidal material it was 

 found possible to separate from the larger soil grains more than 60 

 per cent of all the colloidal matter present hi some soils. 



