72 ANXUAI. TtFJ'ORTS OF DEPAT^TMENT OF AORICULTURE. 



ods used in the soil survey, the basis of the classification of the soils, 

 and the use to which each of the soil types is best adapted. 



At the same time active work is being prosecuted in the further 

 study of some of the individual soil types and soil series that are of 

 great national importance and in the preparation of reports giving a 

 comprehensive view of the uses to which they are now put, and sug- 

 gesting tlieir best use in different parts of the country and under 

 different climatic and industrial conditions. A bulletin describing 

 the Norfolk series has already been prepared, covering the whole 

 question of the best use of these several soils in the important special 

 line of truck farming. A similar bulletin on the Clyde soils, typi- 

 cally developed around the Great Lakes, is in progress, and some 

 preliminary work has been done on some of the other important soil 

 series. 



The reconnoissance surveys have been extended in the Great Plains, 

 until now soil maps have been published or are in course of publi- 

 cation of the western half of two-thirds of North Dakota, South Da- 

 kota, Nebraska, Kansas, the Panhandle of Texas, and a large area in 

 south Texas, giving an almost continuous strip from Canada to 

 Mexico. 



While these maps are on a scale of 4 miles to the inch, it is be- 

 lieved that for many years to come they will serve the purpose of 

 aiding in the agricultural development in this sparsely settled re- 

 gion, where the soils are uniform over large areas and where for this 

 reason greater detail of mapping is not absolutely essential. 



Several of the most experienced men in the soil-survey work have 

 been detailed to assist the Bureau of Forestry in the examination of 

 the soils of the National Forests and to pass upon their agi'icultural 

 value for the information and guidance of the Forest Service in 

 carrying out the law regarding the elimination of agricultural lands 

 from forest reserves. As this work must develop to large proportions 

 in the immediate future, I have included in my estimates an increase 

 of $20,000 for the Bureau of Soils. Only in this wa}^ may the bureau 

 meet the increasing demands that will result from the requirements of 

 the last appropriation act for this department. 



SOIL CHEMISTRY. 



Work has continued during the year on the fundamental and 

 thorough investigation of the composition of important soil types, 

 determining both the mineral components of the soil and all of the 

 elements, including the rare elements that have heretofore been over- 

 looked in the chemical analysis of soils, for the purpose of throwing 

 more light than has heretofore ]3een shed upon fundamental differ- 

 ences or similarities between the mineral parts of soils 



