xxii AGRICULTURAL BULLETIN 



cent. This great increase is made up chiefly of increases of over $1,500,- 

 000,000 in the value of land and of nearly $215,000,000 in the value of 

 buildings. There was also an increase of over $150,000,000 in the value of 

 farm equipment, including implements and machinery and live stock, more 

 than three-fourths of which represents the gain in the value of live stock. 

 In considering the increase of values in agriculture the general increase 

 in the prices of all commodities in the last ten years should be borne in 

 mind. 



FARMS AND FARM PROPERTY. 



Iowa ranks twenty-third in land area and fifteenth in population among 

 the states and territories of continental United States. It has passed out 

 of the class of states that are adding to their total farm area. In fact, it 

 has a little less land in farms than it had in 1900. 



The entire state of Iowa lies within the northern portion of the low 

 plateau which constitutes the upper part of the Mississippi River drain- 

 age basin. The altitude of the southeastern two-fifths of the state ranges 

 from 800 to 1,000 feet, while the altitude of the western and northern 

 parts varies from 1,000 feet to about 1,500 feet in the northwestern portion. 

 With the exception of a small section in the extreme northeastern part 

 of the state, where the Mississippi river is bordered by rugged bluffs, the 

 surface of the state is undulating to rolling and in a few sections hilly. 

 All of the state, with the exception of the section in the northeastern part 

 just referred to, has been subject to repeated glacial invasions. As a re- 

 sult the underlying rocky floor is usually covered to a depth ranging 

 from 15 or 20 feet to extreme depths of over 200 feet, by mechanically 

 ground and thoroughly mixed glacial debris commonly known as the till. 



The chief drainage of the state is eastward to the Mississippi River. 

 The portions of the state adjacent to both the Mississippi and Missouri 

 Rivers are thoroughly drained. The north central portion is much more 

 in need of artificial drainage, and there are also considerable areas within 

 the southern portion of the state in which the natural drainage, particu- 

 larly of the subsoil, is inadequate. 



Five different soil areas are distinguished, consisting of the glaciated 

 plateau covering the north central two-fifths of the state; the deep loess 

 soils bordering the Missouri and Mississippi rivers and also extending 

 from the east in a narrow belt nearly to the center of the state, together 

 covering nearly one-third of the state; the shallow loess soil of the south 

 central section, covering about one-fifth of the state; the small ungla- 

 ciated section in the northeast corner and narrow lines of alluvial soil 

 along the Mississippi and Missouri Rivers. 



The soils are mainly dark brown to almost black clay loams, silt loams, 

 and loams, with a small amount of sandy loams in scattered areas. 

 With few exceptions these soils are deep, fertile, and well supplied with 

 organic matter. Both with respect to topography and soils Iowa is pe- 

 culiarly favored for agricultural exploitation. All of the staple crops 

 of northern climates may be grown within the state. 



