564 IOWA DEPARTMENT OF AGRICULTURE. 



humus. It is a splendid corn soil. The very deep loess which occurs 

 along the Missouri river, from Sioux City to the Missouri boundary, is a 

 deposit which in nature and origin is reduplication of that of the valleys 

 of the Rhine and the Moselle in Germany, which are world-famous for 

 their vineyards. In the southern part of this belt of deep loess, grapes 

 flourish better than elsewhere in the upper Mississippi valley, and a great 

 industry In this branch of horticulture is slowly but surely coming into 

 existence there. 



The southern Iowa loess, which covers, in whole or in part, the counties 

 ol Adair. Madison, Warren, Marion, Mahaska, Keokuk, Washington, > dam? 

 Union, Clarke, Lucas, Monroe, Wapello, Jefferson, Henry, Lee, Van Buren, 

 Davis, Appanoose, Wayne. Decatur, Ringgold, Taylor, Muscatine, and 

 Louisa, is of a somewhat different nature from the Missouri loess. It is 

 not so deep, also whiter in color and more clayey in nature; under favor- 

 able conditions, it forms a better wheat soil than the latter; it is doubt- 

 less poorer in lime. It does not cover the greater part of the land sur- 

 face, but is found principally on the divides and hills, the flanks of which 

 expose large areas of till. As a result two radically different soils occur 

 side by side throughout the southern part of the state. Often a farm 

 will He upon both. It is easy to distinguish them by the following rule: 

 The till is a stiff clay, full of gravel and boulders; the loess is a porous 

 soil, always found on the higher levels, and contains no gravel or large 

 stones. 



The Mississippi loess, which occurs along the Mississippi river and in 

 portions of southeastern Iowa, appears to be intermediate in character 

 between the others. It contains less lime than the latter and is not so 

 clayey as the former. It resembles the Missouri loess, but could scarcely 

 be confused with that of southern Iowa. It forms a good corn soil. In 

 the northwestern part of the state the loess dees net cover the whole 

 country. 



The loess of Iowa is a peculiar fine-grained material which covers half 

 of the area of the state. 



It is generally light-colored, being in various shades of buff and yel- 

 low, sometimes whitish. Although it has much of the appearance of 

 clay, it is never so fine and plastic and rarely makes good brick. It is 

 quite porous in spite of its fine textured appearance; 80 per cent of 

 the particles composing the loess are smaller than grains of fine sand, 

 but are coarser than clay. This is a fortunate circumstance and the one 

 to which loess owes its value as a soil. Its porosity is such that it easily 

 rids itself of excess water and yet, where it is not too deep, it is enabled 

 to draw up from below sufficient moisture for growing crops. Extremes 

 of wet or dry weather, which parch or drown out other soils, have little 

 effect upon loess soils. Loess rarely contains large pebbles or stones. 

 It is usually thickest on the tops of the hills and divides, and along the 

 larger streams. 



In some of the most broken regions of southern Iowa, tile drainage is 

 almost as necessary as in some of the flattest regions of the Wisconsin 

 drift, but for a different reason. This is on account of the peculiar rela- 

 tions of the loess and the till. The loess, it will be remembered, here 

 occupies the higher levels and is a rather porous clay; the till is more 



