796 THE ILLINOIS GLACIAL LOBE. 



ferruginous crust or ochery clay, which is exceedingly refractory, giving 

 very slow access to air or water. With this exception, however, the crust 

 is either absent or is so low down that it docs not seriously affect the soil. 

 Aside from corn, which is liable to be injured by autumn droughts, the lead- 

 ing crops of the State do fairly well. Wheat yields as well as anywhere in 

 the State, while orchards and small fruits bring very profitable returns. The 

 soil needs careful attention, but there is every indication that where properlv 

 cared for it will become as profitable for agriculture as the soils which now 

 enjoy a better reputation. 



Concerning the analyses of the samples of white clay and also of the 

 more porous upland loess (see p. 162) Professor Whitney remarks: 1 



Of the upland loess there are two types— those which are pervious to water and 

 which are valuable agricultural lauds; those which are compact and almost imper- 

 vious to water, locally known as white clays, wliich are so very retentive of moisture 

 as to be always wet and of less agricultural value. The mechanical analysis shows 

 that these two types of land are almost identical in texture, and that the white clays 

 (1321, 1342, 1343, and 1345) have no more clay than the other samples of upland 

 loess, which are considered very fertile lauds. The wetness of these white clay lands, 

 therefore, is not due to the fact that they contaiu more clay, but it must be ascribed 

 to some other cause. They coutain no more organic matter, so that it can not be due 

 to an excessive amount of this material. It must be due, therefore, to one of two 

 .causes — either that there is a hardpan or a layer of impervious clay underlying these 

 lauds which retards the descent of the water and prevents the excess of rainfall being 

 carried down, or it may be due to a difference in the arrangement in the grains. Our 

 laboratory experiments do not seem to indicate that there is any material difference 

 in the arrangement of the graius in these two classes of soils, but this can only be 

 determined with certainty by investigation of the soils in their natural position in the 

 field. If the pervious character of the white clays is due to a difference in the arrange- 

 ment of the grains, the lands ought to be underdrained so that the excess of water 

 may be artificially removed, or the trouble may be greatly alleviated by liming the laud, 

 which will tend to make it more loamy and less retentive of moisture. The effect of 

 kainit and of some of the phosphates would probably have a similar effect on the land 

 if applied regularly for a number of years. If the soils are impervious because of a 

 hardpan or a layer of impervious clay 3 or 4 feet below the surface, then fertilizers will 

 do very little to correct the evil unless the lands are systematically underdrained. 



PEATY AND ORGANIC SOILS. 



The peaty and organic soils occur in basins or in poorly drained 

 tracts where rank vegetation becomes submerged at certain seasons and is 

 thus prevented from atmospheric decay. This class of soils is much more 



'Report of Illinois Board of World's Fair Commissioners, pp. 101-102. 



