THE KNOX SILT LOAM. 7 



crop, while both wheat and oats are decidedly subordinate,. and the 

 tame grasses are only grown to a very limited degree. In tfyeir v "place 

 the prairie grasses are utilized both for pasturage and the ^uftfn'g of 

 wild hay. In this latter region, also, emmer and alla^Df^i occajpy" a 

 considerable acreage. 



IMPROVEMENT IN SOIL EFFICIENCY. 



The first limitation upon the efficient occupation of the Knox silt 

 loam is that of a too rough topography for economic use in the roll- 

 ing to hilly areas bordering the principal streams. These areas 

 should not be considered for tillage purposes under any conditions. 

 Omitting such areas from the consideration of the agricultural uses 

 and efficiency of the type, it is probable that the greatest improve- 

 ment in the yields of the crops now grown may be effected by the 

 incorporation of organic matter into the surface soil, accompanying 

 the establishment of rational and definite crop rotations. 



For the restoration of organic matter to the surface soil of the 

 Knox silt loam there is probably no better method in any area where 

 it occurs than the growing of clover alone, or of mixed clover and 

 timothy, at some point in the regular rotation to be adopted. The 

 stand in grass should not be maintained under ordinary circum- 

 stances for more than two years, and the sod should be turned under 

 in order that the stubble and roots of the grass crops may increase 

 the organic matter content for the production of corn and small 

 grains. Throughout the entire extent of territory within which the 

 Knox silt loam occurs this practice is not only possible, but is highly 

 desirable. In the more western country along the Missouri River 

 alfalfa may and should take the place of clover or of the mixed 

 grasses for this purpose. In some portions of southern Indiana and 

 of northern Kentucky the soil is reported to be " clover sick." In 

 some instances this results from the ravages of a fungous disease, 

 and there is practically no remedy except the abandonment of clover 

 cultivation for a considerable period of time upon the affected fields. 

 In other instances difficulty in the production of the clover crop arises 

 either from a lack of the use of lime in connection with the seeding 

 or from difficulty experienced with the " heaving out " of the clover 

 during periods of repeated freezing and thawing in the winter and 

 spring months. To meet the former condition lime should be ap- 

 plied to the soil at the rate of 1,500 to 2,000 pounds of the burned 

 stone-lime, slaked to a fine powder and spread over each acre. If 

 the powdered limestone is to be used in its place, two or three times 

 the quantity per acre will be required. To remedy the difficulty with 

 the heaving out of clover, adequate surface and subsoil drainage 

 alone are required and will prove fully competent to meet this diffi- 

 culty in all these cases. 



