Physical and Chemical Papers. 87 



THE LOSS OF NITROGEN AND ORGANIC MATTER IN 

 CULTIVATED KANSAS SOILS 



And the Effect of this Loss on the Crop-producing Power of the Soil. 



By ('. O. SwAXSox. 



THE decrease in the crop-producing power of the soil is a 

 fact familiar to all students of agricultural problems. The 

 larger productiveness of virgin soils as compared with the pro- 

 ductiveness of these same soils after they have been under cul- 

 tivation for several decades is well known by the men who 

 broke up the virgin prairie and have continued to cultivate 

 that soil for half a lifetime or more. If we make a study of 

 the figures compiled by the State Board of Agriculture for the 

 foiiy-year period, 1872-1911, we shall find that the leading 

 crops show an average decrease in crop production. In Brown 

 county the average corn production for the first twenty-year 

 period, 1872-1891, was thirty-six bushels, and for the second 

 twenty-year period, 1892-1911, was thirty bushels. Riley 

 county produced an average of thirty-three bushels in the first 

 period and twenty-five bushels in the second. In Sedgwick 

 county the first period shows an average of thirty-two bushels 

 and the second twenty-one bushels. "More live stock" is men- 

 tioned by some people as the panecea for this evil. If that 

 by itself was the cure, then a typical live-stock county, where 

 more grain is fed than raised, should not show this decrease 

 in crop production. Butler is such a county. In the period 

 between 1872 and 1891 the average corn production was thirty- 

 two bushels per acre, and in the second period, 1892-1911, the 

 average was twenty-six bushels. It is not necessary to give 

 more figures to prove this fact. Any one who makes a study 

 of the figures compiled by the State Board of Agriculture will 

 find that there is an average decrease in crop production, and 

 this is true in Butler, Greenwood and Chase, typical live-stock 

 counties, as well as Brown, Sedgwick and Russell, where the 

 type is called grain farming. 



Seed adapted to climate and soil is an important factor in 

 crop production. Seed improvement may not have made all 

 the progress promoters of agriculture desire, but that the seed 

 used by farmers in general is more adapted to the climate and 



