SOIL SESSION. 



131 



TABLE NO. III. 

 Crop yields on Illinois soil experiments. From Vienna Field on Worn Hill land. 



Soil treatment applied. 



Bushels per acre. 



1903 

 corn. 



1901 

 corn. 



1905 

 corn. 



None 



Legume eatch crops 



Legume Lime 



Legume, lime, phosphorus 



Legume, lime, phosphorus and potassium. 



Gain for legume, lime., 

 Value of increase 



5 



8 



7 



11 



31 

 36 

 49 

 49 

 45 



18 

 $B 30 



38 

 43 

 62. 

 57 

 57 



24 

 $8 40 



Soil treatment applied. 



T903 

 wheat. 



1904 

 wheat. 



1905 

 wheat. 



None 



Legume catch crops 



Legume, lime 



Legume, lime, phosphorus 



Legume, lime, phosphorus and potassium. 



Gain for legume, lime and phosphorus. 

 Value of increase 



1 

 11 



1» 



26 



30 



25 

 $17 50 



Upon this red silt loam occupying the worn hills of the extreme 

 southern part of the State, the growing of legumes to increase the nitro- 

 gen content of the soil, is of first importance. An acid condition exists 

 here as well as in the gray silt loam, and the use of from one to two tons 

 of fine ground limestone is advisable in order to get clover to stand and 

 to grow better cowpeas. The first year the season was the limiting 

 factor in production, but in the second and third year the legume and 

 lime treatment has given a substantial increase in corn ; neither phos- 

 phorus nor potassium added to this has increased the yield. The supply 

 of phosphorus is rather low and, undoubtedly, when the nitrogen sup- 

 ply has been brought up, by turning under legumes, phosphorus can then 

 be used with profit. In fact, for the wheat crop, phosphorus can be 

 profitably used from the beginning, as is shown by the increase of sever* 

 bushels the first year, five bushels the second, and eight bushels the third. 



Allow me to say a word in regard to another good form in which 

 to buy the element phosphorus ; that is in the form of fine ground natural 

 rock phosphate. This material is being taken in large quantities from 



