26 



FOR BETTER CROPS IN THE SOUTH 



Phosphorus produced a large increase in each crop even when 

 applied alone, but when applied after nitrogen the increase was 

 exceedingly marked, amounting to 18 bushels increase in corn, 15, 

 in oats, and 20 bushels increase in the yield of wheat. While 

 nitrogen was applied in commercial form (dried blood) in these 

 experiments, these results emphasize the very great importance 

 of using phosphorus in connection with clover and farm manure 

 for improving this soil. 



The use of commercial nitrogen was discontinued after 1905, 

 but the addition of phosphorus produced 1.07 tons more clover 

 in 1906, 19 bushels more corn in 1907, 12.2 bushels more corn in 

 1908, and 10.2 bushels more oats in 1909. 



The possible effect of phosphorus on the clover crop itself 

 may be seen in the results obtained in 1905 on the University of 

 Illinois soil experiment field at Urbana, Illinois, which is also 

 situated on good Illinois prairie soil. By "legume" treatment 



Where both labor and fertility are wasted 



is meant the growing of a catch crop of cowpeas or clover in 

 the corn when it is " laid by." 



Crop Yields in Soil Experiments 

 Typical Corn Belt Prairie Soil, near Urbana, Illinois 



Soil 

 Plot 

 No. 



Three Years' 

 Average Before 



Treatment 

 Corn, Bushels 



60 

 64 

 63 

 61 

 61 



Aver. 

 61.8 

 Bu. 



64 

 62 

 58 

 61 

 62 



Aver. 

 61.4 

 Bu. 



Soil Treatment Applied 



None 



Legume 



None 



Legume, lime _ . 



Lime 



Legume, lime, phosphorus.. 



Lime, phosphorus. 

 Legume, lime, phos., potass. 



Lime, phos., potass. 

 Lime, phos., potass. 



