98 



T. Lyttleton Lyon and James A. Bizzell 



TABLE 39. Comparison of Nitrates in Soil Planted to Certain Crops with Growth 

 OF Millet on the Same Plats 



Crop in 1910 



Relative 

 nitrate 

 content 



Relati^'e 



growth of 



millet 



Oats • 



55 



70 



100 



100 



Potatoes ^ . 



73 



Maize 



54 







It would seem from these results that in this soil the conditions favoring 

 the growth of millet were unfavorable to the formation of nitrates. That 

 this is not true of all conditions is evident from the fact that the millet grew 

 better on the limed than on the unlimed soil, as shown in Table 38; while 

 the nitrates also are higher in the limed plats, as may be observed in Table 

 40, which follows: 



TABLE 40. Nitrates in XJnplanted Sections of Plats Limed and Not Limed 



Plat 



Soil treatment 



Nitrates (parts per million) 





May 4 



June 5 



June 28 



Average 



3612, 3622 



3613, 3623 



3614, 3624 



3615, 3625 



3616,3626 



3617, 3627 



Not limed 



Limed 



Not limed 



Limed 



Not limed 



Limed 



40 

 55 

 40 

 45 



28 

 36 



61 



75 

 77 

 82 

 52 

 85 



42 

 39 

 34 

 36 

 36 

 40 



48 

 56 

 50 

 54 

 39 

 54 









It is evident that, although the previous crop influences greatly the 

 nitrate content of this soil, the growth of millet is not increased thereby. 

 Nitrates are not the limiting factor in the growth of millet on this soil. 



Lime increases the growth of millet and also the formation of nitrates, 

 but apparently its beneficial action on the growth of millet must be due to 

 some cause other than its influence on nitrate formation. 



