70 



T. Lyttleton Lyon and James A. Bizzell 



The maize plats planted on May 22 and harvested on August 20 are 

 represented in Diagram XX. The maize on these plats was allowed to 

 regrow after harvest; in this respect the treatment differed from that of the 



70 



B£fOP£ JUA/e 

 PlMfTINO 



juLr 



j^UGUST 



6£FT. 



OCT. 



DIAGRAM XIX. — Relative nitrate content of soil under maize cultivated, 1912 



previous year. The August figures are based on the analyses made pre- 

 vious to August 20. In September and October there is an increase in the 

 nitrate content of the soil. If the regrowth of maize has a stimulating 

 effect on nitrate formation this increase is to be expected, as the maize 

 made a regrowth of about eighteen inches. 



no 



SEFORE 

 PLANTING 



.JUNE 



JULY 



AUGUST 



SEPT OC 



so 





> 



^ 







, 



70 



i 







^^ 



/^ 





60 











)r 





DIAGRAM XX. — Relative nitrate content of soil under maize harvested August 20 

 and allowed to regrow, 1912 



It will be noted that this was the only set of maize plats in which any 

 marked increase of nitrates occurred. The increase of nitrates under 

 maize at this time of year and coincident with the regrowth, is evidence that 



