1-|() |''()()l» l-lli; I'l.AN IS. 



to llu' Ini'ucr ai)i)li(';iti()ii of iiilrjitc Tlic dilTcrciit luaii- 

 urcs were appTu'd in aiiiouiits suriiciciit to furnish about 

 4 iiins, of iiitro«»-LMi per cyliuiUu-. Calculated on the acre 

 ))asis the niaiiures were a])plied at the rate of about K) 

 tons. 



The crops were g-rown in reii'ular rotation, and con- 

 sisted of the t'ollowiu,*;- : Corn, oats, wheat and timothy. 

 The oats crops were followed in each case ])y a so-called 

 residual cro]) whose function it was to take up suc'.i 

 available nitrogen eouipounds as were not utilized by the 

 main crops. 



Analyses were made of all of the main crops and resid- 

 ual crops. In the case of the wheat, the grain and the 

 straw were analyzed separately. In the case of the timo- 

 thy, the first cutting and aftermath were analyzed sepa- 

 rately. The analytical material for the ten years included, 

 therefore, more than a thousand crop samples. Records 

 were made of the yields of dry matter, of the propor- 

 tions of nitrogen in the dry matter of each crop, of the 

 total nitrogen in each crop, of the proportion of manure 

 and fertilizer nitrogen recovered, and of the relative 

 availability of the several nitrogenous materials em- 

 ployed. In addition to these careful analyses were made 

 of the soil samples drawn from the several cylinders at 

 the end of each rotation. 



The results secured may be briefly siunniarized as fol- 

 lows : 



1. There was a marked falling off in the yields between 

 the first and second rotation, especially in the soils which 

 had received no applications of animal manure. 



2. The nitrogen comj3ounds in li(|uid manure were 

 much superior to those in solid manure as a source of 

 nitrogen to crops. 



3. Larger applications of nitrogen were invariably 

 followed by larger yields of this constituent in the crops. 



4. Nitrate, ammonium sulphate and dried l)lood, when 

 applied in ecpiivalent amounts, were found to possess an 

 unequal value. Xitrate was superior to anunonium sul- 



