Artificial Manures 



315 



the amount of nitrouen re([uirocl, and the jfreater tlie amount of 

 protein subsequentK- s^ntliesized. The hgnin in the compost also 

 increases during the process of decomposition, but to a relatively 

 sniallc>r degree than tlie increase in ash and protein; this increase in 



•r- 



%f: 



\< 









V %. 



... ^?^ 



Fig. 12.5. Effect of artificial manure on growtli of alsike clo\er. Left to right, 



lime and acid phosf)hate; lime, acid phosphate, and straw; lime, acid phosiihate, 



and artificial manure (from Albrecht). 



lignin content is due to the greater resistance of lignin than of the 

 other plant constituents to microbial decomposition. The tempera- 

 ture and moisture content of the compost have an important influ- 

 ence upon the rapidity of decomposition of the straw and upon the 

 formation of the humus. 



A number of formulas have been suggested for supplementing 

 straw and other plant residues to obtain a good artificial compost. 

 Two such formulas follow; 



