118 



Table VI. Effect of ferlilizers, lime, coiunarin, uaiiil- 

 liii, pijruyallol and carbon black on crop 

 yields in Callers Field soil. Crops grown 

 in 2-gallon pots in the greenhonse, 1914- 

 1915. 



SPECIAJ, TREATMENT 



c 



N 1) 



> — "^ 

 ^ t- t/i 



Check — no treatment 



None 



None 



Cal. carbonate, 9.0 grams 



None 



•Cal. carbonate, 9.0 grams 



>Couniarin, 9.0 grams 



4.5 " 



anillin. 



9.0 " 



4.5 " 



9.0 " 



4.5 " 



9.0 " 



4.5 " 



9.0 " 



4.5 " 



9.0 " 



4.5 " 



Pvrogallol, 9.0 grams 



■ " 4 5" _.. 



9.0 •' ... 



4.5 " ... 

 9.0 " 



45 " ... 

 Carbon black, 9.0 grams 



9 " 



V.O " 



K* 



K. .^- P. 

 K. d: P. 

 K., P. &N 

 K.,P. (i N 



K. i P. 

 K. & P. 

 K.,P. iLN 

 K.,P. ^c N 



K. & P. 

 K. ii; P. 

 K.,P. c<cN 

 K., P. >i N 



K. i' P. 

 K. & P. 

 K.. P. d; N 

 K. , P. & N 



K. cSc P. 

 K. , P. c^ N 



100 



1696 

 2053 



1596 

 1389 



1389 

 1353 



1714 

 1396 



1332 



■"K" means 4.5 grain.s of kainil; "N" means 4.5 grams of 

 nitrate of soda; "P" means 4.5 grams of acid pliosjjhate. 



In Tal)li' VI arc reporlcd llie yields obtained when 

 coinnaiin. vanillin, pvrogallol and carl)on black were 

 used alone and in connection with fertilizer combina- 

 tions. 'V\\v green weight of the oat crop is shown in 

 the third column of the table. A study of the results 

 shows that l)oth coumarin and vanillin have materi- 

 ally re<luced the oat crop, whether used alone, or with 

 kainit and phosphate, or with a complete fertilizer. 

 Both of these compounds are very toxic to plants in 

 water cultures, even when used in comparatively small 

 amounts. lu the work here reportecl, large propor- 

 .tions are used, based on the drv soil, and not on the 



