48 



BULLETIN 690, U, S. DEPARTMENT OF AGEICULTURE. 



Table XXIII. — Yields of clover and tobacco obtained in pot tests tvith various 



fertilizers — -Continued. 



SERIES II.— TOBACCO (AFTER CLOVER). 



Fertilizer. 



Application 

 per pot. 



Stalks and 

 leaves 

 per pot. 



Increase 

 per pot. 



Relative 

 increase. 



Grams. 



None 



Limestone 



Dissolved bone . . 

 Rock pliosphate . 



Manure 



Do 



Rock phosphate . 



7.5 

 1.9 

 10.0 

 17.5 

 17.5 

 10.0 



Grams. 

 13.75 

 5.00 

 4.60 

 7.40 

 9.50 



Grams. 



Per cent. 



1.25 



.85 

 3.65 

 5.75 



3.85 



33.3 

 22.7 

 97.3 

 153.3 



102.4 



1 Average of two pots. 



Table XXIV. — Yields of tvheat and clover obtained in pot tests with various 



fertilizers. 



SERIES III.— WHEAT (4-GALLON POTS). 





Applica- 

 tion per 

 pot. 



Whole crop. 



Grain. 



Fertilizer. 



Yield 

 per pot. 



Increase 

 per pot. 



Yield 

 per pot. 



Increase 

 per pot. 



Relative 

 increase. 





Grams. 



Grams. 



134.9 



44.6 



45.6 



44.5 



1 36.3 



Grams. 



Grams. 



Grams. 



Per cent. 





3.8 

 20.0 

 35.0 

 35.0 

 20.0 



9.7 

 10.7 

 9.5 



L4 



14.6 

 15.7 

 16.2 



14.9 



2.7 

 3.8 

 4.3 



3.0 



22.7 





31.9 





36.1 



Do 













SERIES IIL— CLOVER (AFTER WHEAT). 



Fertilizer. 



Applica- 

 tion per 

 pot. 



Weight 

 of first 

 cutting 

 per pot. 



Weight 

 of second 

 cutting 

 per pot. 



Total 

 per pot. 



Increase 

 per pot. 



Relative 

 increase. 





Grams. 



Grams. 



113.8 



45.3 



32.2 



46.5 



} 36. 5 



Grams. 



Grams. 



Grams. 



Per cent. 





3.8 

 20.0 

 35.0 

 3.5.0 

 20.0 



24.6 

 21.0 

 25.0 



24.5 



70.4 



53.2 



. 71.5 



61.0 



41.05 

 23.85 

 42.15 



31.65 



139.9 





81 3 





143.6 



Do 







107.8 







1 Average of two pots. 



It will be noticed that the pots receiving applications of phos- 

 phates, whether water soluble or relatively insoluble, gave consider- 

 able increases in yield over the untreated pots, except in series I, 

 where tobacco was grown the first year. 



The soluble phosphate on the whole gave somewhat better 5delds 

 than the ground rock, although the latter material was applied liber- 

 ally. In the second year of series II, however, when tobacco was 

 grown, the ground-rock pot gave a much greater yield than the pot 

 treated with acid phosphate. Contrary to what one would expect, 

 the pots treated with a mixture of rock phosphate and manure gave 



