1, ” 
EXPERIMENTAL WORK WITH RAW ROCK PHOSPHATE, AT 
employed containing 30 pounds of soil each, and in series 2, pots one- 
half this size (2 gallons) containing 15 pounds of soil were used. 
Series 1 was planted to tobacco the first year, followed by oats the 
second year. Series 2 was planted to clover the first year, followed 
the second year by tobacco. Series 8 was planted to wheat the first 
year and to clover the second year. 
In each instance after the first crop was harvested the soil was 
dried, emptied out of the pots, mixed thoroughly with the fertilizers 
for the following crop, and then returned to the pots. The results of 
these experiments are given in part in Tables XXII, XXIII, and 
XXIV. 
TABLE XXII.—Yields of tobacco and oats obtained in pot tests with various 
fertilizers. 
SERIES IL.—TOBACCO (4GALLON) POTS), 
Yield of 
Applica- Wb 
oe : stalks and | Increase Relative 
Fertilizer. nee 19s lea yes per | per pot. increase. 
(0) 
Grams Grams Grams Per cent 
INOTIO BH ee crane rae Seto Sas cote cle sie slob of bee cies Mees cen eos eee leks Ue Bod BOOBS A eeaoA ineoe oad cas 
GIT CS LOC Be eres le erat oe a orc wists cia cnizinccgias 15.0 12.0 —1.75 —1194,7/ 
Dissolved bone (24 per cent P, O5) eeae cscs sete en aes 3.8 10.3 —3.75 —27.2 
ROcksMhoOsphatessyac-cesocek cco s Soke ttle sje eeu seteansee 20.0 13.2 —0. 55 — 4.5 
Manure SU 6s SOuGG SORE RES SE Ge Seen SSE eee aes Rick, Stele 35.0 9.7 —4.05 —29.4 
JS Ga BBS E OB OO ODE SE Ea SEI oe ee ee eae 35.0 . 
Rock hOsSpliat eee Ms est EE 6 bo edgcc cette 20.0 } 10.3 Sent ~25e1 
SERIES I.—OATS (AFTER TOBACCO). 
Whole crop. Grain, 
Fertilizer. tion per : 
pot. Yields | Increase} Yield | Increase | Relative 
per pot. | per pot. | per pot. |.per pot. | increase. 
Grams Grams. | Grams Grams Grams. | Per cent 
INIMAO SaGk SOS CSRS ee eae ee | (ogg WATE DE tee em aes BOM is 255 Pee 
FIIMEStONG:. sae seer cnt. eek cee 15.0 61.0 13.5 13.5 3.4 33.6 
Dissolved bone (24 per cent P.O;).-.....-. Sa 83.0 35.5 15.0 4.9 48.5 
Rock. phosphatess-2@ tesa oo cee scat cee 20.0 68. 5 21.0 13.4 3.3 32.7 
enure ee Re ee ae tee isiaie cine Bla nloe ce cis 35.0 93.5 46.0 16.5 6.4 63.4 
ee eee a rodeo csisie ee teteelecesd 35.0 r 
Rock phosphate eae eS Me ARP RS 20 0 84.0 36. 5 15 4 5 3 52.4 
1 Average of 2 pots. 
TABLE XXIII.—Yields of clover and tobacco obtained in pot tests with various 
fertilizers. 
SERIES I1.—CLOVER (2GALLON POTS). 
li 3 ee In Relat: 
+): Application| o ee crease elative 
Fertilizer. a pot. cuttings per pot. | increase. 
per pot. 
Grams Grams Grams Per cent 
None........ Lean ss een eam ee kd SSRN IGS. ich SER GiOmI RS 253 ea RES ee eee 
EATITOS LOM Obert rae noe inctsoiclnccisisles siciwiseoiew 7.5 20.4 4.4 Diao 
MISSOlVedeh One Het ei ho) ain ds eee Ween cess on cebe doce 1.9 32.1 16.1 100.6 
ae eS Cesphate pe ee ee RMN a Oe ord ARE eosin sisiceisie ole 10.0 30.8 14.8 92.5 
Soot St ee ee ee a ee ee ee ee 17.5 Door 9.7 60.6 
Rock p ee nephate ween cece cee ween ee eee ee ecco ene re \ 27.6 AG 72.5 
