84 BULLETIN 699, U. S. DEPARTMENT OF AGRICULTURE. 
other two experiments, however, the sand used contained no phos- 
phate, except that added and it is rather surprising that such addi- 
tions of raw phosphate as were made, applications supplying from 
0.008 to 0.014 per cent of phosphoric acid, which is less than that 
contained in a soil abnormally low in this element. should have 
proved so eifective, particularly in the absence of organic matter. In > 
order to test the influence of fine grinding on the availability of raw 
rock phosphate and bones two pot experiments were conducted under 
the direction of W. H. Jordon? of the Geneva station. In one of 
these experiments (1899-1900) 58 pounds of pure quartz sand per pot 
were used to which no organic matter had been added, and in the other 
(1903-4) 48 pounds of sand per pot were employed to which about 3 
per cent of dried ground sphagnum moss was added. In both ex- 
periments all the pots except the blanks were supplied with the nec- 
essary fertilizer elements, the phosphoric acid, however, being 
applied in the forms of acid phosphate, bone, and eee raw rock 
of various degrees of fineness. 
In the first experiment three successive crops of rape were orown 
without renewing the phosphate treatments for the second and 
third crops, but the barley was grown in a separate set of pots. In 
the second experiment the crops grown were peas, barley, and rape, 
but each in separate sets of pots. The plants in every instance were 
allowed to attain the fullest development possible under the condi- 
tions. They were then harvested and weighed. The results ob- 
tained are given in part in Table LI which is compiled from two 
tables taken from Bulletin No. 358, of the Geneva station. 
Taste LI.—Bozr experiment to test the effect of raw rock phosphate of various 
degrees of fineness on different crops; bores contained 46 pounds each of pure 
quartz sand supplied with all fertilizer elements. 
| 
1892-1900 19 
| Appli- | 203-4 
| cation ee aoe Se ys | 
Treatment. | of POs fey bea Lee | 
| nae first | second | third Bei Peas. | Barley.| Rape. 
crop. | crop. | crop. 
i | 
Grams. Grams. ‘Grams. | Grams.| Grams. | Grams.| Grams.| Grams. 
| 2 
MONG NONI bor 
Ad! phosphace = ee 3 72.3 49.3] 26.2| 66.4] 166.7 48.0 
Florida rock: | 
GOsmesh = #2 = ee ee es eo 3 47.5 30.9 25.0 | 7.6) 6£1)} 140.0 4. 
Msnesh. feds wapcice Ti cee 3} 36.5] 30.1] 27.6] -9.0| 63.1] 1657 38. 
OG sTIESh ee ee ee ee Lee renee 3 37.6 2.5) 29.3 | 6.8 | 62.8 | 176.3 56. 
Botti cloth=.0+ 4 as hore ee 3 46.3 28.4) 20.4 i 7.8} 60.3 164.4 58. 
gE (spa cet Ah Moe SEE aS eae 3 45.2 34.0; 31.3 | 7.3) 67.5 | 172.9 58. 
Lig (iat eee Meee es Sees er es ee 3 52. 8 35. 6 32.4 iL1| 68.0] 162.7 57. 
Bone meal | | 
GEmesheehae iis. Sars er Sas 3 4.8 36.9 32.7 9.8} 59.8 | 160.0 46. 
Sites (eee tr SEES Ss Seay 3 33.0 35.9 33.0 7.3] 60.4] 1687 46. 
(OO0smeShe = a8 Pee Se ee 3 54.5 40.1 32.7 6.9 62.7} 175.3 40. 
Boley cloth S-c. 2 3. eee 3 60.9 35.1 36. 0 6.9} 61.6 164.6 44. 
BIMNeS ee a ed = ace ee 3 49.2 39.4 26.7 9.5 59.6} 177.0 48. 
IN. Y. Agr. Expt. Sta. (Geneva), Bul. No. 358 ¢1913). . 
2In the experiments conducted in 1903-4 only 1.5 grams of P;Os per pot were used, but organic matter 
was added in the form of sphagnum moss. 
