a 
EXPERIMENTAL WORK WITH RAW ROCK PHOSPHATE. 31 
TABLE VIII.—Yields of wheat obtained in pot experiment to test the relative 
values of raw rock and steamed bone meal. 
Wheat yields. Increase. 
Treatment. 
Per pot. Per acre. | Per acre. 
Grams. Bushels. Bushels. 
IN OTC Ree arse siaia seis aves dia aiets imeete etal sivis a lsiarsinv etareiciniclsicintetaiavete aeisieie ays 10.0 Pehl eapeieees esse iy) 8 
CIO Wer Naar ertlee rks cle pice wicis ereinictetele wiaie ne aie oieluiclos avelorele Rib ieteteletereraeiotars 16.3 43 16 
PS OMCs Cal MMe ire 2 sea, tas ari Ge sista Gene cree imciaierela ste sini iero ciern Ss eieveiwie eimrelel = 14.7 39 12 
FUOCKsPMOS PHALC Ee Hae ca cee se Selek eee eieine ea ok eins see gale eiotetatale 14.2 38 11 
Clovermmbonepni calls paces iin eee NIL cee tate sree Wc aiereyeya a rehemerd 22.2 59 32 
Cloverarockspnosphaters ae ate see nee ee ee eee eee 23.3 62 35 
WETNESS SSO ode eee BOD SOONG EE Be DEO COU E nea SuS ae REE A SBS Se socerae 16.5 44 17 
ClOwerinlanUnes eee nesasisclele -\elnicis iene nme tla- @ ee o iera ne eeins 22.7 60 33 
IMESODIRE, NOW 100s Saso Sey enon ppe a noseerS Hour eroocseteecaybaroueaes 19. 4 52 25 
Manuncynocksphosphatenc: Ohya: HWE Rie NG yale Sas 19.5 52 oe 
Clover, manure, bone meal ad gon ddouonbocsonse seonagecucoas qosddelHe 23.1 62 35 
Clover manure roca phosphates --\0- sees eens ee nee elne eee gard 62 35 
TE GUESTS hel seis el es RN GO a OTRO AGL EN a an 11.3 30 3 
SHOWer, OWS. ceaccéccécossduedsgccopesouuscueccuoSsbonodscusauoHae 18.4 49 22 
IPs oO anele Woes WAC ake sod dyes eee oseUby sate SseoO SEM ScouresEss 18. 4 49 22 
Potash, rock aun res eyUnre eaintel yal Palast Siti at cedar ZR ae lec shat ach 18.2 49 22 
ClovcrepotashbonemenIy ss oe BEN ey 21.9 58 31 
Clover, potash, ROCKED NOS DALE sere Nee Motiee asin ee wie cieeinie meee meters 21.9 58 31 
Manure, potash oe boon ooo comb nabQU COON be conU aT IOS beNCsaeDDO Cob OD Ha 18.1 48 21 
Chowan, me@ribive, IORSIN. 48 ooo oneh op sbcoed os ceseooossed sees Sosbeceses 19.1 51 24 
Manure, potash, bone meal..-.......-.-.---.--- Hadedoesosoqcusosens 19.3 51 24 
Manure potash, nock phosphates. c/22 5.4. cceie etree cis diss seein 19.0 51 24 
@loversmantre potash bone meal 2. 252 e aa wise ovicin «ole ele le oe 25.3 67 40 
Clover, manure, potash, rocksphosphateriacsecs- cence sticeecee ees: 25.3 67 40 
OTC rea erere tease iatlerele ole leleinielaietelerasiclareteisieleleicleleiainicioinvsis(s isi seieine 10.6 PEMA SSO COCR C 
The beneficial effects of phosphate in this particular experiment 
are quite marked, even though the test was of comparatively short 
duration. The results obtained seem to indicate that raw rock phos- 
phate (an equal money value) may be substituted for bone meal, 
particularly if the phosphate is apphed with manure or turned under 
with a leguminous crop. In practically every instance the raw-rock 
pots equaled or surpassed the bone-meal pots with which they were 
directly comparable. 
A number of papers by Hopkins? on the use of raw rock phosphate 
as a fertilizer appeared in 1908 and 1909, but the field work of the 
Tllinois Station described in several of them is given more fully in 
subsequent publications. One of these circulars? is a reply to a 
pamphlet issued by the National Fertilizer Association advising 
against the use of raw rock phosphates. This circular shows that 
the quotations in this pamphlet from the Experiment Station bul- 
letins are very incomplete and the conclusions drawn are unjustified. 
In 1910, 1911, and 1912 the Illinois station issued several publica- 
tions? on raw rock phosphates, but only one is quoted here, since the 
limited duration of the field work or the meager data given in the 
others hardly justify repetition. 
17}l. Agr. Expt. Sta., Circular No. 116; Buls. Nos. 123 and 125 (1908) ; Circulars Nos. 
127 and 130 (1909). 
2 Circular No. 127 (1909). 
8 Lloyd and Brooks, Bul. No. 144 (1910) ; Hopkins, C. G., Circular No. 141 (1910) ; 
Hopkins and Mann, Circular No. 149 (1911); Lloyd, Bul. No, 155 (1912), 
