Tue Errect or MANGANESE COMPOUNDS ON SOILS AND Puants 391 
TABLE 12. Errect or Duration or Contact or Som with MANGANESE SULFATE, ON 
THE Oxr1pizING PowrR oF THE SoIL 
Date when Date when 
Parts per million of aes Relative 
manganese was oxidation was Saas 
manganese added added atemmamed oxidation 
OMNI PE esc April 3, 1916 November 8, 1916 100 
NOMS ape cire os No we ve November 8, 1916 | November 8, 1916 100 
HON OPENS ee tieae aici wie aly eee aes April 3, 1916 November 8, 1916 185 
WOO nc di. o.d Sea ees Rare eee ere November 8, 1916 | November 8, 1916 112 
In order to test the adsorptive power for manganese, four percolation 
cylinders were filled with Dunkirk silt loam, a kilogram to each cylinder. 
The cylinders were labeled A, B, C, and D, respectively. To soils C 
and D calcium hydroxide was added at the rate of 10,000 parts of CaO 
per million of soil. Soils A and B were untreated. A solution of 
manganese sulfate containing 1000 parts per million of manganese was 
then percolated thru the soils after they had been saturated with distilled 
water. Each successive 100 cubic centimeters of the percolate was 
analyzed for manganese by the colorimetric method described in Bulletin 31 
of the United States Bureau of Soils. The manganese content of the 
percolates, expressed in parts per million, is given in table 13: 
TABLE 13. Manganese Content or Mancanese SuLFaTe Soxution (1000 Parts PER 
Mriuion or MancGaNnese) PERCOLATED THRU DUNKIRK Si_tt Loam 
Successive 100-cc. portions Manganese content in parts per million 
of percolate - 
A B Cc D 
IN oo croc. ot: S ROS en Rte DROP ches er ern cEe vr 0 0 0 0 
D5 o 6:00 v6 6 bcc) CA ERE ONE eee nee eae Trace 111 0 0 
AP Ss he acs whe ma oe 62 286 0 0 
Oo ni0.0b.obd 6 He eee ee eee earn eee 500 400 Trace 0 
Boo'd 0.0 0.0 81 OO IE CREEL CELE OSI Cea Rae 625 417 62 Trace 
11) 3) oi+4 1p bic ua GOREN RS RRR OIEER cops aoe eee 715 455 154 92 
2) 9 oe Sloe OI OGG Be Oho HGR EIS RT ICIOE eee 715 500 218 167 
A ice ne ic gists ceapashatet sca Diais) ete ig) ees 715 525 256 143 
I GPPRP Te Pale cS ajc aecls auninltve ar eyaas tise, ei * = 715 555 357 222 
SPR ere Sree Rs Pe UC ON Bee g) and eth 770 475 307 91 
