384 E. P. Deatrick 
an indication of its resultant effect on the various activities in a complex 
medium. It was therefore deemed advisable to determine, in the first 
place, whether the adelition of manganese sulfate to soil cultures inhibits 
its power to function as in the case of water cultures. Consequently, 
wheat was grown on soil to which manganese sulfate had been added in 
varying amounts. 
In this, as well as in other soil experiments, the soil used was Dunkirk 
silt loam, obtained near the experimental plats of Caldwell Field. The 
results of the chemical and mechanical analyses are given in tables 5 
and 6, respectively: 
TABLE 5. Cuemicat (BuLtk) ANALYsIs oF DuNKIRK SittT Loam | 
Surface Subsoil 
Constituent determined 1 to 12 inches | 12 to 24 inches 
(per cent) (per cent) 
INitromend(IN)) shanty ke ee eens an Ye nek BiG einai A 0.186 0.082 
Orzanicrearbond(@) are eerie nen ea Sore ere 1.670 0.440 
Carbonkdioxid es (CO) ewe eee ee ee eee cue Trace 0.260 
@alciumtoxides(Ca@) ee ee ee eee 0.430 0.830 
Maonestumroxi dey (Vic. ©) pees ee ne 0.450 0.690 
OER Opaoly (KGO))sacaces cogs dannesdavanodonnedesse 1.740 2.110 
Odum Fo xa den GINals ©) Fy pay eye eee oe eer ea 1.090 1.280 
Phosphoricyanhydridex(b2O2)he ee eee eee eel 0.123 0.126 
Mianganeseroxides(MnzOn) ss eee. ee see ne asa 0 0 
TABLE 6. Mecuanicat ANaAtysis oF DUNKIRK SiLt Loam 
Per cent 
inte -oravelt nas Foie ee hn Re esac Pace a Ba oe on 0.5 
Coarse;sand sss ieee ecu re tate AG ners a gel Reh ae eae ai ets cee eh a rr 0.8 
IWedium' Sand! hs okey os mn etre ae PRR eat oo or a ep nye aay Ae nee 0.6. 
Mine isamdst ier Fa Se he ci emery iad 22 OE, ele vine Ps as Oe enter at DT 
ery fine Sain Ghee ee 28s eh eg ae oe eat AY Acts eb ta i 9.5 
fo) A cee a esl A laa ibd i> SoReal GaN RPane | len bea pee SO ate eS oso 5: 67.3 
Clayieet§ A ieee aise Os ae os Bee NE orate 18.6 
The soil was procured in quantity, was allowed to partially dry out in 
the air, and was then passed thru a 2-millimeter sieve. After treatment 
with manganese sulfate the soil was placed in small wire baskets, 350 
