10 
BULLETIN" 441, U. S. DEPARTMENT OF AGRICULTURE. 
Table VIII. — Relative oxidation in plats treated with manganese sulphate and in the 
corresponding check plats growing the same crops. 
Plats. 
Wheat. 
1 
Rye. Timothy. 
Beans. 
Corn. 
Cowpeas. 
Potatoes. 
Untreated " 
100 
283 
100 
132 
100 
75 
100 
109 
100 
76 
100 
107 
100 
Treated with manganese 
105 
With the exception of the timothy and corn plats, the addition 
of manganese sulphate has increased the oxidizing power of the soil. 
In general, however, this increased oxidation agrees with the increased 
yields in the limed soil. This is in contrast to the action of manga- 
nese in this soil while under acid conditions, which caused less oxida- 
tion in the soil and a decreased growth. Under acid conditions the 
Fig. 2.— Rye on a plat treated with manganese. 
effect of oxidizing compounds, such as manganese salts, is much 
lessened or entirely inhibited, while under neutral or slightly alkaline 
conditions this oxidizing power is stimulated. The soil under study 
is of an acid character, naturally poor in its oxidizing power, and is 
physically bad. Methods of cultivation which loosen and aerate 
the soil and chemicals which increase its oxidizing power should 
increase its crop-producing power. With the acid soil, where manga- 
nese gave decreased yields, conditions were such that stimulating 
action on plants and microorganisms of the soil did not come into 
play; or, possibly on account of the acidity of the soil, the effect of 
the manganese led to a stimulation of other biological processes, 
