376 EK. P. Deatrick 
rate of 50 pounds per acre on an acid silty clay loam, its effect each year 
was not beneficial to the crops grown.’ During the following years of 
experimentation the yields of the crops were increased. The soil had been 
found to be very acid, and large quantities of calcium carbonate were applied. 
It appears that the reaction of the soil is a determining factor in the 
action of manganese. Nagaoka (1906-08) notes that the soil increases in 
acidity with the continued application of manganese sulfate. Rousset 
(1909) cites Malpeaux as securing contradictory results with both the 
sulfate and the chloride of manganese, but favorable results with the 
carbonate and the oxide applied in combination with marl. 
Some results have been obtained, however, which point to a decreased 
stimulation when manganese is applied with some form of calcium. 
According to Uchiyama (1907), ‘‘ A manurial mixture of a nearly neutral 
reaction, exerts the best effect. Manures of decisive alkaline or acidic 
nature on the other hand are not so favorable, since the former interferes 
with the effect of the manganese salt, while the latter are not suitable 
for the growth of most plants.’’ Chittenden (1915-16) observed the same 
effect; he states that in two out of three cases manganese sulfate alone 
increased the yield, while the addition of lime to the manganese sulfate 
decreased the yield. 
Many of the apparently inconsistent reports are explainable when 
complete data regarding the experiment are available. Some of the 
applications are too low. Others, as that of Crochetelle (1913), who 
applied an excessive amount (2000 pounds to the acre) of manganese 
sulfate to a ‘‘ calcareous clay,’ are high yet stimulative. 
References to the change which manganese compounds may undergo 
when added to soils are numerous. Nottin (1912) found that manganese 
is adsorbed like potassium or ammonia, and is precipitated by calcium 
carbonate and organic matter; the demanganization of water by cale1um 
carbonate, and the precipitation of manganese found in dolomitized lime- 
stones, indicate that, in alkaline soils at least, the soluble salts of man- 
ganese are changed to oxides. In the soil solution, manganese probably 
occurs in the form of the bicarbonate, as Vincent (1916) concludes. 
Regarding solubility, Masoni (1916) states that the organic acids are 
particularly active in dissolving manganese. He claims that the behavior 
of the carbonates, sulfates, and oxides of manganese may be explained 
as phenomena of hydrolysis and of successive oxidation and reduction. 
