174 M. M. McCooL 



yield of wheat over the product in control cultures. Pots of soil were 

 treated with manganese oxids (Mn02 and Mn304), chlorid, iodid, carbonate, 

 sulfate, phosphate, and nitrate, at the rate of two hundred pounds per 

 acre. Increase in yield was obtained from cultures fertilized with phos- 

 phate, chlorid, sulfate, and the oxid Mn304. Parallel experiments were 

 run with barley. The oxids caused no increase in yield; all other salts of 

 manganese resulted in a correspondingly greater increase in yield of barley 

 than of wheat. 



The studies were continued in 1903 (1904), when again the oxids of 

 manganese applied to pots of soil at the rate of two hundred pounds per 

 acre showed a beneficial influence on wheat; while with barley it was again 

 found that the oxids of manganese do not produce stimulation. 



Loew and Honda (1904) transferred seedlings of Cryptomeria japonica 

 from the forest to frames of soil. Small doses of MnS04 were added to the 

 soil, monthly from May to November inclusive, for two years. The man- 

 ganese acted as a stimulant, causing an appreciable gain in height and 

 total weight of the trees over those grown in the control frames. 



Two plots in a paddy field, each of thirtj^ square meters, were treated 

 with a general fertilizer by Aso (1904). To one was applied in addition 

 two hundred grams of MnCl2. Rice plants were transferred to each plot. 

 Taking the yield of the control plot as a unit, the results obtained from the 

 plot treated with manganese were as follows: 



Total yield 1 .42 



Straw 1.48 



Full grains 1 . 36 



Full grains (husked) 1 . 30 



The results show an increase in the grain of approximately one third, by 

 an application of manganese. In order to be able to draw definite con- 

 clusions from field work, it seems that more plots should be used in the 

 experiments. 



Flax was growTi by Fukutome (1908) in pots containing eight kilograms 

 of soil. Each pot received a general fertilizer as follows: 16 grams s per- 

 phosphate, 10 grams K2SO4, 8 grams (NH4)2 SO4, and 8 grams NaNOs. 

 The pots were then treated with special fertilizers. The special fertilizers 

 and the results obtained are indicated in the following table: 



