88 Effect of Manganese Compounds 



potassium carbonate and 100 kgm. double superphosphate per hectare. 

 Twelve series were worked in triplicate and received manganese 

 sulphate in varying quantities, equivalent to 55 kgm. Mn 2 O 3 per 

 hectare, one set of three being left untreated. The cultivation was 

 normal and the application of manganese was found to influence the 

 yield of rice. 25 kgm. per hectare gave the best result and increased 

 the harvest of grains by one-third ; higher doses of Mn 2 3 gave no better 

 crop. The percentage of grain relative to the straw was also increased. 

 The increase in both respects was evident all through the series from 

 10 to 55 kgm. Mn 2 3 per hectare. The conclusion was reached that the 

 application of this salt to soils poor in manganese would be a commercial 

 advantage. 



The next year (1904) the experiments were extended to observe 

 the after effects of the initial doses of manganese sulphate. The 

 harvest of grain was greatest in those plots that had received 30 kgm. 

 Mn 2 3 per hectare, while it was approached very closely by that from 

 the plot with 25 kgm. MnaOs, which had proved the best in the 

 first year's experiments. The maximum increase of yield over the 

 unmanured plots in the first year was 37 / Q , while in the second year 

 it dropped to 16'9 %. 



Aso (1904) also obtained an increase of one- third in produce of 

 grain when 25 kgm. Mn 3 O 4 per hectare (as manganous chloride) was 

 applied to rice. The development of the plants was improved and 

 the treated plants flowered about four days before the untreated ones. 



Loew and Honda (1904) grew Cryptomeria japonica in beds, treating 

 the soil with various manures and with iron or manganese sulphate. 

 The latter favoured increase in height, and within l years the cubic 

 content of the trees had increased to double. 



Fukutome (1904) grew flax in pot cultures, each pot containing 

 8 kgm. soil, to which was added *4 gm. MnCl 2 . 4H 2 O and *4 gm. 

 FeS0 4 .7H 2 O. This mixture had a marked effect on the growth of 

 the flax, but the individual salts in doses of '4 gm. per 8 kgm. soil 

 had but little effect. 



Namba (1908) applied manganese salts to onion plants in pots with 

 a considerable measure of success. Pots containing 8 kgm. loamy soil 

 were manured and received: 



(1) no manganese, 



(2) 1 gm. MnS0 4 .4H 2 O, 



(3) '2 gm. MnS0 4 . 4H 2 O, 



the manganese sulphate being applied in high dilution as top dressing. 



