ACTION OF MANGANESE LN SOILS. 3 



per acre) caused an increased growth of 37 per cent; that the produc- 

 tion with smaller amounts of the manganese fertilizer increased uni- 

 formly up to 25 kilos per hectare; but with additions larger than this 

 there were no correspondingly larger increases. There was a residual 

 effect, the second year showing an increase of 8 per cent. The third 

 year the experiment was repeated on the same plots and an increase 

 of 15 per cent only was secured where two years before the same 

 application of manganese gave an increase of 37 per cent. The fourth 

 year manganese in the form of sulphate, chloride, and carbonate in 

 amounts of 25 kilos per hectare were used on these plots. Manga- 

 nese sulphate and chloride this time depressed the yield ; the carbon- 

 ate caused no change. It is stated that the plots had become acid, 

 due to the continued application of manganese, and that the weather 

 conditions of the last year were unfavorable to the growth of rice. 



K. Aso 1 has also shown that manganese increases the production 

 of rice. The work was conducted in large plots in the paddy field of 

 the Tokyo College Experiment Station. Manganese chloride was 

 used in amounts of 25 kilos of Mn 3 4 per hectare. The first year 

 there was an increase of 41.8 per cent, yet with continuous culture 

 and an application of the manganese before each crop the increase 

 for the second and third years did not exceed 3 per cent. He attrib- 

 utes the small increase secured the second and third years to the 

 fact that the plot the year before produced a large crop and left the 

 soil in an acid condition. An application of lime made the plot 

 more productive. 



T. Katayama 2 made some experiments with barley, using manga- 

 nese in the form of sulphate. The work was done in large pots hold- 

 ing 8 kilos of soil. The soil had received no fertilizer for five years 

 and was in a deteriorated condition. A general fertilizer was applied 

 to all the pots. The manganese sulphate was applied in amounts 

 from 0.01 per cent to 0.10 per cent as a top dressing. 3 He secured 

 appreciable increases by using the salt at the rate of 0.01 per cent; 

 amounts higher than this caused a decrease. Iron sulphate plus man- 

 ganese also gave stimulation when used in amounts of 0.01 per cent. 



S. Kakehi and K. Baba 4 found that manganese carbonate increased 

 the growth of barley and peas. Their experiments were conducted 

 in pots, using soil which had received a general manuring. The man- 

 ganese was applied at the rate of 0.01 per cent. The stimulation 



1 Aso, K., On the practical application of manganese chloride in rice culture. Bui. Col. Agr. Tokyo, 6, 

 131 (1904-5). On the continuous application of manganese chloride in rice culture. Bui. Col. Agr. Tokyo, 

 7,449(1906-1908). 



2 Katayama, T., On the degree of stimulating action of manganese and iron salts on barley. Bui. Col. 

 Agr. Tokyo, 7, 91 (1906-1908). 



3 These amounts seem excessive, corresponding approximately to an application (the larger one) of 2 tons 

 per acre-foot. 



4 Kakehi, S., and Baba, K., Observations on stimulation of plant growth. Bui. Col. Agr. Tokyo, 7, 455 

 (1906-1908). 



