6 BULLETIN 42, U. S. DEPARTMENT OF AGRICULTURE. 
Repeated applications of small amounts in the form of top-dressing 
seem more favorable than a single application of the same amount 
of manganese salts at the time of manuring before the seed is sown. 
The stimulative action also seems to differ greatly with the character 
of the soil. Leidreiter, 1 working with oats, mustard, beets, and pota- 
toes, found manganese to have a beneficial effect. Similar results 
were obtained with beans with small amounts of manganese; large 
amounts, however, were injurious. Manganese showed best effects 
on humus soils, next on clay soils, and least on sandy soils; this, 
however, varied to a certain extent with the kind of plant and the 
form of the manganese. Labergerie 2 found manganese less effective 
in wet soils than dry, also found that manganese chloride was more 
effective when used with potassium sulphate. 
A very extensive experiment was made by Uchiyama 3 on the 
action of manganese with different manurial mixtures on two soils 
having widely different characteristics. A variety of crops were 
grown, including the cereals, legumes, and vegetables. Each crop 
was stimulated by the treatment, the increase varying from 5 to 60 
per cent. The legumes were most benefited. Repeated applica- 
tions as top-dressing throughout the period of growth gave better 
results than other methods of applying the substance. The amount 
of manganese salts gave best results when applied at the rate of 20 
to 50 kilos per hectare. In these experiments it was found that the 
manganese, when applied with fertilizers that have a neutral reaction 
and to soils that were neither acid nor alkaline, had a better effect 
than when there was an acid or alkaline condition. 
Takeuchi 4 found that leguminous and coniferous plants were 
stimulated more by manganese than were grasses. Barley and 
other grains were least stimulated. 
Kelly's 5 work at the Hawaii experiment station showed that some 
plants were less affected by manganese than others. He worked 
with a soil that was very high in manganese. Pineapples were 
seriously injured. Corn, peanuts, beans, cowpeas, and a number of 
the other legumes were also more or less injured. Sugar cane was 
not so much affected. Certain weeds, cotton, and a number of the 
truck crops were unaffected. 
The results of experiments with manganese as a fertilizer have 
been variable. In general the effect has been a beneficial one. In 
many cases, however, growth has either been retarded, or there has 
been no action. This may be due to certain soil conditions. Few 
i Leidreiter, P., Behavior of manganese in the soil toward some agricultural plants. Inaug. Diss. 
Rostock. (1910). Biedermann's Zentr., 40, 531. 
* Labergerie, Semaine Agr. Paris, 26, 331 (1907). 
s Uchiyama, Influence of stimulating compounds upon the crops under different conditions. Bui. Imp. 
Centr. Agri. Exp. Sta., Japan, 1, No. 2, 37 (1907). 
* Takeuchi, Difference of susceptibility of plants to stimulation. Jour. Col. Agr., Tokyo, 1, 207 (1909). 
b Buls. 23, 26, 28, Hawaii Expt. Sta. 
