Fen fertilization with potash in the light of tests at Leteensuo experimental station

[摘要] On the fen area of the Experimental Station of Leteensuo, with a peat layer consisting of forest sedge peat, potassium fertilization produced a considerable increase of the hay crop yield on the clayed as well as the unclayed bog, when phosphate fertilization had been added. However, clay displayed a considerable potassium fertilizing effect and also other effects, which probably cannot be reproduced by fertilization. The effect of potassium fertilization on the summer cereal crop yield was different in different tests. In two of them, potassium fertilization increased the grain yield but not in the third. The results obtained in this latter instance are thought to have been influenced by the addition of mud through the action of floods. Potassium fertilization had remarkably increased the root crop yields. When phosphate fertilization had not been added, the effect of potassium fertilization was small asa rule. There was no marked difference between the effects of potassium salt and potassium sulphate, although it should be noted that the tests did not contain any treatments with potatoes as the experimental crops, which might show up this difference most clearly.