17 



the Agricultural Academy at Hohenheim remarks in the ninth 

 edition of his work, Practischc Diingcrlchrc: "The results of 

 Schultz-Lupitz and Rimpau-Cunraii are examples of a new 

 method of culture, which is of high importance to the whole 

 of Germany." He says: "Sclmltz-Lupitz has proven in a 

 convincing manner the great financial advantages, if the farmer, 

 as far as possible, manures his soil with the nitrogen of the 

 atmosphere. He plants leguminous plants and proper clover- 

 species for a crop and leaves the roots and stubbles for the 

 succeeding crop as fertilizer in the ground. In this way he has 

 succeeded, under the exclusive application of potash and phos- 

 phate, to raise on very poor soil exceedingly paying crops under 

 the following rotation: 



1. Rye fertilized per hectar (i ha. = 2.47 acres) with 200 



kilogram (i kg. = 2.2 Ibs.) of superphosphate at twenty 

 per cent. P 2 O 5 and 600 kg. of kainit. In the stubbles 

 Lupins are sowed with another 600 kg. of kainit. 



2. Oats. 



3. Potatoes fertilized with 16,000 kg. of stable manure. 



4. Peas, with 200 kg. superphosphate and 600 kg. kainit. 



5. Rye, with 200 kg. superphosphate and 600 kg. kainit. 



6. Clover. 



The only fertilizers used were kainit and superphosphates, 

 and on soil that was not considered worth cultivation. Schultz 

 succeeded by this exclusive potash-phosphate fertilization in pro- 

 ducing sure crops and, what is more, paying crops." 



On the peat soils of Cunrau similar results were obtained by 

 a very liberal application of kainit, the soil not being deficient 

 in nitrogen, but the difficulty consisting in getting the nitrogen 

 taken up by the plants. Of course, such convincing practical 

 results, which seemed to upset, as it were, the theories hereto- 

 fore entertained, induced men like Wagner to experiment 

 so as to ascertain the principle underlying this unexpected 

 phenomenon. 



What is the influence of potash (kali^ upon plant-growth, was 

 the first point that required a thorough clearing up. But Prof. 

 Wagner may be allowed to tell the story in his own words: 



