362 BOW CROPS FEED. 



the soil must contaiu the ash-ingredieuts of plants, together 

 with assimilable nitrogen-com[iounds in proper quantity 

 and proportion. The composition of a very fertile soil is 

 well exhibited by Baumhauer's analysis of an alluvial de- 

 posit from the waters of the Rhine, near the Zuider Zee, 

 in Holland. This soil, which produces large crops, con« 

 tained — 



A glance at the above analyses shows the unusual rich- 

 ness of this soil in all the elements of plant-food, witli ex- 

 ception of nitrates, which were not separately determined. 

 The alkalies, phosphoric acid, and sulphuric acid, were 

 present in large proportion. The absolute quantities of 

 the most important substances existing in an acre of this 

 soil taken to the depth of one foot, and assuming thia 



* The figures are probably too high for ammonia, because, at the time the analy- 

 ses wore made, the methods of estimating this substance in the soil had not been 

 Btudied sufficiently, and the ammonia obtained was doubtless derived in great 

 part from the dfcomposition of humus under the action of au alkali. 



