Rothamsted Symposium on Trace Elements xviii 



Textfigure 19.— Courbes des recoltes en fonction de la concentration 



en Mg dans des milieux differant par leur teneur en phosphore . 113 



Textfigure 20.— Recoltes reelles et action du K dans milieux dif- 

 ferant par le glucose 114 



Textfigure 21.— Recoltes relatives et action du K dans milieux dif- 

 ferant par le glucose 115 



Textfigure 22.— Loi d'action commune de K ou Rb 116 



Textfigure 23.— Action du Mg en presence de deux concentrations 



enRb 117 



Textfigure 24.— Balance trial with copper sulfate added to the food 



of a normal heifer 1 26 



Textfigure 25.— Manganese content of pasture grass and hay with- 

 out considering the type of soil, manuring or the condition of the 



pasture 133 



Textfigure 26.— Manganese values of pasture grass and hay depend- 

 ent on the kind of soil 134 



Textfigure 27.— Manganese in hay originating from the Province of 



Friesland dependent on the kind of soil 135 



» » » 



Plate 1.— Growth of mustard on limed soil 147 



Plate 2.— Mustard on a soil rich in lime 149 



Plate 3.— Influence of increasing amounts of quicklime and potas- 

 sium hydrate on grey speck disease 151 



Plate 4a.— Barley in a nutrient solution 152 



Plate 4fc.— Barley in a "diseased" soil 152 



Plate 5.— Oats in a nutrient solution 153 



Plate 6a.— Oats in a "diseased" soil 154 



Plate 61?.— Wheat in a "slightly diseased" soil 154 



Plate 7.— Tomatoes in a nutrient solution 155 



Plate 8a.—Phaseolus vulgaris, field crop 157 



Plate Sh.—Phaseolus vulgans, grown in solution 157 



Plate 9.—Phaseolus vulgaris, grown in unlimed soil 158 



Plate lOa.—Vicia sativa, field crop 159 



Plate lOh. —Vicia sativa, grown in unlimed plot 159 



