135 



Seekles: Trace Elements in Pastures and Animals 



Similar figures were found for 60 samples of hay originating 

 from the province of Friesland (Figure 27). 



Evidence has been obtained that the pH value of soils plays 

 an important part in the absorption of manganese by pasture grass. 

 The lower the pH value of the soil, the more manganese is being 

 absorbed by the grass. This may well explain the differences 

 observed between manganese in pasture grass and in hay originat- 

 ing from different soils. 



After a critical survey of the results obtained in the Utrecht 

 laboratory concerning the chemical composition, the type of soil, 

 the manuring and the condition of the pastures. Dr. Rameau 

 made a series of supplementary studies. 



so 



iO 

 30 

 20 

 10 



SO 

 40 



10 



r 



10 20 3D iO so 10 20 30 40 SO 



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

 Friesland dependent on the kind of soil.— Left: peat and sand.— Rig^t; clay. 

 —Ahscissa: mg Mn per 100 g (dry matter basis).— Ordinate: percentage of 

 samples.— Prepared in cooperation with J. T. L. B. Rameau. 



As a result of the influence of the pH value of the soil, men- 

 tioned before, a significant difference was found in the manganese 

 content of pasture grass (from sandy soils) of plots fertilized with 

 lime and plots not fertilized. The addition of lime lowered the 

 manganese content of the pasture grass. In this respect, the dif- 

 ferences in hay were not striking. 



The amount of manganese in pasture grass, originating from 

 sandy soils not treated with lime, showed a gradual decrease from 

 the northern to the southern provinces of the Netherlands. It is 



