Rothamsted Symposium on Trace Elements 



134 



samples show values between 15 and 25 mg. Altogether 80 per 

 cent show a manganese value up to 25 mg. The average manga- 

 nese value of 386 samples of pasture grass is 15.8 mg. 



The samples of hay are showing similar manganese values, in 

 70 per cent we find a variation between 5 and 25 per cent. The 

 average manganese value of 259 samples of hay was 16.1 mg. 



A classification of manganese values of the same samples of 

 pasture grass and hay, dependent on the type of soil, is given in 

 Figure 26. 



AV.18.1 



201 



10 



40 

 30 

 20 

 10 



AV.1B.7 



r\Jf^^ 



30 

 20 

 10 



/lf.9.5 



in£ Mu PER lOOjr 



AV. 19.1 



30 



20 



10 







40 

 30 

 20 

 10 



iy.15.2 



AV.1U 



10 2030 40 50 10 20304050 10 203040S0mghtAPER 100^ 



Textfigure 26.— Manganese values of pasture grass and hay dependent 

 on the kind of soil.-Le/t: sand.-Centre: peat.-RigJxt: clay.-Top row: 

 hay; bottom row: grass —Abscissa: mg Mn per 100 g (dry matter basis).— 

 Ordinate: percentage of samples.— Prepared in cooperation with J. T. L. B. 

 Rameau. 



No significant difference was shown to exist between the man- 

 ganese contents of pasture grass and hay originating from either 

 sand, clay or peat. 



Grass originating from sandy soils, however, shows a higher 

 manganese value than grass originating from peat. Grass origi- 

 nating from clay has the lowest manganese content. The average 

 values are 19.1, 15.2, and 11.4 mg, respectively. These differ- 

 ences are significant. 



As to hay, a higher manganese content was observed in hay 

 from sand and peat in comparison with clay. The average values 

 are 18.1, 16.7, and 9.5 mg, respectively. The difference between 

 the first two figures is not significant, but the difference between 

 these and the third is really striking. 



