264 



MATERIALS OF INDIRECT VALUE 



[chap. 



1882-91, the straw ash alone being given because there 

 is practically no variation in the composition of the ash 

 of the grain. 



Table LXXXII.— Percentage Composition of the Ash of Wheat 

 Straw. Mixed Samples representing 10 years, 188J-1891 

 (Rothamsted). 



There is no great variation in the percentage of ash 

 in the dry matter, but while the percentage of potash in 

 the ash of the straw from Plot 13, receiving only potash, 

 is 23-28, it is raised to 2589 when soda and magnesia 



