142 



The Rothamsted Grass Experiments. 



Wheat, 30 bushels=18001b., and 30001b. straw=48001b. 

 total produce. 



Barley, 40 bushels=20801b., and 25001b. straw=45801b. 

 total produce. 



Meadow hay, 1J ton, or 33601b. 



Table XXIX. shows the average amounts of nitrogen, and 

 of most of the mineral constituents, in the above quantities 

 of wheat grain and straw, and barley grain and straw. 

 Meadow hay varies so greatly in its botanical and chemical 

 composition, according to soil, climate, and manuring, that it 

 is necessary to take mean results. 



TABLE XXIX. COMPOSITION OF AVERAGK CROPS or WHEAT, BARLEY, 

 AND MEADOW HAT. 



These figures, read from left to right, will be found most 

 instructive. Assuming as the basis of comparison the mean 

 composition of the manured and the unmanured hay, it is 

 seen that a fairly good crop of hay will remove about one- 

 third more nitrogen than the grain of a fairly good crop of 

 wheat or barley, and practically the same amount as the total 

 produce, grain and straw together, of either of the corn crops 

 Of phosphoric acid, the hay crop will remove somewhat less 

 than the grain alone, and only about two-thirds as much as 



