128 The Hothamsted Barley Experiments. 



and even somewhat in the autumn, with, at the same time, 

 great excess of rain from January to September inclusive, 

 whilst both the deficiency of temperature and the excess of 

 rain were very marked from April to August inclusive, that 

 is, during the whole period of the above-ground growth and 

 the ripening, if such it may be called, of the crop, for in many 

 cases the weight per bushel was less than 501b., whilst the 

 amounts of produce were very greatly below the average. 



VAKIATIONS IN THE CHEMICAL COMPOSITION 

 OF THE BAELEY CEOP. 



The influence of exhaustion of manures, and of variations 

 of season, on the amount of produce of barley having been 

 considered, it is pertinent next to inquire what influence 

 these factors have upon the chemical composition of the 

 produce. An examination of the results of analyses, 

 cleinonstrates the greater influence of variations of season 

 than of manures on the composition of barley grain. There 

 is much greater variation in the proportion of potash in the 

 grain, in different seasons with the same manure, than there 

 is with different manures, and further, the seasons showing 

 the highest amount of potash are those of much higher 

 maturing character than those with the lowest amounts. 

 There is still greater, indeed enormous, variation in the 

 amount of potash in the dry substance of the straw with the : 

 same manure in different seasons. There is also great 

 variation according to manure comparatively little in. 

 presence of a full supply, but considerable without manure, 

 that is, with exhaustion. 



As to the phosphoric acid in the grain, there is here again 

 much more variation in different seasons with the same 

 manure than with different manures. But whilst of potash 

 there is the higher proportion in the better seasons, of 

 phosphoric acid there are lower amounts in the better 



