BARLEY. 99 



low proportion of organic substance produced. Nor can there Woody 

 be any doubt that strength of straw depends on the favour- ^rf^thtf 

 able development of the woody substance ; and the more this straw. 

 is attained the more will the accumulated silica be, so to 

 speak, diluted — in other words, show a lower proportion to 

 the organic substance. 



It may be mentioned that in our own neighbourhood, 

 where the straw-plait industry prevails, the complaint during 

 seasons of bad harvests has been that an unusually large 

 proportion of the straw was brittle and broke in the work- 

 ing ; and considering the character of the seasons, there can 

 be no doubt that this was associated with low development 

 of the woody matter, and high proportion of silica. 



Summary and Conclusions. 



We have now illustrated the influence of exhaustion, of 

 manures, and of variations of season, on the amounts of 

 produce, and on the composition, of barley. 



The results have shown that on the growth of barley for Summary 

 more than forty years in succession on rather heavy ordinary °f results - 

 arable soil, the produce by mineral manures alone was higher 

 than that without manure ; that nitrogenous manures alone 

 gave more produce than mineral manures alone ; and that 

 mixtures of both mineral and nitrogenous manure gave much 

 more than either used alone — indeed generally twice, or 

 more than twice, as much as mineral manures alone. Of 

 mineral constituents, whether used alone or in mixture with 

 nitrogenous manures, phosphates were much more effective 

 than mixtures of salts of potash, soda, and magnesia. The 

 •averages show that, under all conditions of manuring (except- 

 ing with farmyard manure) the produce was less over the 

 later than over the earlier periods of the experiments, a result 

 partly due to the seasons. But the average produce for the Most effect- 

 forty years of continuous growth of barley was, in all cases ^ J^j£" 

 where nitrogenous and mineral manures (containing phos- barley. 

 phates) were used together, much higher than the average 

 produce of the crop grown in ordinary rotation in the United 

 Kingdom, and very much higher than the average in most 

 other countries when so grown. 



It is seen that the requirements of barley within the soil, Barley and 

 and its susceptibility to the external influences of season, are 1 ^ s fJ on ' 

 very similar to those of its near ally, wheat. There are, how- 

 ever, distinctions of result dependent on differences in the 

 habits of the two plants, and in the conditions of their culti- 

 vation accordingly. 



Wheat is with us, as a rule, sown in the autumn, on a 



