132 The Rothamsted Barley Experiments. 



Of recent years Russia has been to the United Kingdom 

 the most important source of barley. France and Germany 

 show fairly equal average amounts, but Germany has sent 

 decidedly the more in the later years. 



CULTIVATION OF WHEAT AND OF BAELEY 

 COMPAEED. 



Lastly, comparing wheat with barley, it is apparent that 

 the requirements of barley within the soil, and the suscepti- 

 bility of this cereal to the external influence of season, are 

 very similar to those of its near ally, wheat ; but there are 

 distinctions of result, dependent on differences in the habits 

 of the plants, and in the conditions of their cultivation 

 accordingly. Wheat is, as a rule, sown in the autumn, in a 

 heavier and closer soil, and has four or five months in which 

 to distribute its roots and get possession of a wide range of 

 soil and subsoil, before barley is sown. Barley is sown in a 

 lighter surface soil, and, with its short period for root 

 development, relies in a much greater degree on the stores 

 within the surface soil. Hence it is more susceptible to 

 exhaustion of surface soil as to its nitrogenous, and especially 

 as to its mineral supplies ; and in the common practice of 

 agriculture it is found to be more benefited by direct 

 mineral manures, especially phosphatic manures, than is 

 wheat when sown under equivalent soil conditions. The 

 exhaustion induced by both crops is, however, characteristi- 

 cally that of available nitrogen; and when, under the 

 ordinary conditions of manuring and cropping, artificial 

 manuring is still required, nitrogenous manures are, as a 

 rule, requisite for both crops, and for the spring-sown one, 

 barley, superphosphate also. 



