548 



Professor Henry E. Armstrong 



[Feb. 19, 



ditions. On account of the scarcity of rain special measures for 

 conserving moisture in the soil are now adopted. Thus in the 

 Adelaide region, in which much wheat is grown, a system of dry 

 farming prevails which involves either placing the land under wheat 

 one year and under bare fallow the next or the wheat year is 

 followed by one in which weeds are allowed to grow up together with 

 the large quantity of wheat spilt during harvesting by means of the 



Fig. 6. — PvAI^'FALL Map of Australia. 



stripper, which merelv takes off the ears ; the weeds are fed off and 

 then follows a year of bare fallow. The land is cultivated sufficiently 

 often during the year of bare fallow to prevent any growth upon it 

 and the upper layer of soil is kept open so as to minimize the loss by 

 evaporation ; in "^this way a fair proportion of the rain which falls 

 during the year is conserved in the subsoil. 



