142 FARMING ON FACTORY LINES 



its early growth, and when moisture resulting from 

 later rains was available, it was too late to be of 

 much use to the stunted crop. In fact, in the month 

 of December, the quickly-tilled portion was quite four 

 feet high, whilst never, during the whole season, did 

 the backward portion present a swathe high enough 

 to cut with the scythe. 



MORE SOIL PHYSICS 



As is generally known, but apparently not 

 sufficiently appreciated, the finer the tilth produced 



I in any crop the more retentive the soil is of moisture. 



f This fact requires to be> kept well in mind, especially 



^ ; in connection with summer tillage. 



Another feature of soil physics is that a soil finely 

 tilled and then heavily rolled will draw up more 

 moisture from the sub-soil and retain more dew 

 moisture than a soil equally finely tilled and not 

 rolled. But a subtle point to be remembered is, that 

 while it is necessary to roll a finely-tilled soil in order 

 to reduce capillarity, the moisture will evaporate 

 more rapidly from a smooth than from a roughened 

 surface. 



A practical demonstration of this phenomenon may 

 be made by pouring equal quantities of water on two 

 boards, one rough-sawn, and the other smooth- 

 planed. It will be observed that the moisture from 

 the smooth board will dry off much more rapidly 

 than it will from the rough-sawn board. The 

 deduction to be made from this is very simple — viz., 

 tillage must first be very thorough, then the soil must 

 be heavily rolled, but after the rolling the harrow 

 should be passed over the smooth surface in order to 

 roughen same, and thus check the evaporation of soil 

 moisture. 



