Cultivation and tillage 



95 



Farmers occasionally leave their ground without a 

 crop for a whole year and cultivate it as often as they 

 can to kill the weeds. This practice is called " fallow- 

 ing," and is very ancient; it is much less common now 



Untouclied plot, many weeds 

 Fig. 44 6. 



that crops like mangolds and swedes arc grown, which 

 can, if necessary, be hoed all the summer. 



We have already seen (p. 69) that ordinary culti- 

 vated plants will not live in a water-logged soil. 



