[v.] HOE TNG 



115 



-oots, can be moved in the spring, the more water 

 vill be saved for the use of the subsequent crop, and 

 :he easier will a good tilth be established. The chief 

 ianger lies on the very fine sandy soils, which, when 

 n a loose condition, are apt to run together under 

 leavy rains and afterwards cake on drying. 



Hoeing and Mulches. 



The principles which have already been developed 

 o explain the effect of an early spring ploughing in 

 aving subsoil water, apply even more markedly to 

 .11 the later spring and summer cultivations, hoeing 

 .nd the like, which have for their object the mainten- 

 .nce of a loose tilth upon the surface. The loose soil 

 >ecomes itself dry, but by reason of its discontinuity 

 nd coarse-grained condition, does not conduct the 

 loisture from the firm subsoil to the surface exposed 

 d sun and wind. Under these conditions the only 

 3ss will be of that water which evaporates from the 

 loist soil into the air spaces of the loose upper layer 

 nd then diffuses into the atmosphere ; the deeper the 

 )ose layer thus formed, the more effective will it be, 

 nd if it is destroyed by a fall of rain, which consolidates 

 le ground and establishes a continuous liquid film 

 om the subsoil water right up to the surface, it should 

 e renewed by a fresh cultivation as soon as the land 

 ill admit of working. It is often noticed that a casual 

 lower during a dry period, or watering a garden unless 

 le operation is done very thoroughly, may result in a 

 reater drying up of the soil than ever, just because 

 film of water is created able to lift water from the 

 lbsoil up to the evaporating surface. The loose hoed 

 round practically forms a mulch, though the protect- 

 ig material is the soil itself instead of straw or kindred 

 ibstances. 



