THE GARDEN PRIMER 



notions. Incidentally it does prevent them from 

 gaining a foothold of course, but its great merit lies in 

 its action on the soil itself. 



Moisture is carried through soil by capillary attrac- 

 tion. When rain or dew falls on the ground it penetrates 

 to plant roots by means of this action, going down and 

 down until it is equalized in the soil or finds a way 

 through into still deeper fissures and drains out into 

 rivers or sp ings. 



With the coming of fair weather after a rain, how- 

 ever, this downward action is immediately reversed 

 on the surface, where the water particles first yield 

 themselves to the air and heat of the sun and pass from 

 the ground completely. Gradually the pull upward 

 of this same capillary force draws the fluid from deeper 

 down until all that the thirsty earth has absorbed is 

 relentlessly taken from it and scattered in the air again 

 as vapor. 



But tillage is the interrupter of this robbery of the 

 sun. It interposes a little, thin blanket of soil particles 

 which are too widely separated from each other for 

 capillary pull to be efficacious, and the soil beneath it is 

 thus enabled to retain the precious drops for a much 

 longer period, even in decided drought. 



Then, too, this finely pulverized, blanketing soil 

 absorbs moisture more readily than a hard-baked, 

 unstirred surface, and even the light precipitation of 

 dew, night after night, is greedily drunk by it. 



So the importance of tilling rests not in its merit 

 as a weed eradicator, you see. But happily it does 



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