VII. 



IRRIGATION AND CULTIVATION. 



AS MEANS OF FIGHTING DROUGHT. 



A SOIL MULCH. — MUCKY COMPOST AND WOOD-ASHES. — SUB- EARTH 

 SOAKING. — SURFACE IRRIGATION. — BOX-DITCH. — SUB-IRRIGATION 

 BY TILE. — IRRIGATION BY WATER PUMPED INTO TANKS. 



It is a mistake to think that cultivation is merely a 

 means of checking or destroying weeds. In reality this is 

 only an incidental benefit. We stir the soil chiefly for the 

 purpose of (i) helping plant growth by admitting air to 

 the soil, thus promoting chemical changes which fit plant 

 foods for ready assimilation by plant roots, and (2) pre- 

 venting the rapid evaporation of the soil water. Cultiva- 

 tion gives us an easy way of providing a soil-mulch through 

 which the water does not readily pass upward. Weeds 

 are simply a manifestation of Nature's kindness to man. 

 They force him to stir the soil when, otherwise, he would be 

 apt to neglect it, letting his plants suffer for want of food 

 and water, and suffering pecuniary loss himself. I cannot, 

 therefore, consider weeds a curse. They do their share of 

 good as a reminder and spur to the flagging grower, and 

 perhaps as much as they do harm. At least they are a 

 necessary evil. 



Preventing Injury by Drought. 

 In localities with fairly regular rainfall the grower can 

 usually succeed in growing good onion crops without arti- 

 ficial irrigation, if he plants on retentive soil which rests 

 on porous sub-soil, and practices the thorough cultivation 



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