54 VERTICAL FARMING 



sluggish action. A corn crop when in the season of most 

 vigorous growth will remove more water from the soil in 

 a day than will a crop of wheat. Some crops are slow, weak 

 feeders, while others feed ravenously, and, while taking up 

 more substance, may be able to overcome more unfavorable 

 conditions. Roots should be thrown down into the soil as far as 

 possible in order to get away from danger of drouth, and 

 excesses of temperature, as well as from injury by cultivating 

 machinery. 



The desirable conditions for a root system can be improved 

 by thorough cultivation of the subsoil, much deeper than any 

 plow can go, by means of explosives. They loosen up the soils 

 so that the roots are not checked in going downward, the rise of 

 capillary water is aided, aeration is improved, and deep reser- 

 voirs of water made accessible. This method more than doubles 

 the depth of the feeding zone. 



Depths to Which Roots Go. The natural tendency of most 

 roots is to go deep into the soil. Many who have not investi- 

 gated this subject believe that roots do not go deeper than one 

 or two feet and cutivate accordingly. On the contrary, they go 

 to much greater depths if the soil conditions permit. Corn 

 roots that have been confined and have occupied all the soil to a 

 depth of 2 feet, will go to a depth of 8 feet if the restriction is 

 removed. Wheat, oats and barley will penetrate from 8 to 10 

 feet, grass roots will go down 6 and 8 feet, while alfalfa has 

 been known to go down over 30 feet. Grapevine roots have 

 been found 22 feet below the surface, while the root systems 

 of trees correspond in extent and branching to the parts above 

 ground. The roots of clover weigh as much as the total weight 

 of the year's crops, while the roots of an oat crop are nearly 

 50 per cent, of the weight of the seed and straw. The total 

 length of all the roots of a wheat plant was found to be about 

 268 feet, of one rye plant 385 feet, and of one corn plant 

 1452 feet. Such facts show that the size and depth of the root 

 systems are generally not appreciated, and are generally under- 

 estimated. It is evident that the roots need a far deeper feeding 



