60 CALIFORNIA VEGETABLES 



lire will produce at least 30 per cent more crop on rich soils than on 

 poor ones, and the crop grown on the rich soil will contain at least 

 45 per cent more food value than that grown on the poor one. In 

 other words, the moisture that would produce 100 pounds of crop 

 on a poor soil would produce at least 130 pounds on a rich soil, and 

 the crop raised on the rich soil would contain on an average 45 per 

 cent more protein, which would still further increase the food value 

 of the crop grown on the rich soil to the equivalent of 188 pounds 

 grown on poor soil; almost twice as much food value on the rich 

 soil as on the poor one from the same amount of moisture. Then 

 again the rich soil will hold more moisture, and if there is plenty of 

 moisture the rich soil can grow two or three times as much crop as 

 the poor soil and with a food value that is higher. 



