CHAPTER VI 

 THE MOISTURE SUPPLY 



The mere presence of an abundance of plant food in the soil 

 will not result in bountiful yields of vegetables. In order that 

 plants may use the food it must be in -solution; and in order that 

 it may be in solution, moisture must be present in the soil. Further- 

 more, the plant food must be in very dilute solution; therefore, 

 large quantities of moisture are necessary to properly nourish the 

 plants. 



In addition to its function as a carrier of plant food, soil mois- 

 ture is essential to the welfare of plants in supplying the water 

 they are continually transpiring from their leaf surfaces. If the 

 water supply at the roots is cut off, the plants wilt, and if the 

 shortage continues, they eventually die. Plants abundantly sup- 

 plied Avith moisture make a more rapid and succulent growth than 

 those less fully supplied. Rapidity of growth, in many kinds of 

 vegetables, means earlier market condition, larger size and better 

 prices. Succulence is closely associated with high quality in many 

 vegetables. Rapid growth makes for a tender product in the root 

 and foliage crops, while slow growth is likely to result in toughness 

 of texture. Large crops of vegetables of good quality are there- 

 fore dependent to a considerable extent upon the moisture supply 

 available to the plants. If no moisture whatever is available, 

 there will be no plant growth. The difference between a desert 

 and a prairie is a matter of moisture; so is the difference between 

 a sage brush plain and an irrigated garden. 



SOURCES OF WAITER SUPPLY 



In humid regions vegetable growers as well as general farmers 

 depend almost exclusively upon the natural rainfall to supply 

 moisture to their growing crops. Even where the annual rainfall 

 is ample for the production of maximum crops, it often happens 

 that on account of unfavorable distribution of the rainfall through 

 the season, vegetable crops suffer severely from lack of moisture 

 at critical times. Cauliflowers fail to head, lettuce runs to seed, 

 turnips turn bitter, sweet corn ''fires" clear to the tassel — all 

 from the lack of a good rain at the right time. The planting of 



35 



