WINTER MEETING. 225 



-ence is upon irrigation. He says : "It is generally calculated that one 

 oubic foot per second of time continuous flow will furnish sufficient 

 water to irrigate 320 acres of land. Irrigating canals are in successful 

 operation with a fall of only one-sixteenth of an inch to the rod." Let 

 Tis make some figures on the above estimate : One cubic foot per second, 

 448 gallons a minute, 645,120 gallons a day ; over 2000 gallons, or 50 

 barrels of water daily per acre (the year round). He says also, "a ten- 

 foot wind-mill would lift enough water 15 feet to irrigate 25 acres." 

 That would mean according to his estimate 50,000 gallons a day, or 

 over 2000 gallons an hour for the pump to lift. Wind-mills may be 

 more energetic in Utah than in Missouri, but Mr. Shoemaker isn't far 

 out of the w^ in his estimate of the amount of water actually required, 

 for accurate determinations have been made by several experiment 

 stations as to the amount of water required in crop production, differ- 

 ing slightly, but upon the average about as follows : 



J'or one pound dry m&.tter. Lbs. water. Tons per acre. 



Barley plant 401 1494 



Oats 501 2221 



Corn '^ 307 2991 



Clover '■ 564 3367 



The above figures point out the necessity of an abundant supply 

 of water, for when this element is lacking growth ceases; or if the 

 quantity is limited, growth is retarded in like proportion. Water is 

 the circulating medium, the common carrier that goes like a miner into 

 the earth, gathers the stores of plant food, bringing them up in solu- 

 tion by capillary action, entering the growing roots of plants, carrying 

 its burdens thence to the utmost leaves of the plant, where the plant 

 food taken from the soil meets the plant food gathered from the air. 

 When these have united in that wonderful chemical laboratory of the 

 leaf, the chlorophyl cells, water again becomes the active distributing 

 agent, conveying by diffusion, it may be, the combined or digested 

 food to each and every part of the plant for assimilation. It carries 

 to the cambium layer its woody structure, to the leaf its velvety folds, 

 to the incipient fruitbud the germs of future growth, and to the fruit 

 the materials of which are constructed the princely apple, the luscious 

 peach or delicious berries — each after its kind — not forgetting in each 

 case to take along the precious pigment that, bathed in the beneficent 

 sunlight, gives such varied colors and pleasing hues to our fruits. 



Such are some of the offices of water in vegetable production. 

 The question recurs, how can we supplement the amount we get in the 

 natural way % The average rainfall in Missouri is about 37.6 inches. 

 This means about 3700 tons to the acre, which would be ample for 



H— 15 



