IRRIGATION IN HUMID CLIMATES 411 



to a loss. That is, every experiment undertaken by 

 Voorhees yielded average large returns, for small fruits, 

 by the application of irrigation water. Phelps, working 

 in Connecticut, in 1895, obtained similar results. Straw- 

 berries grown under irrigation in Connecticut yielded a 

 harvest 159 per cent greater than that obtained without 

 irrigation. 



King conducted a long series of similar experiments 

 under Wisconsin conditions, and his results confirm, in 

 every particular, the conclusions of other investigators. 

 King found that irrigation increased the yield of potatoes 

 46 per cent; cabbage, 12 per cent; corn, 55 per cent; and 

 clover, barley, strawberries, and many other crops under 

 experimentation showed large increases under irrigation. 

 Maxwell studied, for a number of years, sugar-cane irri- 

 gation in the Hawaiian Islands, under an annual pre- 

 cipitation of about 47 inches. During the year 1897-98 the 

 yield of sugar was increased nearly 1,500 per cent by irri- 

 gation. 



It may be that these large increases from irrigation 

 are partly due to the fact that under irrigation much 

 closer planting is allowed without drying out the soil. 

 However that may be, the increase is really due to the 

 fact that there is no shortage of water during the growing 

 period. It has been amply demonstrated that the arti- 

 ficial application of water on humid lands does increase 

 the harvests. Whether the increase and certainty of 

 crop-yield will pay for the cost of building the irrigation 

 system and of applying the water must be worked out by 

 each farmer in accordance with the conditions that sur- 

 round him. Field crops which yield a small acre return 

 may not pay for irrigation, but truck crops, yielding large 

 acre returns, will often pay in one season for the instal- 



