Contents xiii 



PAGES 



Closer Planting Made Possible by Irrigation. Breathing 

 room in the soil limited Soil temperature lowered by 

 close planting Amount of sunshine limited Ten- 

 dency to lodge when planted too close Possible insuf- 

 ficiency of carbon dioxide Amount of carbon used by 

 maize 181-187 



The Maximum Limit of Productiveness for Maize. Mean 

 weight of plants Maximum yields computed Observed 

 yields 187-190 



Observed Yields of Maize per acre, Planted in Different 

 Degrees of Thickness and with Different Amounts of 

 Water. Yields of dry matter Yields of shelled corn. . 190-193 



Influence of Thick Seeding and Irrigation on the Develop- 

 ment of the Plant. Lengthening of the nodes 193-195 



CHAPTER V 



AMOUNT AND MEASUREMENT OF WATER FOR IRRIGATION 

 (pages 196-221) 



The Maximum Duty of Water in Crop Production 196-199 



Conditions which Modify the Amount of Water Required for 

 Irrigation. Peculiarities of crop Character of soil 

 Character of subsoil Character of rainfall Frequency 

 and thoroughness of cultivation Closeness of planting 

 Fertility of land Frequency of applying water 199-208 



Amount of Water Used in Irrigation. In Italy In Spain 

 and France In Egypt General tables Mean amount 

 For sugar cane Highest probable duty, table 

 Bushels of grain per cubic foot of water, table 208-217 



Duty of Water in Eice Culture. 217,218 



Duty of Water on Water-meadows 219,220 



Duty of Water in Cranberry Culture 220,221 



