UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 495 



Contribution from the Office of Public Roads 



and Rural Engineering 



LOGAN WALLER PAGE, Director 



SisS' 1 $-ru 



Washington, D. C. 



February 14, 1917 



SPRAY IRRIGATION. 



By Milo B. Williams, Irrigation Engineer. 



CONTENTS. 



Page. 



Introduction 1 



Economic conditions justifying spray irriga- 

 tion .' 2 



Farm conditions adapted to spray irrigation. . 5 

 Amount of water required for spray irriga- 

 tion 5 



Development of water supplies 6 



Screening water 12 



Types of spray irrigation systems 14 



Stationary-nozzle spray systems 



Stationary overhead spray systems 



Types of pumps for spray irrigation 



The designing of spray irrigation systems 



The designing of pumping plants 



Outline of procedure for installing spray irri- 

 gation systems . . . : 



Cost data 



INTRODUCTION. 



Within the past 10 years the spray-irrigation method has been 

 adopted over a wide area in the United States, especially in the 

 Atlantic Coast States from Massachusetts to Florida. Many spray- 

 irrigation plants have been installed in the North Central States, 

 while scattered installations can be found in practically all southern 

 and western States. 



In spray irrigation water is applied to the surface of soils and to 

 crops in the form of small drops, spray, or mist. 1 



The first systems of spray irrigation were an outgrowth of city 

 lawn sprinkling. It was soon demonstrated that by employing such 

 systems small amounts of water could be applied advantageously to 

 delicate crops, especially for supplementing an uncertain rainfall. 

 This method also was found particularly well adapted for furnishing 

 relatively small quantities of water to truck and small fruit crops 

 throughout the humid region. 



1 Use of Water in Irrigation, by Samuel Fortier. 

 Note. — This bulletin is of special interest to truck and small-fruit growers of the 

 eastern part of the United States. 

 66687°— Bull. 495—17 1 



