Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Agricultural Engineering


Evaporation loss from low pressure spray type sprinklers was investigated with the use of the potassium ion as a chemical tracer in the irrigation water. The experimental set-up consisted of a 121 m line source with low pressure sprinklers attached to 4 m risers simulating the outer span of a center pivot irrigation machine. Potassium ion concentrations were monitored in surface applied water and in the atmosphere at a 60-m downwind location. Evaporation losses ranged from 0.5 to 1.4 % for a smooth spray plate sprinkler and from 0.36 to 0.58 % for a coarse serrated plate sprinkler. Measured evaporation values for the smooth spray plate sprinkler were highly correlated (R2=0.98) with calculated values from Kinzer and Gunn's laboratory work. The results support the use of relatively low evaporation values (less than 3%) for irrigation design purposes. The purpose of this study was to accurately evaluate the evaporation loss from low pressure center pivot and linear move irrigation machines. The specific objectives were as follows: 1. To construct a field system to simulate a continuously moving irrigation machine and to accurately measure sprinkler evaporation losses with the use of a tracer. 2. To determine the sprinkler losses under different climatic conditions. 3. To compare the field results with laboratory data.

Library of Congress Subject Headings

Sprinkler irrigation
Irrigation efficiency
Evaporation (Meteorology)



Number of Pages



South Dakota State University


No Copyright - United State