Thesis - Open Access
Master of Science (MS)
As the world in which we live becomes more crowded, the specter of food shortage looms larger. As long as the world population is increasing, the food supply must also be increased to offset predicted shortages. One area under development is the ocean, and federal money is being invested in research on ocean farming techniques. More immediate gain, however, may be obtained by bolstering the already immense capability of the agricultural community. This may be accomplished by increasing the yield of the land under cultivation, or by enabling more land to be cultivated. Irrigation has been used successfully in aiding both. When and how much water to apply are fundamental questions in the field of irrigation. These questions, as well as the limited supply of suitable water, imply application of water with care and precision. Rising labor costs, coupled with present low water costs have made irrigated agriculture a very low efficiency user. This occurs at a time when competition for water among domestic, industrial, recreational, and agricultural users is increasing at an alarming rate. Automation of surf irrigation offers one way to conserve labor and water in many farming areas. There has already been much development of the mechanical aspects of an automated irrigation system, such as automatically controlled gates and valves. These devices in themselves are labor saving, but even more may be gained through the use of a fully automated system. Ideally, the system should sense the moisture available in the soil, turn on the water supply when the moisture drops to a predetermined level, and turn off the water supply when the moisture content reaches an adequate level. It is the intent of this thesis to investigate an automatic irrigation system which will be reliable and economical. The preliminary literature search uncovered a number of methods used to measure the amount of soil moisture, but none of the methods seemed to meet all the requirements of an automatic system. Emphasis will be placed on finding a moisture sensor which will satisfy the system requirements. This will be done by evaluating existing methods and attempting to develop a new method experimentally.
Library of Congress Subject Headings
South Dakota State University Theses
Number of Pages
South Dakota State University
Hamre, Herman G., "Automatic Irrigation : Sensors and System" (1970). Electronic Theses and Dissertations. 3780.