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Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Agricultural Engineering

First Advisor

Ralph Alcock


A tillage implement that uses a revolutionary method to loosen the soil was built and tested at the Agricultural Engineering Department of South Dakota State University. The tine of the implement moves in a triangular like manner and therefore the implement is called the Deltavator. The motion causes the soil to fail due to tensile loading unlike conventional tillage methods which cause the soil to fail due to compressive loading. The failure due to tensile loading requires less force since soil is strong in compression but weak in tension. The five treatments that were tested included: 1. an undriven tine with a fixed flat shovel; 2. an undriven tine with a fixed tilted shovel; 3. a tine that was driven slower than ideal speed; 4. a tine that was driven at the ideal speed; and 5. a tine that was driven faster than the ideal speed. The shovel was free to pivot during the driven treatments. Treatment 1 was considered to be most similar to a conventional subsoil tillage implement and the motion of the shovel in treatment 4 simulated the theoretical Deltavator motion most accurately. Five repetitions were conducted of each treatment and the rolling resistance. The order of testing was randomly generated. The testing showed that the motion of the deltavator caused a distinct loading cycle which · had the same frequency as the motion of the tine in both treatment 3 and treatment 4. Treatment 4 had an average specific draft of 7.25 kN/m which was 15.7% less than the average specific draft of treatment 1 which was 8.60 kN/m. This difference was statistically significant at the 5 percent level.

Library of Congress Subject Headings

Tillage -- Equipment and supplies -- Design and construction
Agricultural implements -- Design and construction




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