Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
Design of a punch planter for no-till systems
Abstract
A punch planter was designed for no-till conditions. Initially, the penetration forces acting on two different punches were evaluated in laboratory tests with two different soils and varying soil moisture contents and bulk densities. A standard cone penetrometer was used as a reference. Soil samples were prepared using PVC molds with a procedure based on the Proctor test. Bulk density was the factor that resulted in the biggest changes in penetration force. Good correlations were observed between the cone penetrometer data and punch penetration forces. A prototype punch planter for corn was designed and built using a commercial vacuum seed meter. The seed meter was evaluated in the laboratory, vertically and inclined. The prototype planter with the seed meter attached was also evaluated in the laboratory. The results were not significantly affected by the working position of the seed meter nor by speeds between 1.0 and 3.0 m/s for the seed meter and planter prototype. Field tests were conducted at several residue covers at 2.0 m/s and no significant differences in plant spacings were observed. The prototype was modified to be able to plant different population rates. Seed spacings of 136, 165 and 210 mm were obtained by constructing three punch wheels with different punch lengths. Laboratory and field tests were run at speeds of 1.5, 2.0 and 2.5 m/s. The field tests were run in three different residue covers (corn, grain sorghum and soybean). Despite problems with synchronization between the seed meter and punch wheels in some combinations, the length of the punches seemed to cause no significant problems at the speeds tested. A soil cleaning device was designed to reduce the soil disturbance. The volume of soil displaced by the smallest punch wheel was less than half of that displaced by a commercial no-till planter. Planting depth regularity was evaluated, showing good uniformity. Though the results are promising, recommendations for further improvement are proposed, especially related to the synchronization between the seed meter and punch wheel.
Subject Area
Agricultural engineering
Recommended Citation
Molin, Jose Paulo, "Design of a punch planter for no-till systems" (1996). ETD collection for University of Nebraska-Lincoln. AAI9712522.
https://digitalcommons.unl.edu/dissertations/AAI9712522