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.
MONITORING THE MICROENVIRONMENT OF THE TURFGRASS RHIZOTRON (ROOT LENGTH)
Abstract
The microenvironment of the turfgrass rhizotron located at UNARDC near Mead was investigated. The rhizotron facility has two observation rooms, each containing 20 removable root cell containers. Root cell container variation, rhizotron observation room vertical and horizontal temperature gradients, soil temperature profile of the root cell containers versus the adjacent soil, vertical and horizontal temperature gradients within root cell containers, and root cell container media were investigated in the facility. A complete randomized design was used due to a low coefficient of variation between root cell containers of 0.58. The rhizotron observation room without circulation had a mean vertical gradient of 1.1 C in a diurnal cycle. With air circulation the mean vertical temperature gradient was reduced to 0.3 C. Horizontal temperature differences in the observation room had a standard deviation of 0.13. Daily mean temperatures in the observation room ranged from 0.1 to 16.3 C warmer than ambient temperature. Soil temperatures were assessed with thermocouples placed at five levels (i.e. vertical gradient) and three positions per level (i.e. horizontal gradient) in each root cell container. Mean temperature for horizontal gradient had no biological significance at the 25, 300, 600, and 1200 mm level. The 5 mm level had horizontal differences of 2.1 C with biological significance. Soil temperatures in the root cell containers differed from the adjacent soil. Containers had higher temperatures at the 300, 600, and 1200 mm levels than the soil profile due to the observation room influence. Insulation of the root cell container reduced the observation room influence. Silica sand; fritted clay; washed, river-sand; and sand/soil media had different soil temperature profiles. Fritted clay had the lowest temperatures at the 5 and 25 mm levels for the media tested. Media influence on soil temperature declined with depth. Turfgrass growing in fritted clay had the greatest root length in the upper portion of the profile, but sand/soil mix had the greatest total root length. The fritted clay was the best medium with superior topgrowth, lower temperatures, acceptable root growth, lowest bulk density, and ease of handling.
Subject Area
Ecology
Recommended Citation
BARBER, JOEL F, "MONITORING THE MICROENVIRONMENT OF THE TURFGRASS RHIZOTRON (ROOT LENGTH)" (1987). ETD collection for University of Nebraska-Lincoln. AAI8719773.
https://digitalcommons.unl.edu/dissertations/AAI8719773