A COMPRESSION SUCTION TEMPERATURE (CST) CELL FOR SIMULATING THE PHYSICAL-ENVIRONMENT OF PREEMERGENT SEEDLINGS

Citation
K. Weaich et al., A COMPRESSION SUCTION TEMPERATURE (CST) CELL FOR SIMULATING THE PHYSICAL-ENVIRONMENT OF PREEMERGENT SEEDLINGS, Agronomy journal, 86(1), 1994, pp. 212-216
Citations number
16
Categorie Soggetti
Agriculture
Journal title
ISSN journal
00021962
Volume
86
Issue
1
Year of publication
1994
Pages
212 - 216
Database
ISI
SICI code
0002-1962(1994)86:1<212:ACST(C>2.0.ZU;2-3
Abstract
Field investigations of the influence of soil physical conditions on s eedling emergence are hampered by a lack of control and reproducibilit y of the physical variables. Controlled environment studies frequently fail to adequately simulate field conditions and seldom permit invest igation of interactive physical conditions. In this paper, we describe a compression-suction-temperature (CST) cell designed to enable inves tigation of the response of preemergent seedlings to various strength and temperature regimes under unsaturated conditions. The cells allow independent control of soil strength, temperature, and matric potentia l. Suction within the CST cells is controlled by a hanging water colum n, soil strength by application of a uniaxial load, and soil temperatu re by a combination of heating and cooling of the upper and lower cell boundaries. Shoot growth in.six cells was uniform, reflecting the min imal temperature discrepancies between cells. Temperature profiles typ ical of those experienced in the field were reproduced in the cells. M aize (Zea mays L.) shoot growth was responsive to temperature, with ma ximum elongation rates occurring at a constant temperature of 31.5-deg rees-C. Application of 80 kPa of pressure (estimated shear strength of 42.0 kPa) to the seedbed stopped shoot growth, demonstrating the cell 's capacity to alter the strength environment of the preemergent seedl ing.