Articles
SPATIAL VARIATION IN OXYGEN AVAILABILITY IN GROWING MEDIA
Article number
891_22
Pages
195 – 200
Language
English
Abstract
Oxygen availability in growing media can vary significantly, with spatial differences ranging from full aeration to anoxic conditions.
Most measurements determining oxygen in potted media are bulk measurements, which will not reveal this spatial variation.
Thus, novel in situ methods measuring oxygen distribution in the media of potted plants are required.
Oxygen profiles were determined with
1 mm steps from the surface of the growing media to the bottom of the container by the use of microsensors.
This made it possible to determine oxygen variation in space and time.
The oxygen profiles were measured in the growing media of potted roses Rosa sp. Mistral, examining a non-compacted peat medium, as well as a peat medium with addition of either no clay or powder-clay.
The profiles were determined immediately before irrigation and 3, 6 and 12 hours after irrigation in the non-compacted media and 3 and 6 hours after irrigation in the media with or without clay amendments.
Results revealed that oxygen varied in space and time and that the clay amendment affected the oxygen distribution.
A decrease in oxygen content or an anoxic period occurred at the bottom 2 cm of the container after irrigation and lasted several hours.
No anoxic period was observed when powder clay was added, in contrast to the medium with no clay.
The short periods of low oxygen availability did not affect plant growth in any of the treatments.
However, this new method opens up opportunities to increase knowledge on how physical properties affect aeration of growing media.
Most measurements determining oxygen in potted media are bulk measurements, which will not reveal this spatial variation.
Thus, novel in situ methods measuring oxygen distribution in the media of potted plants are required.
Oxygen profiles were determined with
1 mm steps from the surface of the growing media to the bottom of the container by the use of microsensors.
This made it possible to determine oxygen variation in space and time.
The oxygen profiles were measured in the growing media of potted roses Rosa sp. Mistral, examining a non-compacted peat medium, as well as a peat medium with addition of either no clay or powder-clay.
The profiles were determined immediately before irrigation and 3, 6 and 12 hours after irrigation in the non-compacted media and 3 and 6 hours after irrigation in the media with or without clay amendments.
Results revealed that oxygen varied in space and time and that the clay amendment affected the oxygen distribution.
A decrease in oxygen content or an anoxic period occurred at the bottom 2 cm of the container after irrigation and lasted several hours.
No anoxic period was observed when powder clay was added, in contrast to the medium with no clay.
The short periods of low oxygen availability did not affect plant growth in any of the treatments.
However, this new method opens up opportunities to increase knowledge on how physical properties affect aeration of growing media.
Authors
D.B. Dresbøll
Keywords
microsensor, peat, clay, compaction, Rosa sp.
Online Articles (35)