ISHS Acta Horticulturae 779: International Symposium on Growing Media
CO2 CONCENTRATION IN THE ROOT ZONE OF VEGETABLES GROWN IN DIFFERENT SUBSTRATES - PRELIMINARY RESULTS |
| Authors: | N. Gruda, T. Rocksch, U. Schmidt |
| Keywords: | CO2-content, continuous measure, cucumber, grodan, growing media, peat, tomato, wood fiber substrate |
| Abstract:
Gas exchange within the root zone could strongly affect the growth of cultivated plants. In particular, compressed substrates with high moisture levels have low air content. A reduction in oxygen and an increase in carbon dioxide concentration, caused by the microbial activity and root respiration, can also be observed. Currently, there is little information about the relationship between the gas composition within the root zone and plant growth and development. A continuous data collection of CO2 concentration within the root zone can help us recognize the short and long-term changes of soil air composition under different substrates or cultural practices (e.g., temperature, water control, mineral nutrients, etc.). The objective of our investigations is to obtain continuous information concerning the gas exchange in the root zone starting with the determination of CO2 content. In addition, the effects of substrates, aeration, and irrigation on the CO2 concentration in the root area of tomato and cucumber plants were investigated. Changes in individual factors cause changes in CO2 concentrations in the root zone. In peat-based substrates, CO2 concen¬trations were higher than in rockwool. This was probably due to higher microbial activity. In addition, typical diurnal variations were determined. In continuously heated rockwool substrates, a relatively constant but high level of CO2 was recorded. | |
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