Shop    Knowledge center   Technical projects    Sensors    What is the importance of the correct ocygen content in the roots of a plant?


What is the importance of the correct oxygen content in the roots of a plant?

An adequate oxygen content in the root environment is important for the overall quality and water - and nutrients uptake of the roots. In addition, a good oxygen level will contribute to healthier roots, making the plant more resistant to pathogen fungi. Despite the clarity of its importance there is as yet little attention for the monitoring and regulating of the oxygen content. In this article, our specialist explains about the importance of correct oxygen content in the roots of a plant.

The importance of oxygen in the root environment

For the respiration of plant cells, it is important that there is sufficient oxygen present. The proportions of water and air in the soil or substrate is largely determining for the oxygen quantity. The air contains 21% oxygen. In water, oxygen values are measured up to around 12 milligram per liter. This dissolved oxygen value is of major importance, because the respiration of cells takes place in the plasma.

Also measurements show that the oxygen content has a visible effect on the development of the plant. This applies to foliage growth as well as the development of the roots. The following images clearly show this effect:


 Influence of oxygen on cucumber growth
       Influence of ocygen on the growth of lettuce

Influence of oxygen on cucumber growth

 

Influence of oxygen on the growth of lettuce


Causes of oxygen shortage

Organic pollution or the emergence of a biofilm in a drip irrigation system could cause reduction of oxygen contents. When the water is stagnant, the oxygen in it is consumed by, for example, bacteria and the oxygen content will drop to critical values (<4 mg/l) within an hour. For that reason, regular purification and cleaning of piping is an important measure to safeguard against oxygen shortage. Apart from this, a continuously wet mat could contribute to an oxygen shortage. Roots will in that case not have the opportunity to optimally take up oxygen or the available nutrients. Also practice tests have demonstrated that oxygen shortage near the roots can be attributed to high temperatures in the substrate mat. This high mat temperature and a too wet mat are ideal growth conditions for bacteria and fungi (Pythium in particular), making them reproduce easily.

Consequences of oxygen shortage

Oxygen, assimilates, water and CO2 ensure the formation of ‘energy-rich connections’. These connections are imperative for the uptake of nutrients, among others and to keep cells under tension. Additionally, it ensures that sodium is being kept outside the roots. 

In case of a shortage of oxygen in the root environment fewer energy-rich connections can be formed. This will have all kinds of negative consequences. For example, root growth will be strongly diminished, or will even come to a full stop. Also the uptake of nutrients will be strongly reduced, which may lead to deficiency symptoms. In practice, in case of oxygen shortage, often higher nitrite values are measured. This is because nitrate (NO3) is converted to nitrite (NO2) in case of a lack of oxygen (O). Too high nitrite values are toxic for both humans and plants. 

Oxygen shortage in the summer

Especially in the summer, oxygen shortage is a major. Due to the high temperature, the oxygen content could drop below 4mg (or 10%) in a very short period of time. When this happens, it will cause problems/stress for the plant. 

Measuring oxygen content using sensors

Since the oxygen content is influenced by multiple factors (for example irrigation strategy, climate control and temperature) and is therefore hard to predict, it is important to adequately monitor the content. There has always been attention for oxygen, but until recently it was not possible for growers to measure it in a proper and reliable way. Nowadays there is in fact a solution available. Applying new technology, sensors have been developed that you can use yourself to both determine and monitor the oxygen content in the substrate. These sensors gather data that can subsequently be compared, via a platform, with other cultivation factors to ultimately assess the relationships. This may lead to new insights in the area of climate control, irrigation and plant resilience.

Ben PetersQuestions about the oxygen content in the roots of a plant

Do you have a question about the oxygen content in the roots of a plant, or would you like customized advice? Then contact product specialist Ben Peters, or ask your question via below form. If you ask your question by use of form below, we will contact you as soon as possible, even within 24 hours on working days.


Related articles:
- Which sensors can you use to collect date in horticulture?
Maintenance and inspection - Sensors