EC and Salt Measurement on Peat-based Substrates vs Peat Alternatives

While the tools to measure substrates’ parameters in ornamental horticulture don’t change based on the growing media, the way substrates behave do, based on their components.

Bark-, wood fiber- or coir-based substrates behave in a far less predictable way when compared to peat. For example, they have a lower buffering capacity, have wider pH fluctuations or require nitrogen fixation. Monitoring relevant parameters such as EC, salinity, moisture and/or nutritional elements’ level is fundamental to grow healthy and beautiful ornamental plants.

Before learning why EC and salinity monitoring is important, here below a quick summary of main differences between peat and alternative substrates:

EC and Salinity: Difference between Peat Substrates and Non-peat-based Substrates

The EC, or Electric Conductivity, tells the salinity of irrigation water. EC is the measure of how well water conducts electricity and, in a nutshell, how well roots are able or not to absorb water. High EC for plants can lead to phytotoxicity, leaf burn, reduced growth, as explained in this article on the effects of high electrical conductivity (EC) on ornamental plants.

Measuring EC is useful in peat-based substrates to determine the right nutrient levels but is even more important in peat-reduced or peat-free growing media. The so-called new substrates, especially those containing compost, can feature some salts leading to a higher initial EC which can quickly lead to toxicity in the early stages of plant growth. For this reason, a high EC at the beginning of growing stages is especially dangerous when working with (rooted) cuttings or seedlings, as the young roots are highly susceptible to root burn.

Furthermore, peat alternatives often have lower nutrient buffer capacities compared to peat. Their lower buffer capacity gives, as a consequence, large fluctuations in nutrient levels with each fertilization, since nutrients are quickly lost after irrigation. With larger fluctuations in nutrient levels, chances of creating a nutrient deficiency or toxicity are bigger.

Therefore when using peat-alternative substrates, it is important to take regular EC or salt measurements in order to adjust the fertilizer schedule according to the nutrients present in the substrate and assure no toxicity nor burns and grant regular growth.

EC and Salt Measuring Devices for Ornamental Plants Production

The most used tools to measure electric conductivity is the EC measuring devices, while substrate’s salinity is mostly measured with PET 2000 activity meter, like explained in this article on tools to measure substrates’ parameters in ornamental horticulture.

Conclusions

Regular measurements are a practice professional plant growers should include in their routine. Detecting inconsistencies and/or deficiencies at an early stage might make the difference between a class I production or a bad economical result. Deficiencies may occur even before their symptoms are visible, like widely explained in our article about nutrient deficiencies in ornamental plants, showcasing symptoms, images and treatment.

These subjects might be complex therefore, for personalized guidance, contact your regional technical support by visiting your country’s website or fill in the form you can reach from the banner at the bottom of this page.