To grow blueberries in pots, it is necessary to control the EC of the electrical conductivity around the roots. For blueberries, the value of the electrical conductivity in the roots recommended < 1.5 mS/cm; 2.0 mS/cm and above value is destructive for them. This can be controlled in two ways

  1. Pore EC (ECp) — the electrical conductivity of the solution in the pores of the substrate, exactly where the roots are.

→ This is what the plant actually “feels”.

  1. Drainage EC (ECd) — the electrical conductivity of the water that comes out of the pot (drainage).

→ This is a “mixed signal” that depends on many factors.

In short, the drainage EC shows what came out of the pot, and the pore EC shows what conditions the roots are in.

Drainage EC depends on:

  • Pore EC (ECp)
  • Leakage fraction (LF) — how much water goes through the drainage. The latter depends on the irrigation regimes, the amount of evaporation and the impact of rain, which we have in abundance in Western Georgia. Therefore, the use of drainage EC (ECd) to control the condition in the pot is associated with difficulties

Because of this

  • For fertilizer/fertigation correction — the main indicator is ECp (pore EC).
  • For starting/stopping irrigation — the main indicator is VWC (moisture) in the substrate.
  • Use drainage EC as an indicator of “system health” (leaching, flushing, emitter operation, distribution), but do not use it to adjust the fertigation dose.

Note that pore EC (ECp) is not the soil/substrate EC that most sensors measure. The sensor measuring ECp is Teros 12.

The common sensors in our country (Sentec Drill & Drop and others) cannot measure it.

Agron 4500, 5500 and 2500 receive this sensor via direct connection or radio connection from any point in the area.

Which means you can have multiple checkpoints in an area.

It is possible to set conditions for this device based on this sensor and automatically manage the fertigation and irrigation of the pots. For example, if the EC of the pores (ECp) exceeds 1.5 mS/cm, it will send you a warning SMS, and if it reaches 2.0 mS/cm, it will stop fertigation and start flushing the substrate.