Electrical conductivity Management inside Greenhouse

• EC is a measure of the ability of a solution to conduct electricity, directly related to the concentration of dissolved salts (ions) in the soil, substrate, or nutrient solution.
• Its unit is dS/m (decisiemens per meter) or mS/cm (millisiemens per centimeter).

Significance of EC

• Indicates nutrient concentration in irrigation/nutrient solution.
• Helps prevent over-fertilization or nutrient deficiency.
• Balances osmotic pressure between root zone and soil solution.

Importance of EC Management

• Ensures optimal nutrient availability to crops.
• Prevents salt injury and physiological disorders.
• Maintains osmotic balance for proper water uptake.
• Essential for precision fertigation in hydroponics and soilless culture.

Recommended EC Ranges for Greenhouse Crops

• General safe range: 1.5–3.0 dS/m.
• Below 1.0 dS/m: Nutrient deficiency risk.
• Above 3.5–4.0 dS/m: Salt stress and reduced growth.

Crop examples:

• Tomato: 2.0–3.5 dS/m
• Cucumber: 1.7–2.5 dS/m
• Lettuce: 1.2–1.8 dS/m
• Strawberry: 1.0–1.5 dS/m

Factors Affecting EC in Greenhouses

• Irrigation water quality (salinity, bicarbonates, chloride).
• Type of fertilizer (high salt index fertilizers increase EC).
• Evapotranspiration: High evaporation → salts accumulate.
• Drainage: Poor drainage increases EC in root zone.
• Growing medium: Cocopeat has better buffering than rockwool or sand.

Methods of Monitoring EC

• Handheld EC meters for soil, nutrient solution, or runoff.
• Soil extract testing (1:2 or saturated paste extract).
• Automated EC sensors in fertigation tanks for continuous monitoring.
• Leachate analysis: Drainage EC compared with input EC.

Management of EC inside Greenhouse

• Growers must regularly measure the EX and adjust/replace it as needed.
• Use water filtration systems, add water softeners to manage EC.
• Proper nutrient management is important in maintaining optimal EC levels in the water. Fertilizers that are formulated for specific EC ranges can be used, or growers can use techniques such as foliar feeding to supplement nutrient levels.
• Water filtration: Some growers use water filtration systems, such as reverse osmosis or ion exchange, to remove any unwanted mineral ions from the irrigation water and maintain optimal EC levels.
• Leaching: Applying water to the soil surface and allowing it to drain away, or by applying water directly to the root zone.
• Use EC-tolerant crops barley, sugar beet, cotton, tomato, cabbage, broccoli, etc.