Yes, you can calculate leachate (extracted groundwater by lysimeter) in liters per hectare (L/ha) by standardizing the collected leachate volume to the surface area represented by the lysimeter and scaling to a hectare.

Calculation steps:

• Step 1: Measure the total volume of leachate collected from your lysimeter over a given period in liters (L).
• Step 2: Determine the surface area covered by the lysimeter in square meters (m²).
• Step 3: Convert the leachate volume to "equivalent water depth" in millimeters (mm) by dividing the volume (L) by the lysimeter area (m²). Recall that 1 mm water depth over 1 m² equals 1 liter.
• Step 4: Calculate the total leachate in L/ha:

Leachate (L/ha)=(Leachate volume (L)Lysimeter area (m2))×10,000Leachate (L/ha)=(Lysimeter area (m2)Leachate volume (L))×10,000

where 10,000 is the number of m² in 1 hectare.

This conversion is widely used in lysimeter studies to express leachate per unit area and enables comparison between sites and scaling up to field or landscape level. Expressing results in mm (where 1 mm = 10 m³/ha = 10,000 L/ha) is common; conversion between mm and L/ha is direct, as 1 mm leachate = 10,000 L/ha.

A recent and authoritative reference that describes the calculation method for leachate collected with lysimeters is the book chapter: "Use of lysimeters for monitoring soil water balance parameters and nutrient leaching" by Meissner, R.; Rupp, H.; Haselow, L. (2020), in the volume Climate Change and Soil Interactions, edited by Prasad, M.N.V. and Pietrzykowski, M., published by Elsevier. This chapter details various lysimeter types and explains the determination of soil water balance parameters, including the calculation and scaling of leachate quantities using area-based conversions, following the principles outlined in your previous question. This reference provides both the methodological background and practical calculation steps similar to what you described, and covers current best practices in lysimeter studies.

Pradeep Kumar Dash

Formula to calculate leachate in l/ha:

If you know the volume of leachate collected (e.g., from a lysimeter) in liters (L) and the surface area of the lysimeter in square meters (m²), use this formula:

Leachate (l/ha)=(Leachate (L)Lysimeter area (m²))×10,000\text{Leachate (l/ha)} = \left( \frac{\text{Leachate (L)}}{\text{Lysimeter area (m²)}} \right) \times 10,000Leachate (l/ha)=(Lysimeter area (m²)Leachate (L)​)

This is often done with soil monolith lysimeters. I'm not sure it makes much sense with suction or porous cup lysimeters.

Example of soil monolith lysimeter, that I drew: Article Fall Fertilization Timing Effects on Nitrate Leaching and Tu...