What is the leaching requirement formula?

LR = ECi / (5×ECe_max - ECi), where ECi is irrigation water electrical conductivity (dS/m) and ECe_max is the maximum tolerable soil saturation extract EC for the crop (dS/m). Minimum irrigation water needed = ETc / (1-LR). Per FAO Irrigation and Drainage Paper 29 (Ayers and Westcot, 1985).

What are ECe threshold values for common crops?

ECe threshold (dS/m) — very sensitive: carrot 1.0, strawberry 1.0; sensitive: bean 1.0, onion 1.2; moderately sensitive: corn 1.7, potato 1.7; moderately tolerant: tomato 2.5, alfalfa 2.0; tolerant: cotton 7.7, sugarbeet 7.0; highly tolerant: barley 8.0, bermudagrass 6.9. Source: FAO Paper 29, Table 1.

Leaching Requirement Calculator

Calculate the leaching requirement (LR) to prevent soil salinization and maintain acceptable root zone salinity for irrigated agriculture.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How to Use

Enter the values for the patient or scenario you are assessing. Calculate the leaching requirement (LR) to prevent soil salinization and maintain acceptable root zone salinity for irrigated agriculture. Use the leaching requirement result to inform your clinical assessment.

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Frequently Asked Questions

What is the leaching requirement formula?

What are ECe threshold values for common crops?