Evaluation of lime requirement tests for minesoils

Area of Science:

• Soil Science
• Environmental Science
• Mine Reclamation

Background:

• Minesoil restoration requires accurate liming to achieve stable pH.
• Standard lime requirement procedures vary in their long-term effectiveness.
• Aluminum toxicity is a key factor affecting minesoil pH.

Purpose of the Study:

• To evaluate standard lime requirement procedures for minesoils.
• To identify an accurate method for forecasting long-term liming needs.
• To establish a procedure for determining optimal lime application rates.

Main Methods:

• Six standard lime requirement procedures were tested on twelve minesoils.
• Potassium chloride-extractable aluminum was measured using the Yang exchangeable acidity procedure.
• A modified Yuan procedure was developed and validated.

Main Results:

• One standard procedure accurately forecasted long-term lime requirements.
• Extractable aluminum, multiplied by 2.24, accurately predicted liming needs.
• The modified Yuan procedure recommended applying 2.24 Mg CaCO3 equivalent lime per hectare per MEQ Al(3+)/100g minesoil to reach pH 5.5.

Conclusions:

• The modified Yuan procedure provides an accurate method for determining minesoil lime requirements.
• Lime application based on this procedure ensures long-term minesoil pH stability (40 months observed).
• This research aids in effective minesoil reclamation and management.