pH measures how acid or alkaline the soil is, and it controls which nutrients roots can actually take up.
What happens
- Acid soil (low pH): phosphorus, calcium and magnesium become scarce; aluminium can harm roots.
- Alkaline soil (high pH): iron, zinc and manganese are locked up, showing as pale, yellowing new leaves.
- Most crops grow best around 6 to 7.
What to do
Test the soil before the season. Lime raises pH in acid soils; organic matter and sulphur-based products help lower it in alkaline soils, slowly. Changing pH takes time, so start early.
Fertilizer applied to a soil with the wrong pH is often wasted money.
Have a question, or need agricultural advice?
Contact us
