Problems related to pH and practical solutions
We all know that the optimal pH level for most crops is between 6 and 7.5. But what do other values mean?
How pH affects yields:
Low pH < 7 (acidic soil):
- Phosphorus is maximally available up to 5.8. pH < 5.4 – phosphorus binds to iron and aluminium and becomes less available
- Trace elements (iron and manganese) may be present in excess, potentially toxic to plants.
- Calcium and magnesium become deficient, which affects plant health.
High pH > 7 (alkaline soil):
- Iron, zinc, copper and boron become less available due to the formation of insoluble bases or basic salts, which can cause leaf chlorosis.
Ways to adjust the pH:
To increase the pH of acidic soils:
- Lime application: Neutralises acidity, improves calcium and magnesium availability.
- Application of dolomite flour: Enriches the soil with calcium and magnesium, increases the pH.
To lower the pH of alkaline soils:
- Use of ammonium sulphate: Provides nitrogen and lowers pH, improving micronutrient availability.
- Addition of elemental sulphur: Lowers pH, improves availability of iron, copper, and other trace elements.
- In addition, as the activity of soil microorganisms increases, a lot of carbon dioxide is released into the soil, which leads to a decrease in pH.
General recommendations:
- Apply phosphate fertiliser close to the root of the plants to ensure better absorption.
- Enrich with organic materials – this improves soil structure, reduces erosion and nutrient leaching.
Test the soil regularly to help detect changes in the pH level and correct them in time.