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.