pH can lock nutrients that are already in the soil

Phosphorus, iron, manganese, zinc, and others change how available they are as pH moves. You can pour more on and still see hunger if the chemistry will not let the root take them.

Correct pH and organic matter with local advice, then re-test. Do not stack products against a lock.

If iron sprays become a monthly habit on high-pH ground, the pH job is unfinished.

In this series

• Test soil before you buy another bag
• Irrigation is nutrient management
• pH can lock nutrients that are already in the soil
• Leaf colour is a clue, not a diagnosis
• Microbes and root fungi deliver what a bag cannot
• Return what you harvest so fertility does not walk off the field