What kind of soils benefit most from rock phosphate addition?

Rock phosphate primarily benefits acidic soils because of its chemical composition and how phosphorous is made available to plants. In acidic soils, the pH level is typically below 6.0, which enhances the solubility of rock phosphate, allowing phosphorus to be more readily available for plant uptake. Phosphorus is essential for plant growth, influencing root development, flowering, and fruiting processes.

In contrast, in alkaline soils, rock phosphate is less effective due to the high pH, which decreases solubility and thus limits phosphorus availability. Saline soils can present challenges for plant growth due to high salt concentrations, and they do not specifically benefit from rock phosphate addition. While clay soils may hold nutrients better due to their fine texture, the specific reaction and benefit of rock phosphate are more pronounced in acidic soils where phosphorus might typically be less available.

Therefore, the addition of rock phosphate is most beneficial in acidic soils where its solubility is maximized, leading to improved phosphorus uptake by plants.