What is another acidic extraction method for assessing soil phosphorus?

The Mehlich Test is a widely recognized method used to assess soil phosphorus levels, particularly in acidic soils. This extraction method employs a solution that contains both sulfuric and hydrochloric acid, which helps to solubilize phosphorus and make it available for measurement. The key aspect of this method is its effectiveness in capturing the phosphorus that is available to plants, particularly in situations where soil pH is low.

In contrast, the Olsen Test is primarily designed for alkaline soils and may not be as effective in acidic conditions, while the Bray Test is specifically tailored to acidic soils but uses different extraction solutions. The Universal Test, although a comprehensive approach, is not typically established as a standard test for soil phosphorus in the same way as the Mehlich Test. As such, the Mehlich Test stands out as a reliable, established method for extracting phosphorus from acidic soils, making it an appropriate choice for this question.