Researchers have developed a more accessible and cost-effective method for determining the biologically active form of phosphorus in soil. This approach could lead to a deeper understanding of phosphorus movement within ecosystems and its role in supporting agricultural production.

Phosphorus is essential for plant growth and food production, yet its natural reserves worldwide are limited. Therefore, studying the processes of phosphorus accumulation, transformation, and release in soil is crucial for maintaining soil fertility, minimizing losses of this element, and reducing negative environmental impacts.

In a study published in the Journal of Agricultural and Marine Sciences, an international team of experts improved a laboratory method for measuring DNA-associated phosphorus (DNA-P) in soils. DNA-P refers to the organic phosphorus pool linked to living microorganisms. Since microbes constantly absorb, transform, and release nutrients, this form of phosphorus reflects the biologically active part of the soil phosphorus cycle.

The modified analytical procedure was tested on 32 soil types across the United Kingdom. The new method proved to be simpler and more affordable to use, while still maintaining the necessary accuracy and sensitivity for reliable measurements. One of the key improvements was the elimination of enzymatic treatment steps previously considered essential. However, ultrafiltration remained necessary to separate DNA-P from other phosphorus-containing compounds, ensuring the precision of the analysis.

The study showed that DNA-P makes up only a small fraction of the total organic phosphorus in soils, but its concentration is closely linked to factors such as pH, microbial biomass phosphorus, organic matter, and water-soluble phosphorus in the soil. These correlations indicate that DNA-P is primarily associated with living soil microorganisms rather than stable phosphorus reserves, and can serve as an indicator of the active portion of the phosphorus cycle dependent on microbial activity.

The improved method provides researchers with a more practical tool for studying biologically active phosphorus in soils and assessing the influence of microbial communities on phosphorus availability for plants. As the need for more efficient use of limited phosphorus resources in agriculture grows, such methods are becoming increasingly relevant. This new approach can support further research in soil fertility, nutrient management, and the development of sustainable food production systems.