Microbial Communities and Nutrient Dynamics in Acidic Soils

Acidic soils, characterised by low pH and high concentrations of soluble aluminium and iron, present a major challenge for global agriculture and ecosystem health. In these environments, microbial communities play a crucial role in mediating nutrient availability and detoxifying harmful elements. Acidophilic bacteria and fungi adapt through specialised membrane transporters and the production of organic acids, which can chelate aluminium and mobilise phosphorus. Nitrogen cycling processes—such as biological nitrogen fixation, nitrification and denitrification—are strongly influenced by pH, with shifts in community composition altering rates of ammonia oxidation and nitrate reduction. Phosphorus dynamics are similarly controlled by microbial solubilisation of mineral phosphates, whilst arbuscular mycorrhizal fungi enhance nutrient uptake under stress. Community assembly in acidic soils is driven by soil chemistry, plant genotype and management practices such as liming and organic amendments. Complex co-occurrence networks reveal keystone taxa that stabilise nutrient cycles, offering targets for sustainable interventions to improve crop resilience and soil restoration worldwide.

Research from Nature Portfolio

Recent work has investigated the impact of salt stress on soil enzyme activities and rhizosphere bacterial communities in soybean grown on acidic substrates. Under saline conditions, activities of catalase, urease, sucrase, amylase and acid phosphatase declined markedly, coinciding with shifts in bacterial assemblages. Stress-tolerant genotypes enriched taxa such as Alicyclobacillus, Tumebacillus and Bacillus, which are implicated in osmotic adjustment and nutrient mobilisation. Soil drivers—namely sodium, nitrate, ammonium and available phosphorus—were found to dictate community structure. Notably, the simplified microbial network under salt stress indicates both vulnerability to further perturbation and the potential for targeted microbial enrichment to bolster nutrient cycling and crop performance.

Microbial Communities and Nutrient Dynamics in Acidic Soils publication trend

The graph below shows the total number of articles in microbial communities and nutrient dynamics in acidic soils across all publications each year (not limited to Nature Index journals).

Technical terms

Acidic soil: Soils with low pH (typically below 5.5), high soluble aluminium and reduced availability of essential nutrients.

Rhizosphere: The narrow soil zone directly influenced by root exudates and associated microbial assemblages.

Aluminium toxicity: Growth inhibition and nutrient uptake impairment caused by soluble Al³⁺ ions in low-pH soils.

Phosphorus solubilisation: Microbial conversion of insoluble phosphate compounds into forms accessible to plants.

Co-occurrence network: A graphical representation of potential interactions among microbial taxa based on their co-abundance patterns.

References

1. Effects of salt stress on soil enzyme activities and rhizosphere microbial structure in salt-tolerant and -sensitive soybean. Scientific Reports (2023).
2. Rhizosphere Soil Fungal Communities of Aluminum-Tolerant and -Sensitive Soybean Genotypes Respond Differently to Aluminum Stress in an Acid Soil. Frontiers in Microbiology (2020).
3. Distinct Patterns of Rhizosphere Microbiota Associated With Rice Genotypes Differing in Aluminum Tolerance in an Acid Sulfate Soil. Frontiers in Microbiology (2022).
4. Nitrogen Source Preference in Maize at Seedling Stage Is Mainly Dependent on Growth Medium pH. Agronomy (2022).