Soil pH Measurement and Fertility Management

Soil pH measurement lies at the heart of fertility management, guiding decisions on the application of lime, inorganic fertilisers and organic amendments to optimise crop productivity and minimise environmental impacts. As a master variable, pH controls nutrient solubility, microbial activity and cation exchange capacity, thus determining whether essential elements such as nitrogen, phosphorus and potassium are readily available to plants. Traditional laboratory methods—suspensions in water or dilute calcium chloride—offer reproducibility but can mask in situ hydrogen-ion activity, while emerging field sensors and pointed electrodes aim to capture true rhizosphere conditions without dilution artefacts. Precise pH assessment informs liming rates, selection of fertiliser formulations and timing of organic inputs, enabling site-specific management across diverse agroecological zones. Furthermore, pH interacts with soil texture, organic matter content and exchangeable bases to shape buffering capacity and long-term soil resilience. In the context of climate change and global food security, harmonised measurement protocols and integrated fertility strategies are essential for sustaining yields, protecting water quality and preserving soil health on a planetary scale.

Research from Nature Portfolio

Long-term trials have demonstrated that conservation tillage combined with targeted organic amendments can maintain neutral to slightly acidic pH in arid and semi-arid soils, while boosting soil health indices and crop yields. Studies reveal that poultry manure applied at moderate rates not only increases organic matter but also enhances the buffer capacity against acidification, stabilising cation exchange capacity and base saturation. Complementary use of biochar in conservation tillage systems further moderates soil acidity, reduces nutrient leaching and promotes a favourable microbial community structure. These findings underscore a holistic approach to fertility management that integrates tillage practices, organic inputs and pH control to achieve sustainable productivity in resource-limited landscapes.

Soil pH Measurement and Fertility Management publication trend

The graph below shows the total number of articles in soil ph measurement and fertility management across all publications each year (not limited to Nature Index journals).

Technical terms

Soil pH: A logarithmic measure of hydrogen-ion activity controlling nutrient solubility and microbial processes.

Cation exchange capacity (CEC): A quantitative index of soil’s ability to retain and exchange positively charged ions, linked to fertility and buffering.

Base saturation: The percentage of exchange sites occupied by calcium, magnesium, potassium and sodium, indicative of soil acidity status.

In situ measurement: Direct assessment of soil properties in their natural context, avoiding dilution and preserving rhizosphere dynamics.

References

1. On the determination of soil pH. Agricultural and Food Science (1965).
2. Organic amendments and conservation tillage improve cotton productivity and soil health indices under arid climate. Scientific Reports (2022).
3. Comparison of cation exchange capacity extraction methods for soil data harmonization and soil classification in Central and East Europe. Geoderma (2024).
4. Advantages of a novel in situ pH measurement for soilless media. Frontiers in Plant Science (2024).