Soil Acidification Management in Agricultural Systems

Soil acidification arises primarily from the prolonged use of ammonium‐based fertilisers, elemental sulphur inputs, legume cultivation and acid deposition. Progressive acidification depletes base cations (Ca2+, Mg2+, K+), increases aluminium saturation and impairs nutrient availability, root growth and microbial activity, with consequent declines in crop yield and soil structure. Management strategies centre on the application of alkaline amendments—principally lime (calcium carbonate or oxides) and gypsum (calcium sulphate)—to neutralise acidity, replenish base cations and mitigate aluminium toxicity. Complementary approaches include precise fertiliser placement, organic matter incorporation, cover cropping and tailored crop rotations that enhance nutrient cycling and buffer pH fluctuations. Emerging practices leverage soil‐specific amendment rates, depth‐targeted placement and integration of biological amendments to foster resilient soil biota. Effective acidification management supports sustainable intensification, reduces greenhouse‐gas trade-offs linked to liming and underpins global food security by maintaining optimal pH for nutrient uptake and soil health.

Research from Nature Portfolio

Recent studies have quantified the impact of liming on nutrient mineralisation in highly weathered, high-organic-matter (humic) soils. Experimental incubations demonstrated that lime additions elevate ammonium and nitrate stocks, enhance extractable phosphorus pools and boost microbial biomass C and N, suggesting improved nutrient supply in tropical humic contexts. Complementary long-term field trials under wheat–maize rotations have shown that combining quicklime with inorganic fertilisers markedly raises soil pH, exchangeable Ca2+ and Mg2+, while suppressing Al3+, leading to substantial gains in phosphorus use efficiency and cereal yields. These findings underscore the critical role of paired fertiliser–liming regimes in optimising nutrient dynamics and crop productivity in acidic cropping systems.

Soil Acidification Management in Agricultural Systems publication trend

The graph below shows the total number of articles in soil acidification management in agricultural systems across all publications each year (not limited to Nature Index journals).

Technical terms

Soil acidification: The process by which soil pH declines due to hydrogen and aluminium ion accumulation.

Liming: The addition of calcium-based alkaline materials to raise soil pH and supply base cations.

Cation exchange capacity (CEC): The total capacity of soil to hold exchangeable cations on clay and organic matter surfaces.

Base saturation: The proportion of exchange sites occupied by basic cations (Ca2+, Mg2+, K+, Na+) relative to total CEC.

Aluminium saturation: The fraction of exchange sites occupied by Al3+, a key indicator of acid-induced toxicity.

Phosphorus use efficiency (PUE): The ratio of crop yield to phosphorus applied, reflecting nutrient use performance.

Humic soils: Highly weathered soils rich in stable organic matter, common in tropical regions and prone to acidity.

References

1. Soil acidification and the importance of liming agricultural soils with particular reference to the United Kingdom. Soil Use and Management (2016).
2. Effects of lime application on nitrogen and phosphorus availability in humic soils. Scientific Reports (2020).
3. Interaction of liming and long-term fertilization increased crop yield and phosphorus use efficiency (PUE) through mediating exchangeable cations in acidic soil under wheat–maize cropping system. Scientific Reports (2020).
4. The effects of pH on nutrient availability depend on both soils and plants. Plant and Soil (2023).
5. Yield responses of arable crops to liming – An evaluation of relationships between yields and soil pH from a long-term liming experiment. European Journal of Agronomy (2019).
6. Modulation of the soil microbiome by long-term Ca-based soil amendments boosts soil organic carbon and physicochemical quality in a tropical no-till crop rotation system. Soil Biology and Biochemistry (2021).