Phosphorus Dynamics in Intercropping Systems

Intercropping—cultivating two or more crop species in proximity—alters the acquisition, mobilisation and cycling of phosphorus (P) compared with monocultures. Complementary root architectures and physiological strategies can enhance P uptake by exploiting distinct soil P pools. Legume–cereal combinations, for instance, benefit from legume-driven acidification and organic acid exudation, which mobilise sparingly available P forms, while cereals exploit altered rhizosphere chemistry through increased phosphatase activity. At the microbial level, diverse cropping assemblages foster communities enriched in P-solubilising bacteria and mycorrhizal fungi that release P from mineral or organic complexes. Field experiments reveal that intercropping often sustains higher soil P availability under low-input regimes, although without careful fertiliser management intercropped plots may exhibit faster depletion of labile P pools. Recent advances have elucidated the temporal dynamics of P uptake, demonstrating early-stage complementarity followed by facilitative interactions when soluble P is exhausted. Such insights highlight the potential of tailored intercropping designs to reduce dependence on mineral P fertilisers, mitigate environmental impacts and enhance global food security.

Research from Nature Portfolio

Studies have investigated the shift from early complementarities to facilitation in wheat–faba bean systems under depleted soil P. Initial growth stages feature complementary P foraging, with faba bean exudation of carboxylates and enhanced phosphatase activity solubilising inorganic and organic P fractions. As available soil P declines, interspecific rhizosphere interactions intensify, resulting in a 30–120 % increase in wheat biomass P compared with monocropping. This progression underpins enhanced P-use efficiency, suggesting that synchronising crop phenologies and root exudation patterns can maximise P acquisition from marginal soils.

Phosphorus Dynamics in Intercropping Systems publication trend

The graph below shows the total number of articles in phosphorus dynamics in intercropping systems across all publications each year (not limited to Nature Index journals).

Technical terms

Intercropping: Cultivation of two or more crops in proximity to exploit complementary resource use.

Rhizosphere: The soil zone influenced by root exudates, where microbial and chemical interactions modulate nutrient availability.

Olsen-P: A standard measure of plant-available phosphate in calcareous soils, based on sodium bicarbonate extraction.

Acid phosphatase: An enzyme secreted by roots or microbes that hydrolyses organic P compounds, releasing inorganic phosphate.

Carboxylate exudation: Release of organic acids (e.g., citrate, malate) by roots to solubilise mineral-bound P.

Land equivalent ratio (LER): A metric comparing intercropped yield to the sum of monoculture yields, indicating resource-use efficiency.

References

1. Major Crop Species Show Differential Balance between Root Morphological and Physiological Responses to Variable Phosphorus Supply. Frontiers in Plant Science (2016).
2. Diversity and Co-occurrence Patterns of Soil Bacterial and Fungal Communities in Seven Intercropping Systems. Frontiers in Microbiology (2018).
3. Organic Acids Regulation of Chemical–Microbial Phosphorus Transformations in Soils. Environmental Science and Technology (2016).
4. Belowground Interactions Impact the Soil Bacterial Community, Soil Fertility, and Crop Yield in Maize/Peanut Intercropping Systems. International Journal of Molecular Sciences (2018).
5. Shift from complementarity to facilitation on P uptake by intercropped wheat neighboring with faba bean when available soil P is depleted. Scientific Reports (2016).