Acid phosphatase role in chickpea/maize intercropping

Area of Science:

• Agricultural Science
• Plant Physiology
• Soil Science

Background:

• Organic phosphorus (P) constitutes a significant portion of total soil P in agricultural systems.
• Chickpea is known to enhance P uptake from organic sources in intercropped systems.
• Understanding the mechanisms of organic P mobilization is crucial for sustainable agriculture.

Purpose of the Study:

• To quantify acid phosphatase excreted by chickpea roots.
• To examine the role of acid phosphatase in facilitating P uptake by intercropped maize from phytate.
• To compare P mobilization and uptake in hydroponic and soil intercropping systems.

Main Methods:

• Hydroponic experiments with maize and chickpea grown together or separately, with P supplied as phytate or inorganic phosphate.
• Soil culture experiments with varying degrees of root separation between maize and chickpea, with P supplied as phytate.
• Quantification of acid phosphatase activity in root exudates and rhizosphere soil.

Main Results:

• Intercropped maize showed significantly higher P uptake from phytate compared to monoculture in hydroponics (2.1-fold increase).
• In soil, maize P uptake from phytate was enhanced by chickpea, especially with mesh or no root barriers (2.2 and 1.5 times increase, respectively).
• Acid phosphatase activity was higher in roots and rhizosphere of chickpea, particularly when supplied with phytate, indicating its role in organic P mobilization.

Conclusions:

• Chickpea effectively mobilizes organic phosphorus (phytate) in both hydroponic and soil environments.
• Acid phosphatase secreted by chickpea roots plays a key role in facilitating organic P uptake by intercropped maize.
• Maize/chickpea intercropping enhances the utilization of organic P through interspecific facilitation, contributing to improved P nutrition.