Phosphorus acquisition characteristics of cotton ('Gossypium hirsutum' L.), wheat ('Triticum aestivum' L.) and white lupin ('Lupinus albus' L.) under P deficient conditions

A rhizobox experiment was conducted to examine the P acquisition characteristics of cotten ('Gossypium hirsutum' L.), wheat ('Triticum aestivum' L.) and white lupin ('Lupinus albus' L.) under P-deficient conditions. We aimed to identify whether cotton is physiologically efficient at acquiring P through release of protons, phosphatases or carboxylates. Plants were pre-grown in the upper compartment of rhizoboxes filled with a sand and soil mixture to create a dense root mat against a 53 μm polyester mesh. For each species, two P treatments (0 and 20mg P kg⁻¹) were applied to the upper compartment in order to create P-deficient and P-sufficient plants. At harvest, the upper compartment with intact plants was used for collection of root exudates while the lower soil compartment was sliced into thin layers (1 mm) parallel to the rhizoplane.