A solid‐phase buffer technique to maintain low concentrations of phosphate in nutrient solutions

Abstract

An inexpensive and mechanically simple technique has been developed to maintain realistically low P concentrations in nutrient solutions using a solid‐phase buffer. Phosphate is adsorbed on alumina in a PVC column, and the resulting alumina‐F is desorbed against nutrient solution circulated through the column. Kinetics of P adsorption and desorption indicate that the solid‐phase‐P has rapidly and slowly desorbing components and that buffering capacity is limited by desorption from the solid phase. The technique has been used to maintain F concentrations as low as 0.4 minol m^‐3 for 26 days in experiments with maize (Zea mays L.), and in solution cultures with prune (Prunus domestica L.) trees. Effects of P supply on P accumulation and P transport are discussed.

Key words:

• Solution culture
• alumina
• accumulation
• transport
• maize
• prune