Availability and Uptake of Phosphorus and Zinc by Maize in the Presence of Phosphate-Containing Zn-Al-LDH in a Calcareous Soil

Abstract

In this research, the potential application of phosphate containing zinc-aluminum-layered double hydroxide (Zn-Al-P-LDH) to enhance the availability of P and Zn compared to triple superphosphate (TSP) in a calcareous soil was investigated. First, soil availability of P and Zn at two P levels (18 and 45 mg kg–1) of Zn-Al-P-LDH and TSP were compared in a 70-day incubation procedure. Second, a pot experiment was performed to study the effect of these treatments on growth and on P and Zn uptake by maize. Incubation experiment showed that, in contrast to the TSP, addition of both P levels of LDH increased P availability during the incubation period. Furthermore, the soil-available Zn in LDH was significantly enhanced compared to TSP and control treatments. This observation suggested that ion exchange accompanied by partial dissolution mechanism possibility happened for studied LDH. However, the values of shoot dry weight and leaves P uptake were significantly higher for LDH than TSP treatment just at 18 mg P kg-1 level probably due to its effect on adequate Zn supply along with P. Therefore, Zn-Al-P-LDH might be a candidate as dual-purpose fertilizer if its limitations in terms of high Zn content to be overcome.