A novel nanosized FePO4 fertilizer is as effective as triple superphosphate in sustaining the growth of cucumber plants

The behaviour of nanofertilizers (NFs) in plant-soil systems can differ from that of conventional chemical fertilizers due to their peculiar chemical-physical properties. Their effectiveness is still poorly understood. In this study, we evaluated the P fertilization potential of a novel nanosized FePO4 NF (FePNF) in a plant-soil microcosm in a pot experiment. The efficacies of FePNF and a conventional P fertilizer (triple superphosphate, TSP) in sustaining the growth of cucumber plants were evaluated. Plants were grown for 28 d on a P-deficient soil, and determinations were made of plant growth parameters, mineral nutrient concentrations in plant tissues, P availability in soil, activities of soil enzymes involved in C, N, P, and S mineralization, and soil microbial community structure. No significant differences were found in plant dry weight, leaf area, chlorophyll content, or root growth between the FePNF and TSP treatments. Conversely, P availability in soil and P concentration in plant tissues at the end of the plant growth period were significantly higher after TSP fertilization compared to FePNF fertilization, whereas no significant differences were observed for other nutrients. Among the measured soil enzyme activities, there were no significant differences in the activities of soil acid phosphatase, beta-glucosidase, and arylsulfatase between the FePNF and TSP treatments, while soil alkaline phosphatase activity was higher in the TSP treatment than in the FePNF treatment and the protease activity was higher in the FePNF treatment than in the TSP treatment. The FePNF and TSP treatments showed significant differences in soil archaeal, bacterial, and fungal community structures, although the microbial community profiles generally clustered closer to each other in the two treatments. We concluded that FePNF can be an efficient alternative to the conventional P fertilizer TSP.