Nano and traditional phosphate fertilizers: exploring their effects on microbiomes and plant growth
Out of necessity, plant nutrient requirements must be locally met, which explains the importance of soil fertility and soil microbiome community structure. Soil communities were examined in long-term maintained fertilizer and warming treatments in the Arctic tundra. The microbiomes associated with Arctic birch (Betula glandulosa) within the 5 treatment plots (control, high nitrogen (N), high phosphorus (P), high N and P, and warming) near Daring Lake, NWT were sampled. Microbiome analysis of bacterial and fungal communities with 16s rRNA and ITS analysis respectively, showed some differences in bacterial communities with an increase in the family Xanthomonadaceae present in the N & P treatment, while control and warming treatments showed similar soil microbiome structures. Fungal analysis showed an increase in the genus Thelephora in the high P treatment. Microbial communities and plant growth were analyzed in the presence of nano-phosphate fertilizer. Nano-hydroxyapatite (nHA) has been proposed as a more environmentally friendly and more efficient method of P-fertilization. nHA, characterized to be needle-like in shape and ~35 nm in width, was used to evaluate the impact on early microbiome establishment in soybean (Glycine max) in an agriculturally realistic manner. The V4 region of bacterial 16s rRNA was used to determine the microbiome structure in the soil and rhizosphere. Little difference was found in the structure of the soil and rhizosphere microbiomes between controls and nHA treatments. Growth experiments implementing nHA at agricultural levels of P2O5, added to the soil at the time of planting, did not show a significant increase in growth, biomass, or yield compared with controls, suggesting that the needle-shaped nHA do not function as an effective fertilizer when implemented in this manner. The effectiveness of nano-fertilizers is likely influenced by their physicochemical properties (i.e. shape and surface) and their interactions with the soil matrix, making it important to evaluate these factors when designing new nano-phosphate fertilizers. As such, traditional P fertilization as used in the Daring Lake plots, is more effective and has a higher impact on the associated microbial community structure.