Citrate-Stabilized Amorphous Calcium Phosphate Nanoparticles Doped with Micronutrients as a Highly Efficient Nanofertilizer for Environmental Sustainability

Abstract

The increase in the global use of phosphorus (P) fertilizers for crop production has generated a series of unintended negative consequences. In response, there is growing interest in developing new fertilizers that curb adverse effects. Among them, amorphous calcium phosphate (ACP) is a viable alternative because of its tunable solubility for P release, high specific surface area, and ability to be doped with vital microelements essential for crops. Herein, we prepared a series of citrate-stabilized ACP nanoparticles (ACPc) doped with micronutrients (B, Cu, Mg, and Zn) and analyzed their dissolution and nutrient release characteristics. Comparative analysis of undissolved ACPc, released ions, and pH of eluted buffer showed a strong positive correlation between the P release rate and the corresponding change in buffer pH. The competitive advantage of ACPc against a monocalcium phosphate (MCP), a conventional commercial fertilizer, for providing P nutrition to plants was tested in lettuce (Lactuca sativa) plants in a greenhouse study. The results showed that undoped ACPc stimulated a 20% higher lettuce crop yield than that of MCP, and the doping with multimicronutrients increased the yield by 22%. More importantly, P resource use efficiency (RUE), calculated based on crop yield and P lost in leachate, was significantly higher in all ACPc than MCP and was about an order of magnitude higher in undoped and multimicronutrient doped ACPc. These results demonstrate that multimicronutrient doping in ACPc is a more efficient and sustainable approach for the dual delivery of P and micronutrients and thus contributes toward meeting the global food demands while minimizing the negative environmental impacts of agriculture.

Small organic molecules containing amorphous calcium phosphate: synthesis, characterization and transformation

“…c) The hydroxy group of citrates can interact with phosphate ions and/or d) The phosphate ions can interact with the carboxyl group of citrates (Indurkar et al, 2023b). Previous reports have also shown citrate's efficacy in stabilizing ACP (Chen et al, 2014;Sakhno et al, 2023).…”

Examining the Correlation of the Nano-fertilizer Physical Properties and Their Impact on Crop Performance and Nutrient Uptake Efficiency

“…Al-Juthery et al [58] discovered nanoamino acids, and nanopotassium increased the nutritional value of wheat by increasing the concentration of essential micronutrients (Zn, Mn, Fe, and Cu) in the grain. Another study by Rahman et al [99] revealed that applying nano-fertilizer resulted in high nutrient use efficiency and significantly improved the nutritional value of tomatoes. Thus, it is imperative to ensure that plants have access to nutrients during their growing cycle to produce food with a high nutritional value and high yield that will meet the nutritional requirements of the population.…”

“…The improvement of the soil properties resulted in improved water and nutrient retention in the soil and increased the growth parameters of the maize crop compared to the traditional fertilizers. Carmona et al β [99] reported that amorphous calcium phosphate (ACP) demonstrates high solubility compared to nanocrystalline apatite (nAp) and exhibits higher surface reactivity, allowing ACP to have larger nutrient payloads compared to nAp. According to Sakhno et al [100], amorphous calcium phosphate (ACP) has been found to be a viable substitute for conventional fertilizers.…”

Fostering Inclusive Scientific Communities: A Pathway to Innovation in Agriculture

“…Examples of other papers on nanomaterials relevant for pesticide formulations are as follows: sustainable nanomaterial approaches to essential oil delivery for disease prevention in soy; pesticide formulation processes using polymeric nanoparticles; metal–organic frameworks for controlled release insecticide formulations; utilizing plant virus nanoparticles as delivery vehicles in soil; and bacteria-based nanobiopesticides for plant disease management . Other examples of novel applications that have been published this year are smart gene delivery systems for plants using amine-functionalized carbon dots, nitrogen-doped carbon dots to address drought stress in maize, and nanoparticles doped with micronutrients and P to reduce nutrient leaching to groundwater . The team looks forward to receiving new papers from scientists around the world on sustainable nanomaterial research in 2024.…”

“…Additional thanks go out to our Editorial Advisory Board members who have provided important guidance and peer reviews and have published their own research this year. The wide range of topics published by our EAB members illustrates their broad expertise ranging from plant science , to soil science and agronomy, − sustainable nanomaterials and formulants, ,,− pesticide discovery, environmental chemistry, − and food safety …”