Nanocomposites for Delivering Agrochemicals: A Comprehensive Review

Abstract

Excessive application of fertilizers negatively affects soil health, causes low nutrient utilization efficiency in plants, and leads to environmental pollution. The application of controlled-release fertilizer is gaining momentum to overcome this crisis. Engineered nanocomposites (ENCs) have shown tremendous promise for need-based delivery of agrochemicals (macro- and micronutrients, pesticides, and other agrochemicals). This review provides comprehensive coverage of synthesis of nanocomposites, their physical–chemical characterization, and techniques to achieve sustained release and targeted delivery to the crops, emphasizing their beneficial role in plant production and protection. Related aspects like feasibility of the application, commercialization of the nanoformulations, and biosafety concerns are also highlighted. This will be helpful to develop a critical understanding of the current state of the art in the controlled release of agrochemicals through nanocomposites. The pressing issues like scale up production, cost analyses, field-based trials, and environmental safety concerns should be given greater attention in future studies.

Nano-Enable Materials Promoting Sustainability and Resilience in Modern Agriculture

“…Nanofertilizers have been shown to improve crop yield and quality with improved nutrient use efficiency and reduced production costs [ 44 ]. The advantages of nanofertilizers over sole inorganic fertilizers rely on their slow-release targeted delivery system associated with cementing nanomaterials ( Figure 2 ) [ 45 ].…”

<strong>Role of Nanoscience in Agriculture</strong>

“…The properties of nanomaterials such as type of material, shape, size, crystal phase, solubility, exposure and dosage concentrations are considered to be of the potential risk to human health [130]. However, some experts point out that food products containing nanomaterials available in the market are probably safe to eat, then also this area needs to be investigated more actively because detailed studies are required to address the impact and safety concern of nanomaterials within the human body when exposed to nanomaterials via food [131].…”

Alginate Nanohydrogels as a Biocompatible Platform for the Controlled Release of a Hydrophilic Herbicide

“…To this aim, the AI can be embedded, adsorbed, or encapsulated in a nanoparticle or a micelle that modifies its solubility, mobility, lifetime, and/or bioavailability. Nanocarriers, such as polymeric nanohydrogels, nanospheres, nanocapsules, porous hollow silica nanoparticles, double-layered hydroxides, and modified or natural clays have been proposed [2,25,26]. For example, the use of an alginate-based nanohydrogel can positively influence dicamba leaching potential, reducing the amount of AI that could be washed out or volatilized after treatment [20,27].…”

“…The miniemulsion formation requires an energy input, coming from hot/cold homogenization [32], high-pressure homogenization [33], ultrasounds [34], or even phase transitions [35,36]. Direct (oil-in-water, O/W) miniemulsions are characterized by oily droplets, where hydrophobic AIs can readily be solubilized [25,37]. Conversely, inverse (water-in-oil, W/O) miniemulsions can be employed for the encapsulation of hydrophilic AIs as an aqueous dispersed phase is homogenized into an oily continuous phase [37][38][39].…”