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The application of nanocomposite fertilisers represents a progressive stride towards harmonising agronomical techniques with environmental conservation. Many studies have been embarked upon to gauge the effectiveness of fertilisers, engaging various substances encompassing polymers, clay minerals, and an amalgamation of synthetic and natural elements. Among these, using clay minerals, such as glauconite, which are both economical and readily accessible, provides an attractive substitute for numerous artificial substances. Glauconite is an adept inhibitor, consisting of nano and micro-particles with vast specific surface areas that maintain surface charge and provide ion-available interlayer sites, thus facilitating nutrient interchange. This study explores constructing and using nanocomposite fertilisers from glauconite amalgamated with a carbamide solution-gel. The ensuing nanocomposite exhibits enhanced intercalation between ammonium and glauconite, as substantiated by extensive analyses using techniques such as XRD, TEM, FTIR, TG-DSC, SEM-EDS, Brunauer-Emmett-Teller (BET) analysis, soil leaching experiments, lab and field agricultural tests. The mineral nanocomposites, replete with an assortment of novel functionalities, disclose that 20% of the carbamide solution results in an escalation of the intercalated N ratio to 8, predominantly within the smectite layers of glauconite. The decrease of a specific surface, the total pore volume and the average pore size in the nanocomposite reflects the adsorption of carbamide substances within the meso- and macropores of glauconite particles. The chemically synthesised glauconite nanocomposite retains an original spherical morphology, accompanied by a distinctive microlayer near the surface, and exhibits an increased nitrogen ratio, indicative of a superior filtration capability. Controlled-action nitrogen and potassium nanocomposite fertiliser were realised using glauconite as an inhibitor. The expectation of targeted and controlled release of nutrients such as ammonium, nitrate and potassium is facilitated by their multifarious forms within the glauconite. Chemically tailored glauconite nanocomposite confers numerous benefits, including a micro-granular mineral structure, a permeable internal morphology, the encapsulation of N compounds within diverse pore structures, and accessible potassium. Such characteristics of the nanocomposite aid in invigorating plant growth and development when these fertilisers are dispensed onto the soil. [ABSTRACT FROM AUTHOR]

This study reports on the development of nanocomposites utilizing a mineral inhibitor and a micronutrient filler. The objective was to produce a slow release fertilizer, with zinc sulfate as the filler and halloysite nanotubes as the inhibitor. The study seeks to chemically activate the intercalation of zinc into the macro-, meso-, and micropores of the halloysite nanotubes to enhance their performance. As a result, we obtained three nanocomposites in zinc sulfate solution with concentrations of 2%, 20%, and 40%, respectively, which we named Hly-7Å-Zn2, Hly-7Å-Zn20, and Hly-7Å-Zn40. We investigated the encapsulation of zinc sulfate in halloysite nanotubes using X-ray diffraction analysis, transmission electron spectroscopy, infrared spectroscopy (FTIR), and scanning electron microscopy with an energy-dispersive spectrometer. No significant changes were observed in the initial mineral parameters when exposed to a zinc solution with a concentration of 2 mol%. It was proven that zinc was weakly intercalated in the micropore space of the halloysite through the increase in its interlayer distance from 7.2 to 7.4. With an increase in the concentration of the reacted solution, the average diameter of the nanotubes increased from 96 nm to 129 nm, indicating that the macropore space of the nanotubes, also known as the "site", was filled. The activated nanocomposites exhibit a maximum fixed content of adsorbed zinc on the nanotube surface of 1.4 wt%. The TEM images reveal an opaque appearance in the middle section of the nanotubes. S SEM images revealed strong adhesion of halloysite nanotubes to plant tissues. This property guarantees prolonged retention of the fertilizer on the plant surface and its resistance to leaching through irrigation or rainwater. Surface spraying of halloysite nanotubes offers accurate delivery of zinc to plants and prevents soil and groundwater contamination, rendering this fertilizer ecologically sound. The suggested approach of activating halloysite with a zinc solution appears to be a possible route forward, with potential for the production of tailored fertilizers in the days ahead. [ABSTRACT FROM AUTHOR]

This article investigates the intercalation of carbamide within globular glauconite involving the chemical activation of glauconite with carbamide solution-gel at varying concentrations of total nitrogen (N). Mineral nanocomposites were prepared with a multitude of novel functions. As the N concentration of the initial solution increased, the proportion of intercalated N enhanced to 8%. A 20% of N concentration in carbamide solution maximizes intercalation. Intercalation occurs in the interlayer of smectite layers (micropores) in glauconite. In nanocomposites, the decrease in specific surface space, total volume pores, and average pore size reflect the absorption of carbamide in meso- and macropores of glauconite globules. Glauconite nanocomposites retain a spherical particle morphology and a distinct microlayer close to the surface. The increased proportion of nitrogen in the microlayers close to the surface indicates a high filtration capacity of the globules. The near-surface microlayer serves as a diffusion channel for the glauconite interior, where new substances are absorbed in the micro- (interlayer) and macropores. The stepwise kinetics of nutrient release, which supports the various forms of carbamide absorption in glauconite, distinguishes the nanocomposites. In addition to N-compounds, glauconite nanocomposites are mineral sources of the available potassium (K) in soils. As a result, chemically manufactured glauconite nanocomposites have some following advantages: the micro-granular mineral form, a permeable inner near-surface microlayer, incubated in micro-, meso-, and macropores N-compounds, and the available K. [Display omitted] • Nitrogen intercalation occurs in the interlayer spaces (micropores) of smectite layers of glauconite. • Adsorbed carbamide in meso- and macropores is reflected in decreased specific surface area, total volume, and pore sizes. • Studied glauconite nanocomposites keep globular morphology and a distinctive near-surface microlayer. • The surface micro-layer performs a solute-supplying function for the core part of glauconite globules. • The nanocomposites have a stepwise pattern of nutrient release. [ABSTRACT FROM AUTHOR]