Mechanochemical Preparation of Slow Release Fertilizer Based on Glauconite–Urea Complexes

Preparation, Features, and Efficiency of Nanocomposite Fertilisers Based on Glauconite and Ammonium Dihydrogen Phosphate

This paper studies the chemical and mechanochemical preparation of glauconite with ammonium dihydrogen phosphate (ADP) nanocomposites with a ratio of 9:1 in the vol.% and wt.%, respectively. The methods include X-ray diffraction analysis, scanning electron microscope with energy-dispersive X-ray spectroscopy, transmission electron microscopy, infrared spectroscopy, and differential thermal analysis with a quadruple mass spectrometer. The manufactured nanocomposites keep the flaky glauconite structure. Some glauconite unit structures have been thickened due to minimal nitrogen (ammonium) intercalation into the interlayer space. The globular, granular, or pellet mineral particles of nanocomposites can be preserved via chemical techniques. Globular and micro-aggregate particles in nanocomposites comprise a thin film of adsorbed ADP. The two-step mechanochemical method makes it possible to slightly increase the proportion of adsorbed (up to 3.2%) and intercalated (up to 6.0%) nutrients versus chemical ways. Nanocomposites prepared via chemical methods consist of glauconite (90%), adsorbed (1.8-3.6%), and intercalated (3.0-3.7%) substances of ADP. Through the use of a potassium-containing clay mineral as an inhibitor, nitrogen, phosphorus, and potassium (NPK), nanocomposite fertilisers of controlled action were obtained. Targeted and controlled release of nutrients such as phosphate, ammonium, and potassium are expected due to various forms of nutrients on the surface, in the micropores, and in the interlayer space of glauconite. This is confirmed via the stepwise dynamics of the release of ammonium, nitrate, potassium, and phosphate from their created nanocomposites. These features of nanocomposites contribute to the stimulation of plant growth and development when fertilisers are applied to the soil.

Mechanical Activation of Smectite-Based Nanocomposites for Creation of Smart Fertilizers

This research presents the mechanical creation of smart fertilizers from a mixture of smectite and urea in a 3:2 ratio by using the planetary milling technique. The smectite–urea composites show intercalation between urea and mineral, which increases steadily with increasing activation time. A shift of X-Ray Diffraction basal reflections, intensities of Fourier transform infrared spectroscopy (FTIR) peaks, and weight losses in thermogravimetric analysis (TG) document the systematic crystallo-chemical changes of the composites related to nitrogen interaction with activation. Observations of the nanocomposites by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) corroborate the inference. Nitrogen intercalates with smectite in the interlayer space and remains absorbed either within micro-aggregates or on the surface of activated smectites. Soil leaching tests reveal a slower rate of nitrogen than that of traditional urea fertilizers. Different forms of nitrogen within the composites cause their differential release rates to the soil. The formulated nanocomposite fertilizer enhances the quality and quantity of oat yield.

Improving growth properties and phytochemical compounds of Echinacea purpurea (L.) medicinal plant using novel nitrogen slow release fertilizer under greenhouse conditions

Medicinal plant production is most important than other agricultural plants due to their phytochemical compounds effects on human health. Paying attention to plant nutrition requirement is so important. In order to assess the effect of nitrate (NO₃⁻) dosage supplies from two types of fertilizers on growth and phytochemical properties of Echinacea purpurea rhizomata cum radicibus, an experiment with completely simple design was carried out under greenhouse conditions. Two types of fertilizers (new invented nitrogen (N) slow release fertilizer and urea chemical fertilizer) at three dosages (50, 100, and 150 mM) were applied. Plant growth parameters and total phenolic (TPC), total flavonoids (TFC), polysaccarides content, essential oil content, caffeic acid derivatives, and anti-radical scavenging activities of E. purpurea were assessed. The results showed the significant (p ≤ 0.01) differences among treatments, both in growth and phytochemical properties. Using of N slow release, especially in 150 mM dosage, significantly increased all the plant growth and phytochemical properties. The dried E. purpurea rhizomata cum radicibus contained more caftaric acid (max 12.56 mg g⁻¹ DW) and chicoric acid (max 7.56 mg g⁻¹ DW) than other derivatives. Despite the impact of heavy metals on yield and growth of E. purpurea, the concentration of all heavy metals and micronutrients (boron (B), cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), and zinc (Zn)) in studied soil and fertilizer samples was less than United States Environmental Protection Agency (USEPA) limits of contamination. Based on the results, using of N slow release fertilizers can improve phytochemical properties of the plant due to its polymeric structure and can be a suitable substitution of chemical fertilizers, especially in medicinal plants growth.