Salens, as chelating, double Schiff base ligands, are an important group utilized in transition metal catalysis. They have been used to build interesting functional metal-organic frameworks (MOFs). However, salens interacting with amino acids have also found applications in receptors. Here, we intended to form a “green” glycine-derived salen fragment, but the available literature data were contradictory. Therefore, we optimized the synthetic conditions and obtained the desired product as two different crystallographic polymorphs (orthorhombic Pcca and monoclinic P₂₁/c space groups). Their structures differ in conformation at the glycine moiety, and the monoclinic form contains additional, disordered water molecules. Despite the high stability of Schiff bases, these newly obtained compounds hydrolyze in aqueous media, the process being accelerated by metal cations. These studies, accompanied by mechanistic considerations and solid-state moisture and thermal analysis, clarify the structure and behavior of this amino acid Schiff base and shed new light on the role of water in its stability.

The aim of the study was to determine the effect of three new solid fertilisers (based on Salmag^®) with innovative IDHA chelate additives (Cu, Mo and Fe) on the yield, yield (grain, straw), biometric characteristics and chemical composition (total N, Ca, Mg and Cu, Mo, and Fe) of spring wheat and soil properties in the pot experiment. The nitrogen dose in all fertilised plots was 140 mg kg⁻¹ of soil (60% before sowing, 40% at tillering). Before sowing, uniform fertilisation with phosphorus (60 mg kg⁻¹ of soil) and potassium (60 mg kg⁻¹ of soil) were also applied. At the stem elongation stage, nitrogen fertilisers, especially Salmag^® with Cu, promoted an increase, and Salmag^® with Mo and Fe promoted a decrease in leaf greenness at other growth stages of spring wheat. All nitrogen fertilisers had a positive effect on height (especially Salmag^® and Salmag^® with Mo) and yield (especially Salmag^® with Cu and Mo) of spring wheat grain and straw. The effect on grain yield was stronger, while Salma^g® with Fe was slightly weaker than pure Salmag^®. All applied nitrogen fertilisers increased total N in grain and straw and Ca and Mg in spring wheat straw. Nitrogen fertilisers enriched with micronutrients generally had a weaker effect than Salmag^® on the content of total N in grain (in contrast to straw) and Ca and Mg. The addition of Cu, Mo, and especially Fe chelates increased the content of chelated elements in spring wheat, especially in straw. The pH value of the soil after harvest of spring wheat was slightly higher after the application of Salmag^® and lower in the soil fertilised with Salmag^® with Mo and Salmag^® with Fe than in the control. Salmag^® and Salmag^® with Cu showed a significant increase in soil Mg and all nitrogen fertilisers (especially Salmag^® with Fe) in soil Ca content after spring wheat harvest. Salmag^® with Cu caused the greatest increase in soil Cu content. The new fertilisers with Mo chelate and especially with Cu chelate showed a significant effect on yield formation and quality of spring wheat.

Ammonium nitrate fertilizers have a tendency to cake during storage. The aim of this study was to examine the effectiveness of organic coatings for preventing the caking of ammonium nitrate fertilizers and to assess the influence of the composition and physicochemical properties of the anti-caking agents used as coatings for fertilizers on their effectiveness. CAN (calcium ammonium nitrate) and AN (ammonium nitrate) fertilizers were coated with three anti-caking agents. A GC–MS technique was used for the identification and quantitative determination of the composition of the organic coatings. The influence of the following physicochemical parameters of the preparations was assessed: density, viscosity, melting point, water content, and base number. The effectiveness of anti-caking agents was determined by measuring the force needed to crush the clumped uncoated and coated fertilizers, which were previously subjected to thermal cycles under load. Composition studies showed that all the tested preparations contained hexadecylamine and octadecylamine in comparable amounts and a slack wax. The results demonstrate that the key parameters of an effective anti-caking agent are low water content, appropriate viscosity, and appropriate content of fatty amines. This study can facilitate the development of innovative coatings with similar or higher efficiency, yet with a reduced negative impact on the environment.

The use of mineral fertilisers has increased in recent years, but this has had a negative effect on the environment, including causing the water in rivers and lakes to become too rich in nutrients, a process known as eutrophication. Current research focuses on producing fertiliser materials that are environmentally friendly. The aim of this study was to examine the impact of novel specialised organic-mineral fertilisers (OMFs: NP 24-12, NP 10-10, and NP 10-10 Zn⁺) on the yield and chemical composition of maize. These fertilisers were compared with a control (no fertiliser) and with other fertilisers (mixture of commercial fertilisers (MCFs): NP 24-12 and NP 10-10) that were used as a reference. All fertilisers increased the SPAD index at the fifth leaf unfolded stage of maize, with the majority (apart from OMF NP 10-10) also increasing it at the panicle emergence stage. MCF NP 10-10 had the most positive effect on the plant height, while OMF NP 10-10 had the least positive effect. All fertilisers had a positive effect on maize growth and development, with MCFs NP 10-10 and NP 24-12 having by far the strongest effect on increasing crop yields. The yield of plants fertilised with OMFs NP 24-12, NP 10-10, and NP 10-10 Zn⁺ was lower than the yields of plants fertilised with MCF NP 24-12 and MCF NP 10-10. OMF NP 10-10 caused a greater increase in the contents of all elements, and OMF NP 24-12 caused a greater increase in most elements (except P and Ca) in maize than MCFs did at an identical NP ratio. OMF NP 10-10 Zn⁺ was found to have a significant impact on the mineral composition of maize, resulting in a decline in Ca and P levels, along with a notable increase in Mg, Zn, and Cu concentrations. The most significant differences were observed for Cu and Zn. The OMFs, notably NP 24-12 and NP 10-10, exhibited a comparatively diminished acidifying impact in comparison with the MCFs. The application of fertilisers resulted in a significant increase in soil nutrient levels, with most fertilisers increasing the soil N, P, and Zn contents. Additionally, the OMFs led to an increase in Cu. However, MCFs NP 24-12 and NP 10-10 reduced the soil Cu and Mn contents. Studies should include other species as they have different needs. Field experiments are also needed.

Many of today’s innovative materials used to carry trace elements (TEs) are derived from chelates. Most of the materials used for this purpose have been produced on the basis of EDTA, which is not considered to be environmentally friendly due to its high persistence. Research is therefore being carried out to produce materials that do not pose an environmental risk. Therefore, a study was carried out to determine the effects of newly developed innovative materials with embedded biodegradable and environmentally safe chelates (IDHA—iminodisuccinic acid—and N-butyl-D-gluconamide ligands) containing copper, molybdenum and iron on the yield, biometric characteristics and chemical composition of soybean and selected soil properties. It is difficult to find publications on their effects in soybean cultivation. The greatest increase in soybean leaf greenness index (SPAD) was found after the addition of pure Salmag^® (Sal.^®). The effect of the chelates on the SPAD index was lower, with Sal.^® + Fe chelate having the greatest effect during the vegetative development stage and Cu chelate having the greatest effect during the flowering stage. Sal.^® + Cu, especially with Fe, accelerated pod and seed ripening in the last vegetative stage of soybean. Sal.^® + Cu had the most favourable impact on plant height, pure Sal.^® on the pod number per plant, Sal.^® + Fe on the seed number per pod, Sal.^® with Mo and Fe chelates on soybean seed yield, and pure Sal.^® on fresh weight remaining above-ground part yield, while pure Sal.^® and Sal.^® + Fe had the most favourable impact on dry weight aerial yield. The fertiliser materials (especially Sal.^® + Cu) generally increased the N content of the tested soybean organs and the Cu content of the other above-ground soybean parts (especially those containing chelates) and had an antagonistic effect on the Mg content of the soybean above-ground parts. Sal.^® + Cu also had a negative effect on the Fe content of other above-ground soybean parts. Sal.^® + Fe had a positive impact on the iron content, and Sal.^® + Mo had a positive impact on the molybdenum content of soybean. The applied fertilisers had little effect on the contents of Cu, Mo and Fe in the soil. There was only a significant increase in the Cu content of the soil after the addition of Sal.^® + Cu and a significantly smaller increase under the influence of Sal.^® without chelates, as well as an increase in the Mo content of the soil with Sal.^®. The present study confirms the beneficial impact of the novel materials with chelates. It has been demonstrated that the presence of materials containing Mo and, in particular, Cu has a considerable effect on the yield and quality characteristics of soybeans.