Marzena Sylwia Brodowska

The mineral composition of cereals is one of the key indicators of the quality of agricultural raw materials, determining both nutritional value and technological and processing properties. Complex interactions between nutrients, especially sulfur and selenium, can significantly modify the accumulation of macroelements in plant tissues. The aim of the study was to assess the effect of different doses of sulfur (S₁—15 kg S ha⁻¹ and S₂—30 kg S ha⁻¹) and selenium (Se₁—10 g Se ha⁻¹ and Se₂—20 g Se ha⁻¹), as well as the timing of selenium application, on the phosphorus, potassium, calcium and magnesium contents in the grain and straw of spelt and common wheat. The results obtained indicate clear interspecies differences and a non-linear, often species-specific response to selenium doses. In common wheat grain, the application of selenium at two doses increased potassium and magnesium contents by 4–9% and 4–11%, respectively, and it reduced calcium content by 14–18% in spelt wheat grain. In spelt wheat straw, selenium application resulted in an 11% decrease in potassium content and an 8–10% decrease in calcium content. In common wheat, on the other hand, the straw responded with a 17% (Se₁) and 13% (Se₂) increase in magnesium content, accompanied by an 8–10% decrease in potassium content. Sulfur exhibited species-specific effects. In spelt wheat straw, it increased phosphorus content by 5–10%, calcium by 11% and magnesium by 15%. In common wheat straw, sulfur also reduced potassium accumulation by 5% and calcium by 23% (S₁) and 9% (S₂). The timing of selenium application modified the results of their content, but did not show a universal reaction pattern: earlier application increased the P content in spelt straw, while later application promoted an increase in Ca content in common wheat grain.

In order to achieve high-quality yields, it is essential to provide plants with the necessary nutrients, including selenium (Se) and sulphur (S), to meet their nutritional requirements. This study aimed to determine the effect of selenium (0, 10 and 20 g Se ha⁻¹) and the date of its application (in the tillering phase and in the stem elongation phase) and sulphur application (0, 15 and 30 kg S ha⁻¹) on the content of selenium and various forms of sulphur (total sulphur, sulphate sulphur and organic sulphur) and the N:S ratio in winter spelt wheat and winter common wheat. The research hypothesis assumed that different doses of selenium and sulphur and the timing of their application would have a beneficial effect on the Se and S content in the grain and straw of spelt wheat and common wheat. Selenium fertilisation significantly increased the content of this element in the grain of spelt wheat and common wheat. The concentration of selenium was also influenced by the timing of its application in the plant growth environment. However, the dose of selenium and the timing of its application were not associated with significant changes in the content of both forms of sulphur in the tested plants. The experimental factors used did not contribute to the achievement of selenium levels toxic to humans and animals. The presence of sulphur in the growth environment of spelt wheat and common wheat was associated with an increase in the content of both total sulphur, sulphate sulphur and organic sulphur in their grain and straw, especially in spelt wheat straw by an average of 17%, 29% and 23%, respectively, and in common wheat straw by 26%, 18% and 57%, respectively. The sulphur content in the plant growth environment was not associated with a change in the selenium content in the grain of the tested plants. The results of our study suggest that the optimal dose of selenium for biofortification of humans and animals is 20 mg Se ha⁻¹ on clay soil, applied during the stem elongation phase of spelt and common wheat. Biofortification of wheat with selenium and sulphur is a good method of supplementing deficiencies of this element in the human diet.

For many years, deficiencies in selenium (Se) and, sometimes, sulphur (S) have been observed in populations in most European countries and other parts of the world. This study aimed to determine the effect of selenium (0, 10 and 20 g Se ha⁻¹) and the date of its application (in the tillering phase—BBCH 22–24 and in the stem elongation phase—BBCH 31–34) and sulphur application (0, 15 and 30 kg S ha⁻¹) on the content of various forms of nitrogen (total nitrogen, protein nitrogen, ammonium nitrogen, and nitrate nitrogen) in winter spelt wheat and winter common wheat. Selenium application influenced nitrogen distribution in wheat. In spelt, grain total-N decreased by 4%, while common wheat straw increased by 13%. Application timing had no significant effect on total-N. Sulphur slightly raised total-N in common wheat grain and straw. Selenium reduced protein-N in spelt grain by 7% but increased it in common wheat straw by 18%. Ammonium-N in straw rose by 24–27%, while nitrate-N declined in grain and straw of both species. Sulphur-enhanced mineral N forms (ammonium-N by 6–16%, nitrate-N by 7–24%), especially in the early stages. Se–S fertilization strategies should consider their competitive uptake and impact on N metabolism.

The growing world population is putting pressure on food and feed production. For many years, selenium deficiencies have been observed in the diets of the inhabitants of most European and other continental countries, both in the environment and in food and fodder. Therefore, it is becoming necessary to supplement these deficiencies. A 3-year field study was therefore carried out to determine the effect of sulphur (0, 15 and 30 kg S ha⁻¹) and selenium (0, 10 and 20 g Se ha⁻¹) on the yield and biometric traits of winter forms of spelt wheat and common wheat, as well as the timing of application (at the tillering stage, BBCH 22–24, and the stem-shooting stage, BBCH 31–34). Sulphur fertilisation had a slight but positive effect on both the grain and straw yields of both wheat species, especially spelt wheat. The highest increase in spelt wheat grain and straw yield and common wheat straw yield was obtained after applying sulphur at a dose of 15 kg S ha⁻¹, by 3%, 5% and 5%, respectively. In the case of selenium, a higher dose (20 g Se ha⁻¹) had the most beneficial effect on the grain yield of spelt wheat (5% increase) and common wheat (8% increase). In turn, a lower dose of this element (10 g Se ha⁻¹) contributed to an increase in the straw yield of both wheat species, by 10% and 17%, respectively. The yield of spelt and common wheat was not dependent on the timing of Se application. The beneficial effect of S and Se fertilisation on the growth and development of the tested plants is also indicated by the high (exceeding 1) tolerance index for Se and the yield response for S. The effect of S and Se on the weight of a thousand grains was not clear-cut. The density of spelt and common wheat ears increased as a result of the impact of S and Se (S: by 6% and 5%; Se: by 10% and 15%, respectively). Delaying the application of Se contributed to an increase in the density of the tested plants.

The aim of the study was to assess the impact of fertilizer type (urea, compound fertilizer), biodegradable coating type (linseed oil or hemp oil based) and nitrogen dose (135 and 180 kg N·ha⁻¹) on the yield of corn intended for silage. A three-year field experiment was conducted using a randomized block design with three replicates. The test plant was corn intended for silage. The field experiment was conducted in a factorial design comprising three experimental factors: fertilizer type (two levels), coating type (two levels), and fertilizer dose (two levels). Controlled-release fertilizers (CRF) based on biodegradable coatings are an emerging solution in sustainable nitrogen management, yet their field-scale performance remains insufficiently validated. This study investigated how biodegradable coatings based on linseed and hemp oils affect nutrient release dynamics and maize yield under three-year field conditions. The study represents the first field validation phase translating laboratory coating characteristics into agricultural performance metrics. Statistical analysis (ANOVA, Tukey’s test) showed that in the first year of the study, the greatest impact on plant height and corn yield was observed in the case of type of fertilizer used (η²_p up to 17.83%), type of coating (η²_p up to 63.15%) and their interaction (η²_p up to 11.92%). The symbol η²_p (partial eta squared) represents a measure of effect size in analysis of variance (ANOVA). The largest plant size (average 307–310 cm) and the highest yield (107.33 t·ha⁻¹) were obtained in the case of yields in which compound fertilizer or urea with coatings were used in relation to the series in which fertilizers without coatings were applied (differences up to 11 t·ha⁻¹). Statistical analysis using repeated measures ANOVA confirmed a significant time effect, with fertilizer effectiveness declining in subsequent years of the experiment (p < 0.05). In the experiment, no effect of the tested factors on the number of corn cobs was found (η²_p < 2.27%). The highest fresh matter yield for silage production was obtained with coated NPK compound fertilizer (98.80 t·ha⁻¹), representing a 48% increase compared to the unfertilized control (66.90 t·ha⁻¹). The results of the study indicate that the use of coated compound fertilizers—NPK has the most beneficial effect on yield and biometric parameters of plants in the first growing season after their soil application. The enhanced nutrient release from biodegradable coatings provided greatest benefits in the first growing season, with diminishing effects in subsequent years due to coating degradation and residual soil nutrient accumulation.

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.

Intensive research has been conducted for many years to develop environmentally friendly techniques for plant cultivation that optimize the fertilization process. One of the most promising areas within the fertilizer industry is using microbiologically enriched fertilizers, which incorporate beneficial bacteria or fungi. Biofertilizers are the focus of studies on both their production technologies and their effects on crop growth and yield, presenting a potential alternative to conventional mineral fertilizers. The prolonged and improper use of mineral fertilizers, along with inadequate plant protection, a lack of organic fertilization, and poor crop rotation practices, negatively impact soil health, disrupting microbial populations and ultimately diminishing yield quality and quantity. Microorganisms, particularly specific groups known as plant growth -promoting rhizobacteria (PGPR) and beneficial fungi, are estimated to make up 85% of the total soil biomass and play a crucial role in soil fertility by mineralizing organic matter, suppressing pests and pathogens, forming humus, and maintaining proper soil structure. They also provide optimal conditions for plant growth. Soil microorganisms can be categorized as either autochthonous, naturally present in the soil, or zymogenic, which develop when easily assimilable organic matter is added. Key microorganisms such as Micrococcus, Bacillus, Azotobacter, and nitrogen-fixing bacteria like Rhizobium and Bradyrhizobium significantly contribute to soil health and plant growth. Microbially enhanced fertilizers not only supply essential macro- and micronutrients but also improve soil quality, enhance nutrient use efficiency, protect plants against pathogens, and restore natural soil fertility, fostering a balanced biological environment for sustainable agriculture.

The European Commission proposed the European Green Deal, aiming to reduce plant nutrient losses by at least 50% while preventing soil fertility deterioration and reducing fertiliser use by at least 20% by 2030. Of particular importance for environmental reasons is the reduction of nitrogen fertilisation rates. UAN is a highly concentrated nitrogen fertiliser in an aqueous solution of nitrate and urea ammonium nitrate. This study evaluated the effectiveness of fertilisation in pepper and tomato cultivation using UAN mixtures with potassi um thiosulphate in proportions selected based on a model pot experiment. The field experiment was conducted from 2019 to 2020 at the Felin Experimental Farm of the University of Life Sciences in Lublin. The test plants were sweet peppers of the Balta F1 cultivar (Capsicum annuum L.) and tomatoes of the Mirsini cultivar (Lycopersicon esculentum Mill.). The experiment included the following variable factors: nitrogen dose (2 levels: N1 – optimum nitrogen rate and N2 – nitrogen rate reduced by 25% from the optimum dose) and fertiliser composition (2 levels: pure UAN – N : K0 : S0, UAN with potassium thiosulphate – N : K1: S1). Taking into account the pepper yield and the accumulation of nitrogen, phosphorus, potassium and sulphur in the fruit, the most favourable fertilisation combination was the combination of an optimal nitrogen dose (170 kg N ha‒1) with potassium thiosulphate. The reduction of the nitrogen dose and the treatment of fertilisation with a dose of 128 kg N ha‒1 with potassium thiosulphate favoured an increase in the vitamin C content of the pepper fruit. The effect of nitrogen dose on tomato fruit yield was modified by the year of the study. Thus, in tomatoes, it is possible to reduce the nitrogen dose depending on weather conditions. At the same time, the addition of potassium thiosulphate is recommended, which has a beneficial effect on the fruit’s potassium, phosphorus and sulphur and vitamin C content. There was no significant effect of varying nitrogen and potassium fertilisation on the dry matter content of pepper and tomato fruit, while the effect on calcium, magnesium and extract content was inconclusive.

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.

Mineral phosphorus is a non-renewable resource that is constantly decreasing due to intensive fertilizer production. In total, 90% of mined phosphate ore is used for fertilizer purposes, so the demand for phosphorus is the highest in this sector. In this respect, it is advisable to strive to close the phosphorus cycle. In addition, economically viable phosphate-bearing deposits are concentrated in just a few locations worldwide. This comes down to the fact that most countries are simply dependent on imports of this raw material. This and the growing amount of waste have contributed to the search for alternative sources of phosphorus. One example of such phosphorus-containing waste that has fertilizer potential is sodium–potassium phosphate waste from polyol production. This article describes the effect of suspension fertilizers based on polyol production waste on the content of macronutrients in maize intended for green fodder. Fertilizers containing only basic nutrients (NPK) and fertilizers enriched with secondary components (S, Mg) and micronutrients (Zn, Mn, B) were evaluated. The conducted studies confirmed the effectiveness of the tested suspension fertilizers. The content of macronutrients in the dry mass of maize was at a similar level compared with the results obtained in the control, in which Fosdar was used for fertilization, which confirms the suitability of these products for agricultural use.