Current challenges in sustainable development and environmental protection are driving scientists and engineers to innovate and mitigate the negative impact of human activities on ecosystems. Strict legal requirements in the European Union (EU) underscore the need for changes to materials used in fertilizers because all components must be biodegradable by July 2024. The EU has published new guidelines for biodegradable materials based on ISO 17556, which assesses degradability in soil. One of the main directions to meet these expectations is the use of enhanced-efficiency fertilizers made from biodegradable materials. This review critically analyses recent advances in using natural raw materials as mineral fertilizer coatings, addressing a significant gap in the evaluation of their commercial viability. The properties of cellulose and lignin as coating materials and their modifications are discussed, including cellulose acetate, ethylcellulose, cellulose acetate butyrate, and phenolated and oxypropylated lignin. These findings provide practical guidance for fertilizer manufacturers seeking to comply with upcoming regulations while maintaining product efficacy.

This study aimed to examine the influence of long-lasting moderate (45% field water capacity—FWC) and severe (30% FWC) water stress and application of sulphur (elemental sulphur or sulphate) on the growth, yield and mineral composition of wheat and maize. Concentrations of macro- and micronutrients were determined in the aboveground parts of the plants. Drought stress caused a marked decrease in the growth parameters of both plants. Under both optimal water conditions (60% FWC) and moderate water stress (45% FWC), grain yields of wheat grown without sulphur application were not significantly different. Applying elemental sulphur caused an increase in grain yield under moderate stress, whereas sulphate was more effective in wheat grown under adequate water supply. Severe water stress significantly lowered wheat yield, regardless of sulphur fertilisation. Increasing water stress resulted in a greater reduction in maize growth, with an average 50% decrease in dry mass under severe water stress. Both crops maintained relatively high levels of macro- (N, P, K, Mg, Ca, S) and microelements (Mn, Fe, Cu, Zn) and did not suffer noticeably from deficiencies in such. Sulphur application did not modify these relationships. In conclusion, sulphur fertilisation may be recommended in wheat cultivation when plants are exposed to moderate water stress.

Foliar fertilization makes it possible to quickly supply plants with deficient nutrients, in case of both their deficiency in the soil and hindered uptake. Crops are characterized by varying nutrient requirements for micronutrients, as well as varying sensitivity to their deficiency. The paper presents practical aspects of the foliar feeding of plants with micronutrients using foliar fertilizers, and their general classification and characteristics. The requirements of basic crops (cereals, rapeseed and corn) for the application of micronutrient fertilization and the degree of their sensitivity to micronutrient deficiency were characterized. The market of foliar fertilizers and the directions of its development were evaluated. The possibilities of foliar fertilizers containing amino acids and silicon, and the possibility of using them for biofortification are presented. It was found that foliar fertilization is one of the most popular and effective methods for the biofortification of plants, as it allows the delivery of the right amount of specific elements in a specific stage of plant development and is thus an economical and environmentally safe procedure. In conclusion, the analysis of the foliar fertilizer market shows that its development is very dynamic, and foliar fertilization is becoming one of the basic elements in effective crop production. Further expansion of the range of foliar fertilizers produced should be expected in accordance with the growing expectations of agricultural producers.

This paper focuses on the agronomic evaluation of a synthetic NPK (N in the form of urea, P and K in the form of phosphate monopotassium) fertilizers blended with four types of pine (Pinus sylvestris L.) wood biochar prepared at different thermal regimes (300 °C, 400 °C, 600 °C and 700 °C). The evaluation of benefits was done based on crop nutritional status and soil fertility. The pot experiment was set up with fertile Haplic Luvisol fertilized with 1.85 g kg⁻¹ of blends of biochar (1.25 g) with urea (310 mg) and KH₂PO₄ (290 mg), which is equivalent to 500 kg ha⁻¹ (biochar ~67.6%; N ~7.8%; P ~3.6%; K ~4.7%) applied before sowing. Only NPK blends made with biochar containing 75% or 85% carbon increased the biomass of 27-day old wheat seedlings from 12% to 20% in comparison to NPK applied alone. These blends raised the content of Mn and Fe in plants but decreased the contents of Ca and Mg. All the tested mixtures enhanced soil fertility by increasing the content of humic acids. Additionally, the content of potentially phytotoxic phenolic compounds was lower. In general, the addition of biochar to NPK fertilizer did not show a negative effect on crop quality. The overall results of the study suggest that the application of low doses of biochar to synthetic fertilizer can benefit crops and can support soil fertility.

This article focuses on the agronomic evaluation of the supplementation of mineral NPKMg fertilizers with elemental sulfur, magnesium, potassium, or ammonium sulfates in pot experiments with ryegrass growing in a sandy Arenosol with very low sulfur content. A benefit evaluation was carried out on the basis of biomass production, crop nutritional status, and changes in the content of soil organic matter fractions. Furthermore, the total number of bacteria, nitrogen-fixing bacteria, and fungi was estimated using the qPCR technique in soil samples after 60 days of ryegrass growth. The combined application of NPKMg and sulfur or sulfate fertilizers significantly increased the summary yield of three cuttings of fresh ryegrass biomass in the range of 32.3% to 82.7%. The application, especially in the form of sulfates, significantly decreased the content of free phenolic acids. Furthermore, compared to the control, i.e., soil with NPKMg applied alone, an increase in the content of glomalin-related proteins and a decrease in the amount of water-soluble organic carbon compounds were observed. Neither the number of DNA marker copy numbers of the total bacterial community nor the nitrogen-fixing bacteria were noticeably different. In turn, the total number of genetic markers for fungi was significantly higher in soils with potassium or ammonium sulfates compared to the control soil. The general results suggest that the application of sulfur fertilizers with NPKMg mineral fertilizer can benefit crops and support soil fertility due to the stabilization of aggregates and the decrease in water-soluble organic compounds.

This study aimed to examine the influence of increasing doses of chromium (Cr) (26, 39, and 52 mg kg(-1) soil) and elemental sulfur (S) (60 mg kg(-1) soil) on growth, yield, and mineral nutrition in wheat and maize. Macro- and micronutrients and Cr concentrations were determined in the aboveground parts of plants. All examined doses of Cr caused a marked decrease in the fresh and dry weight of maize. Wheat was more tolerant than maize, and lower Cr doses caused a small but statistically significant increase in the total yield. Wheat accumulated more than twofold Cr than maize, and the concentrations increased with higher Cr concentrations in the soil. The application of S significantly improved the total biomass production and lowered the Cr content in both plants. Cr changed the mineral nutrition in both cereals, but the pattern of changes observed was not the same. Applying S alleviated some adverse effects caused by the Cr. Hence, it is concluded that the application of elemental S may be an effective strategy to reduce adverse effects in plants grown on soil contaminated by heavy metals, especially Cr.