Due to the increasing demand for food, the agricultural sector is facing a huge challenge related to its production without having a negative impact on the environment. The above issues are regulated by the current EU policy, indicating the need to conduct plant production by the European Green Deal strategy (2020), based on reducing the use of chemical plant-protection products by 50% and reducing the level of mineral fertilization by 20% by 2030. Using appropriate techniques of applying mineral fertilizers, which have a positive effect on the development and activity of soil microorganisms, the availability of nutrients in the soil can be increased while reducing fertilizer applications. This study aims to show whether the use of foliar nitrogen fertilizers in combination with sulfur in a two-year field experiment with triticale stimulates the multiplication of selected groups of microorganisms and the level of soil enzymatic activity. In addition, effects on the content of available forms of nutrients in the soil, triticale yield, and total nutrient uptake were analyzed. It is shown that the applied foliar fertilizers enriched with sulfur, compared to fertilization with ammonium nitrate, contributed to a 100% increase in the number of analyzed groups of microorganisms, urease, and alkaline phosphatase activity; a 44% increase in dehydrogenase activity; and a 15% increase in acid phosphatase activity. The hybrid application technique, with reduced doses of nitrogen fertilizers enriched with sulfur by 20 and 25%, resulted in grain yields exceeding 8 t/ha. Moreover, compared to conventional fertilization based on ammonium nitrate, an increase in the grain yield of triticale was obtained in the range of 16 to 24%, as well as an increase in the accumulation of nutrients in the plant. It is shown that foliar fertilization is a promising alternative to standard fertilization techniques.

At present, there is growing consumer interest in Triticum spelta L., which has high nutritional value. This species is recommended for cultivation in organic farming. In this system of agriculture, biofertilizers are an alternative to mineral fertilization. Biofertilizers stimulate plant growth by providing nutrients through the biological fixation of molecular nitrogen from the air or by increasing the availability of insoluble nutrients in the soil and by synthesizing substances that stimulate plant growth. Green manure biomass and root secretions provide growth material for soil microorganisms, and microorganisms return nutrients to the soil and plants through nutrient decomposition and conversion. Considering the many benefits of using biofertilizers and growing cereals with cover crops for green manure in cereal rotations, field research was carried out on an organic farm to evaluate the soil microbes and the amount of biomass from green manures and their follow-up effect on Triticum spelta L. yields using biofertilizers. Two factors were researched: (I) biofertilizers: control object (no biofertilizer), Azotobacter chroococcum + Azospirillum lipoferum Br 17, Arthrobacter agilis + Bacillus megaterium var. phosphaticum, and combined application of atmospheric nitrogen-fixing bacteria with phosphate solubilizing bacteria; (II) green manures: control object (no green manure application), Trifolium pratense L., Trifolium pratense L. + Lolium multiflorum L., and Lolium multiflorum L. The results show that the most favorable abundance of microorganisms determined in the soil after harvesting Hordeum vulgare L. was recorded after the application of biofertilizers containing atmospheric nitrogen-fixing bacteria with phosphate-solubilizing bacteria under a mixture of Trifolium pratense L. with Lolium multiflorum L. Plowing green manure from a mixture of Trifolium pratense L. with Lolium multiflorum L. resulted in an average increase of 39% in grain yield of Triticum spelta L., while the application of a biofertilizer containing Azotobacter chroococcum + Azospirillum lipoferum Br 17 + Arthrobacter agilis + Bacillus megaterium var. phosphaticum resulted in an average increase of 63%. The proposed spelt wheat cultivation technique can be recommended for agricultural practice due to the positive response of grain yield, but it may also be an important direction for further research to reduce the negative impact of agriculture on the environment.

Weed infestation of cereal crops in organic farming is becoming a serious problem in agriculture. Sustainable agriculture requires the search for and implementation of crop management techniques that will reduce weeds without negatively impacting the environment. This research refers to the principles of integrated plant protection in sustainable agriculture, allowing the use of chemical plant protection products to be limited to the absolute minimum. Technology for growing spring barley based on the use of bacterial consortia in combination with living mulch (LM) can be an interesting approach to this problem. The aim of this three-year field research was to determine the effects of bacterial consortia and LM on the level of weed infestation in the organic spring barley crop. Two factors were tested in the experiment: bacterial consortia factors: control (without bacterial consortia); 1—Bacillus megaterium var. phosphaticum and Arthrobacter agilis; 2—Bacillus subtilis, Bacillus amyloliquefaciens, and Pseudomonas fluorescens; and LM: control (without LM); red clover; red clover + Italian ryegrass; and Italian ryegrass. This research demonstrated that the bacterial consortia tested significantly reduced both the biomass and number of weeds, including the following dominant weeds: Chenopodium album, Sinapis arvensis, Elymus repens, and Tripleurospermum inodorum. The use of LM also significantly reduced the weed infestation of spring barley stands. The lowest biomass and number of weeds, with the exception of Elymus repens, were recorded on objects with LM Italian ryegrass in spring barley in combination with bacterial consortium 2. The introduction of cultivation with LM Italian ryegrass or its mixture with red clover and the use of bacteria should be recommended for the practice of sustainable agriculture, which will reduce weeds through an ecological method.

The research was conducted on an organic farm in Poland in 2019-2022. The purpose of the research was to determine the effect of plant growth-promoting rhizobacteria and cover crops plowed as green manure on the biomass, number, and species composition of weeds found in Triticum spelta grown in...

Soybean (Glycine max (L.) Merr.) is a key legume with high agronomic and nutritional value, widely cultivated for its high-protein seeds and its capability to improve soil fertility through biological nitrogen fixation. Recently, co-inoculation strategies combining Rhizobia bacteria with growth-enhancing fungi from the genus Trichoderma have gained increasing attention as a way to enhance soybean productivity and resilience under variable environmental conditions. The present study, conducted in 2023–2024, examined how seed inoculation treatments (Bradyrhizobium japonicum and Trichoderma viride) affect soybean productivity, seed quality, and soil biochemical changes expressed as the activity levels of selected soil enzymes—dehydrogenases (DHA), catalase (CAT), acid phosphatase (ACP), and alkaline phosphatase (ALP)—as well as the biological fertility index (BIF). The findings indicated that co-inoculation positively influenced plant productivity and produced the highest seed yields among all treatments tested, exceeding the control by 25.6%. Furthermore, inoculated seeds were characterized by improved seed quality, expressed by higher germination capacity (80%) and greater average seedling length (4.74 cm). The bacterial strains used to inoculate soybean seeds increased soil biochemical activity and improved fertility, particularly under unfavorable rainfall distribution during the growing season. Co-inoculation can be recommended as an effective and environmentally friendly element of soybean cultivation technology, supporting yield stability in variable weather conditions. Further research is recommended in longer multi-year series and under various habitat conditions.