Local adaptation of plants to environmental conditions is gaining attention, particularly in the context of climatic change and the microbiota that are associated with it. It should be noted that endophytes play a large role in shaping plants. These are microorganisms that reside within plant tissues without causing any apparent harm to their host. It should also be highlighted that endophytes play an essential role in ecosystems by contributing to plant health through multiple mechanisms. We suggest that endophytes affect some animals, as they are used in the ecological niche in which animals thrive. Thus, we analyzed this aspect of endophytes as persistent but impermanent inhabitants of various ecological niches. Therefore, the aim of the current review is to present the knowledge (from the last 10 years) on plant endophytes, their applicability in agriculture and endophytes affecting animals. We focused on bioproducts and biofertilizers containing endophytes, which are indirectly connected with agrobiotechnology, and the legal conditions associated with the marketing of these products, which also impact some animals, as they are used in the ecological niche in which animals thrive.

The choice of appropriate agricultural practices has a significant impact on soil quality, crop productivity, or soil microbial community. Ten representative soil samples were collected in Wierzchucin Królewski (Kujawsko-Pomorskie Province, NW Poland), an agricultural area belonging to the Potulicka Foundation Group. The cropping systems included a maize monoculture grown continuously for over 30 years and an intercropping mixture (Gorzow mixture) applied in 2020. The study aimed to determine the effect of the intercropping system on the quality and biodiversity of the studied soils and to identify bacterial indicators of sensitivity and resistance to long-term maize monoculture. Therefore, in this study, the impact of the intercrop mixture application on the chemical and biological soil properties and on the diversity of the bacterial community was evaluated by amplifying the 16S rRNA gene sequences and indicators of sensitivity and resistance to long-term maize monoculture were recommended. The results showed that intercropping had a positive effect on soil features and increased the richness and diversity of soil bacteria at the taxonomic level of genera compared to the maize monoculture. Massilia and Haliangium were proposed to be bacterial indicators of sensitivity, while Sphingomonas was recommended to be an indicator of resistance to long-term maize monoculture. Overall, our results evidenced that using an intercropping system may be a sustainable agricultural practice in this area and in north-western Poland.

Nitrogen (N) is an essential element for plant productivity; hence, it is abundantly applied to the soil in the form of organic or chemical fertilizers, which consequently have a negative impact on the environment. Therefore, the main objective of our study was to investigate the structure and richness of the soil mycobiome in response to reduced nitrogen fertilization under two cropping systems: plowing (P) and no-till (NT). Moreover, the scope of the study perfectly falls into the EU "From Field to Table" strategy, which recommends a 20 % reduction of nitrogen fertilization of agricultural soils by 2030. In our study, the samples were collected twice during a single growing season: before maize sowing (without fertilization) and after harvesting the crop (four different fertilization rates). The mycobiome structure was identified based on the next generation sequencing (NGS) technique. Overall, our research has proved that the cropping system is important in terms of the formation of the fungal mycobiome structure and relative abundance. In addition, we confirmed that soil properties have a significant impact on fungal communities. We determined that a 20 % lower nitrogen fertilization rate (92.0 kg N ha^-1) had a positive effect on the abundance of fungal communities. Moreover, the highest biodiversity at each of the taxonomic levels tested (phylum, class, genus) in the NT system and at the class and genus levels in the P system was also evidenced at the 20 % lower N fertilization rate. We also recommended potential indicators confirming the positive impact of reduced fertilization in two cropping systems: plowing - Epicoccum, Metarhizium, Mycosphaerella, and Paraconiothyrium and no-till - Peziza, Podospora, Metarhizium, Trechispora, and Umbelopsis.

The European Commission’s “Farm to Folk” (F2F) strategy recommends reducing fertilizers by at least 20% by 2030. In this aspect, the main goal of our study was to verify whether a 20 and even 40% reduction in nitrogen (N) fertilization rate would be sufficient to maintain soil fertility (expressed as dehydrogenase activity—DHA, humic acid substances—HA substances, E4/E6 ratio), and yields of wheat and rapeseed cultivated in strip-till technology. Two fields (10 ha each) were established for wheat and rapeseed cultivation, and soils (0–20 cm) were sampled before sowing and after harvesting. It was found that a 20% fertilization reduction does not adversely affect the biological activity expressed by DHA. Nevertheless, the reduction in nitrogen (N) fertilizer rates led to a slight decrease in the E4/E6 ratio, which could serve as a potential indicator of fertilization reduction. DHA, E4/E6 ratio and content of HA substances were also dependent on the crop. Following harvesting, both rapeseed and wheat exhibited a positive correlation between the E4/E6 ratio and the degree of fertilization rate (FR), as well as yield.

The main goal of the study was to determine changes in the bacterial structure in bottom sediments occurring over the seasons of the year and to estimate microbial metabolic activity. Bottom sediments were collected four times in the year (spring, summer, autumn, and winter) from 10 different measurement points in Cardinal Pond (Ślesin, NW Poland). The Next-Generation Sequencing (MiSeq Illumina) and Community-Level Physiological Profiling techniques were used for identification of the bacterial diversity structure and bacterial metabolic and functional activities over the four seasons. It was evident that Proteobacteria, Acidobacteria, and Bacteroidetes were the dominant phyla, while representatives of Betaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria predominated at the class level in the bottom sediments. An impact of the season on biodiversity and metabolic activity was revealed with the emphasis that the environmental conditions in summer modified the studied parameters most strongly. Carboxylic and acetic acids and carbohydrates were metabolized most frequently, whereas aerobic respiration I with the use of cytochrome C was the main pathway used by the microbiome of the studied bottom sediments.

The European Commission’s “Farm to Folk” strategy recommends reducing fertilizers by at least 20% by 2030. In this context, the aim of this study was to verify whether a 20 and 40% reduction of nitrogen (N) fertilization rate will be sufficient to maintain soil chemical features, fertility, and yields in monoculture maize cultivation in the no-tillage (NT) system versus the traditional plowing (PL) system. We also examined which tillage system (PL, NT) allows the reduction of fertilization while maintaining good yields of the tested soils. Two fields (10 ha each) were established for PL and NT maize cultivation, and soils (0–20 cm) were sampled twice per year—before maize sowing and after maize harvesting. A broad range of chemical and biological parameters were monitored (i.e., pH, forms of nitrogen, phosphorus and carbon, content of selected macronutrients and humic substances, and respiration activity). It was concluded that the 20% reduction in N fertilization (after 4 years of use) did not have an adverse effect on the soil’s chemical and biological features, which mainly depended on the season of the year. The maize yield seemed to be higher in the PL system, which was mostly the result of the tillage system rather than the N dose. The study will be continued in the next vegetation season to further verify our findings, especially with regard to the maize tillage system and yields.