The excessive use of mineral fertilizers causes many negative consequences for the environment as well as potentially dangerous effects of chemical residues in plant tissues on the health of human and animal consumers. Bio-fertilizers are formulations of beneficial microorganisms, which upon application can increase the availability of nutrients by their biological activity and help to improve soil health. Microbes involved in the formulation of bio-fertilizers not only mobilize N and P but mediate the process of producing crops and foods naturally. This method avoids the use of synthetic chemical fertilizers and genetically modified organisms to influence the growth of crops. In addition to their role in enhancing the growth of the plants, biofertilizers can act as biocontrol agents in the rhizosphere at the same time. Biofertilizers are very safe for human, animal and environment. The use of Azotobacter , Azospirillum , Pseudomonas , Acetobacter , Burkholderia , Bacillus , Paenibacillus and some members of the Enterobacteriaceae is gaining worldwide importance and acceptance and appears to be the trend for the future.

Study on potential mechanisms influencing the growth of raspberry and strawberry plants showed that the most active was Bacillus sp. strain AF75BC producing IAA and siderophores, and having the ability to release phosphorus. The latter feature was also present in the strains Sp115AD (B. subtilis) and SP116AC (Paenibacillus polymyxa). Two of the tested strains: SP116AC and JaFGU (Lysobacter sp.) showed the ability to fix atmospheric nitrogen, while the AF75AB2 (Bacillus sp.) produced siderophores and IAA. All strains showed an antagonism toward the most important pathogens of strawberry and raspberry, i.e. Verticillium dahliae, Botrytis cinerea, Phytophthora cactorum and Colletotrichum acutatum, limiting their growth to a different extent on the PDA medium. Inoculation of raspberry roots with the tested bacteria resulted in an increase of some growth parameters of their above-ground part in cv. Poemat. In the case of cv. Polana, a significant increase was found only in the chlorophyll content in the leaves. All the inoculants caused an increase in dry mass of roots in cv. Polana, and in cv. Poemat similar effect was observed after applying Inoculants 1 and 3. The treatments of strawberry roots with any of the inoculants resulted in a significant increase in the total leaf surface area in cv. Rumba, but they had no effect on the chlorophyll content in the leaves of either cultivar. All the inoculants significantly increased the total length of roots and their total surface area in cv. Rumba. This parameter also increased in cv. Elsanta, and the number of root tips also significantly increased in this cultivar. Our study showed that the tested inocula is a promising alternative as a bio-fertilizer for small fruit production in sustainable and organic agricultural systems.

Open Access Agricultural Journals published by Institute of Agricultural Economics and Information

A study conducted over three consecutive years examined the effects of using biochar, organic fertilizer and microorganisms on soil pH and the concentrations of macro and microelements in the soil. A tendency to increase soil pH was seen where biochar was used. The highest concentration of phosphorus was found in the soil after the application of organic fertilizer with the addition of microorganisms. The most potassium was found in the soil treated with biochar together with organic fertilizer, while the most magnesium was in the soil fertilized with organic fertilizer alone and organic fertilizer together with microorganisms. All the fertilization combinations resulted in an increase in boron and copper levels in the soil. The accumulation of iron in the soil was promoted by organic fertilization alone and organic fertilization together with microorganisms. The highest amount of manganese in the soil was found after fertilization with biochar together with organic fertilizer. In the combination where organic fertilizer was applied, the soil contained the most sodium, while the highest zinc content was found in the soil fertilized with biochar and organic fertilizer. The greatest increase in the carbon content in the soil occurred after the use of biochar together with microorganisms and biochar with organic fertilizer. The same treatments also resulted in the highest amount of organic matter. The study shows that the use of biochar, organic fertilization and the combined use of biochar and organic fertilization improved the quality of the soil.

In the years 2008–2015, field experiments were conducted on the vines of cultivars ‘Solaris’ and ‘Regent’ grafted on SO4 rootstock. The following treatments: 1. control (untreated), 2. NPK (mineral fertilization 70 kg N·ha⁻¹; 40 kg P·ha⁻¹; 120 kg K·ha⁻¹), 3. mycorrhizal substrate (AMF – Arbuscular Mycorrhizal Fungi), 4. NPK + AMF, 5. manure (before planting), 6. NPK + manure (before planting), 7. Bioilsa, 8. NPK + Bioilsa, 9. BF-Ecomix, 10. NPK + BF-Ecomix, 11. Ausma and 12. NPK + Ausma were applied to evaluate the usefulness of biostimulants and mineral and organic fertilizers in organic grapevine production in “cool climate” conditions of Poland. The tests did not show a definite positive effect of the biostimulants and organic fertilizers on growth, yielding and healthiness of the cultivars ‘Solaris’ and ‘Regent’. There were no substantial differences in total marketable yield in the years 2009 to 2015 between control and other treatments. Grapevines planted in soil rich in minerals grew and yielded well despite no mineral fertilization for a number of years. In 2014, when the air humidity was high during vegetation, intensive rotting of the berries of cultivar ‘Solaris’, caused byBotrytis cinerea, was observed on plants fertilized with NPK.