The effects of biogas fermented liquid waste on the production and mineral nutrition cucumber (Cucumis sativus) plant growed in greenhouse

Biogas plants are preferred for electricity generation in Turkey as well as all over the world. Organic wastes are used in biogas production. It is possible to use the wastes that arise naturally as a result of biogas production as organic material. In many plants, the slurry resulting from the process is separated into solid and liquid form by separators. Various studies are carried out in order to use these wastes as fertilizers and return them to the soil to contribute to the ecological balance and the economy in agriculture. In this study, biogas fermented liquid wastes obtained from two different biogas plants were applied to cucumber plants grown in greenhouses at 5 different doses (0, 2, 4, 6 and 8 tons da-1 ). The chemical fertilization needed by the plants was continued and the differences between the biogas fermented liquid waste doses were examined. Yield and quality differences between doses were evaluated by statistical analysis. According to the results of the research, it was determined that the application doses of material A (liquid fermented product: SFU) increased the plant height and wet weight parameters at the highest dose, and the N content increased in direct proportion with the increasing doses. While the Ca concentration of the leaves showed the highest value at 8 ton da-1 dose, the highest values for Zn and Cu were observed at 2 ton da-1 application. The highest value was observed in fruit yield at 8 ton da-1 dose. Although there were small increases in EC values in soil samples, it was determined that plant growth was not adversely affected. The maximum application dose (8 tons da-1 ) provided the highest values for P and K contents in the soils. The highest values of plant height and wet weight parameters of material B (liquid fermented product: SFU) application doses were observed in the 4 ton da-1 application. In the Zn content of the leaves, it was determined that the maximum Zn accumulation was achieved in 2, 4 and 6 tons da-1 applications. It has been revealed that 4 tons da-1 application is the most effective dose for yield, N, Zn and Mn contents in fruits. In the study in which the effects of different doses of fermented liquid wastes generated in biogas plants were observed, it was observed that dose increases did not have a linear effect on the investigated parameters. During the cultivation, only N-P-K fertilization was applied to the plants and other nutrients were not applied to reveal the performance of the waste material. In these conditions, it was revealed that there was a general increase in Zn contents, which is one of the microelements, and these levels did not reach toxicity levels. It is thought that the fermented liquid product produced in biogas plants has positive effects on some development parameters in agricultural areas, that agricultural practices can be taken as a basis in the disposal of these wastes, and that the use of liquid fermented wastes in soils after some processes can provide significant advantages.