The impact of mineral and organic fertilizers on potato yield, quantitative and qualitative indicators, and functional value

Background: Potatoes are a crucial component of the human diet, often referred to as the "second bread." The food security and safety of a country are significantly influenced by the volume of potato production, highlighting its strategic importance. As a staple crop worldwide, the potato is not only a versatile and delicious food, but also a rich source of nutrients and bioactive compounds, positioning it as a functional food with the potential to improve health and aid in the prevention and management of various chronic diseases. As potato cultivation technologies progress, it is important to select appropriate fertilizers, as these can significantly impact tuber quality and their status as a functional food. The potential accumulation of harmful compounds in potato tubers poses risks to consumer health, making careful fertilizer selection essential. Objective: The objective of this research is to assess the impact of both mineral and organic fertilizers on the quantitative and qualitative parameters of potato tubers, with the aim of evaluating their potential as a raw material for functional food production. Methods: Investigations were conducted from 2021 to 2023 in the Stepanavan community of the Lori region, Republic of Armenia, using mineral (ammonium nitrate) and various organic fertilizers (Sugar Transfer, Humate, Biohumus, and Organomix). The experiments followed a randomized complete block design comprising 5 variants and 4 replications. Each experimental plot covered an area of 25 m². During the vegetation period, phenological observations were carried out, and the effects of the applied nitrogen and organic fertilizers on the growth capacity of the above-ground organs, crop yield, and quality indicators of tubers were measured. The chemical composition and functional value of the tubers were determined and evaluated by laboratory analysis in the state-certified FDI laboratory. Results: The findings from three-year studies revealed that the utilization of organic fertilizers not only enhances tuber yield but also increases dry matter and starch content, while significantly reducing the accumulation of residual nitrogen in the tuber's chemical composition. Among the tested organic fertilizers, Biohumus exhibited remarkable performance, yielding 41.9 t ha⁻¹ and producing high-quality tubers with a residual nitrogen content of 57.4 mg kg⁻¹, which is 2.6 mg kg⁻¹ below the specified permissible norm. In contrast, the application of ammonium nitrate resulted in a slightly higher tuber yield of 42.6 t ha⁻¹, however the residual nitrogen content was 72.7 mg kg⁻¹, exceeding the specified permissible norm by 12.7 mg kg⁻¹. Therefore, it is recommended to apply Biohumus into the furrow during potato planting. Additionally, foliar nutrition with a 0.2% solution should be provided at the beginning of the first soil loosening and during the blooming stage (how does the study support this result?). Conclusion: The utilization of organic fertilizers, particularly Biohumus, in potato cultivation emerges as a promising technology for sustainable agriculture. It offers the potential to achieve high yields of tubers with elevated functional and nutritional value, while also mitigating the risk of residual nitrogen accumulation in the tubers. Keywords: Potato, organic and mineral fertilizers, yield, functional and nutritional value residual nitrogen