Effect of Drip Fertigation with Nitrogen Application on Bioactive Compounds and the Nutritional Value of Potato Tubers before and after Their Long-Term Storage

Abstract

The nutritional value and the content of bioactive compounds in potato tubers are influenced by many soil, climate and agrotechnical factors. This study investigated the effect of drip irrigation and nitrogen fertilization by broadcasting and fertigation on the content of dry matter, starch, monosaccharides, total sugars, vitamin C, polyphenolic compounds, chlorogenic acid and antioxidant activity in tubers of “Augusta” potatoes. Additionally, the magnitude of the changes in the tested components during their long-term storage (6 months) was also assessed. Drip irrigation had a significant positive effect on the content of dry matter, starch, vitamin C, monosaccharides, sucrose, total sugars, total polyphenols, chlorogenic acid and antioxidant capacity. Compared to broadcasting fertilization, fertigation significantly increased the content of vitamin C, total polyphenols and chlorogenic acid, as well as the antioxidant activity of potato tubers. Long-term storage contributed to a decrease in the tested components. The exception was the content of monosaccharides, where a more than twofold increase was noted, especially in the case of irrigated tubers. The results of the research showed a beneficial effect of drip irrigation and fertigation on the content of bioactive compounds and the nutritional value of “Augusta” potato tubers.