Grain yield and nutritional properties of buckwheat (Fagopyrum esculentum M.) grown with varying nitrogen doses and irrigation levels.

Buckwheat has gained high demand and popularity worldwide in recent years. There are very few studies on the combined use of irrigation and nitrogen applications for the plant. In this study, the effects of different nitrogen dose (0, 30, 60, 90 kg ha) and irrigation levels (50%, 75%, 100% of ETo value calculated with the use of evaporations from Class-A pan) applied via fertigation on water use, yield and grain nutritional properties in buckwheat were investigated. The study was carried out in 2020-2021 according to the randomized block design with 3 replications for two years. The highest grain yield was obtained with 100% irrigation level and 90 kg ha nitrogen dose. The increase in nitrogen doses caused significant increases in crop water productivity (CWP) and irrigation water productivity (IWP) values. Plant water consumption (ET) varied between 339 (I0×N50) - 617 (I100×N90) mm. Yield response factor (ky) was determined to be between 1.32 for N0 and 1.49 for N30 according to nitrogen doses, and it was determined that the buckwheat plant was sensitive to water stress. The concentrations of significant constituents, including protein, resistant starch, and fatty acids (oleic acid, linoleic acid), were augmented with elevated irrigation levels and nitrogen fertilization. In addition, mineral contents (Ca, Mg, Fe, Zn, P) increased significantly with increasing irrigation and nitrogen doses. As a result, 100% irrigation level and 90 kg ha nitrogen dose are recommended in buckwheat cultivation for optimum grain yield and nutrient content. It was determined that these applications provided the most suitable results in terms of both quality and yield.