This paper analyses the effects of soil and foliar fertilization with sodium selenate (VI) on the selenium content in spring wheat grain. The research was carried out at the Departmental Experimental Station of the Institute of Agriculture WULS in Skierniewice in 2018 and 2019. The dose of selenium used was 5.00 g Se·ha⁻¹ in various development stages of spring wheat. The results showed that selenium fertilisation did not affect the size of the grain yield, but both soil and foliar fertilisation significantly increased the content of selenium in wheat grain compared to the control group. The highest Se content was obtained with the method of soil fertilisation combined with the foliar application with a total dose of 10.00 g·ha^-1 Se in the stem elongation phase (S + F2), and in the tillering and stem elongation phase (S + F1 + F2), which resulted in the values of 0.615 and 0.719 mg·kg⁻¹ Se in grain, respectively. On this basis, it was concluded that the best time to carry out foliar fertilisation treatment is in the stem elongation phase (BBCH 30–39). The results show that the greatest increase in selenium content in the grain is achieved with soil and foliar fertilisation combined.

Selenium is a micronutrient that is important for the proper functioning of the body. The research presented in this paper investigated the impact of various methods of selenium fertilization at various stages of plant growth on its content in grain and the quality properties of spring wheat (Triticum aestivum L.). Selenium fertilization did not affect the grain yield; however, it increased the selenium content in the grain. The research results showed that the accumulation of Se depends not only on the dose of the fertilizer but also on the stage of plant growth when the element is introduced. The most effective method of fertilization proved to be seed treatment and soil application combined with the foliar application at the tillering and stem elongation stages (G + S + F1-2), as well as at the stem elongation stage alone (G + S + F2). In terms of quality characteristics, the impact of selenium fertilization was observed only in the case of the falling number and the total protein content; all the parameters allowed for the grain to be classified as suitable for bread-making. Selenium fertilization can be considered as a safe way of increasing the Se content in spring wheat, which may contribute to an increase in the technological quality of the grain and its nutritional value.

Selenium (Se) is a micronutrient that is insufficiently present in the human diet. Increasing its content in food through appropriately matched agricultural practices may contribute to reducing Se deficit in humans. The study covered the effect of grain, soil, as well as grain and soil fertilization with selenium combined with foliar application at different stages of spring wheat (Triticum aestivum L.) development. The fertilization involved the application of sodium selenate. Fertilization with selenium had no significant effect on the grain yield. Grain application, soil application, and grain and soil application combined with foliar application at particular development stages of the plant significantly contributed to an increase in selenium content in grain. The study showed that the accumulation of selenium in spring wheat depends on the type of fertilization and term of its application. The best method of introducing selenium into the plant is grain and soil fertilization combined with foliar application at the stage of tillering and stem elongation (G + S + F1-2) for which the highest selenium content was obtained (0.696 mg·kg⁻¹ Se). The applied biofortification methods contributed to the increase in selenium in the grain of spring wheat.