## 4 Discussion  
This study gives a comprehensive view of Zn and Se biofortification in different soybean genotypes. The accumulation of macro- and microelements differs among the biofortification treatments and soybean varieties, as well as their removal by the plant. Nutrient removal with harvest is an important factor of sustainability nutrient management strategies of the production systems [61; 62; 63; 64]. In this study, the differences in nutrient status in the soybean grain were more expressed among varieties than among biofortification treatments (Figure 1). [PERSON] et al. [65] found that newer Brazilian soybean genotypes increased nutrient removal with 11.1, 26.9, 45.0, and 31.6% for N, P, K, and Mg, respectively, removed compared to those grown in the past. Moreover, the authors stated that P showed the removal of 4.95 kg/t, and K of 20.6 kg/t of soybean grain yield. The breeding programs were more focused on maximizing the grain yield [66; 67], but nowadays, the genetic approach and transfer of the nutrients into the plant tissue should also be taken into consideration, which requires a new research approach [68]. Except for the genotype, [PERSON] et al. [55] stated that various factors, such as soil temperature, pH, microbiological activity, and moisture, influence the accumulation of the elements in plant organs. Even though plants can absorb large amounts of some nutrients, this may not increase their yield, but it can have a huge influence on the yield quality [69; 70; 71]. Nutrient removal is very important to adjust plant's needs for the nutrients added by the fertilizer and increase NUE. For three peanut (Leguminosae family) varieties, [PERSON] et al. [72] found the average nutrient removal by the pods followed the order P \(>\) N \(>\) K \(>\) S \(>\) Mg \(>\) Ca. With the meta-data analysis, [PERSON] et al. [73] showed differences in soybean grain micronutrient status over the years (1974-2019) in Brazil. The authors stated that the N content of the soybean grain increased by 1.1 kg for each tonne of seed yield and that Ca, Mg, and S were not affected by the seed yield. In the present study, the biofortification treatment decreases the content of P in the soybean seed (Figure 1a). [PERSON] et al. [74] reported that the physiological response of the P \(\times\) Zn interaction in plants remains poorly understood. Although both P and Zn are essential elements for plants, in certain circumstances, they can act antagonistically to each other, which can lead to a decrease in yield, either due to P or Zn deficiency [75]. Antagonism most often occurs when one of the elements is present in large quantities. Most often, Zn deficiency in plant tissues occurs with excessive P application, but P deficiency with excessive Zn application is also possible, although rarely. [PERSON] et al. [74] reported that for cotton plants, excessive P uptake reduces Zn shoot concentration and that Zn supply regulated acid phosphatase activity which facilitated adaptation responses to P deficiency. In this study, the biofortification Zn treatment significantly increases Mn content in the soybean grain (Figure 1a). Manganese has a favorable effect on the formation of nodules in soybeans and therefore, it is an important nutrient for soybeans. In the plants, Mn and Zn interact with each other, which can have a possible impact on the yield [75; 76; 77]. In sweet corn (_Zea mays_ var. _saccharata_), [PERSON] et al. [78] found Mn and Zn in the way that Zn content in the roots increases with increasing Mn levels, whereas increasing levels of Zn in the nutrient solution decreased Mn concentration in roots. [PERSON] et al. [79] reported that Zn and Mn foliar application helped with the absorption of N, P, and K.  
Higher concentrations of Zn and Se in the grain and vegetative mass confirm the effectiveness of the biofortification treatments. However, some of the genotypes were found to be superior to others.