Soybean is a valuable protein and oilseed crop ranked among the most significant of the major crops. Field experiments were carried out in 2016–2019 in South-East Poland. The influence of soybean cultivars (Aldana, Annushka), nitrogen fertilizer (0, 30, 60 kg∙ha⁻¹ N) and inoculation with B. japonicum (control, HiStick^® Soy, Nitragina) on the content of fatty acids (FA) in soybean seeds was investigated in a three-factorial experiment. This study confirms the genetic determinants of fatty acid composition in soybean seeds and their differential accumulation levels for C16:0, C16:1, C18:1n9, C18:2, C18:3, and C20:0 as well saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids. Increasing the rate from 30 to 60 kg ha⁻¹ N did not produce the expected changes, suggesting the use of only a “starter” rate of 30 kg ha⁻¹ N. Inoculation of soybean seeds with a strain of Bradyrhizobium japonicum (HiStick^® Soy, BASF, Littlehampton, UK and Nitragina, Institute of Soil Science and Plant Cultivation–State Research Institute, Puławy, Poland) is recommended as it will cause a decrease in SFA and C16:0 acid levels. This is considered nutritionally beneficial as its contribution to total fatty acids determines the hypercholesterolemic index, and it is the third most accumulated fatty acid in soybean seeds. The interaction of cultivars and inoculation formulation on fatty acid content of soybean seeds was demonstrated. An increase in the value of C16:0 content resulted in a decrease in the accumulation of C18:1, C18:2, and C18:3 acids. The content of each decreased by almost one unit for every 1% increase in C16:0 content. The dominant effect of weather conditions on the FA profile and C18:2n6/C18:3n3 ratio was demonstrated. This suggests a need for further evaluation of the genetic progress of soybean cultivars with respect to fatty acid composition and content under varying habitat conditions.

Soybean is a thermophilic and photophilic plant very sensitive to weather course during the vegetation period. This trait limits soybean cultivation in higher latitude countries. This field study aimed to evaluate the effects of three sowing dates on the development, the duration of vegetative and generative stages, and the yield of two soybean cultivars (Lissabon and Merlin) under conditions in south-western Poland in the years 2016–2019. The sowing date determines the temperature and the day length available for soybean plants, influencing development and yield. Delaying the sowing date by 20 days in relation to the earliest (16–21.04) resulted in the shortening of the length of the vegetative development by 12 days and the shortening of the entire vegetation period by 14 days. The delayed sowing date (06–19.05) under the conditions of south-western Poland (Lower Silesia) contributed to a significant decrease in yield. Lissabon produced greater soybean yield than Merlin. Special attention should be paid to proper seed sowing dates in soybean agriculture practice. It is necessary to breed soybean genotypes adapted to day length and thermal conditions of the cultivation area to achieve the maximum seed yield.

Faba beans are considered to be one of the most important leguminous crops. The species is characterized by high nutritional value, in terms of both energy and protein content, which makes it suitable for food and feed production. Fungal diseases are among the key biotic factors responsible for a decline in faba bean yields. In this study, the yield and health status of faba bean seeds from the region of Warmia and Mazury (WM) and the region of Lower Silesia (LS), in Poland, were determined. Correlations between weather conditions vs. the yield of faba bean seeds and the occurrence of saprophytic and pathogenic fungi were analyzed. The study revealed that temperature and precipitation influenced the development and yield of faba beans in successive growth stages. Temperature exerted the greatest effect on the yield of faba beans during inflorescence emergence (BBCH 55-Biologische Bundesanstalt, Bundessortenamt and CHemical Industry), whereas the effect of precipitation was the maximum at the 4–5 leaves unfolded stage (BBCH 34–35) and at the end of flowering (BBCH 69). The occurrence of saprophytic, pathogenic, and toxin-producing fungi was influenced by temperature and precipitation in the flowering stage (BBCH 61–64).

Fertilisation has a significant impact not only on the yielding, but also on the quality of the harvested biomass. Among energy crops, Miscanthus × giganteus are some of the most important plants used for combustion process. The chemical composition of biomass has significant impact on the quality of combustion biomass. The effect of nitrogen fertilisation (with dose of 60 kg N ha⁻¹) in different terms of biomass sampling on the content and uptake of crude ash, potassium, calcium and sulphur by rhizomes, stems, leaves and the aboveground part of miscanthus was evaluated in the paper. Nitrogen fertilisation contributed to the increase of ash content in the rhizomes and the aboveground part of plants. Independently of nitrogen fertilisation potassium content decreased in the whole vegetation period; in the case of stems this decrease amounted 60%. Calcium content in various parts of plants was highly differentiated compared to potassium content. Average calcium content in the aboveground parts was 2.68 higher compared to rhizomes. Nitrogen fertilisation affected significantly on potassium, calcium and sulphur uptake in all examined parts of plants (except stems in the case of calcium uptake). Uptake of crude ash under nitrogen fertilisation was significantly higher in all examined parts of plants during the whole vegetation period.

Sowing depth and density are factors which affect development and yielding due to their influence on plants’ competition for water, light and nutrients. The aim of the present research was to evaluate the effect of sowing depth (5 and 8 cm) and density (45, 60, 75 seeds m²) on the development and yield of two morphotypes of faba bean. Higher plants were found at 8 cm sowing depth in 2011 and 2013, in turn, plant density before harvest, at 5 cm in 2011 and 8 cm in 2013. The greatest seed yield was observed while sowing shallower in 2011 (4.50 t ha⁻¹) and 2012 (6.62 t ha⁻¹), and deeper in 2013 (3.53 t ha⁻¹). Cultivar played in important role in shaping plant height and seed yield in all years of the experiment, as well as in straw yield in 2012. Bobas characterized by the greatest seed productivity in all years of experiment compared to Granit, as well as quantity of straw yield in 2011 and 2012 (3.51 and 4.88 t ha⁻¹, respectively) and therefore can be recommended for cultivation. Taking into account plant density before harvest in 2011–2013 as well as straw yield in 2011 and 2013, the most favorable sowing density is 75 seeds per m².

Faba beans (Vicia faba L.) are a high-protein legume crop that can be widely cultivated in most climates in Europe. The amino acid composition of the faba bean protein is also beneficial for monogastric animals since it contains a great deal of lysine, an amino acid that is deficient in cereals. Two genotypes of faba beans were cultivated at three sowing densities (45, 60 and 75 seeds per m²) during three growing seasons (years 2013–2015). The aim of the research was to assess accumulation of nutrients (N, P, K, Ca and Mg) of two faba beans in seeds and straw under different sowing densities. A field experiment was conducted in 2013–2015 at fields of Wroclaw University of Environmental and Life Sciences in southwestern Poland from which plant material was used for chemical analysis in terms of determining the accumulation of the following elements—N, P, Mg, K and Ca—in the seeds and straw. The results showed that the genotypes of the faba bean varied greatly in accumulation of nutrients in various sowing densities and in following years of research. However, the average accumulation of nitrogen, calcium and magnesium in seeds for three years (2013–2015) was significantly higher in the Bobas cultivar under 60 seeds per m² as well as in both tested cultivars using 75 seeds per m². Accumulation of potassium and phosphorus in seeds was highest in both analyzed cultivars using 60 and 75 seeds per m² (average for 2013–2015). Considering accumulation of elements in the straw of faba bean, it is shown that the concentration of potassium and calcium was the highest in both tested cultivars under the effect of sowing density at 60 and 75 seeds per m² while the concentration of nitrogen, phosphorus and magnesium did not differ significantly as an effect of the interaction of cultivar and sowing date (average for 2013–2015). Weather conditions played an important role in accumulation of nutrients of both faba bean genotypes in the years of research (2013–2015).