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.

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).

Soybean (Glycine max [L.] Merr.) cultivation is expanding in Central Europe due to the development of early-maturing cultivars and growing demand for plant-based protein produced without the use of genetically modified organisms. However, nitrogen (N) management remains a major challenge in temperate climates, where variable weather conditions can significantly affect nodulation and yield. This study evaluated the effects of three nitrogen fertilisation doses (0, 30, and 60 kg N·ha⁻¹), applied in the form of ammonium nitrate (34% N) and two commercial rhizobial inoculants—HiStick Soy (containing Bradyrhizobium japonicum strain 532C) and Nitragina (including a Polish strain of B. japonicum)—on nodulation, nitrogen uptake, and seed yield. A three-year field experiment (2017–2019) was conducted in southwestern Poland using a two-factor randomized complete block design. Nodulation varied significantly across years, with the highest values recorded under favourable early-season moisture and reduced during drought. In the first year, inoculation with HiStick Soy significantly increased nodule number and seed yield compared to Nitragina and the uninoculated control. Nitrogen fertilisation consistently improved seed yield, although it had no significant effect on nodulation. The highest nitrogen use efficiency was observed with moderate nitrogen input (30 kg N·ha⁻¹) combined with inoculation. These findings highlight the importance of integrating effective rhizobial inoculants with optimized nitrogen fertilisation to improve soybean productivity and nitrogen efficiency under variable temperate climate conditions.

Faba bean is a high-protein legume that can be successfully grown in most climates around the world. It is one of the most popular pulses cultivated in Poland. Its seeds are a source of plant protein, used most often in feed production. Field experiments and laboratory seed analyses were carried out in 2022 and 2023 to assess the effect of the application of nitrogen-fixing bacteria on the yield and seed quality of a low-tannin faba bean cultivar. The factor was tested at four levels: control, seed inoculation with Rhizobium leguminosarum bv. viceae, foliar spraying with Methylobacterium symbioticum, and seed inoculation and spraying (double application). The application of N-fixing bacteria had a positive effect on faba bean seed yield. In 2022, plants responded most effectively to a double application, increasing seed yield by 25.4%, while, in 2023, the highest seed yield was obtained after inoculation (12.3% increase). Although the single application of bacteria caused a decrease in seed protein content, the double application (inoculation and spraying) significantly enhanced seed protein content. The protein productivity per hectare was compensated by the higher seed yield and increased by 41.7% in 2022 and 14.9% in 2023 compared to plots where N-fixing bacteria were not applied. This work shows that it is possible to use different strains of N-fixing bacteria in faba bean cultivation and this can significantly improve yields while reducing the need for synthetic nitrogen fertilizers, which supports sustainable production.

Soybean is the crop of the future, especially for countries with a high demand for food and feed protein. Therefore, soybean cultivation is moving north to countries at higher latitudes, where temperatures, photoperiodism, and rainfall distribution are not always able to meet soybean requirements. The aim of this study was to evaluate three sowing dates as a factor influencing soybean cultivars yield and seed chemical composition in agroclimatic conditions of south-western Poland. In the years 2016–2019, a field experiment was conducted in Lower Silesia region, near Wroclaw, with three sowing dates: early (mid-April), 10-day delayed (at the turn of April and May), and 20-day delayed (first half of May), and two soybean cultivars: Merlin and Lissabon. In this location, soybean sowing is recommended in mid-April, possibly at the turn of April and May. The cultivars tested differed in yield and yield component values in the years of research, but generally, the Lissabon was better suited to local conditions. Results were discussed with findings of other domestic research, to investigate the problem of the soybean sowing date in Poland. The recommended sowing date for soybean was found to vary from region to region. These differences are due to the length of the growing season in each location and the varied adaptation of cultivars to the local climatic conditions.