The practice of cultivating crops in a controlled environment using a soilless culture method is seeing an increasing level of popularity. The aforementioned challenges include addressing climate change, combating pests and diseases, mitigating falling soil fertility, and ensuring constant production and quality. One of the potential crops that could be grown with such a method is soybean. Soybean cultivation in a controlled environment using soilless culture still needs more information, especially regarding nutrient solution management of certain soybean varieties. Thus, this study investigated the impact of nutrient concentrations and variety on soybean growth, yield, and chemical composition. This research was carried out in a plant growth chamber using expanded clay aggregate as a soilless substrate. The treatments were four nutrient concentrations: 0% (control), 50%, 100%, and 150%, and two different varieties: Martina and Johanna. The findings of this research revealed that there were significant differences in nutrient treatments on all parameters measured. Application of nutrient concentration at 50% resulted in the most profound root size for both varieties. Applying 100% nutrient concentration produced a higher 100-grain weight for the Johanna variety. Application of nutrient concentration at 150% resulted in the highest shoot weight and shoot:root ratio for both varieties, with varietal differences. Furthermore, applying nutrient concentration at 150% also produced the highest grain yield/pot, protein yield, and lipid yield for both varieties. Thus, the nutrient concentration between 100% and 150% gave a positive effect and can be applied for planting Martina and Johanna using this system.

The future of wheat production depends on our ability to adapt to changing growing conditions. It is expected that intercropping will be more emphasized where natural source of nitrogen may increase the resilience of cereals. Our investigation was made in two growing seasons (2020–2021, 2021–2022) with three winter wheat varieties (GK Szilárd, Cellule, GK Csillag) and a winter pea variety (Aviron) in Szeged-Öthalom. Each plot was 10 square meters in four repeats in randomized block design. We used a seed mixture of both species with three sowing densities. In this study, we represent a development process of two winter-sown species, then yield components evaluated by cumulative yield production analysis and multivariate regression. Mixtures were only beneficial for wheat in the case of GK Szilárd 50% and Aviron 75%, Cellule 75% and Aviron 100% (in 2021), Cellule 100% and Aviron 50% (in 2022), GK Csillag 75% and Aviron 50%. The yield was determined by the number and weight of grains in both species (and also number of pea pods). Knowledge of the development process of the companion plants is a key issue in creating an effective intercrop. This self-sustaining, low input and energy efficient cropping practice has a great potential in temperate areas.

Soilless cultivation systems in a controlled environment are increasingly being used due to several global issues such as climate change, pest and disease problems, declining soil fertility quality and limited agricultural land. Soybean is one of the potential crops that can be grown using the soilless planting system in a controlled environment. Therefore, a study was conducted to investigate the effect of nutrient concentrations on the early development of two soybean varieties. Four different nutrient concentrations (0%, 50%, 100% and 150%) were applied, and two soybean varieties (Martina and Johanna) were tested. This study was designed in a split-plot experimental design where the nutrient concentration was the main plot and the variety was the sub-plot. The data record was started after fertilization. The plant growth data were collected for five weeks. All the data were analyzed statistically using SPSS V.23 software. The results of the study found that the nutrient concentration affected the number of leaves and leaf area. The number of leaves was higher in the treatment using 100% and 150% nutrients. Meanwhile, the leaf area increased with increasing nutrient concentration from 0% to 150%. The nutrient concentration then interacted with the variety in influencing the plant height. The plant height of the Martina variety was higher than the Johanna variety when 0% and 100% nutrients were applied. The variety also affected the leaf area and interacted with the number of weeks in affecting the SPAD readings and number of leaves. Thus, the two tested varieties (Johanna and Martina) have distinct early growth patterns that differ from one another as affected by the nutrient concentrations and plant age (number of weeks).

This research examined the effectiveness of zinc foliar fertilizers. Two winter wheat varieties, GK Pilis and Zvezdana, were tested in a Zn-limited meadow chernozem soil. Crop yields and chlorophyll concentrations of the leaves were examined in the growing seasons of 2020/2021 of favorable weather conditions and 2021/2022 of drought weather conditions. In the experiment, three treatments were carried out with monozinc foliar fertilizer of a concentrated 12% (w/v) zinc sulfate heptahydrate solution, and the fourth plot was designed as the untreated control. The first monozinc treatment was applied at a dose of 1 L ha⁻¹ and the second monozinc treatment at a dose of 2 L ha⁻¹. These treatments were applied at tillering (BBCH 21–22). The third monozinc treatment was applied at a dose of 1 L ha⁻¹ at tillering and flag leaf emergence (BBCH 21–22, BBCH 37). Samples were taken several times in the vegetation period, and measurements were made using different methods (SPAD, determination of total chlorophyll concentration from acetone solution) before and after Zn treatments. In 2020/2021 of favorable weather conditions, the yield of Zvezdana was 5.47 t ha⁻¹ and that of Gk Pilis was 6.11 t ha⁻¹, compared to 2021/2022 of drought weather conditions, in which year the yield of Zvezdana was 3.14 t ha⁻¹ and that of Gk Pilis was 2.79 t ha⁻¹. Yields of both varieties increased with increasing NPK nutrient doses. In 2021/2022, even at nutrient level D (NPK basal fertilizer and two-times N topdressing), we harvested on average twice as much as in 2020/2021 at nutrient level A (N basal fertilizer and once N topdressing). No significant effects were found between the foliar fertilizers in 2020/2021. In 2021/2022, Zn treatments, mainly at four nutrient levels tended to increase the yields of both varieties. The first treatment resulted in a grain yield reduction of 3% for GK Pilis, and the second treatment resulted in a grain yield reduction of 1.2% for Zvezdana. After the second and third treatments, grain yield reductions were 0.1%–0.5%. Although there was no significant difference in terms of the main averages, foliar fertilizer was found to be effective in the second year. The relationship between chlorophyll and grain yield was found to depend on the year and variety. A weak correlation (r = 0.33, p < 0.05) was found between the total chlorophyll concentration in leaves for Zvezdana in 2021, and a medium correlation for GK Pilis (r = 0.67, p < 0.05). Concerning grain yield and chlorophyll concentration, a strong correlation (r = 0.81, p < 0.05) was found for Zvezdana in 2022, and a weak correlation (r = 0.44, p < 0.05) for GK Pilis. A strong correlation was found between the total leaf chlorophyll concentration and SPAD index in both years (r = 0.81, p < 0.05)

Light and nutrient availability are critical factors of plant growth and development, particularly at the early stages, where they significantly influence the establishment and survival of young seedlings. The morphological parameters and the biomass accumulation of soybean were measured in a hydroponic vertical farm in the first 14 days of seedling growth in two successive experiments under two types of lighting environments and at three nutrient concentration levels. The lighting conditions were set by two parallel variable-spectrum linear luminaires positioned above the lower and upper edges of the cultivation trays. In the first lighting environment, seedlings were exposed to a constant photosynthetic photon flux density (PPFD) with red and blue photon irradiance ratio (R/B) varying in broad range from the lower to the upper end of the cultivation trays. In the second environment, the spatial R/B distribution was uniform, and the PPFD varied between two maxima at the edges and a minimum in the middle of the trays. The R/B ratio within the 0.6–6 interval had little or no effect on plant development. We report the dependence of growth traits as a function of PPFD in the range of 30–290 µmol m⁻² s⁻¹ in full-strength, half-strength, and blank nutrient solutions. The light response for shoot height and the first internode length was mainly influenced by blue light. We observed a rapid decline in growth between 6–20 µmol m⁻² s⁻¹ blue photon irradiance. The shoot height and first internode length did not change significantly at higher blue light intensities. The lengths of the first internode and the root dry mass did depend on the nutrient solution strength. All other growth traits, including stem diameter, leaf size, shoot mass, root mass, and SPAD readings, showed a linear correlation with PPFD and electrical conductivity. The leaf mass and root mass ratios indicated that soybeans adopt a nutrient search strategy by giving preference for root growth while increasing shoot height at the expense of the shoot diameter in conditions of low nutrient availability and low light intensity. The functional relationships determined in the experiments provide valuable inputs to plant growth models. The methodology we employed could also be used to study other plant species and to investigate the interactive effects of specific nutrients and lighting conditions.

Light and nutrient availability are critical factors of plant growth and development, particularly at the early stages, where they significantly influence the establishment and survival of young seed-lings. The morphological parameters and the biomass accumulation of soybean were measured in a hydroponic vertical farm in the first 14 days of seedling growth in two successive experiments under two types of lighting environments and at three nutrient concentration levels. The lighting condi-tions were set by two parallel variable-spectrum linear luminaires positioned above the lower and upper edges of the cultivation trays. In the first lighting environment, seedlings were exposed to a constant photosynthetic photon flux density (PPFD) with red and blue photon irradiance ratio (R/B) varying in broad range from the lower to the upper end of the cultivation trays. In the second en-vironment, the spatial R/B distribution was uniform, and the PPFD varied between two maxima at the edges and a minimum in the middle of the trays. The R/B ratio within the 0.6-6 interval had little or no effect on plant development. We report the dependence of growth traits as a function of PPFD in the range of 30-290 µmol m⁻² s⁻¹ in full-strength, half-strength, and blank nutrient solutions. The light response for shoot height and the first internode length was mainly influenced by blue light. We observed a rapid decline in growth between 6-20 µmol m⁻² s⁻¹ blue photon irradiance. The shoot height and first internode length did not change significantly at higher blue light intensities. The lengths of the first internode and the root dry mass did depend on the nutrient solution strength. All other growth traits, including stem diameter, leaf size, shoot mass, root mass, and SPAD readings, showed a linear correlation with PPFD and electrical conductivity. The leaf mass and root mass ratios indicated that soybeans adopt a nutrient search strategy by giving preference for root growth while increasing shoot height at the expense of the shoot diameter in conditions of low nutrient availability and low light intensity. The functional relationships determined in the experiments provide valuable inputs to plant growth models. The methodology we employed could also be used to study other plant species and to investigate the interactive effects of specific nutrients and lighting conditions.