The successful production of soybeans is largely dependent on the sowing time, because every sowing outside the optimal time contributes significantly to yield losses. This field study aimed to evaluate the effects of sowing time (optimal—April 5; late—April 27) on the quantitative and quality traits of three soybean genotypes (Galina—0 maturity group; Sava—I maturity group; and Rubin—II maturity group) under dryland conditions in Vojvodina Province (Serbia) during 2017 and 2018. The genotype Sava had higher yield in climatic-unfavorable 2017, while Rubin had a higher yield in climatic-favorable 2018. The yields significantly decreased when the soybeans were sown in late April due to reductions in the number of pods per plant, seed weight per plant, and 1000-seed weight. The reduction in yield components was likely due to the accelerated senescence of plants and the negative effect of high temperature and low precipitation during the seed filling stage. Accordingly, the various sowing times and properly chosen genotypes provide a better utilization of soil and water resources. A proper genotype selection and sowing time can contribute to a high yield. At the same time, the protein and oil contents can be altered by the sowing time, especially under water stress during the reproductive stage.

The main nitrogen (N) sources in soybean production originate from soil fixing bacteria Bradyrhizobium spp. and from mineralization of soil organic N. These sources of N are often not sufficient to cover the N needs of the soybean. The present two-year field study aimed to evaluate the effects of soybean genotypes (Valjevka and Galina) and rates of starter fertilizer N (0, 30, 60, and 90 kg ha −1 ) on quantitative and qualitative parameters and on rain use efficiency (RUE) under contrasting weather conditions in the Pannonian region of Serbia. A field study conducted during two different growing seasons: first year with unfavorable weather conditions and second year with favorable weather conditions. As expected, the quantitative parameters, oil content, and RUE were higher in the year with favorable growing season, the second one. According to measured parameters, the genotype Valjevka performed higher yield potential as compared to the genotype Galina. The highest values of quantitative parameters and RUE were recorded at 60 kg N ha −1 , protein content at 90 kg N ha −1 and oil content 0 kg N ha −1 (control). This study suggests that proper genotype selection and application of 60 kg N ha −1 as a starter dose with rhizobial inoculation could contribute to the high yield, while protein could be altered by N amount, independently on genotype.

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Maize silage is source of palatable and high-energy forage for ruminants. Therefore, production of high quality forage maize represents an essential strategy for stable production of milk and meat on livestock farms. This study examined the effect of harvest date (early dent, at half milk line, at three quarters milk line and black layer) on the quantitative and qualitative parameters of whole maize plant under contrasting climatic conditions in the Srem -Serbia. A 2 × 4 factorial (two years and the four cutting times) randomized blocks design was used, with three replications. The plant height, stem diameter, number of leaves per plant, forage yield, dry matter yield and dry matter content were higher in 2014 probably due to favorable weather conditions. With the delay of the harvest the forage yield, crude protein content, acid detergent fiber (ADF) and neutral detergent fiber (NDF) decreased, and dry matter yield, dry matter content and ear percentage increased. Sufficiently high dry matter content and ear percentage were achieved at the third harvest. However, the delay of harvested time reduces the quality parameters of the biomass, but this loss in the entire plant is moderated by grain filling.

The standard technology of seed processing uses mainly chemical products. Recent researches showed that toxic materials from chemical fertilizers can be harmful to humans, animals and the environment. Currently the attention of researches is shifting away from chemical fertlizers and toward alternative that consumers perceive to be natural, Plant Growth Promoting bacteria (PGP). PGP bacteria could be a way to reduce chemical fertilizer doses. This was the reason to test the ability of Bacillus megaterium, Azotobacter chroococcum to produce hormone auxin (IAA). Bacterial strains were identified by PCR amplification and sequencing of the 16S rRNA gene. Indole-3-acetic acid (IAA) was detected and quantified by MRM experiment. This study conducted that maize seed inoculation with IAA from species mentioned above showed positive effects. They had statistically significantly higher root and steam height compared to control seedlings. Bacterial strains tested in this study may be recommended as PGP (Plant Growth Promoting) bacteria, due to their positive effects and eventually can be used to reduce chemical fertilizers doses.