Improvement of crop cultivation technologies is focused on increasing crop productivity and improving yield quality, and at the same time on minimizing risks posed to the natural environment. The use of biostimulants contributes to the increase in the productivity of plants, especially under their exposure to stress induced by negative environmental stimuli. A field experiment was conducted in three growing seasons (2014–2016). Seeds of soybean of the Atlanta cultivar were sown in the third decade of April. Two synthetic biostimulants were used in the growing period in the form of single (stage BBCH 13-15) or double (stage BBCH 13-15, BBCH 61) spraying: Atonik (in concentrations of 0.1 and 0.2%) and Tytanit (in concentrations of 0.07 and 0.13%). Atonik, the first tested biostimulant, contained three phenolic compounds: sodium p-nitrophenolate, sodium o-nitrophenolate, and sodium 5-nitroguaiacolate. The Tytanit preparation contained a titanium complex, magnesium oxide, and sulfur (VI) oxide. This work presents a complex study addressing the action of the biostimulants Atonik and Tytanit and demonstrates their effect on the physiological traits, plant productivity, and seed yield quality of Glycine max L. The conducted experiment proved that the biostimulant type, as well as the number of its applications and its concentration, modified the biometric traits, crop productivity, as well as yield quality and the nutraceutical and antioxidative potential of soybean seeds. It was also found that by positively affecting plant growth and seed yield, the Atonik and Tytanit also resulted biostimulants decreased the protein and lipid contents in seeds. A double application of these preparations in their higher concentrations had a more positive impact on soybean seed number and soybean seed yield. The use of both Atonik and Tytanit resulted also in an increased antioxidative activity of soybean seeds. The greatest increase in this activity was observed after the application of the Tytanit preparation. Dietary fiber fraction analysis demonstrated an increase in the acid-detergent fiber, lignin, and cellulose contents in soybean seeds as a result of biostimulant application; however, the increase was greater upon the use of Tytanit. In contrast, the neutral-detergent fiber, cellulose, and hemicellulose contents were observed to decrease in all analyzed combinations of crops treated with the tested preparations.

In recent years, attempts have been made to use preparations that allow obtaining high and good quality yields, while reducing the application of pesticides and mineral fertilizers. These include biostimulants that are safe for the natural environment and contribute to the improvement of yield size and quality, especially after the occurrence of stressors. Their use is advisable in the case of crops sensitive to such biotic stress factors like low temperatures or drought. One of these is soybean which is a very important plant from the economic viewpoint. Field experiments were established in the years 2014-2016 in a random block design in four replicates on experimental plots of 10 m². Three soybean cultivars: Annushka, Mavka, and Atlanta were planted in the third decade of April. Fylloton biostimulant was used at 0.7% or 1% concentrations as single spraying (BBCH 13-15) or double spraying (BBCH 13-15, BBCH 61) in the vegetation period. The number of seeds per 1 m², seed yield, thousand seed weight, number of pods per plant, number of nodes in the main shoot, height of plants, and protein and fat contents in seeds were determined. The content of phenolic compounds, antioxidant capacity and antioxidant effect of soybean seeds were assayed as well. Foliar treatment of soybean with Fylloton stimulated the growth and yield of plants without compromising their nutritional and nutraceutical properties. The double application of the higher concentration of Fylloton was favorable for the plant height, seed number and soybean yield. Moreover, the highest number of pods was obtained after single treatment of plants with the lower biostimulant concentration. There was also a positive effect of using this biostimulant on the content and activity of some bioactive compounds, such as phenolics and flavonoids, and on the reducing power.

An experiment was conducted to investigate into the effects of Ecklonia maxima extract (Kelpak SL) on yield, protein and ash contents of two bean cultivars. The study was carried out in 2012 - 2014 in Poland. During the growing season, 0.2% and 0.4% solutions of the bio-stimulant were applied by single and double spraying of plants against a control. The highest number and weight of grains were found when the plants of ‘Toska’ cultivar were single sprayed with 0.2% seaweed extract. Double spraying the plants with the 0.4% solution of Kelpak SL increased the number, its weight and the number of pods in cultivar ‘Aura’. The application of Kelpak SL increased protein content of grains in both bean cultivars. Higher the dose the double foliar application of the bio-stimulant, more was the ash content of the grain of plants of ‘Toska’ cultivar.

Biodiesel has become more attractive material for its properties such as biodegradability, renewability and very low toxicity of its combustion products. A higher quality of this fuel is essential in its potential commercialization. Analytical methods used in biodiesel analysis are constantly refined. The most popular analytical techniques include chromatography and molecular spectroscopy. The ATR-FTIR spectroscopy is one of the most important methods of spectroscopy. This paper presents the results of studies on selected oils of natural origin using ATR-FTIR infrared absorption spectroscopy. Three types of oils from pumpkin seeds and winter rapeseed were analysed. The main fatty acids were also determined in all the samples.

The content of heavy metals in soil should be continuously monitored, especially in organic crops. Exceeding the permissible concentrations of these elements may lead not only to inhibition of plant growth but also to ingestion into the organisms of animals that feed on these plants. Heavy metals usually enter the soil via precipitation or manure. There is a noticeable increase in interest in digestate for fields fertilization. Therefore, the authors decided to test the heavy metal content in substrates (slurry and solid input) and digestate. The 15x3 samples tested showed that only trace amounts of heavy metals were present. The study shows that the content of these elements in the digestate is not the sum of the elements supplied to the digester with the substrates. In most of the samples tested, lead concentrations did not exceed 5 mg‧kg ⁻¹ . The lowest amounts of cadmium (an average of 0.28 mg‧kg ⁻¹ ) were observed in the slurry, and the highest (an average of 0.34 mg‧kg ⁻¹ ) in the solid substrate fed to the digester. Slurry had the lowest mercury and cadmium contents (average 0.012 mg‧kg ⁻¹ and 5.8 mg‧kg ⁻¹ ). The highest concentration of chromium was registered in the digestate (average 3 mg‧kg ⁻¹ ) and this was on average 0.3 mg‧kg ⁻¹ higher than the feedstock and 0.5 mg‧kg ⁻¹ than the slurry

The operation of an agricultural biogas plant is associated with the formation of a large amount of digestate. The basic trend in digestate management, after taking into account its physicochemical properties, should be its use as a fertilizer. The possibility of the agricultural use of digestate as a fertilizer was determined. Digestate obtained from the agricultural biogas plant was tested for the content of macronutrients and heavy metals. The content of macronutrients was also determined in soil for winter rape cultivation. The analysis showed an increase in the yield depending on the digestate dose applied. In addition, an increase in the fat and protein content was found in winter rape seeds. The best results of mean values were obtained during the application of the 50,000 L ha⁻¹ dose. The average diameter of the stem base was 1.48 cm. The average height was 36.20 cm. The seed yield was 3.44 t ha⁻¹. The thousand seed weight was—5.34 g. The fat and protein contents were 43.62% and 22.95%, respectively. By applying a digestate dose of 50,000 L ha⁻¹, the highest content of macronutrients, as well as polyunsaturated fatty acids (PUFA) (31.17%), monounsaturated fatty acids (MUFA) (61.89%) and saturated fatty acids (SFA) (6.87%), was recorded.