Search Results (45)

Biochar and algal extracts are promising organic soil amendments, but their synergistic effects on soil organic matter and the sorption complex are still insufficiently understood. Therefore, a 30-day laboratory incubation experiment was conducted using a Haplic Luvisol to evaluate the effects of biochar (S+B), an N-rich algal extract (S+AGN), and their combined application (S+AGN+B) in comparison with the untreated control soil (S). The results showed that biochar led to a substantial increase in soil organic carbon (Corg) by 49% in S+B and by 50% in S+AGN+B treatments compared to S. Labile carbon (C_L) increased by 48% in S+B and by 40% in S+AGN+B. The algal extract alone did not significantly affect either C_L or Corg. Non-labile carbon increased by 2.22 g kg⁻¹ in S+B but slightly decreased in the combined treatment (−2.00 g kg⁻¹), indicating different dynamics of stable carbon fractions when both amendments are applied simultaneously. The combined treatment S+AGN+B, however, had the strongest effect on soil sorption properties. Specifically, the sum of basic cations was the highest among all treatments (189 mmol(+)kg⁻¹, i.e., +18–28 mmol(+)kg⁻¹ compared to S, S+B, and S+AGN), while the cation exchange capacity (CEC) reached the highest values (198 mmol(+)kg⁻¹, representing an increase of 7–27 mmol(+)kg⁻¹ compared to the other treatments). The base saturation remained high across all treatments, and the highest value was observed in S+AGN+B (95.6%). PCA confirmed that the combined treatment produced the most pronounced shifts in the multivariate parameter space and demonstrated a synergistic effect exceeding the effects of the individual organic amendments. Overall, the results indicate that biochar is the dominant factor contributing to the accumulation of stable carbon and the improvement of CEC, whereas the algal extract enhances the accumulation of labile carbon fractions and synergistically promotes the saturation of the sorption complex. The combined application of biochar and algal N effectively increases soil organic matter and sorption capacity. Full article

The aim of this research was to determine the response of white mustard (Sinapis alba L.) cultivated in 2021–2022 in Lucim (53°23′06″ N 17°50′08″ E) in Poland to the soil nitrogen doses: N₄₀—40 kg N·ha⁻¹, N₆₀—60 kg N·ha⁻¹, N₈₀—(40 + 40)-80 kg N·ha⁻¹, as well as the method of its foliar application (0%—no foliar fertilization, 50%—half of the nitrogen dose and 75%—⅔ of the nitrogen dose). The effect of mustard cultivation on the activity of soil dehydrogenase, arylsulfatase, and rhodanese was examined. The highest white mustard seed yield was obtained after application of 80 kg N·ha⁻¹ (1.577, 1.597 Mg·ha⁻¹) and after application of Multi-N_50% (1.490, 1.515 Mg·ha⁻¹). Total nitrogen (50 g·kg⁻¹) content was highest in seeds from treatments fertilized with 80 kg N·ha⁻¹. Similar total nitrogen content in seeds was obtained using a 50% dose of foliar nitrogen. Increasing nitrogen doses resulted in a decrease in the crude fat yield in seeds. However, a significant increase in this nutrient content was observed after application of 50% foliar nitrogen. Soil nitrogen fertilization increased the enzymatic activity of dehydrogenases, particularly at the N80 dose. The activity of this enzyme was positively correlated with the obtained mustard seed yield, as well as with its quality measured by total phosphorus and crude fat content. Full article

Biochar has been widely recognized for its potential to improve soil quality and mitigate greenhouse gas (GHG) emissions. A field experiment was conducted in a temperate climate zone of Slovakia on Haplic Luvisol and evaluated the long-term impact of biochar on soil properties, nitrous oxide (N₂O) emissions, and winter wheat (Triticum aestivum L.) yield. Biochar was applied in 2014 at rates of 0, 10, and 20 t ha⁻¹ and reapplied in 2018 at the same rates, combined with nitrogen (N) fertilization (0, 140, and 210 kg N ha⁻¹). Measurements, conducted from March to October 2021, showed that biochar improved soil water content, increased soil pH, and enhanced soil organic carbon content. However, the concentrations of NH₄⁺-N and NO₃⁻-N generally decreased across all the treatments compared to their respective controls. Biochar reapplication rate at 20 t ha⁻¹, especially combined with second level of N-fertilization, led to a significant reduction in cumulative N₂O emissions by 38.40%. Winter wheat yield was positively correlated with both biochar application (10 and 20 t ha⁻¹) and N levels (140 and 210 kg N ha⁻¹), but these differences were not statistically significant (p > 0.05). The positive effects of biochar on soil properties and yield declined over time, with no significant yield differences observed 7 years after the initial application and 3 years after reapplication. These findings suggest that while biochar can enhance soil conditions and reduce GHG emissions in the short term, its long-term effectiveness remains uncertain. Further research is needed to explore alternative biochar feedstocks, application methods, and strategies to sustain its benefits in agricultural systems. Full article

Sustainable soil management through the use of an appropriate tillage system can positively change the edaphic parameters. The aim of the present study was to compare the effects that reduced tillage (RT) and conventional tillage (CT) systems have on changes in selected physical and chemical properties and enzymatic activity in various soil types. The study included the following soil types: Eutric Fluvisol, Mollic Fluvisol, Haplic Chernozem, Haplic Luvisol, Eutric Regosol, Eutric Gleysol, and Stagnic Planosol. Soil samples were collected in the Danubian Lowland and Eastern Slovak Lowland. The following parameters were determined in the soil samples: soil texture, pH, hydrolytic acidity and the sum of basic exchangeable cations, the contents of carbon (TOC), nitrogen (TN), and dissolved organic carbon (DOC), and the activities of dehydrogenases (DEH), catalase (CAT), peroxidases (PER), alkaline phosphatase (AlP), acid phosphatase (AcP), proteases, and β-glucosidase (BG). The reaction of the analysed soils, in the RT and CT cultivations alike, ranged from acidic to neutral, and the sorption properties differed between individual soil types. The TOC ranged from 16.53 to 42.07 g kg⁻¹ for conventional cultivation and from 15.51 to 38.90 g kg⁻¹ for reduced tillage. The values of enzymatic soil quality indices values correlated with TOC, DOC, and TN, as well as with pH, the sum of exchangeable base cations, cation exchange capacity, and degree of base saturation of the sorption complex. The tillage system determined changes in the activity of the studied enzymes, but the intensity and direction of these changes depended on the soil type. Based on the enzyme activity results, soil quality indices such as GMea and TEI were calculated. TEI proved to be a more sensitive indicator than GMea. It was shown that, of all studied soil types and regardless of the cultivation system, Eutric Gleyosols had the most variable properties. For conventional tillage, Haplic Luvisol and Eutric Regosol were characterised by the greatest uniformity. In general, the edaphic properties of soils under conventional tillage differed from those of soils under simplified tillage. Full article

Bioenergy production generates huge amounts of ash from biomass combustion. One of the attempts to utilize them is to use them in agriculture as fertilizers. The response to this challenge is a three-year field experiment (2018–2021) where the effect of fertilization with ash from forest biomass (approx. 70%) and agricultural biomass (approx. 30%), and soil type (Gleyic Chernozem and Haplic Luvisol), on the fatty acid (FA) profile of winter rape seeds (Brassica napus L. ssp. oleifera Metzg) was studied. Environmental factors modified the accumulation of fatty acids in winter oilseed rape seeds to the greatest extent and included all labelled unsaturated and saturated fatty acids from C12:0 to C24:0, with exceptions. In warm and dry years, C18:1n9c, C18:2n9c and C18:3n6 accumulated more, while cooler and humid years promoted an increase in the content of, among others, C20:2, C24:1, C18:3n3, C20:4 and C22:2. Cultivation of plants in Gleyic Chernozem soil promoted the accumulation of unsaturated fatty acids C18:3n3 and C18:3n6 in winter rape seeds—important from the nutritional point of view. The soil type Haplic Luvisol influenced a larger number of saturated acids and promoted an increase in their content to a greater extent than the Gleyic Chernozem soil type. Among unsaturated fatty acids, fertilization had an effect only on C18:3n3 with mineral fertilization (variant D1) and a very high K dose (variant D5) and C24:1 with the highest K dose (variant D6). No negative changes in the proportions of FAs, including omega-3 and omega-6, were demonstrated under the influence of BA application. Full article

Trends in soil organic carbon (SOC) were analyzed in the soils from the oldest Czech long-term field experiment, the Prague-Ruzyně Long-Term Fertilizer Experiment, conducted on Haplic Luvisol since 1955. The aim of the work was to compare the long-term dynamics of SOC in contrasting crop rotations and different fertilization regimes. The trial design includes two crop rotations (CR): simple CR with two-year rotation of sugar beet and spring wheat, and multi-crop rotation (MCR) with nine crops. Four fertilization treatments were chosen for SOC analysis: unfertilized control, only mineral fertilization (NPK), farmyard manure application (FYM), as well as FYM and NPK application. SOC content was significantly affected by both fertilization and crop rotation practices. In the simple CR, both the unfertilized control and the NPK treatment exhibited a consistent decline in SOC content over the study period, with percentages decreasing from an initial 1.33% in 1955 to 1.15% and 1.14%, respectively. Although the FYM and FYM + NPK treatments showed an increase in SOC content in the 1990s, a gradual decline was recorded in the last two decades. This decrease was not observed in MCR: positive C balances were recorded in all treatments within MCR, with the largest increase in SOC stock occurring when NPK was combined with FYM. In contrast, over the last decade, C balances have decreased in simple CR for all treatments except FYM. This trend coincides with changes in the local climate, particularly rising temperatures. The results indicate that diversified crop rotations and FYM fertilization are effective in mitigating the negative impacts of changing environmental conditions on SOC stocks. Full article

Humic substances (HSs) constitute a primary component of soil organic matter (SOM) and play a crucial role in soil formation and fertility. However, comprehensive information regarding quantitative and qualitative changes in HS following biochar’s application to soil still needs to be improved. This study reports on the impact of biochar application at rates of 0, 10, and 20 t ha⁻¹ (B0, B10, B20), both with and without nitrogen fertilisation at varying levels (N0, N1, N2), on SOM and HS contents throughout the cropping seasons between 2014 and 2019. The findings reveal changes in SOM and HS contents due to biochar addition and fertilisation. Notably, the most substantial increase in soil organic carbon content was observed in the B20N1 and B10N1 treatments, in stark contrast with the reference B0N0 treatment. A decrease in humification of SOM was noted across all treatments involving biochar, whether alone or combined with different N fertilisation levels. An interesting positive change in HS contents was observed in B10N2, where an increase in humic acids and a decrease in fulvic acids enhanced HS stability and improved HS quality. These findings shed light on the intricate dynamics of SOM and HSs in response to biochar application and nitrogen fertilisation over multiple vegetation seasons of crops on loamy Haplic Luvisols in Central Europe. Full article

Taking into consideration its physico-chemical properties, digestate should be used primarily as a fertiliser. The possible ways of using digestate as a fertiliser in agriculture were identified, and digestate collected from an agricultural biogas plant was tested for its macroelement and heavy metal content. The research was conducted on Haplic LUVISOLS soil according FAO classification. The area of the land plots was 75 m². All measurements were carried out in ten replicates. Seed yield was determined at 2.6 t ha⁻¹. The thousand-seed weight was similar in the three growing seasons, and averaged 171.49 g to 184.44 g for the three years under analysis. For the control object, the average thousand-seed weight from the three years of the experiment was 168.56 g. This parameter was significantly influenced by the year of analysis. The highest protein content was obtained in 2022 (an average of 20.3%), which was significantly higher than in 2021 (20.13%) and 2020 (20.12%). The analysis showed an increase in the average value for the three harvest years regarding the fat content of the multiflora bean seeds depending on the post-harvest digestate dose, ranging from 0.47% to 0.61%. In the control object, the average fat content for the three harvest years under analysis was 0.41%. The year under analysis had no significant impact on fat content. A positive correlation was found between the digestate dose and protein, fat, and carbohydrate contents per 100 g of beans. Increasing the dose resulted in statistically significant differences from the lower dose. The obtained results show an increase in macroelement content depending on the digestate dose applied. The average carbohydrate content per 100 g of beans for the three years under analysis ranged from 49.78 g to 54.01 g, while the calcium content per 100 g of beans ranged from 109.23 mg to 124.00 mg. In contrast, the magnesium content in 100 g of bean ranged from 129.91 g to 137.01 mg, the phosphorus content in 100 g of bean from 366.99 mg to 387.00 mg, and the potassium content in 100 g of bean from 1341.20 mg to 1394.06 mg. Statistical analysis revealed statistically significant differences except for potassium, where no differences were found for the two highest doses. In addition, no differences were found in the average phosphorus and potassium content between the years under analysis. The study showed an increase in yield depending on the amount of digestate applied. The highest dose used in the experiment provided the most nitrogen and macronutrients, with a positive effect on yield velocity, protein and fat content, micronutrients, and macronutrients in beans. Full article

Fertilisation with ash from biomass combustion has a positive effect on the quality of nutrients in agrifood raw materials, improving their chemical composition and bioavailability. In the experiments carried out, the protein content and the profile of free amino acids in barley flour were examined from cultivation fertilised with biomass ash at various doses. Barley flour from Haplic Luvisol soil was characterised by a significantly higher (by 13.8% on average) total protein content compared to flour obtained from grains from Gleyic Chernozem soil. The highest protein content but a low content of free amino acids were found in the grains of plants fertilised with the mineral NPK (D1). An increase in the total pool of free amino acids in flour was observed, especially in the case of Haplic Luvisol soil. On average, after fertilising, significantly more ASP, ASN, GLU, GLY, ALA, and CYS were obtained in variant D4 (1.5 t·ha⁻¹), and there were also significantly more TAU and GABA than in the control, up by 30.2% and 23%, respectively. A beneficial effect of fertilisation on the essential amino acid content in barley flour was found, but only up to the dose of D4, when it was significantly higher than in the control and under mineral fertilising (D1), up by 23.7% and 9.2%, respectively. High ash doses reduced the content of free amino acids in the tested barley flour. This study confirmed that using an alternative method of fertilising with plant biomass ash has a beneficial effect on protein quality and nutritional value. Full article

The following study analyzed the impact of fertilizing barley with fly ash from biomass combustion grown on two types of soil, Haplic Luvisol (HL) and Gleyic Chernozem (GC), on the properties of starch. The experiment was conducted in 2019 (A) and 2020 (B), and barley was fertilized with ash doses (D1–D6) differing in mineral content. In the tested barley starch samples, the amylose content, the clarity of the paste, and the content of selected minerals were determined. The thermodynamic characteristics of gelatinization and retrogradation were determined using the DSC method. Pasting characteristics, flow curves, and viscoelastic properties of starch pastes were performed. Starches differed in amylose content and paste clarity. The highest gelatinization and retrogradation enthalpy (ΔH_G and ΔH_R) values were recorded for samples GCD1A and HLD5B. None of the tested factors significantly affected the pasting temperature (PT), but they had a significant impact on the remaining parameters of the pasting characteristics. The average PT value of barley starches was 90.9 °C. However, GCD2A starch had the highest maximum viscosity and the highest rheological stability during heating. GCD2A paste was characterized by the highest apparent viscosity. It was shown that all pastes showed non-Newtonian flow and shear-thinning and had a predominance of elastic features over viscous ones. The resulting gels had the characteristics of weak gels. Ash from burning wood biomass is an innovative alternative to mineral fertilizers. It was shown that the use of such soil fertilization influenced the properties of barley starch. Full article

This research aimed to study interannual and seasonal dynamics of different potassium compounds in orchard soil and the potassium status of sour cherry trees affected by the application of nitrogen and potash fertilizers. Afield experiment was started in 2017 at an orchard located in the forest-steppe zone of the Central Russian upland. Urea and potassium sulfate were applied to the soil once a year in early spring with rates from N30K40 to N120K160 kg/ha. The content of exchangeable and water-soluble potassium compounds was determined in soil samples five times throughout the growing season from May to September 2018–2020. The content of non-exchangeable potassium was determined twice, in 2017 and 2020. The interannual and seasonal dynamics of plant-available potash in unfertilized soil depended on the weather patterns and the uptake of potassium by trees. In the unfertilized plots, the first signs of potassium nutrition insufficiency appeared, such as low leaf and fruit potassium status and a decrease in the non-exchangeable potassium reserves in the20–40 cm soil layer. The annual fertilization led to the gradual accumulation of exchangeable potassium in the root zone. The accumulation was accelerated with increasing rates. When the exchangeable potassium level in the topsoil reached 200 mg/kg, the intensification of both the seasonal fluctuations in potash content and the potash leaching into the depths of the soil occurred in all treatments. In the conditions of our experiment, one-time treatments with superfluous potassium rates (over 80 kg/ha) did not provide an enlarged stock of plant-available potash in the soil but caused unreasonable losses of it due to leaching. An increase in fertilizer rates was not essential for normal metabolic processes and did not manifest itself as an increase in potassium content in leaves and fruits or as an increase in yield. Full article

Soil respiration (SR) is a main component of the carbon cycle in terrestrial ecosystems, and being strongly affected by changes in the environment, it is a good indicator of the ecosystem’s ability to cope with climate change. This research aims to find better empirical SR models using 25-year-long SR monitoring in two forest ecosystems formed on sandy Entic Podzol and loamy Haplic Luvisol. The following parameters were considered in the examined models: the mean monthly soil or air temperatures (T_soil or T_air), the amount of precipitation during the current (P) and the previous (PP) months, and the storage of soil organic carbon (SOC). The weighted non-linear regression was used for model parameter estimations for the normal, wet, and dry years. To improve the model resolutions by magnitude, we controlled the slope and intercept of the linear model comparison between the measured and modeled data through the change in R₀—SR at zero soil temperature. The mean bias error (MBE), root-mean-square error (RMSE), and determination coefficient (R²) were used for the estimation of the goodness of model performances. For the sandy Entic Podzol, it is more appropriate to use the models dependent on SOC (TPPC). While for the loamy Haplic Luvisol, the Raich–Hashimoto model (TPPrh) with the quadratic T_soil or T_air dependency shows the better results. An application of T_soil for the model parameterization gives better results than T_air: the TPPC model was able to adequately describe the cold-period SR (T_soil ≤ 2 °C); the TPPrh model was able to avoid overestimations of the warm-period SR (T_soil > 2 °C). The TPPC model parameterized with T_soil can be used for the quality control of the cold-period SR measurements. Therefore, we showed the importance of accounting for SOC and the water-holding ability when the optimal SR model is chosen for the analysis. Full article

Soil structure (SS) plays an important role in relation to climatic change, with the most important task the decreasing of CO₂ in the atmosphere by carbon sequestration in the soil and the prevention of floods by better water infiltration into the soil. However, the evaluation of its condition is very different because of the various parameters and their inappropriate uses. The aim of this study was to determine the responses of the parameters of SS on the soil type and tillage system as the most important factors that influence it through changes in the soil organic matter and soil texture. The soil factor, which was represented by seven soil types (EF, Eutric Fluvisol; MF, Mollic Fluvisol; HC, Haplic Chernozem; HL, Haplic Luvisol; ER, Eutric Regosol; EG, Eutric Gleysol; DS, Distric Stagnosol), should be included in all evaluations of SS because of the specifics of each soil type. The tillage factor (shallow non-inversion-reduced, RT; deeper with inversion-conventional, CT) was chosen because of a high sensitivity of SS to soil disruption by cultivation, which represents high potential for the mitigation of climate change. The study included 126 sampling places in different parts of Slovakia on real farms (7 soil types × 3 localities × 3 crop rotations × 2 tillage systems × 2 soil depths). The soils were analysed for the aggregate fraction composition, particle size distribution, and parameters of organic carbon. The data of different parameters of SS were calculated and evaluated. The most sensitive parameter of the tested ones was the coefficient of structure (K_st), which manifested up to the level of the fractions of humus substances and indicated a better condition of SS in more productive soils than less productive soils. The coefficient of soil structure vulnerability (K_v) and mean weight diameter in water-resistant macroaggregates (MWD_w) showed a worse condition of SS in the soils, which developed on Neogene sediments. A better condition of SS in RT was predicted particularly by the primary parameters (index of crusting, I_c; critical content of soil organic matter, S_t), and in CT, they were mainly the secondary parameters (K_st; water-resistant of soil aggregates, K_w). Overall, the suitability of the parameters of SS should be evaluated in relation to a specific soil type with its characteristics and should not be used universally. Full article

Legumes have a wide range of positive effects on soil properties, including nitrogen and carbon storage, soil structure and the phytosanitary condition of crops. From an agronomic point of view, legumes are most valued for their ability to take up atmospheric nitrogen in symbiosis with nitrogen-fixing bacteria. The aim of this research was to determine the effect of legume residues (peas, fodder beans, narrow-leaved lupins) on the N (N_total) and organic carbon (C_org) accumulation in soil and N leaching under temperate climate conditions. The experiment was carried out in lysimetric equipment in 2016–2023. The effect of legumes on C_org and N_total accumulation in soil and N leaching were studied in a Fabaceae–Cereals sequence. Three species of legumes—peas, fodder beans and narrow-leaved lupines—were tested; spring barley (Hordeum vulgare L.) was grown as a control treatment. The lysimeter surface area was 1.75 m² and the experimental soil layer was 0.60 m (sand loam Haplic Luvisol). It was found that after harvesting, more residues were incorporated into the soil with lupines (p < 0.05), which, compared to pea and bean residues, increased N_total and C_org concentrations in the soil. There was a strong correlation (r = 0.95) between the N_total concentration in the soil and the N amount incorporated with residues. Mineral N released during residue decomposition was leached from the humic horizon under conditions of excess moisture in the autumn–winter period and increased the nitrate concentration in the lysimeter water. The increase in concentration was recorded within 5 to 6 months after the application of the residues. As a result, the N leaching losses increased on average by 24.7–33.2% (p < 0.05) during the year of legume cultivation. In the following year, after legume residue incorporation, the effect of residues on nitrate concentration and N leaching decreased and did not differ significantly from that of barley residues. Full article

Prolonged drought stress may have a significant impact on the structure and activity of the soil microbial community. Our study aims to investigate the impact of short-term drought (2 months) on the microbial community structure, enzymes, and metabolic diversity in four agricultural soils (Gniewkowo (G), Lulkowo (L), Wielka Nieszawka (N) and Suchatówka (S) sites) in Poland. These four types of soil were selected based on differences in their texture (gleyic luvisol Phaeozem in G (rich in clay and humus), stagnic luvisol in L, fluvisol in N and haplic luvisol in S (sandy)). We investigated the (1) number of bacteria, actinomycetes (formally phylum Actinomycetota) and fungi; (2) microbial community (16S rRNA and ITS amplicon regions); (3) biological activity by community-level physiological profiling (CLPP); (4) soil enzyme activities (dehydrogenases (DH), phosphatases (acid ACP and alkaline ALP) and urease (UR)); and (5) soil chemical properties. At the end of our experiment, we observed a significant decrease in soil moisture content with the highest in the soil from the S site. Overall, there was no change in total bacteria, but actinomycetes and fungal numbers increased after the 1st week with a decrease in moisture content. ACP activity decreased in three out of four analyzed soil samples. The exception was in sample G, where activity increased for 1–2 weeks and then decreased. ALP activity significantly increased with a decrease in moisture in the 1st week and was lowest at the end of the experiment. DH activity increased up to the 4th week in the G and N samples and up to the 2nd week in the L and S samples. UR activity showed variations in the analyzed samples. A reduction in the utilization of carbon sources (except D-mannitol and L-asparagine) was noted with the highest reduction in the G sample followed by the L, N and S samples. Thus, the pattern of changes was different depending on the analyzed soil type. The 16S rRNA and ITS amplicon sequencing revealed a decrease in the relative abundance of Pseudomonadota, Basidiomycota, Apicomplexa, and increased abundance of Actinomycetota, Bacillota and Ascomycota under prolonged drought conditions. With this, we concluded that drought conditions resulted in a significant alteration of soil microbial communities, enzyme activities, and metabolic diversity in the investigated soils. Full article