Luvisol Soil Research Articles

Biochar-induced changes in soil microbial communities: a comparison of two feedstocks and pyrolysis temperatures

BackgroundThe application of a biochar in agronomical soil offers a dual benefit of improving soil quality and sustainable waste recycling. However, utilizing new organic waste sources requires exploring the biochar’s production conditions and application parameters. Woodchips (W) and bone-meat residues (BM) after mechanical deboning from a poultry slaughterhouse were subjected to pyrolysis at 300 °C and 500 °C and applied to cambisol and luvisol soils at ratios of 2% and 5% (w/w).ResultsInitially, the impact of these biochar amendments on soil prokaryotes was studied over the course of one year. The influence of biochar variants was further studied on prokaryotes and fungi living in the soil, rhizosphere, and roots of Triticum aestivum L., as well as on soil enzymatic activity. Feedstock type, pyrolysis temperature, application dose, and soil type all played significant roles in shaping both soil and endophytic microbial communities. BM treated at a lower pyrolysis temperature of 300 °C increased the relative abundance of Pseudomonadota while causing a substantial decrease in soil microbial diversity. Conversely, BM prepared at 500 °C favored the growth of microbes known for their involvement in various nutrient cycles. The W biochar, especially when pyrolysed at 500 °C, notably affected microbial communities, particularly in acidic cambisol compared to luvisol. In cambisol, biochar treatments had a significant impact on prokaryotic root endophytes of T. aestivum L. Additionally, variations in prokaryotic community structure of the rhizosphere depended on the increasing distance from the root system (2, 4, and 6 mm). The BM biochar enhanced the activity of acid phosphatase, whereas the W biochar increased the activity of enzymes involved in the carbon cycle (β-glucosidase, β-xylosidase, and β-N-acetylglucosaminidase).ConclusionsThese results collectively suggest, that under appropriate production conditions, biochar can exert a positive influence on soil microorganisms, with their response closely tied to the biochar feedstock composition. Such insights are crucial for optimizing biochar application in agricultural practices to enhance soil health.

The productivity of selected soybean cultivars grown using various cultivation methods

Soybean is an important legume crop globally due to its rich protein, oil content, and functional components. The purpose of this study was to evaluate the yield of selected soybean cultivars depending on cultivation methods. The three-year field experiment, conducted from 2018 to 2020 at the Agricultural Experimental Station in Kępa-Puławy, Osiny farm (Institute of Soil Science and Plant Cultivation – State Research Institute in Puławy), investigated these variations. The first experimental factor was the soil cultivation method: A – conventional tillage, B – reduced tillage, and C – strip tillage. The second variable was soybean cultivar: ‘Aldana’ and ‘Merlin’. The soybean cultivars were selected for their differing maturity rates: ‘Aldana’ (000) is an early cultivar, while ‘Merlin’ (000++) semi-late cultivar. The field experiment utilised a split-plot design on Luvisol soil with sandy loam texture, belonging to a good rye complex, class IIIb–IVa, and was replicated four times. The study showed that the productivity (seed and protein yield) of the ‘Merlin’ cultivar grown in the central-eastern part of Poland was approximately 8% higher than that of the ‘Aldana’ cultivar. The cultivation method had a relatively minor influence on soybean yield, the content of selected nutrients, morphological features, and elements of the yield structure. The soil in strip-tillage method was more compact than the soil cultivated with a plough. After harvesting soybeans at a depth of 30, and 40 cm, the compactness of soil in strip-tillage or with reduced tillage was much lower than in spring, highlighting a positive effect of soybean cultivation on loosening the arable layer.

Residues of Symbiont Cover Crops Improving Corn Growth and Soil-Dependent Health Parameters

Cover crops have emerged as a crucial tool in promoting sustainable agricultural practices, particularly in improving soil quality and soil–plant health. This study investigates the impact of single cover crop plants each with varying fungal and/or bacterial symbiosis capacities in a pot experiment. The growth of non-symbiont Ethiopian mustard (Brassica carinata), the associative bacterium symbiont black oat (Avena strigosa) and the double (fungus–bacterium) endosymbiont broad bean (Vicia faba) was studied on three distinct soil types, namely a less-fertile sandy soil (Arenosol), an average value of loam soil (Luvisol) and a more productive chernozem soil (Chernozem). Beside the biomass production, nitrogen content and frequency of AM fungi symbiosis (MYCO%) of cover crops, the main soil health characteristics of electrical conductivity (EC), labile carbon (POXC) and fluorescein diacetate enzyme activity (FDA) were assessed and evaluated by detailed statistical analysis. Among the used soil types, the greatest biomass production was found on Chernozem soil with the relatively highest soil organic matter (2.81%) content and productivity. Double symbiotic activity, assessed by soil nitrogen content and mycorrhiza frequency (MYCO%), were significantly improved on the lowest-quality Arenosols (SOM 1.16%). In that slightly humous sandy soil, MYCO% was enhanced by 45%, indicating that symbiosis was crucial for plant growth in the less-fertile soil investigated. After the initial cover crop phase, the accumulated biomass was incorporated into the Luvisol (SOM 1.64%) soil, followed by the cultivation of corn (Zea mays, DK 3972) as the main crop. The results indicate that incorporating cover crop residues enhanced labile carbon (POXC) by 20% and significantly increased the FDA microbial activity in the soil, which positively correlated with the nutrient availability and growth of the maize crop. This study emphasizes the importance of selecting suitable cover crops based on their symbiotic characteristics to improve soil quality and enhance soil–plant health in sustainable agricultural systems.

Long‐term assessment of macro‐ and micronutrients in foliage of European beech (Fagus sylvatica L.) in thinned versus unmanaged old‐growth stands

AbstractBackgroundScience‐based decisions regarding forest management require the knowledge of the impact of thinning regimens on the forests’ vitality and resilience. There is no systematic study analysing the role of forest management approaches on the nutritional status of forests, serving as a surrogate for their health and growth.AimsWe assessed the impact of ‘heavy thinning from above’ versus ‘no management’ on the foliar chemistry of old‐growth European beech stands on a calcareous site with cambisol/chromic luvisol soil in Thuringia, Germany.MethodsMacro‐ and micronutrients were analysed by serial foliar analysis of six trees per experimental plot over 13 years (2009–2021). To assess potential differences of foliar chemistry between the two plots and over time, a linear mixed‐effects model was applied.ResultsFoliar concentrations of all macro‐ and micronutrients were not significantly different between the two plots (p > 0.05), demonstrating that the management approach had no relevant impact on the nutritional status of beech trees growing at the calcareous site. Furthermore, all foliar concentrations were dynamic over the 13‐year evaluation period. Hence, long‐term forest monitoring is crucial to capture the complex interplay between the trees and environmental conditions.ConclusionsSerial foliar analysis allows for a reliable evaluation of a forest's nutritional status. The results indicate that either regimen, that is, ‘heavy thinning from above’ or ‘no management’, shall not pose any risk in terms of growth and stability. Our results add to the understanding of beech forest dynamics and may provide a further piece for science‐based strategies of sustainable forest management.

The microbiome structure and shifts in surface and subsurface soil horizon of Haplic Luvisol under different crops cultivation

The presented study investigated the comparative approach to evaluate prokaryotic and fungal soil communities in association with various plant crops along the genetic soil horizon using a high-throughput sequencing technique, with special emphasis on subsoils. We evaluate the diversity, abundance and structure of soil microbiome through the depth profiles in Haplic Luvisol (Cutanic) soil collected from lucerne, pear orchard, vineyard, and wheat crop. The structure of soil microbial communities differed due to crop type as well as depth of soil layer. Additionally, some basic physicochemical properties (e.g. total organic carbon - TOC, total nitrogen - TN, dissolved organic carbon - DOC, dissolved nitrogen – DN, pH, clay content) as well as mass and morphological parameters of the plant roots were determined. The highest clay content was noted in illuvial (Bt) horizons (in all profiles). The content of the studied C and N forms was the highest in the Ap horizon and in some subsurface layers and generally decreased with depth. Generally, the highest TOC, TN and DOC content was noted in the orchard profile, while the lowest occurred in the vineyard profile. The opposite trend was found for available Mg content. In turn, the highest DN was determined in the winter wheat profile. Overall, the decrease of the abundances of the most dominant phyla with depth was observed. Using a holistic approach via microbiome investigation of bacterial and fungal communities along soil horizon in a long-term land use with different plant cultivation, we showed that land management not only affect α-diversity but also shift the structure and the composition of bacterial and fungal communities in response to land use, in particular we identified the highest values of biodiversity indicators were found under lucerne and the lowest under vineyard. Future work needs to include the importance of soil type in shaping soil microbial communities under the same land use and plant cultivation, especially under subsurface soil layers.

Analysis of the Physico-Chemical Properties of Bean Seeds after Three Years of Digestate Use

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.

Size-resolved distribution of trace elements in lysimeter soil solutions under contrasting long-term agricultural management to assess their bioavailability

The chemical species of trace elements (TEs) in agricultural soils is highly variable under diverse conditions, requiring tools with clear resolution and minimal disturbance for exploration. A novel surgical (316L) stainless steel (SS) lysimeter with a 5 μm pore size was developed to collect field soil solutions. The size-resolved distribution of TEs were characterized into total (nitric acid digestion), particulate (0.45–5 μm), dissolved (<0.45 μm), colloidal (1 kDa to 0.45 μm), and mainly ionic (<1 kDa) fractions in the lysimeter soil solutions. Total concentrations of TEs (dry weight basis) in acid digested Gray Luvisolic soils were analyzed. Most TEs in lysimeter soil solutions were present in particulate phases, relevant to their geochemical affinities and occurrences in soil minerals. Among dissolved fractions, As, Ba, Co, Li, Mn, Tl, and V existed as mainly ionic species in the soil solutions. Copper, Pb, Al, Th, and U showed variable associations with dissolved organic matter (DOM) and/or inorganic colloids among agricultural treatments. Inorganic NPKS or NKS fertilizer applications with lower pH (5.25–5.74) enhanced mobility and potential bioavailability of Ba, Co, Li, Mn, and Pb present in mainly ionic species, compared with other locations (pH 5.82–6.37). Manure application exhibited a dual effect, potentially increasing bioavailability for As, Tl, and V due to probably enhanced cation exchange capacity (CEC), while also facilitating specific adsorption of Cu and U on DOM, potentially reducing their bioavailability depending on DOM molecular weight. Colloidal and ionic Al and Th concentrations were higher in forest soils than agricultural soils, with extremely low potential bioavailability of Th attributed to strong precipitation with inorganic colloids and adsorption on DOM. The lysimeter sampling and size fractionation method provided a clear insight into agricultural effects on TE distributions and enhancing understanding of agricultural soil health in terms of TE bioavailability in situ.

Analysis of the Free Amino Acid Profile of Barley Grain from Organic Fertilisation with Ash from Biomass Combustion.

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.

Positive effects of plant diversity on dry matter yield while maintaining a high level of forage digestibility in intensively managed grasslands across two contrasting environments

AbstractThe local abiotic and environmental conditions of a grass‐based farming system may influence the agricultural benefits of mixtures in comparison to pure stands. We investigated the effects of species identities and interactions between grass, legume, and herb species on dry matter yield and sward digestibility and explored how contrasting environments may affect these relationships. We established experimental plots across 11 mixtures and 4 monocultures of perennial ryegrass (Lolium perenne L.), chicory (Cichorium intybus L.), white clover (Trifolium repens L.), and red clover (Trifolium pratense L.) established at two seeding densities in two sites Brody and Szelejewo (Poland) and managed them over a 3‐year period. The two sites were close geographically and had similar climates, but differed in soil types (Luvisols and Cambisols, respectively). We confirmed that the annual DM yields were generally higher on Cambisols soil as compared to Luvisols soil; both individual species effects and species interaction strengths differed across the two contrasting environments. The predicted annual DM yield for the 4‐species mixtures in general gave comparable or higher yields compared to monocultures across the 3 years, with the mixtures giving around 10%–30% higher yields than the weighted average of the monocultures of the constituent species. Analysing the transgressive overyielding it turned out that there was no significant difference between the 4‐species mixtures and best performing monoculture. The benefits of species diversity in our study was greater on less productive site because we found larger overyielding of the 4‐species sward on the Luvisols soil than on the Cambisols soil. Additionally, the effect of mixtures composed by 4‐species increased the yield stability compared to monocultures in the 3‐year period of our study, particularly on Cambisols soil. Sward digestibility applied to average values did not differ much between sites with mixtures performing similarly to monocultures. The reason for that could have been the dynamics of sward botanical composition during study years shifted towards increased perennial ryegrass and decreased proportions of chicory in the sward as well as the observed phenomenon that the species in mixed swards progressed to successive growth stages more slowly than in pure sowing.

Integrating enhanced efficiency fertilizers and nitrogen rates to improve Canada Western Red Spring wheat

Granular urea fertilizer applied at planting is prone to nitrogen (N) losses in certain environments. Enhanced efficiency fertilizers (EEFs) are developed to mitigate losses and optimize plant uptake. To determine the benefits of EEFs in grain yield and quality enhancement in Canada Western Red Spring (CWRS) wheat, an experiment was conducted from 2019 to 2022 at eight sites in Alberta and Saskatchewan, Canada. The effects of five N sources [urea; urea + urease inhibitor, N-( n-butyl)thiophosphoric triamide (NBPT); urea + nitrification inhibitor, nitrapyrin; urea + dual-inhibitor, NBPT + dicyandiamide; and polymer-coated urea, ESN® (Environmentally Smart Nitrogen®)] and four N rates (60, 120, 180, and 240 kg N ha−1) on CWRS wheat production were examined. Results indicated that N source affected grain yield in Dark Brown Chernozem soils but not in Black Chernozem or Dark Grey Luvisol soils. In Dark Brown Chernozem soils, a dual inhibitor increased grain yield by 3.1% and 3.9% relative to urea and polymer-coated urea, respectively, while all other EEFs attained similar results. The use of a dual inhibitor EEF led to greater net returns compared to urea and polymer-coated urea in the Dark Brown Chernozem soils. Grain protein concentration increased linearly with increasing N rate from 60 to 240 kg N ha−1. Generally, a rate of 120 kg N ha−1 was optimal for CWRS wheat grown in Canadian prairie conditions when coupled with EEFs, particularly a dual inhibitor, and grain yield and protein were often responsive.

Soil carbon turnover and balance in the priming effects of basalt, montmorillonite, and kaolinite in a Luvisol soil

Soil carbon turnover and balance in the priming effects of basalt, montmorillonite, and kaolinite in a Luvisol soil

The effective monitoring of eleven crucial parameters that describe the condition of cultivated Haplic Luvisol soils using fourier-transformed near-infrared spectroscopy

The study aimed to develop a cost-effective and rapid approach for monitoring eleven crucial parameters that describe the health of cultivated Haplic Luvisol soils. To achieve this, the diffuse reflectance spectra in the NIR spectral region, between 1100 and 2500 nm, were registered, and partial least-squares (PLS) models to predict the concentrations of the critical parameters, including organic carbon, total nitrogen, the available soil nutrients (phosphorus, potassium and magnesium), the exchangeable cations (calcium, magnesium and potassium), the pH levels (determined in deionized water or KCl solution and hydrolytic acidity), were built. The validation results, which are expressed as RMSE and R2val that were obtained for validation the samples, demonstrate that the proposed approach is a reliable and efficient way to monitor the health of Haplic Luvisol soils. Specifically, excellent predictions were obtained for the total nitrogen, organic carbon and pH, which was determined in KCl solution with R2val values equal to 0.9696, 0.9573 and 0.9176, respectively. Additionally, very good PLS models were constructed to estimate the pH levels determined in deionized water, exchangeable magnesium, and potassium, which achieved R2val values of 0.8650, 0.8383, and 0.8329, respectively. For the remaining parameters, the corresponding R2val values were above 0.7294.

Characterisation of Luvisols Based on Wide-Scale Biological Properties in a Long-Term Organic Matter Experiment.

Soil organic matter is a biological system that functions as an integrated whole. These assemblies have different properties, functions, and decomposition times. SOM is one of the main determinants of soil productivity. Our studies were carried out in a temperate deciduous oak forest on Luvisols soil. In the DIRT Project (Detritus Input and Removal Treatments), the following treatments were applied: Double Litter, Double Wood, Control, No Litter, No Root and No Input. Our objective was to compare the effect of withdrawal or doubling of organic matter on the protein pattern of the soil and the biological activity and changes in labile C (permanganate-oxidizable carbon) content in a long-term organic matter manipulation experiment. Patterns of thermostable proteins, soil dehydrogenase enzyme activity, CO2 emission, and POXC content were measured at the most biologically active soil depth of 0-5 cm after 23 years of treatment. Our results show that the enzyme activities of the litter removal treatments were significantly reduced compared to the doubling treatments, as were the values of soil respiration. The same significant difference was also detected in the C content of the soils of the treatments. Based on cluster analysis of the protein profile of the soil samples, the No Litter and No Input treatments were significantly different from the other treatments. This shows that specific organic matter is needed to enhance soil biological activity and the associated POXC content.

Presence of Spodoptera frugiperda Multiple Nucleopolyhedrovirus (SfMNPV) Occlusion Bodies in Maize Field Soils of Mesoamerica.

The occlusion bodies (OBs) of lepidopteran nucleopolyhedroviruses can persist in soil for extended periods before being transported back on to the foliage for transmission to the host insect. A sensitive insect bioassay technique was used to detect OBs of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) in 186 soil samples collected from maize fields in the southern Mexican states of Chiapas, Tabasco, Campeche, Yucatán, and Quintana Roo, as well Belize and Guatemala. Overall, 35 (18.8%) samples proved positive for SfMNPV OBs. The frequency of OB-positive samples varied significantly among Mexican states and countries (p &lt; 0.05). Between 1.7 and 4.4% of S. frugiperda larvae that consumed OB-positive samples died from polyhedrosis disease. Restriction endonuclease analysis using PstI and HindIII confirmed that the soil-derived isolates were strains of SfMNPV and that genetic diversity was evident among the isolates. The prevalence of OB-positive soil samples did not differ with altitude or extension (area) of the maize field, but it was significantly higher in fields with the presence of living maize plants compared to those containing dead plants or crop residues (p &lt; 0.05). Georeferenced soil samples were used to identify soil types on digitized soil maps. Lithosol and Luvisol soils had a higher than average prevalence of OB-positive samples (42-45% positive) (p = 0.006), as did Andosol, Gleysol, and Vertisol soils (33-60% OB-positive), although the sample sizes were small (&lt;5 samples) for the latter three soils. In contrast, Cambisol soils had a lower than average prevalence of OB-positive samples (5% positive). Bioassays on Acrisol, Fluvisol, Phaeozem, and Rendzina soils resulted in intermediate levels of OB-positive samples. We conclude that certain soil types may favor OB persistence and virus-mediated biological pest control. The soil is also likely to provide a valuable source of genetic diversity for the design of virus-based insecticides against this pest.

THE INFLUENCE OF THE BIOLOGICAL ACTIVATOR NUTRILIFE ON THE YIELD AND QUALITY OF ONIONS

Belonging to the Alliaceae family, onion (Allium cepa L.) is one of the most important and popular vegetable and spice crops grown all over the world. Onions are demanding on soil fertility. It is especially demanding to the increased concentration of mineral salts in the soil. At the beginning of the growing season, onion plants must be supplied with nitrogen. A high yield of onions is obtained on light fertile sandy and loamy soils with a pH of 6-7. Correct provision of plants with macro- and microelements can have a beneficial effect on the growth and yield of turnip onions, which is extremely important on poor soils. At the time when environmental protection is becoming an important concern, new friendly methods of stimulating plant growth are being investigated, among others, by applying macroelements, microelements and various growth stimulants to the leaves. One of the new products is Nutrilife, a biological activator. It is a combination of macro- and microelements (EDTA), humic and fulvic acids, enzymes and amino acids. The field experiment was carried out in east-central Poland, 85 km east of Warsaw, on Luvisol soil. The aim of the studies was to determine the effect of Nutrilife applied to leaves during the BBCH 19 stage, with the simultaneous reduction of nitrogen or phosphorus soil doses by half, on the yield and the content of dry matter and sugars in onion. The Nutrilife activator allowed half reducing mineral nitrogen or phosphorus doses, while the yield was the same as in the case of full NPK treatment. The effect of Nutrilife on onion dry matter content was dependent on the weather conditions in the years of research and the applied mineral fertilizer treatment. There was no significant effect of the activator on the total sugar content.

The Assessment of Soil Quality in Contrasting Land-Use and Tillage Systems on Farm Fields with Stagnic Luvisol Soil in Estonia

Soil quality indicates the soil’s ability to provide ecosystem services. Reducing the tillage intensity has been suggested as an alternative to conventional tillage for sustaining soil quality. This study aimed to evaluate the effect of soil tillage systems on individual soil quality indicators in comparison to those on grassland with Stagnic Luvisol soil in Estonia. Four soil management systems were compared: no-tillage (NT), minimum tillage (MT), conventional tillage (CT) and grassland (G) as a reference. Soil quality indicators included physical (bulk density, water-stable aggregates, porosity, air-filled pores, moisture content, water-holding capacity, penetration resistance and water permeability), chemical (total N, total soil organic C, permanganate oxidisable C, pH, P, K, Ca and Mg) and biological (earthworm abundance) parameters. CT soils had a significantly lower aggregate stability compared to MT and G soils. The higher penetration resistance of CT under an arable layer suggested the presence of a plough pan. NT improved the soil’s physical quality at 5–10 cm, which was indicated by higher moisture content, water-holding capacity and porosity and a lower bulk density, whereas penetration resistance exceeded 2 MPa in the lower part of the topsoil. NT also had significantly lower total soil organic C and total N compared to MT and G. The absence of tillage in the NT and G systems may have improved the soil’s resistance to moisture loss under dry conditions, which, in turn, improved the soil habitability for earthworms a despite higher density. In general, NT or MT stabilised or increased the soil quality compared to CT.

Effect of Varying Nitrogen and Micronutrient Fertilization on Yield Quantity and Quality of Sunflower (Helianthus annuus L.) Achenes

Sunflower is a good alternative crop in rotation, even in light soils. This is due to the changing climate, economic factors and the need to reduce agriculture pressure on the environment. In this field experiment, the effect of soil nitrogen doses (60 and 90 kg ha−1) and additional foliar fertilization (B, Cu, Fe, Mn, Mo, Zn) on selected plant characteristics, yield and quality of sunflower achenes was assessed. The single-factor experiment was conducted in 2020 and 2021 on Luvisol soil. It was shown that a higher nitrogen dose had a positive effect on plant biometric features, protein content in achenes, as well as LAI (leaf area index) and SPAD (soil plant analysis development) indices. Additionally, the applied double foliar spraying resulted in an increase in yield components and quality of achenes. Sunflower yielding depended on the interaction of weather conditions with fertilization. In the first year of the research, high yields were obtained after applying 60 or 90 kg N ha−1 in combination with double foliar fertilization (3.68 and 3.65 t ha−1, respectively). A significantly lower yield was recorded after applying only the 60 kg N ha−1 dose. This was not statistically confirmed in the second year of the study, with a higher average yield of 3.79 t ha−1. Economic calculations showed that the optimal option was to use 60 kg N ha−1 together with single or double foliar fertilization. Fertilizing with 90 kg N ha−1 in combination with micronutrient spraying was the least profitable.

Layered application of phosphate fertilizer increased winter wheat yield by promoting root proliferation and phosphorus accumulation

Reducing the possibility of a potential phosphorus (P) resource crisis and increasing P use efficiency (PUE) by improving P fertilizer management is of paramount importance for truly sustainable agricultural production. However, information on how layered application of phosphate fertilizer at different soil depths affects yield and PUE in winter wheat (Triticum aestivum L.) is limited. Here, a 2-year field experiment was conducted in Gleyic Luvisols (ISSS, Isric, F.A.O, 1998) soil to compare the effects of surface fertilization (0–8 cm) with those of layered fertilization (LF) treatments including, uniform layered fertilization (1:1:1), elliptical layered fertilization (1:2:1), and trapezoidal layered fertilization (1:2:3), at soil depths of 0–8, 8–16, and 16–24 cm, on the spatial distribution of roots in different soil layers, and P accumulation at different growth stages of winter wheat in the 2016–2017 and 2017–2018 growing seasons. Our results showed that, compared with surface fertilization, all the LF treatments significantly increased yield by 6.3–20.6% and PUE by 4.7–11.2% points. Furthermore, elliptical layered fertilization resulted in the highest yield and PUE rate. The LF treatments effectively reduced topsoil (0–8 cm) root distribution by 10.8–14.7%, and increased deep-soil (8–100 cm) root distribution by 14.7–21.1% compared with surface fertilization. Linear regression analysis indicated that available P at 0–8 and 8–16 cm soil depths significantly correlated with yield. Additionally, results of structural equation modeling showed that available P at soil depths of 0–8, 8–16, and 16–24 cm had a significant positive effect on root morphology, but only at the 8–16 cm soil layer did available P have a significant positive effect on P accumulation of winter wheat. Overall, our findings suggest that elliptical layered fertilization effectively increased yield and PUE by promoting root proliferation and P accumulation in winter wheat.

Gray Luvisols are polygenetic

With respect to the pedosphere, human activities in the last 100 years have been the major driver of soil change. Despite human activities being one of the main soil forming factors recognized by soil scientists (in addition to climate, organisms, parent material, relief, groundwater, and time), the Canadian System of Soil Classification (CSSC) emphasizes soil as a natural body. We argue human agricultural activities are direct and indirect drivers of significant changes to the carbon balance and cycling in A horizons of Gray Luvisolic soils in western Canada, resulting in changes to A horizon carbon stocks, structure, and micromorphology. Evidence from scientific literature, in-field soil profile observations, and the National Pedon Database are presented in support of our argument. We propose a polygenetic, two-stage model of Gray Luvisol soil formation. The first stage is dominated by the climate forcing of the Holocene, resulting in a relatively stable boreal forest ecosystem including perturbations from natural and human-induced wildfire and other disturbances. The second stage is dominated by direct, human-driven disturbances such as cultivation, release of exotic fauna (earthworms), and indirect human-driven disturbances associated with anthropogenic climate change. Further, we propose modest amendments to the CSSC to reflect a polygenetic model of soil genesis in Gray Luvisolic soils that preserve the balance between observation and interpretation inherent in the system.

Effects of soil bund spacing on runoff, soil loss, and soil water content in the Lake Tana Basin of Ethiopia

Land degradation is primarily caused by accelerated soil erosion rate, which results in a loss in soil fertility and agricultural production. An improved understanding of the effect of soil bund spacing is a precondition for sustainable land management practices on sloping highlands. We examined the effects of bund spacing on soil loss, runoff, and soil water content on teff (Eragrostis tef [Zucc.] Trotter) cropland in an area of 9 % slope on Luvisol soil in the Aba Gerima (micro) watershed of the Lake Tana Basin, Ethiopia. We measured these parameters during 2018 and 2019 on five adjoining runoff plots (each 30 m long × 3 m wide) separated by metal sheets 0.35 m high. We used a plot with no bunds as a control. In the other four plots, we installed bunds at spacings of 27.2, 12.7, 7.87, and 5.45 m. Both runoff and soil loss were considerably higher in the control plot than in the plots with bunds. Narrower bund spacings resulted in substantial reductions of runoff and soil loss. The two-year average runoff depths in the control, 27.2, 12.7, 8.97, and 5.45 m bund spacing plots were 517, 454, 365, 306, and 243 mm, respectively. Average soil loss for the control plot was 25.7 ton ha−1, whereas it was 17.9, 11.8, 6.5, and 4 ton ha−1 for the 27.2, 12.7, 8.97, and 5.45 m bund spacing plots, respectively. The efficiency of soil bunds in enhancing soil water content increased with reduced soil bund spacing. Over the course of the measurement period, average soil water levels for soil bund spacings of 27.2, 12.7, 8.78, and 5.45 m were 0.30 kg kg−1, 0.31 kg kg−1, 0.32 kg kg−1, and 0.32 kg kg−1, respectively. Further cost–benefit analyses and statistical tests are needed to determine optimum bund spacings in the Ethiopian highlands.