Wide Range Of Soils Research Articles

Five decades' experience of long‐term soil monitoring, and key design principles, to assist the EU soil health mission

AbstractThe European Union has a long‐term objective to achieve healthy soils by 2050. The European Commission has proposed a Directive of the European Parliament and of the Council on Soil Monitoring and Resilience (Soil Monitoring Law, SML), the first stage of which is to focus on setting up a soil monitoring framework and assessing soils throughout the EU. Situated in NW Europe, the UK has substantial experience in soil monitoring over the last half century which may usefully contribute to this wider EU effort. A set of overarching principles have and continue to guide design of national soil monitoring and may prove helpful as other European countries embark on similar monitoring programmes. Therefore, we present the principles of design from five decades of national soil monitoring. The monitoring discussed is based on a stratified‐random design, has matured in support of policy questions, and operates over space and time scales relevant to the SML. The UK Centre for Ecology & Hydrology (UKCEH) Countryside Surveys (CS) of Great Britain and Northern Ireland, Welsh Government, Environment and Rural Affairs Monitoring and Modelling Programme (ERAMMP) and the England Ecosystem Survey (EES) monitoring programme are national programmes currently operating in the UK. Some important lessons learnt include: adopting a question‐based approach; having a clear robust statistical design for the purpose; selecting indicators that address policy and underlying scientific questions; and selecting indicators that can detect change and use robust and well‐tested methodologies across a wide range of soil and land use types, remaining valid over long time scales, supporting thinking long‐term. Technical lessons learned include the proven cost effectiveness of a stratified‐random design including replication, while adopting a common stratification layer of stable environmental attributes aids comparability between monitoring programmes. Common protocols are vital for future intercomparisons, but a full ecosystem approach that includes co‐located soil and vegetation samples for interpreting a co‐evolving system has proved hugely advantageous. UK monitoring programmes offer a range of experience that may prove valuable to future soil monitoring design to address the major societal challenges of our time, such as maintaining food production and addressing climate change and biodiversity loss.

Permaculture enhances carbon stocks, soil quality and biodiversity in Central Europe

Permaculture is proposed as a tool to design and manage agroecological systems in response to the pressing environmental challenges of soil degradation, climate change and biodiversity loss. However, scientific evidence on the effects of permaculture is still scarce. In this comprehensive study on a wide range of soil and biodiversity indicators, we examined nine farms utilizing permaculture and paired control fields with locally predominant agriculture in Central Europe. We found 27% higher soil carbon stocks on permaculture sites than on control fields, while soil bulk density was 20% lower and earthworm abundance was 201% higher. Moreover, concentrations of various soil macro- and micronutrients were higher on permaculture sites indicating better conditions for crop production. Species richness of vascular plants, earthworms and birds was 457%, 77% and 197% higher on permaculture sites, respectively. Our results suggest permaculture as effective tool for the redesign of farming systems towards environmental sustainability.

Impact of two acquisitive plants on N cycle on different soils: The invasive Fallopia japonica does it and so does the native Dactylis glomerata!

Invasive plants may alter ecological and ecosystem processes, including the N-cycle. The Fallopia species complex is a well-studied invasive species whose N-resource acquisition traits define it as an acquisitive species. However, the study of the impacts of invasive plants on the N-cycle never considers the N-acquisition strategy as a reference for choosing another suitable plant control. The purpose of this study is to assess the impacts of an invasive species (Fallopia japonicaFJ) on the N-cycle and to compare with those caused by a native acquisitive species (Dactylis glomerataDG), all compared to unplanted soils. A four-months mesocosm experiment was conducted by growing FJ and DG on nine different soils and measuring their impacts on N-cycle microbial activities (free-living nitrogen fixation FLNF, denitrification DEA, nitrification NEA), on N-mineral forms and on functional N-cycle gene abundance (nifH, AOA, AOB, nirS, nirK) as well as the total bacterial community gene (rRNA 16S). The nine soils differ in microbial enzymatic activities, N-mineral form concentrations, physico-chemical factors, texture, and gene abundances. Plant effects on FLNF, NEA and DEA are only soil dependent and no effect of invasive status was found. In addition, the native plant DG generally affected microbial parameters over a wider range of soils than the invasive plant. Stronger impacts of the native DG on microbial gene abundances were found compared to the invasive FJ. A stronger effect of the invasive plant was found for the soil NO3− concentration, with a significant decrease under the FJ than under the DG. Under both FJ and DG, NH4+ concentrations were not significantly affected. In conclusion, the invasive status in the ecosystem of the two plants studied cannot be explained through their impacts on microbial enzymatic activities and gene abundances of the soil N-cycle and the soil N mineral pools.

Comparing laser-induced breakdown spectroscopy and visible near-infrared spectroscopy for predicting soil properties: A pan-European study

Soil organic carbon (SOC), texture, clay/organic carbon (OC) ratio, and extractable phosphorus are among the key soil descriptors representing the physical, chemical, and biological properties. However, analyzing these soil properties using conventional methods of analysis is time-consuming and often involves the use of hazardous chemicals. Therefore, scaling these methods to analyze more samples covering large geographical distributions within a reasonable turn-around time has become a challenge. In this study, two rapid techniques, namely laser-induced breakdown spectroscopy (LIBS) and visible and near-infrared spectroscopy (vis-NIRS), were compared for the prediction of SOC, texture, extractable phosphorus, and clay/OC ratio. A total of 896 samples collected from 23 European countries from the Land Use/Cover Area frame Survey (LUCAS) database were used to represent a wide distribution in terms of soil texture and geographical coverage. The data was manually split into calibration and validation samples while ensuring a representative geographical distribution in the calibration and validation set for the selected samples. Partial least square regression (PLSR) models were developed for both LIBS and vis-NIRS and compared based on prediction accuracy. LIBS outperformed vis-NIRS in predicting SOC, sand content, and clay/OC ratio, with root mean square error of prediction (RMSEP) values of 1.79 %, 12 %, and 7.69, respectively. Conversely, vis-NIRS yielded slightly higher RMSEP values for SOC, sand content, and clay/OC ratio predictions at 1.88 %, 15 %, and 8.13, respectively. Both LIBS and vis-NIRS performed similarly in predicting clay content, with an RMSEP of 6 %. However, there was a low predictive ability for silt and phosphorus concentration, as shown by the weak correlations (R2 < 0.5) between the predicted and reference soil properties. There was no significant difference between LIBS and vis-NIRS predictions for clay, silt, and SOC content (p > 0.05). However, there was a significant difference between the predicted sand content (p = 0.011) and clay/OC ratio (p < 0.001). The overall better performance of LIBS highlights its potential for application in a wide range of soils, especially for soils covering large geographical distributions and varying soil properties. Further, both techniques present opportunities for rapid determination of soil properties important for evaluating soil health on continental scales.

Relationships between Soil Moisture and Visible–NIR Soil Reflectance: A Review Presenting New Analyses and Data to Fill the Gaps

The ability to precisely monitor soil moisture is highly valuable in industries including agriculture and civil engineering. As soil moisture is a spatially erratic and temporally dynamic variable, rapid, cost-effective, widely applicable, and practical techniques are required for monitoring soil moisture at all scales. If a consistent numerical relationship between soil moisture content and soil reflectance can be identified, then soil spectroscopic models may be used to efficiently predict soil moisture content from proximal soil reflectance and/or remotely sensed data. Previous studies have identified a general decrease in visible–NIR soil reflectance as soil moisture content increases, however, the strength, best wavelengths for modelling, and domain of the relationship remain unclear from the current literature. After reviewing the relevant literature and the molecular interactions between water and light in the visible–NIR (400–2500 nm) range, this review presents new analyses and interprets new 1 nm resolution soil reflectance data, collected at &gt;20 moisture levels for ten soil samples. These data are compared to the results of other published studies, extending these as required for further interpretation. Analyses of this new high-resolution dataset demonstrate that linear models are sufficient to characterise the relationship between soil moisture and reflectance in many cases, but relationships are typically exponential. Equations generalising the relationship between soil MC and reflectance are presented for a number of wavelength ranges and combinations. Guidance for the adjustment of these equations to suit other soil types is also provided, to allow others to apply the solutions presented here and to predict soil moisture content in a much wider range of soils.

A new method for disentangling the coupling effect of slaking and mechanical breakdown on aggregate stability: Validation on splash erosion

Aggregate breakdown strongly influences soil erosion process, during which slaking and mechanical breakdown are two dominant breakdown mechanisms. Despite of many methods on aggregate stability, there is a paucity of satisfactory one to disentangle how these two mechanisms interact in aggregate breakdown. Herein, on the basis of Le Bissonnais method (1996) including three treatments (i.e., fast wetting (FW), stirring after pre-wetting (WS), and slow wetting (SW)), a new treatment of water-stirring after fast wetting (SF) was proposed in order to evaluate the coupling effect of slaking and mechanical breakdown on aggregate stability. The coupling effect of slaking and mechanical breakdown was larger to a varying extent than their individual effects, and its difference with slaking showed a unimodal variation with increased aggregate stability. This new method can partition the unique and shared effects of these two breakdown mechanisms; the shared effect (0–77%) decreased logarithmically with increased aggregate stability; the unique effect of slaking (16–52%) showed a unimodal variation and much larger than that of mechanical breakdown (0–17%). As validated by previously published splash erosion data over a wide range of soils (including various soil types, land uses, textures and parent materials), the proposed aggregate stability indices in this new method showed better performance in predicting splash erosion compared to existing ones (e.g., RSI×RMI and RSI/RMI). Collectively, this new method facilitates a systematic understanding on aggregate breakdown mechanisms and exhibits great superiority in aggregate stability measurement and erosion prediction.

Distinct dynamics of plant- and microbial-derived soil organic matter in relation to varying climate and soil properties in temperate agroecosystems

Global environmental change can substantively alter soil carbon storage and dynamics in agroecosystems. However, investigations of soil organic matter (OM) composition associated with various environmental factors are still limited, and this hinders the understanding of soil carbon biogeochemistry in agricultural settings. Soil samples were collected at two times (time 0 and 8 or 10 years) from 10 agricultural sites across Canada and New Zealand with varying soil properties (i.e., soil texture, pH) and climates (MAT, mean annual temperature; MAP, mean annual precipitation). The soils were analyzed for organic carbon, nitrogen and soil OM composition using molecular-level techniques that included targeted compound-specific and solid-state 13C nuclear magnetic resonance analyses. Soil carbon contents were similar over time and were not correlated with environmental factors. Molecular-level characterization of soils found that the preservation and degradation of specific soil OM components differed. Simple sugars and microbial-derived compounds (i.e., fungi-derived ergosterol and microbial-derived lipids) persist less with time in soils compared to other OM components. However, the increased cutin- and suberin-derived compounds at most sites and similar alkyl carbon contents with time suggested that cutin- and suberin-derived compounds were longer-lived compared to other soil OM compounds. Correlation analyses indicated that temporal differences in fungal-derived ergosterol were positively correlated with silt content (r = 0.78). An inverse correlation was observed between lignin degradation and silt content (r = −0.75). Cutin- and suberin-derived compounds were negatively correlated with MAT (r = −0.69); when the analysis was restricted to only Canadian sites, cutin- and suberin-derived compounds and their degradation were correlated with MAP and MAT (climate variables). Further, partial correlation analysis revealed that the correlations between soil texture and the temporal shifts in soil OM composition were indirectly regulated by MAP but not MAT. Overall, distinct environmental constraints were observed for specific OM components in agroecosystems, suggesting that the preservation mechanisms are not uniform across a wide range of soils under different climates and soil properties.

Interactive effect of different inorganic nitrogen sources and bacteria inoculation on productivity, grain quality, and economic returns of pearl millet (Pennisetum glaucum [L.] R. Br.)

ABSTRACT Nitrogen (N) is required by the plants in large quantities and obtaining higher yield without its application is a challenging task. Pearl millet (Pennisetum glaucum [L.] R. Br.) is grown on a wide range of soils in Pakistan, and average yield is lower than most of the millet producing countries in the world. Growth, development, and nutrient accumulation can be improved by bacteria inoculation combined with inorganic fertilizers. This two-year study inferred the effect of different nitrogen (N) sources [urea, calcium ammonium nitrate (CAN), nitrophos and ammonium nitrate (NH4NO3)] combined with seed inoculation with endobacteria (EB) and rhizobacteria (RB) or no seed inoculation on growth, yield, profitability, and grain quality of pearl millet. The CAN + seed inoculation with RB significantly increased grain (115.7% and 116.4% during 1st and 2nd year) and biological yield (45.5% and 22.6%), and economic returns (234% and 128%). Likewise, N supply through urea increased grain N, protein, iron (Fe) and zinc (Zn) contents. In the same way, AN + seed inoculation with RB significantly improved soil microbial population. In conclusion, N supply through CAN + seed inoculation with RB could be used to improve the productivity, and net economic returns of pearl millet.

Characterization of Partial Drainage during Medusa Flat Dilatometer Testing

Abstract The flat dilatometer (DMT) is a widely recognized in situ test for site characterization and parameter identification. The penetration procedure is stopped periodically for total stress measurements (A, B, and C pressures) along a circular, expandable membrane, situated at one side of the blade. Changes in pore water pressure are not measured during test execution and are assumed to remain constant for data interpretation. The enhanced Medusa DMT equipment used in this study enables a fully automated test execution and requires no manual membrane expansion by the operator. Changes in pore water pressure can be studied by measuring the A pressure automatically over time at a defined membrane expansion. In the present study, Medusa DMT were executed at three test sites (Rhesi and Lokalbahn Salzburg in Austria; Fucino in Italy) to investigate, on the one hand, partial drainage effects in different soil types using variable membrane expansion rates and repeated A readings and on the other hand, to study the influence of partial drainage on existing correlations (used for parameter identification). The present results indicate that partial dissipation of generated excess pore water pressures occurs in a wide range of soils during test execution. The degree of dissipation can additionally be influenced by the soil heterogeneity, especially in silty soils. Soil parameters and intermediate parameters determined based on A readings are less influenced by partial drainage effects compared with parameters, derived from the difference of corrected B and A readings. The influence of partial drainage on the latter correlations increases in fine-grained soils, characterized by small differences in B and A pressure. Therefore, pressure readings should be corrected about partial drainage effects based on an enhanced testing procedure, considering repeated A readings (DMT-RA).

Influence of weather conditions on variability of breeding valuable characteristics of winter rye varieties in Kirov region

Long-term results of the research on the influence of weather conditions on the formation of economically biological and technological characteristics of winter rye varieties are valuable for further use in practical breeding, as well as in solving the problem of realizing their biological potential in a wide range of soil and climatic factors. The aim of the research was to evaluate the influence of weather conditions on the variability of yield, economically biological characteristics and baking properties of 10 winter rye varieties of different geographical origin for the subsequent creation of varieties adapted to the conditions of Kirov region. As a result of eight years of research (2015-2022), the variability of 19 biological and technological characters was analyzed in different weather and climatic conditions (index of environmental conditions from +1.44 to -1.39). The highly stable characteristics were grain nature, ear density and relative ear productivity (CV = 1-8 %). The least stable traits were yield and winter hardiness (CV = 75-89 %). Analysis of variability of characteristics by varieties revealed the most adapted to changes in weather conditions varieties - Rushnik, Falenskaya 4, Flora, Alisa (from 2-3 to 38-42 %). The principal component method with visualization on a biplot chart was used to assess the influence of characteristics on yield formation. It was revealed that the yield was more dependent on the weight of 1000 grains, snow mold damage, winter hardiness, resistance to lodging, length and weight of the ear, number of spikelets and grains in the ear, weight of grain per ear and plant, relative productivity of the ear. These traits determined 65.9 % of yield variability. The second biplot chart allowed to identify the most stable varieties for 8 years of study – Rushnik, Falenskaya 4, Flora and Alisa. It was found that the variety of winter rye Alisa realizes its yield potential both in years with optimal conditions of vegetation and in conditions of excessive moisture, but differs from the varieties Falenskaya 4, Flora and Rushnik in high ear productivity and can be used as a source material for breeding.

Comparative study on changes in biochemical constituents, yield and quality of lemongrass (Cymbopogon flexuosus) grown under different soil types

ABSTRACT Lemongrass (Cymbopogon flexuosus) is a perennial aromatic grass suitable for cultivation on a wide range of soils. This study aims to evaluate the feasibility of lemongrass for utilizing alkaline lands and to examine the biochemical, yield and quality response of lemongrass cultivars on different soils. In this experiment, soils with different soil texture, i.e. S1- Clay loam soil; S2- Loamy sand soil; S3- Sandy loam soil; S4- Loam soil, were taken from different geographical locations. Physico-chemical properties, initial soil status of selected soil types were tested. Growth parameters, biochemical enzymes, yield and quality parameters of lemongrass varieties were determined. Post-harvest status of soils was also analyzed. Soil calcareousness and other soil characteristics like cation exchange capacity significantly impacted lemongrass varieties on biochemical properties such as proline content, lipid peroxidation, nitrate reductase activity, herb and oil yields, and constituents of essential oil. The herbage and oil yield of lemongrass significantly decreased with an upsurge in soil calcareousness. The total citral content in the essential oil was highest for the variety ‘Krishna’ (85.33%) grown in clay loam soil and lowest in ‘CIM-Shikhar’ variety (65.09%) grown in sandy loam soil. Post-harvest data of soils showed significant impact on soil ameliorating potential of lemongrass.

Global Marketing of Persian Clover (Trifolium resupinatum L.) Accessions Based on Eco-geographical Distribiution

Iran is considered one of the important centers of diversity of the Persian clover. In order to introduce the best populations for their marketing and sales, 48 accessions were collected from various parts of country and relationship between geographical distribution with ecological factors were studied. The results showed that the distribution of populations is mainly in the north, northwest and the center of country. Altitude and rainfall are two important environmental factors in the distribution of this species. Also it can grow on a wide range of soils but does better on fertile heavy moist clays. It is suggested that the accessions of Persian clover that are grow and cultivated in the north and northwest of the country are more important in marketing in terms of favorable geographical conditions, which should be considered by marketers.

Environmental and agronomic determinants of hairy vetch (Vicia villosa Roth) seed yield in rainfed temperate agroecosystems

Vicia villosa Roth, commonly named hairy vetch (HV), is one of the most promising cover crop (CC) legumes, commonly included in strategies aimed at increasing agriculture sustainability. Due to the generally low yield, the availability of commercial seed is often limited. The objective of this study was to identify management and key weather factors governing the variation in HV seed yield. The study comprises a database of 96 fields dedicated to HV seed production distributed in the Pampas region of Argentina, under a wide range of soil and weather conditions. Among the wide range studied, it was found that only poorly drained soils reduced HV seed yield. Crop protection practices, through the application of insecticide plus fungicide, and the axial threshing harvest system were the most important management tools determining high HV seed yield (> 600 kg ha−1). The inclusion of honey bees (HB) as pollinators did not significantly increase the seed yield, which might be due to alternative pollinator activity coming from neighbouring fields. A boundary function showed that an annual precipitation of 680 ± 243 mm and a sowing date during late autumn-early winter appeared to be sufficient to maximise seed yield under rainfed conditions. On the other hand, heat stress (>30 °C) during flowering and seed filling constrained the seed yield. A simplified crop model was developed to explain the effect of the most important factors on the seed yield. Crop management practices that increased the photosynthetic activity, such as foliar protection, were associated with increased seed yield.

Comparison of soil analytical methods for estimating plant-available potassium in highly weathered soils

Context The NaHCO3-extractable soil K test (Colwell K) is the most frequently used method for soil K across Australia, but there is still uncertainty about the suitability of K testing guidelines for heavy-textured soils. Aims To determine whether Colwell K is suitable for predicting plant-available K on loam- and clay-textured soil types developed from highly weathered soil parent materials in Western Australia (WA). Methods Nine soil K testing methods were used to determine plant-available K on 21 soil types with a wide range of properties collected from three depths on the northern, central and southern farmlands in WA. Key results Quartz and K-feldspars were the dominant minerals in all soils, while limited white mica (1–2%) was identified in less than 10% of samples. The amount of K extracted by silver thiourea was only about 70% of the amounts extracted by NaHCO3 (Colwell K) and NH4OAc. Soil non-exchangeable K extracted by nitric acid and sodium tetraphenyl borate were from similar K pools, while aqua regia K was 1–6 times higher than these values. Conclusion There was no systemic difference or proportional bias between NH4OAc K and Colwell K, and both had good model performance (R2 &gt; 0.86) for total K uptake by wheat in a single growing season in a wide range of soils. Implication In this diverse range of soils formed from weathered parent materials, the reliance on exchangeable K for plant K uptake suggests that plant-available K will be vulnerable to rundown due to negative K balances.

Evaluation of the diffusive gradients in thin-films (DGT) technique for measuring nitrate and ammonium in soil

Environmental context Nitrate (NO3−) and ammonium (NH4+) are the most important soil nitrogen forms for plant growth. However, conventional extraction techniques may introduce artefacts affecting the measurement of plant-available N concentrations following sampling and sample preparation processes. This is the first study of the DGT technique being used to measure NO3-N and NH4-N in a wide range of soils, compared with conventional KCl extraction, and examined different factors that contribute to the plant-availability of these ions in soils. The knowledge would help to optimise soil nitrogen management practices, increase economic benefits and reduce environmental impacts. Rationale The availability of soil nitrogen for plant uptake can be affected by numerous soil factors such as soil texture, moisture and organic matter content, temperature and microbial activity. Conventional extraction techniques may affect the measurement of plant-available N concentrations following sampling and sample preparation processes, including drying, sieving, homogenising, freezing and thawing. The diffusive gradients in thin-films (DGT) technique can overcome some limitations of the conventional extraction techniques and has been used to successfully estimate the plant-available fractions of nutrients, such as P, K, Zn, Cu and Mn in soils. Therefore, it is important to evaluate the use of DGT for measuring NO3− and NH4+ in a wide variety of soils and examine the factors that contribute to the plant-availability of these ions in soils. Methodology The experiment evaluated the ability of the DGT technique to measure NO3-N and NH4-N in soils using binding layers containing A520E anion exchange resin or Microlite® PrCH cation exchange resin, respectively. The DGT results were compared to those from conventional KCl extraction. Results The A520E- and PrCH-DGTs showed good detection limits for NO3-N (6.90 µg L−1) and NH4-N (6.23 µg L−1) and were able to measure potentially available NO3-N and NH4-N in unfertilised soils. The mass of NO3-N and NH4-N that accumulated on the DGT device increased linearly across soil concentrations ranging from 5 to 300 mg kg−1 NO3-N (depending on soil type) and 5–300 mg kg−1 NH4-N; which is equivalent to fertiliser rates of 75–450 kg ha−1 N. DGTs were used to measure potentially available NO3-N and NH4-N in ten soils with various physical and chemical properties. The DGT results were compared with conventional KCl extraction used to determine soil mineral N. DGT and KCl extraction measured values were significantly correlated with each other for NO3-N (R2 = 0.53; P-value &lt; 0.001), but the relationship between the two measurements was weaker for NH4-N (R2 = 0.20, P-value = 0.045). Discussion The results suggest that the two methods sample different N pools in the soils, with DGT targeting the NO3-N and NH4-N that are available in soil pore water and attached to labile solid phases.

Characterization of Bt Cotton Growing Soils Producing Varying Cotton Yields in Dharwad and Haveri Districts of North Karnataka, India

Bt cotton is being cultivated on a wide range of soils in northern transitional zone of Dharwad and Haveri districts in north Karnataka. A field survey was conducted during kharif 2021-22 to study the physico-chemical properties and nutrients status of soil and Bt cotton productivity. A total of 153 locations were selected in Dharwad and Haveri districts. Surface soil samples were collected at fifty per cent flowering stage and kapas yield was recorded at first and second picking stages. In the study area, kapas yield ranged from 3.59 to 25.85 q ha-1 with a mean value of 15.95 q ha-1. Bulk density, soil porosity, maximum water holding capacity and moisture content at field capacity ranged from 1.12 to 1.70 Mg m-3, 35.85 to 57.74%, 34.08 to 76.27% and 13.63 to 45.76%, respectively. Soils were near neutral to slightly alkaline in reaction (6.60 to 8.80), non-saline (0.15 to 0.82 dS m-1), slightly to moderately high in free lime content (4.10 to 18.40%) and low to high in soil organic carbon (1.50 to 12.60 g kg-1) content. Available nitrogen, phosphorus (P2O5), potassium (K2O) and sulphur contents in soils of cotton fields ranged from 113.06 to 562.82, 10.50 to 89.56, 110.16 to 497.28 kg ha-1 and 5.06 to 25.67 mg kg-1, respectively. Similarly exchangeable calcium and magnesium contents in soils ranged from 10.10 to 35.24 and 2.98 to 17.01 cmol (p+) kg-1, respectively. DTPA extractable iron and zinc contents and hot water soluble boron content in soils ranged from 1.86 to 9.51, 0.20 to 1.10 and 0.10 to 0.75 mg kg-1, respectively. Nutrient indices showed that soils of the study area were low in available nitrogen, medium in available phosphorus, potassium and sulphur contents. Iron, zinc and available boron contents were deficient in soils.

Active antibiotic resistome in soils unraveled by single-cell isotope probing and targeted metagenomics

Antimicrobial resistance (AMR) in soils represents a serious risk to human health through the food chain and human-nature contact. However, the active antibiotic-resistant bacteria (ARB) residing in soils that primarily drive AMR dissemination are poorly explored. Here, single-cell Raman-D2O coupled with targeted metagenomics is developed as a culture-independent approach to phenotypically and genotypically profiling active ARB against clinical antibiotics in a wide range of soils. This method quantifies the prevalence (contamination degree) and activity (spread potential) of soil ARB and reveals a clear elevation with increasing anthropogenic activities such as farming and the creation of pollution, thereby constituting a factor that is critical for the assessment of AMR risks. Further targeted sorting and metagenomic sequencing of the most active soil ARB uncover several uncultured genera and a pathogenic strain. Furthermore, the underlying resistance genes, virulence factor genes, and associated mobile genetic elements (including plasmids, insertion sequences, and prophages) are fully deciphered at the single-cell level. This study advances our understanding of the soil active AMR repertoire by linking the resistant phenome to the genome. It will aid in the risk assessment of environmental AMR and guide the combat under the One Health framework.

Агробиологические особенности и хозяйственно полезные характеристики фестулолиума сорта Аллегро

One of the directions of increasing the efficiency of feed production is the creation and introduction of new varieties of forage grasses with improved economically useful characteristics and a wide range of adaptive properties. Festulolium is a new crop with high fodder qualities, which has a pronounced trend towards expanding the area of crops in the country in recent decades. This is largely due to the creation of a line of new varieties of this crop, the accumulation of positive experience of use in production condi-tions for the procurement of high-quality feed. The Allegro variety was bred as a result of intergenera-tional hybridization of perennial ryegrass and meadow fescue, has a high adaptive potential for cultivation in a wide range of soil and climatic conditions, is characterized by high feed and seed productivity. The variety is winter-hardy, medium-resistant to snow mold and spotting, in comparison with ryegrass, resis-tant to lodging, with a high shoot-forming ability. It is characterized by competitiveness when sowing in grasslands. According to the type of development, it belongs to winter plants and does not form genera-tive shoots in the year of sowing. It is characterized by a high yield of green mass — 25–30 t/ha, with the observance of agricultural cultivation techniques and sufficient moisture supply, it is able to form up to 40–50 t/ha of green mass in total for three mowing. The highest yield of green mass is formed in the second or third years of life. The content of carbohydrates in the dry matter of the green mass in the tube exit phase is 13.4–15%, crude protein — 11–13%, crude fiber — 26%.

Multifunctional landscapes for dedicated bioenergy crops lead to low-carbon market-competitive biofuels

Switchgrass is a promising feedstock for cellulosic biorefineries, due to its ability to maintain comparatively high biomass yields across a wide range of soil and climatic conditions. However, there is an incomplete understanding of the economic and environmental tradeoffs associated with cultivating switchgrass on low-productivity land for conversion to biofuels. This study surveys prior literature and demonstrates a new integrated assessment framework, including agroecosystem, ecosystem services valuation, technoeconomic, and life-cycle assessment models, to quantify and contextualize the economic and environmental impacts of switchgrass cultivation on marginal land with downstream conversion to biofuels. Monetizing and incorporating the value of ecosystem services, such as improved water quality benefits from nitrate and sediment reductions, climate change mitigation benefits from CO2 emission reduction, and recreational and pollination benefits from increased biodiversity, the modeled multifunctional landscape reduces the ethanol production cost by 33.3–58.9 cents/l-gasoline-equivalent ($1.3–2.2/gge). Planting switchgrass in low productivity land improves soil health, resulting in the carbon footprint reduction credit of 12.8–20.2 gCO2e/MJ. For an improved switchgrass-to-ethanol conversion pathway with the maximum benefits from ecosystem services, the minimum ethanol selling price and carbon footprint of ethanol, respectively, could reach to 31 cents/l-gasoline-equivalent (47% reduction relative to average gasoline price) and 3 gCO2e/MJ (97% reduction relative to gasoline). This low carbon renewable ethanol leads to substantial State and/or Federal policy incentives (∼$1/l-gasoline-equivalent) providing a large benefit to biorefinery operators, farmers, and the public as a whole.

A phospho-compost biological-based approach increases phosphate rock agronomic efficiency in faba bean as compared to chemical and physical treatments.

Under arid and semi-arid conditions, direct application of phosphate rock (PR) as a source of phosphorus (P) for crop production is likely influenced by agricultural practices and soil properties. Different approaches could be used to improve the agronomic efficiency of low-grade PR over a wider range of soils and crops. In this study, biological, physical, and chemical treatments of low-grade Moroccan PR were investigated and compared through agronomic trials on faba bean grown under alkaline soil conditions. The physical treatment was based on blending PR with triple superphosphate (TSP) at 75:25 and 50:50 ratios, the biological treatments involved co-application of PR with compost at 50:50 ratio and phospho-compost elaborated from PR (20%), sewage sludge (46%), and wheat residues (34%), while the chemical treatment was obtained by a 30% acidulation of PR by phosphoric acid. Control treatments consisting of zero P application (control), PR alone, and TSP alone were considered to assess the effectiveness of the abovementioned techniques to improve PR agronomic efficiency. A pot experiment was conducted in sandy soil (Jorf Lasfar, central Morocco) for 60 days in a completely randomized design considering eight treatments. All treatments, except the control, were amended with 52 mg kg-1 of P from different PR-based fertilizers before sowing. At the flowering stage (60-day-old plants), results indicated that all PR treatments significantly improved plant growth, root nodulation, and nutrient uptake compared to the control. The relative agronomic efficiency of pretreated PR was significantly higher with phospho-compost treatment (86%) than the partially acidulated PR (78%) or the PR/TSP blend 50:50 (64%). Likewise, P uptake, P use efficiency, number of root nodules, and N uptake all were improved under PR treatments. Our finding revealed that the biological technique based on phospho-compost yielded better compared to chemical and physical treatments.