Soil Development Research Articles

Integrated transcriptomic and metabolomic analyses reveal key metabolic pathways in response to potassium deficiency in coconut (Cocos nucifera L.) seedlings.

Potassium ions (K+) are important for plant growth and crop yield. However, the effects of K+ deficiency on the biomass of coconut seedlings and the mechanism by which K+ deficiency regulates plant growth remain largely unknown. Therefore, in this study, we compared the physiological, transcriptome, and metabolite profiles of coconut seedling leaves under K+-deficient and K+-sufficient conditions using pot hydroponic experiments, RNA-sequencing, and metabolomics technologies. K+ deficiency stress significantly reduced the plant height, biomass, and soil and plant analyzer development value, as well as K content, soluble protein, crude fat, and soluble sugar contents of coconut seedlings. Under K+ deficiency, the leaf malondialdehyde content of coconut seedlings were significantly increased, whereas the proline (Pro) content was significantly reduced. Superoxide dismutase, peroxidase, and catalase activities were significantly reduced. The contents of endogenous hormones such as auxin, gibberellin, and zeatin were significantly decreased, whereas abscisic acid content was significantly increased. RNA-sequencing revealed that compared to the control, there were 1003 differentially expressed genes (DEGs) in the leaves of coconut seedlings under K+ deficiency. Gene Ontology analysis revealed that these DEGs were mainly related to "integral component of membrane," "plasma membrane," "nucleus", "transcription factor activity," "sequence-specific DNA binding," and "protein kinase activity." Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that the DEGs were mainly involved in "MAPK signaling pathway-plant," "plant hormone signal transduction," "starch and sucrose metabolism," "plant-pathogen interaction," "ABC transporters," and "glycerophospholipid metabolism." Metabolomic analysis showed that metabolites related to fatty acids, lipidol, amines, organic acids, amino acids, and flavonoids were generally down-regulated in coconut seedlings under K+ deficiency, whereas metabolites related to phenolic acids, nucleic acids, sugars, and alkaloids were mostly up-regulated. Therefore, coconut seedlings respond to K+ deficiency stress by regulating signal transduction pathways, primary and secondary metabolism, and plant-pathogen interaction. These results confirm the importance of K+ for coconut production, and provide a more in-depth understanding of the response of coconut seedlings to K+ deficiency and a basis for improving K+ utilization efficiency in coconut trees.

The Effect of Molybdenum Fertilizer on the Growth of Grass–Legume Mixtures Related to Symbiotic Rhizobium

Molybdenum (Mo) is required by the enzymes involved in many metabolic processes related to plant growth and development. However, the effects of Mo addition on plant growth and beneficial microorganisms in mixed grasslands are unclear. We conducted a greenhouse experiment to examine the effects of different Mo addition levels (10 and 20 mg Mo kg−1 soil in the form of Na2MoO4) on the growth of perennial ryegrass–white clover in two low-Mo soils, as well as their symbiotic microorganisms. Our results showed that the addition of Mo had a significant impact on plant growth in limestone soil but not in yellow loam soil (p < 0.05). Compared with no addition of Mo fertilizer in limestone soil, an addition of 10 mg Mo kg−1 significantly increased the plant community shoot and root biomass (p < 0.05). However, this improvement was not observed with an addition of 20 mg Mo kg−1. The shoot nitrogen and phosphorus content in both soil types was unaffected by the Mo addition (p > 0.05), whereas the 10 mg Mo kg−1 addition significantly increased the shoot nitrogen and phosphorus uptake in limestone soil (p < 0.05). This increase in plant community productivity was primarily due to the increased growth of both species, caused by the enhanced activation of the symbiotic rhizobium. We conclude that Mo supply may promote N utilization and uptake in mixed grassland by increasing the activity of symbiotic rhizobium, resulting in a higher yield of mixed grassland, which is critical for sustainable agricultural development in low-Mo soils.

SOIL CONTENT OF SOME OXIDES AS A FUNCTION OF THE DEVELOPMENT IN NINAVAH GOVERNORATE / NORTH IRAQ

The objective of this study was soil development by using some weathering parameters, soil samples were selected from four different locations in Ninavah Governorate (Al-Hadher, Al-Qayarah, Hamam al-alil, Tallafer, Faidah). The studied areas were selected according the variation of environmental conditions and climate. Chemical analysis was conducted using (XRF) Technique. Results of XRF Analysis also showed a clear increasing in immobile oxides of (SiO2, Fe2O3 and Al2O3) and trace (rare) elements (ZrO, MnO and TiO2) in Faidah soil and gradually decreased in Tallafer, Hamam al-alil, Al-Qayarah and reach its lowest levels in Al-Hadher soil. However the mobile oxides of (CaO) and the loss in ignition was increased in Al-Hadher soil and gradually decreased in Al-Qayarah, Hamam al-alil, Tallafer and reach its lowest levels in Faidah soil. Calculation of weathering indices has been done such as modified weathering potential index (MWPI), plagioclase index of alteration (PIA), weathering ratio (WR), bases / alumina (B/A), and weathering index (WI-1), (WI-2). Results of weathering indices included that the highest levels of weathering levels was found in Faidah soil (High Average rainfall) and the lowest weathering levels in Al-Hadher soil (Low Average rainfall ).

Anthropogenic impact on erosion, pedogenesis and fluvial processes in the central European landscapes of the eastern Harz mountains forelands (Germany)

The Holocene development of soils and sediments at three sites in the eastern Harz foreland was investigated using field and laboratory methods and integrated into the regional Holocene record of this central European landscape.Apart from early Holocene processes, the history of mid-to late Holocene slope erosion was found to be closely linked to the local land-use history. By c. 1000 BP, soil erosion is a process that is detectable throughout the study area.The studied Chernozemic soils that now cover large areas of the studied landscape are of varying Holocene age. Linear radiocarbon age-depth relations of soil organic matter and indicative changes in soil mineral composition suggest that the Chernozem was formed by long-lasting anecic earthworm cast accumulation at the soil surface. Persistent periods of landscape openness maintained by local preindustrial agriculture explain the promotion of anecic earthworms in naturally forested landscapes of central Europe and act as temporally transgressive drivers of landscape change.An early to mid-Holocene phase of reduced fluvial activity was followed by the onset of Holocene flooding, which correlates with the onset of mining in the Harz Mountains around ca. 3000 BP (e.g. Helme). The onset of flooding of the small streams Zapfenbach and Liethe coincided with the documented medieval and modern mining phases in the eastern Harz. At all sites, present-day flooding frequencies are higher than during the early to mid-Holocene. Shifts in river system behaviour attributable to anthropogenic activities in the Harz Mountains are therefore considered another Anthropocene marker.Based on our observations, we propose that land-use-induced alteration of central European low Mountain rivers and the formation of Holocene Chernozems in subhumid central Europe, in addition to anthropogenic-induced Holocene soil erosion, are included in the cadastre of early Anthropocene processes. These processes have left distinct traces in the continental geologic record. Thus, they would support arguments for long-term time transgressive anthropogenic transformation of Earth surface systems. However, the tipping points for these processes are dated differently (soil erosion - ca. 1000 BP, river activity - ca. 3000 BP, Chernozem formation - diachronous since the Neolithic) and are closely linked to local and regional land use history. Thus, our results are another example that the definition of “golden spikes” remains a critical undertaking, especially for the beginning of the Anthropocene.

Engineering Properties and Microscopic Mechanisms of Composite-Cemented Soil as Backfill of Ultra-Deep and Ultra-Narrow Foundation Trenches

The backfilling of lime soil in ultra-deep and ultra-narrow foundation trenches is a difficult construction link, and ordinary-cemented soil has drawbacks, including poor strength, impermeability, and frost resistance. To solve these problems, fly ash (FA)–water glass (WG)-composite-cemented soil is developed based on a background project. The three-factor orthogonal tests are conducted on the unconfined compressive strength (UCS) of the composite-cemented soil, and the optimal engineering mix proportion is proposed for the FA-WG-composite-cemented soil. Its UCS is compared with that of cemented soil only doped with FA or WG (FA- and WG-cemented soil). In addition, the cyclic wetting–drying tests, cyclic freeze–thaw tests, and impermeability tests are carried out to study the endurance of the composite-cemented soil in cold regions rich in water. The hydration products of the composite-cemented soil are investigated through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, and the curing mechanism of the composite-cemented soil is discussed from the microscopic perspective. The research results indicate that the mixing ratio of cement is crucial to the strength development of the cemented soil; the mixing ratio of FA greatly influences the strength development of the cemented soil in the middle and late stages; the mixing ratio of WG only slightly affects the strength. The ratio of cement, FA, and WG of 9%:12%:3% is the optimal engineering mix proportion of the composite-cemented soil. Compared with ordinary-cemented oil and FA- and WG-cemented soil, the composite-cemented soil shows significantly improved compressive load-bearing capacity. The permeability coefficient of the composite-cemented soil is always obviously lower than that of the ordinary-cemented soil after any curing period. Despite the mass loss, the composite-cemented soil is superior to the ordinary one in overall endurance after wetting–drying and freeze–thaw cycles. Through SEM and XRD analysis, the content of hydration products of the composite-cemented soil is found to be obviously higher than that of ordinary-cemented soil after any curing period, and the hydrates exert stronger cementing action on soil particles in the composite-cemented soil. The contents of C-S-H gel and Aft crystals in the composite-cemented soil are apparently larger than those in the ordinary-cemented soil. Under the alkali activation of WG, the FA produces free SiO32− and AlO2−, which undergo the polymerization reaction with Ca2+ to generate C-S-H gel and C-A-H gel, further promoting the hydration of cement.

Similar vegetation‐geomorphic disturbance feedbacks shape unstable glacier forelands across mountain regions

AbstractGlacier forelands are among the most rapidly changing landscapes on Earth. Stable ground is rare as geomorphic processes move sediments across large areas of glacier forelands for decades to centuries following glacier retreat. Yet, most ecological studies sample exclusively on stable terrain to fulfill chronosequence criteria, thus missing potential feedbacks between geomorphic disturbances and vegetation colonization. By influencing vegetation and soil development, such vegetation‐geomorphic disturbance feedbacks could be crucial to understand glacier foreland ecosystem development in a changing climate. We surveyed vegetation and environmental properties, including geomorphic disturbance intensities, in 105 plots located on both stable and unstable moraine terrain in two geomorphologically active glacier forelands in New Zealand and Switzerland. Our plot data showed that geomorphic disturbance intensities permanently changed from high/moderate to low/stable when vegetation reached cover values of around 40%. Around this cover value, species with response and effect traits adapted to geomorphic disturbances dominated. This suggests that such species can act as “biogeomorphic” ecosystem engineers that stabilize ground through positive feedback loops. Across floristic regions, biogeomorphic ecosystem engineer traits creating ground stabilization, such as mat growth and association with mycorrhiza, are remarkably similar. Nonmetric multidimensional scaling revealed a linked sequence of decreasing geomorphic disturbance intensities and changing species composition from pioneer to late successional species. We interpret this linked geomorphic disturbance‐vegetation succession sequence as “biogeomorphic succession,” a common successional pathway in unstable river and coastal ecosystems across the world. Soil and vegetation development were related to this sequence and only advanced once biogeomorphic ecosystem engineer species covered 40%–45% of a plot, indicating a crucial role of biogeomorphic ecosystem engineer stabilization. Different topoclimatic conditions could explain variance in biogeomorphic succession timescales and ecosystem engineer root traits between the glacier forelands. As glacier foreland ground is widely unstable, we propose to consider glacier forelands as “biogeomorphic ecosystems” in which ecosystem structure and function are shaped by geomorphic disturbances and their feedbacks with adapted plant species, similar to rivers and coasts.

Linking microbial biogeochemical cycling genes to the rhizosphere of pioneering plants in a glacier foreland

Glacier retreat raises global concerns but brings about the moment to study soil and ecosystem development. In nutrient-limited glacier forelands, the adaptability of pioneering plant and microbial species is facilitated by their interactions, including rhizosphere effects, but the details of this adaptability are not yet understood. In the rhizosphere of five pioneering plants, we comprehensively deciphered the microbial taxonomic and functional compositions. Two nitrogen-fixing microbial genera, Bradyrhizobium and Mesorhizobium, were among the most abundant taxa in the rhizomicrobiome. Moreover, several rhizobial genera, including Rhizobium, Pararhizobium, Allohrizobium, and Sinorhizobium, head the list of major modules in microbial co-occurrence networks, highlighting the vital roles of nitrogen-cycling taxa in the rhizomicrobiome of pioneering plants. Microbial genes involved in nitrogen, sulfur, phosphorus, and methane cycles were simultaneously correlated with microbial community dissimilarity, and 12 functional pathways were detected with distinct relative abundances among soils. Zooming in on the nitrogen-cycling genes, nifW, narC, nasA, nasB, and nirA were mainly responsible for the significant differences between soils. Furthermore, soil pH and the carbon/nitrogen ratio were among the topsoil properties interacting with nitrogen and sulfur cycling gene dissimilarity. These results explicitly linked biogeochemical cycling genes to the rhizomicrobiome and soil properties, revealing the roles of these genes as microbial drivers in mediating rhizosphere soil–plant–microbiome interactions.

Measurement of leaf chlorophyll content in Harumanis mango cultivated in a greenhouse using SPAD meter

The Soil and Vegetation Analysis Development (SPAD) value was correlated to the actual value of chlorophyll content in the Harumanis mango leaf using a developed regression model. Distribution of chlorophyll content in Harumanis mango leaves were mapped using Geospatial Analyst in the ArcGIS. Total chlorophyll content and SPAD value were well established with the polynomial regression model with coefficient of determination (R2) of 0.925. The results show that the measured SPAD value in the morning were comparable to those value made in the evening and the Harumanis leaves located in the middle of the greenhouse have 25–31.3% lower chlorophyll content compared to other parts of the greenhouse.

Progressive belowground soil development associated with sustainable plant establishment during copper mine waste revegetation

Critical to the environmental sustainability of hard rock mining is the reclamation of disturbed lands following mine closure through revegetation. Improved understanding of associations between above- and belowground processes that characterize successful plant establishment is critical to the implementation of more efficient revegetation strategies for nutrient-poor mine waste materials. The specific objective of this five-year temporal study was to identify progressive biotic and abiotic indicators of primary soil development on mine waste rock (WR) on a slope hydroseeded with native plant species, and to quantify comparative effects of plant lifeform on soil development. Aboveground plant diversity and belowground substrate properties were measured annually at 67 m intervals along transects following the slope contour. Seeded WR was compared to unseeded WR and the adjacent native ecosystem. A temporal increase in WR microbial biomass was observed in seeded WR relative to unseeded areas. Microbial community analysis found the unseeded WR to be defined by oligotrophic microbes, whereas targeted grass and shrub root zone samples demonstrated significant increases in specific cellulose and lignin degrading and N-cycling phylotypes. More extensive chemical and biological fertility development was observed in shrub root zones relative to grass. Ten chemical and biological indicators increased significantly in shrub WR relative to unseeded WR, whereas grass WR was only enriched in bacterial 16S rRNA gene copy number/g substrate and bacterial/archaeal and fungal diversity. In addition, the shrub root zone had significantly higher nitrogen-cycling potential than grass root zones or unseeded WR. Thus, both grasses and shrubs improve belowground WR development; however, shrub establishment had greater fertility outcomes. Concurrent belowground fertility development is critical to sustainable plant establishment. Coupled evaluation of above- and belowground metrics provides an improved quantitative assessment of revegetation progress and a valuable tool to guide management decisions.

The Soils of Early Farmers and Their Neighbors in the Southern Buh Catchment (Ukraine): Micromorphology and Archaeological Context

The problems regarding hunter-gatherer/early farmer interactions are quite an important topic in southeast European archaeology. According to the available data, the two economic subsistence systems have coexisted for some 2000 years during the 6th–4th millennia cal BC (Telegin 1985; Lillie et al., 2001). In some areas, hunter-gatherer and early farmer sites are located just a few kilometers apart. The Southern Buh River valley has yielded evidence of Linear Pottery culture, early Trypillia and Trypillia B1 Neolithic settlements as well as hunter-gatherer sites with pottery attributable to the so-called sub-Neolithic or para-Neolithic (Haskevych et al., 2019; Kiosak et al., 2021). Trial-trenches have been opened within some of these sites, which have been radiocarbon-dated from Bern University laboratory (LARA). Soil samples for micromorphological analysis have been collected from these sites to interpret their paleogenetic formation. The soil development is attested since, at least, the beginning of the 5th mill BC, followed by the developed of chernozem soils, which was interrupted by an erosional episode in the end of 5th millennium BC. The available data show that the soils of early farmers arable as are the present day ones. The early farmers were able to exploit relatively heavy soils to cultivate wheat and barley as early as 5250–5050 cal BC. In contrast, the sites of ceramic hunter-gatherers were often located on the soils which formed under wet conditions along seasonally flooded riverbanks, which were almost unsuitable for agricultural practices.

Study on Microstructure of Cemented Organic Soil in Dianchi Lake, China

The organic soil in the Dianchi Lake area contains much humic acid (HA), and the impact of HA on cemented soil has attracted much attention. In this study, test soil is prepared based on the actual HA content of the soil in Dianchi Lake, and cement is added to prepare samples. Unconfined compressive strength (UCS), scanning electron microscopy (SEM), energy-dispersive analysis (EDS), and X-ray diffraction (XRD) tests are conducted on the samples. The strength development and microstructure changes of cemented organic soil are studied. The results show that (1) cemented soil strength decreases with the increase in HA content and increases with the cement mixing ratio; (2) SEM and EDS tests show that with the increase in HA content, the connection between soil particles gradually changed from surface–surface to point–surface, point–edge, or point–point connection. A large overhead structure is inside the cemented soil, and its integrity weakens with increased HA content. However, elements such as Ca, Si, and Al exist in the pores of cemented soil, indicating that cement hydration products are cemented between soil particles. XRD testing shows that with the increase in HA content, the intensity of the diffraction peaks of hydration products in cemented soil gradually decrease. (3) In general, HA will gradually deteriorate the integrity of cemented soil and reduce its strength. When the HA content is more than 15%, the effect of HA on strength is more prominent. However, increasing the cement mixing ratio can effectively weaken HA’s negative effect on cemented soil’s strength. When the cement mixing ratio is between 15% and 25%, the strength of cemented soil with high HA content can be effectively increased. However, this approach is not conducive to the protection of the environment.

Palaeoenvironmental research at Hawelti–Melazo (Tigray, northern Ethiopia) – insights from sedimentological and geomorphological analyses

Abstract. The sites of Hawelti–Melazo in the Tigray region of the northern Ethiopian Highlands is an archaeological hotspot related to the D'mt kingdom (ca. 800–400 BCE). The existence of several monumental buildings, which have been excavated since the 1950s, underline the importance of this area in the Ethio-Sabaean period. We investigated the geomorphological and geological characteristics of the site and its surroundings and carried out sedimentological analyses, as well as direct (luminescence) and indirect (radiocarbon) sediment dating, to reconstruct the palaeoenvironmental conditions, which we integrated into the wider context of Tigray. Luminescence dating of feldspar grains from the May Agazin catchment indicate enhanced fluvial activity in the late Pleistocene, likely connected to the re-occurring monsoon after the Last Glacial Maximum (LGM). The abundance of trap basalt on the Melazo plateau, which provides the basis for the development of fertile soils, and the presumably higher groundwater level during the Ethio-Sabaean Period, provided favourable settlement conditions. The peninsula-like shape of the Melazo plateau was easily accessible only from the east and northeast, while relatively steep scarps enclose the other edges of the plateau. This adds a possible natural protective function to this site.

Particle size composition characteristics of weathered debris from grey–green slate under the action of freeze–thaw and dry–wet cycles

The material basis for soil formation is rock weathering debris. Understanding the particle size composition characteristics of rock weathering debris and its impacts is important for improving the soil structure of dry farmland in the central dry zone of Ningxia,China. In this study, the particle sizes of weathered debris collected from grey–green slate after indoor simulations of freeze–thaw and dry–wet cycles tests were examined. The results were as follows: (1) Under 16 treatments, the weathering debris of grey–green slate contained about 10% or less very fine sand and coarse silt, while clay, fine silt, and fine sand were the most abundant sizes (at least 60% of the total). (2) Under each treatment, the average particle size of the grey–green slate weathered debris was 5.52Ф (silt grade). The overall skewness was high, but the symmetry was poor. The particle size frequency distribution curve had many broad peaks or multiple peaks. (3) The fractal dimension was associated with very fine silt but had a strong negative correlation with fine sand and medium-coarse sand. The results indicate that fractal dimension can reflect the grain size characteristics of weathered debris. The mineral element content of the grey–green slate somewhat affected the fractal dimension, and it positively correlated with environmental electrical conductivity (EC) and element-leaching amount; it negatively correlated with particle size, temperature, and pH. According to the findings, the fractal dimension can accurately represent the particle size distribution of weathered debris. The generation of grey–green slate weathering debris should be considered in the formation and development of local soil.

Application of Jeevamrit Improves Soil Properties in Zero Budget Natural Farming Fields

Zero Budget Natural Farming (ZBNF), utilizing natural resources, multiple cropping systems, and cow-dung- and urine-based products to improve soil biology, has been practiced by thousands of farmers in India. However, without any scientific proof, this traditional and ancient technique is mocked as a bugged theory in the scientific community. In the current study, we have investigated the effect of Jeevamrit—cow-dung- and urine-based formulation—on soil chemical and microbial properties of the ZBNF field coupled with metagenomic analysis and the economics of ZBNF. The percentage increase in soil properties, such as organic carbon, available phosphorus, and available potassium, was recorded up to 46%, 439%, and 142%, respectively, while micronutrients, such as Zn, Fe, Cu, and Mn, also increased up to 98%, 23%, 62%, and 55%, respectively, from 2017 to 2019. Whole genome metagenomic analysis revealed that Proteobacteria were dominantly present, and bacterial phyla including Bacillus, Pseudomonas, Rhizobium, and Panibacillus. On the other hand, Ascomycota was the dominating fungal phyla present in the soil sample. Further, functional analysis showed a high representation of genes/enzymes involved in amino acids and carbohydrate metabolism contributing to soil fertility, plant growth, defense, and development. Additionally, the cost–benefit ratio of ZBNF was double the farmer’s practice when tested with the rice and wheat cropping system. The results from this study provide a new proof of concept and understanding of the potential of the ZBNF component, i.e., Jeevamrit, in improving soil properties.

Quantification of Physiological Parameters of Rice Varieties Based on Multi-Spectral Remote Sensing and Machine Learning Models

Estimating plant physiological indicators with remote sensing technology is critical for ensuring precise field management. Compared with other remote sensing platforms, low-altitude unmanned aerial vehicles (UAVs) produce images with high spatial resolution that can be used to clearly identify vegetation. However, the information of UAV image data is relatively complex and difficult to analyze, which is the main problem limiting its large-scale use at present. In order to monitor plant physiological indexes from the multi-spectral data, a new method based on machine learning is studied in this paper. Using UAV for deriving the absorption coefficients of plant canopies and whole leaf area, this paper quantifies the effects of plant physiological indicators such as the soil and plant analyzer development (SPAD) value, whole leaf area, and dry matter accumulation on the relationship between the reflectance spectra. Nine vegetation indexes were then extracted as the sensitive vegetation indexes of the rice physiological indicators. Using the SVM model to predict the SPAD value of the plant, the mean squared error (MSE), root mean squared error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and symmetric mean absolute percentage error (SMAPE) values of the model were 1.90, 1.38, 0.13, 0.86, and 4.13, respectively. The results demonstrate that the rice plants display a considerable biochemical and spectral correlation. Using SVM to predict the SPAD value has a better effect because of a better adaptation and a higher accuracy than other models. This study suggests that the multi-spectral data acquired using UAV can quickly estimate field physiological indicators, which has potential in the pre-visual detection of SPAD value information in the field. At the same time, it can also be extended to the detection and inversion of other key variables of crops.

Development of artificial potting soils mixed with various local agronomical ores, ameliorants, agricultural and manufacturing wastes

In the process of growth and development, cultivated plants synthesize dry matter by removing mineral nutrients from the soil. Therefore, the root layer of cultivated plants must be rich in elements of mineral nutrition. Their economic removal as a result of alienation from the grown crop requires a return to the soil to increase its fertility and ensure the productivity of the upcoming harvest. The research aims to develop artificial grounds mixed with various local agricultural ores, ameliorants, and waste from agricultural and industrial production, including macro- and microelements. Studies were conducted under artificial conditions in the phytotron of Bashkir State Agrarian University. In the control variant, oats had the highest productivity and plant survival (57.0%), slightly lower - in spring wheat (43.0%), and the lowest - in pea (28.0%) because of potting soil acidity. The authors believe that the addition of zeolite to the soil increases the productivity of peas by 20.0%; spring wheat by 20.9; oats by 24.0%; with phosphogypsum by 38.0, 24.9 and 30.0%, respectively. The most effective in the experiments was the variant of potting soils with defecate. The growth in pea plants was 44.0%, spring wheat - 29.10 and oats - 234.0%. Potting soils and their components have excellent prospects in crop production in Russia.

Evaluation of soil-vegetation interaction effects on water fluxes revealed by the proxy of model parameter combinations.

The coupled development of soil and vegetation leads to a close interaction between their attributes and impacts the sustainability of eco-hydrology at different scales. In this study, a distributed hydrological model of a watershed was created with the Soil and Water Assessment Tool (SWAT) in a representative tributary watershed for investigating such effects. The results quantify the intensity and interval of the relationship and the impacts on hydrological composition between major model parameters. Among the examined interactions, SCS runoff curve number (CN2) and soil bulk density (BD) show the strongest interaction and effects on surface runoff, lateral flow, percolation, groundwater flow, and soil water content. The interaction between CN2 and BD highlights the importance of the soil surface and topsoil for runoff generation processes. In addition, the soil-vegetation interactions show clear seasonal effects due to impacts from the changes in land use and precipitation patterns, which influence the river discharge and flow variability more significantly at the sub-basin scale than at the watershed scale. The insight into the interactions and hydrological effects of soil and vegetation may help improve the spatial planning for ecological sustainability and hydrological extrema mitigation with a more reliable reflection of the spatial heterogeneity.

Spatial patterns of prokaryotic communities in kettle hole soils follow soil horizonation

Kettle holes are small lentic wetlands <1 ha that are often embedded in agricultural landscapes. These small landscape elements are influenced by their surroundings, as fertilizers and eroded soils are transported into these wetlands. Further, kettle holes often display highly variable water tables, resulting in differences in soil development and spatiotemporal habitat changes. The impact of these spatial heterogeneities of kettle hole soils on prokaryotic communities remains mostly unknown. In this study, we collected soil cores from different positions within a kettle hole and the adjacent farmland. The soil cores were divided into different horizons due to soil development and erosion processes. Basic soil parameters were determined and prokaryotic community analysis was performed based on 16S rRNA gene amplicon sequencing and qPCR. The results indicate that prokaryotic communities were only weakly differentiated by landscape element (PERMANOVA R2 = 0.08, P = 0.001), but showed a clear pattern according to soil horizons (R2 = 0.28, P = 0.001), though not to soil depth. Overall, the organic-rich horizons hosted prokaryotic communities with a significantly higher abundance and richness compared to mineral soil horizons. The mineral horizons that were groundwater-influenced harbored communities that were most similar to the ones in organic-rich peaty horizons. Like the peaty horizons, these colluvial horizons harbored high relative abundances of taxa being associated with different redox-sensitive biogeochemical cycles, including Geobacteraceae, Nitrosomonadaceae, Nitrospiraceae and Desulfobacterota. This indicates, that microorganisms contributing to biogeochemical processes find ideal conditions in these horizons due to fluctuating water levels and thus fluctuating redox conditions. Our findings indicate that small-scale heterogeneities in kettle holes are relevant for the localization of microorganisms being involved in different biogeochemical cycles. This heterogeneity needs to be considered when evaluating the ecological relevance of kettle holes as landscape elements.

Development of complex indicators and evaluation of efficiency for dump-type earthmoving and transport machines

Introduction. In modern market conditions, dump-type earth-moving transport machines especially need to analyse the marketing of these machines. Therefore, some acquired earth-moving machines during the development of soils with stony inclusions (typical for the RK) quickly wear out their cutting edges of the knife, then gradually fail the machines themselves, thereby not justifying their cost, i.e. are not operated effectively in practice. The goal is to choose from a variety of types of machines the most effective models of earth-moving and transport machines of the dump type, adapted to the conditions of the ground background of the Republic of Kazakhstan with the help of developed complex evaluative indicators.Methods and materials. As materials, the well-known 6 specific, generalized parameters and additionally developed by the authors of 20 assessment indicators (specific, generalized, differential and integral) were used to evaluate the competitiveness of the projected new design of the working body of the earth-moving transport machine of the dump type, as well as the operated these machines.Outcomes. As a result of the analysis of the interaction of the working body of the bulldozer with the developed soil and the study of their parameters, the estimates were developed and formed to assess the effectiveness of the bulldozer. The field tests of the proposed six promising design solutions for a bulldozer with different blades were carried out to compare the structures with each other and evaluated them in quantitative form. According to the calculated estimates, the efficiency of the bulldozer blade was evaluated for six variants of structural executions and graphs of changes in the estimated indicators from experimental data were built on their numerical values, allowing to evaluate the technical and economic efficiency for various designs of bulldozer blades.Discussion and conclusion. The analysis of the estimated indicators: material consumption G/Gпр and G/P show, that with the improvement of the blade design (cutting off the two lateral upper parts of the blade and adding the two lower side – extension knives), the metal intensity decreases, and the volume of the maximum set of drawing prisms increases, respectively, the productivity of the bulldozer increases; energy intensities, N/П, N/Gпр and G∙N/P2 show, that with the improvement of the design of the bulldozer blade, energy performance improves, i.e. the energy consumption spent on the development of a single volume of soil decreases; the specific force per unit width of the R/B knife and the specific power per unit width of the N/B knife are reduced. Generalized power savings and power loads R · N/B2 shows that, with the improvement of the blade design, their values almost do not change (the blade of the type design and the blades with equipment - a protruding middle knife and side scarves sharply (jumpingly) increase the volume of the prism drawing.

Structural layout and operating parameters for a large rotor of a direct-flow bucket wheel type aggregator

Introduction. The problem of accelerating and cheapening the construction of roads without reducing their quality can be solved by creating a complex of continuous units. Units, following each other, carry out the whole complex of works aimed at the construction of roads. The use of satellite navigation opens up broad prospects for full automation of units. Therefore, the overall goal is to create a complex of units that carry out the continuous construction of roads, mainly in automatic mode. One of the devices that make up the continuous units is a direct-flow bucket wheel type aggregator. The use of direct-flow bucket wheel type aggregators for soil development is constrained by insufficient theoretical substantiation of their parameters. Before analyzing the interaction of the elements of the working bodies of a direct-flow bucket wheel type aggregator with the soil, it is necessary to clarify the structural layout for the rotor of a direct-flow bucket wheel type aggregator.The method of research. Some design parameters of a direct-flow bucket wheel type aggregator are derived from logical reasoning. Other parameters of the direct-flow bucket wheel type aggregator are obtained by constructing schemes for the impact of the knife on the ground in the plane and spatial modelling. Initially, the rotor of a direct-flow bucket wheel type aggregator with a diameter of one meter was adopted for calculation.Results. The circular and end knives are assigned the numbers № 1, № 2, № 3, etc. as it approaches from the periphery of the rotor to the axis of its rotation. On the basis of the adopted methodology, the design of the knife attachment, the front and back corner of the circular and end knives have been clarified. An extremely small distance from the axis of rotation of the rotor to the nearest point of the knife is established. Hence the conclusion is made that in addition to a large rotor, in conjunction with it, it is necessary to install a small rotor. The circumferential velocity of the blade of no. 1 circumferential knife and the angular velocity of the large rotor are determined. It is customary to arrange the knives in three rows, that is, the rows of knives around the circumference are deployed at an angle of 120° relative to each other. The feed on the end knife was revealed, that is, the thickness of the layer cut by the end knife.Conclusion. On the basis of the adopted methodology, the geometric and mode parameters of a large rotor of a direct-flow bucket wheel type aggregator have been determined. An extremely small radius of location of the circular and end knives of the large rotor is established. To excavate the soil near the axis of rotation for the rotor of the direct-flow bucket wheel type aggregator, a small rotor with a higher angular velocity shall be coaxially installed. The direction of rotation of the small rotor shall be opposite to the direction of rotation of the large rotor in order to partially compensate for the reactive moment produced by the large rotor.