Soil Processes Research Articles

Evaluation of soil properties variability along a toposequence in Wasinmi, Southwest Nigeria

Abstract Topography significantly influences soil development and characteristics within an uneven agricultural field. Therefore, a comprehensive understanding of soil attributes and processes through detailed pedological knowledge is crucial for effective soil management. This research was carried out in Wasinmi, southwestern Nigeria, to delineate and categorise the soils across different slopes for agricultural insights. Three soil profiles were excavated across the topographical sequence, specifically designated as upper, middle, and lower slope positions. The prevailing soil texture was sandy loam with a discernible trend of lighter soil colour as the slope descended and soil depth increased. The pH of the soil ranged from moderately acidic to slightly acidic. The saturated hydraulic conductivity and soil organic matter content were lowest on the lower slope. Available phosphorus distribution varied inconsistently with higher concentrations of heavy minerals observed at the upper slope. The study underscored the influential role of topography in soil property variations and the need for tailored management practices. The classification of the soils revealed Typic Plintustults in the upper and middle slope positions, while the soils in the lower slope were identified as Typic Kandiaquults. This study demonstrated that topography significantly influenced soil properties, thereby emphasising the need for informed practices to better support the long-term sustainability of land use and agricultural outputs in topographically diverse landscapes.

European agricultural soil management: Towards climate‐smart and sustainability, knowledge needs and research approaches

AbstractCurrent soil‐ and land degradation seriously challenge our societies; it contributes to climate change, loss of biodiversity and loss of agricultural productions. Yet, soils are also seen as a major part of the solution, if maintained or restored to provide ecosystem services. Climate‐smart sustainable management of soils can provide options for soil health maintenance and restoration. In the European Union, the resource management and sustainability challenge are addressed in the Green Deal that, among other goals, aspires towards a healthy climate‐resilient agricultural sector that will produce sufficient products without damaging ecosystems and contribute to better biodiversity and mitigate climate change. The European Joint Programme (EJP) SOIL was set up to contribute to these goals by developing knowledge, tools and an integrated research community to foster climate‐smart sustainable agricultural soil management that provides a diversity of ecosystem service, such as adapting to and mitigating climate change, allowing sustainable food production, and sustaining soil biodiversity. This paper provides an overview of the potential of climate‐smart sustainable soil management research to the targets of the Green Deal that are related to soils most directly. The EJP SOIL EU‐wide consultation (interviews and questionnaires) and literature analysis (national and international reports and papers) done in the first year (2020–2021) generated a wealth of data. This data showed that there are specific manners to do research that are essential for it to be effective and efficient and that can actively contribute to the Green Deal targets. We concluded that research needs to be: (i) interdisciplinary, (ii) long‐term, (iii) multi‐scaled, from plot to landscape, (iv) evaluating trade‐offs of selected management options for ecosystem services and (v) co‐constructed with key stakeholders. Research on climate‐smart sustainable soil management should be developed (1) on plot scale when mobilizing soil processes and on landscape scale when addressing sediment and water connectivity and biodiversity management; and (2) address the enabling conditions through good governance, social acceptance and viable economic conditions.

Антропогенді ластаған биогеоценоздарды диагностикалауда топырақ мезофаунасының түр құрамын пайдалану

Soil invertebrates are an important driving force behind many basic soil processes, such as the formation of soil aggregates, water retention, and absorption of organic matter. Earthworms, being permanent inhabitants of the soil, play the role of an indicator transmitting information about the state of this environment. In this work, anthropogenic pollution of urban and suburban biogeocenoses was revealed by studying the species composition and abundance of lumbricides. Soil samples were taken from 8 sites in Almaty and the region, physico-chemical parameters were studied. In background and slightly polluted biogeocenoses, the number of earthworms averages 64.6%, and in polluted regions 55.2%. When determining the content of toxic elements in urban and background (natural) biocenoses, four main elements were identified that affect the species and quantitative composition of the mesofauna: lead, cadmium, arsenic and mercury. The maximum content of cadmium and arsenic is observed in soils near oil depots: the cadmium content was 0.25±0.0024 mg/kg, and the arsenic content was 2.84±0.05 mg/kg. And in the soil near the thermal power plant of the Algabas microdistrict of the Alatau district, the maximum content of lead and mercury was recorded, which reached 16±0.70 mg/kg and 0.048±0.012 mg/kg, respectively.

Influence of tillage methods on carbon dioxide emissions in spring wheat crops

The agriculture intensification is associated with an increase in anthropogenic load on arable soils. Tillage leads to disruption of the natural process of soil formation in connection with which the soil biota activity changes and the carbon cycle is disrupted. The purpose of the study is to establish the effects of the tillage method on the carbon dioxide emission in spring wheat crops. The emission of carbon dioxide during the growing season of spring wheat varies significantly depending on the soil processing method and temperature. At the beginning of spring wheat development, the daily emission of carbon dioxide during the dump and subsurface tillage method does not exceed 36.0 and 36.2 CO2 kg/ha using zero technology provides a reduction in production CO2 production to 27.8 kg/ha*day. With an increase in soil temperature by July 24, the daily emission increases on a dump and subsurface background to 105.5 and 106.0 CO2 kg/ha*day, on a zero background to 95.4 CO2 kg/ha*day. In the future, it decreases. The total carbon losses during the dump and subsurface tillage methods are 2829 and 2793 kg/ha, the use of zero tillage technology reduces carbon losses in grain agrocenosis by 18%.

SPECIFICITY OF FORMATION OF GENETIC NATURE OF PROFILE-DIFFERENTIATED SOILS OF THE CARPATHIAN REGION AND DIAGNOSTICS OF ELEMENTARY SOIL PROCESSES

The problems of improving the genetic diagnostics of profile-differentiated soils of the Precarpathian region on the basis of elementary soil processes as one of the most important tasks of soil science are considered. The influence of elementary soil processes on the formation of the morphological picture of the soil profile and their diagnostic criteria based on changes in the mineral part of sod-podzolic (brownish-podzolic) and brownish-podzolic soils is substantiated. It is shown that podzolisation and loessification createfavourable conditions for gley-eluviation and its fsrst phase- «bleaching», which lead to the lightening of eluvial horizons, possible destruction of the mineral part of the soil and are considered as concomitant. An assumption has been made about one of the mechanisms of formation of albeluvial leaks in the eluvial horizon of profile-differentiated soils of the Precarpathian region. The concequences of the passage and the diagnostic criteria for the separation of ashing (acid hydrolesis) leaching and gley-eluviation are presented. The indicators of loss and accumulation of silt fraction in the soil profile are analysed sn terms of the concequences of profile formation and related soil formation processes. Most of the studied sections of profile-differentiated soils of the Precarpathian region of different nomenclature and classification have similar parameters of silt loss from the upper eluvial thickness and its accumulation in the illuvium. The parameters of silt deficit in the profile and its illuvial accumulation indicate a similar intensity of the development of the profile-forming process of podzolisation in sod-podzolic (brownish-podzolic) and brownish-podzolic soils. The diagnosis ofa higher degree of podzolisation of profile-differentiated soils by the thickness of the eluvial and humus-eluvial horisons is not always consistent with the loss of silt from the eluvial layer compared to medium-podzolic soils.

Properties of dark gray forest soil in the cultivation of cereals according to various basic processing systems

The purpose of the research is to establish the influence of various systems of basic dark gray forest soil processing with prolonged use on the transformation of the most important fertility elements. The results of prolonged (1988-2022) exposure to processing systems in the grain-steam crop rotation are presented: dead fallow, winter rye, spring wheat, spring barley, in the northern forest-steppe of the Tyumen region of the Russian Federation. The basic tillage systems were compared: dump, non-dump, combined, differentiated, flat-cut, surface. The peculiarities of the transformation of fertility elements under prolonged exposure to basic processing systems of varying intensification degrees are determined. It was found that the long-term use of basic treatment systems of varying minimization degrees in conditions of complex chemicalization ensured the formation of water-physical properties, nutritional conditions and phytosanitary conditions in their values slightly inferior or close to the control version of the dump processing system. Tillage systems with minimization elements reduced the energy efficiency coefficient in comparison with the dump system against the background of fertilizer application by 4.5‑11.5%, against the background without fertilizers – by 7.7‑18.4%. The lowest decrease in efficiency in comparison with the dump processing system for both nutrient backgrounds was for the combined processing system – 4.5‑7.7 %.

Taking sides? Aspect has limited influence on soil environment or litter decomposition in pan-European study of roadside verges

In addition to well-known effects on species ecophysiology, phenology, and distributions, climate change is widely predicted to impact essential ecosystem services such as decomposition and nutrient cycling. While temperature and soil moisture are thought to influence litter decomposition, elucidating consistent soil process responses to observed or predicted shifts in climate have proven difficult to evidence. Here we investigated how aspect (i.e., north-south orientation), a natural model for variation in soil temperature, influenced soil physico-chemical conditions and decomposition of two standardised litter types (Green tea and Rooibos teabags) in Pole-facing (PF) and Equator-facing (EF) roadside verges spanning a 3000 km and 27° latitudinal gradient across Europe. Despite average daily temperatures being 1.5 - 3.0 °C warmer on EF than PF slopes, there were only minor region-specific differences in initial soil physico-chemical conditions and short-term variation in litter decomposition (i.e., litter mass loss was higher in EF-verges for the first month of deployment only) associated with aspect. We conclude that previously observed differences in soil environments and the decomposition process associated with slope orientation, is largely litter or environment specific, although medium-term soil-decomposition in semi-natural grassland ecosystems may also be insensitive to the magnitude of temperature variation within the range predicted by the IPCC SSP1–2.6 emissions scenario. Nonetheless, consistent average and extreme temperature differences between adjacent PF- and EF-aspects along roadside verges provides a model system to explore exactly how resilient the soil environment and the micro-organisms responsible for decomposition, are to temperature variation.

The Effect of Conventional and Conservative Tillage Systems on Microbial Community Composition and Physiological Activity in Soils from Bărăgan Plain

The paper aimed to present the results of research carried out on size, taxonomic composition and physiological activity of soil microbiota for assessing the effect of classic (conventional) and conservative (minimum tillage) agriculture systems applied in a zone affected by aridification from Bărăgan Plain. Significant differences concerning the quantitative parameters characterizing the bacterial and fungal communities from the two soil systems of tillage have been evidenced. Total counts of bacteria doubled and total counts of fungi was with one order of magnitude higher in soil minimum-tilled than in soil under conventional tillage system. Soil respiration values registered for both conservative and conventional systems are considered to characterize high levels of microbial physiological activities, with slightly higher values for minimum tillage system application than for conventional system. The beneficial effect of conservative system was evidenced by higher values of diversity indices registered for both bacterial and, especially fungal communities, as compared with those characterizing the communities from soil under conventional tillage system. The minimum tillage system favoured the increasing of abundance and diversity of actinomycetes, the dominance of Pseudomonas and Bacillus bacterial species and fungal species belonging to genera Aspergillus, Trichoderma, Mortierella and Paecilomyces in composition of soil microbiota, with multiple roles in main soil processes: decomposition of vegetal residues, synthesis of humus precursors, carbon sequestration, alleviation of various abiotic stress (drought, salinity), increasing accessibility of nutrients for plants, yields, biocontrol of plant pathogens.

Investigating the accuracy and comparability of various lime prediction methods for Irish grassland mineral soils

AbstractSoil pH is a foundational element of agronomy, profoundly influencing biological, chemical and physical soil processes. Adjusting soil pH is a paramount factor for enhancing soil health and productivity with far‐reaching environmental benefits. Over time soil naturally tends towards acidity, a process expedited by intensive agriculture practices. To determine the extent of necessary pH corrections, precise soil pH testing is imperative. Various methods including buffer systems, titrations, lime incubations and algorithms considering soil texture are used to assess a soil's lime requirement and each method carries distinct advantages and disadvantages. The Shoemaker–McLean–Pratt (SMP) buffer method is extensively used in Ireland and internationally; however, safety concerns owing to the use of hazardous chemicals required within the method have been highlighted. This study investigates various soil lime requirement tests and compares their performance against a lime incubation study. A proposed alternative to the SMP buffer test for Irish grassland soils is also investigated. Analysis of results obtained indicates that the SMP buffer method demonstrated the highest r2 value of .497 when correlated with lime incubation results, while the calcium hydroxide titration method closely aligns with the SMP buffer method with an r2 value of .816, followed by the modified Mehlich buffer method with an r2 value of .763.

ESTIMAREA INTENSITĂȚII ALEATORII A FORȚELOR DE TRACȚIUNE ÎN SUPORTURILE ORGANELOR DE LUCRU ALE UNUI CULTIVATOR

The investigation on the unpredictability of the distribution of traction resistance forces on the working bodies of a specific type of MCLS complex cultivator is presented in the paper. The validation of the random character of the force that loads the active bodies is used to indicate the mathematical model that must be followed for the research of the soil processing system. Also, the research results elucidate some hypotheses issued in the conception and design of the machine: the more intense load for the working bodies from the lines of working bodies located immediately after the tractor, the existence of working bodies that are constantly more intensively requested and the causes. According to the literature, it is to be assumed that the forces that demand the working bodies, the supports, and the machine frame have a random nature. The conclusions of the descriptive, inferential statistical study (which do not quantify the random intensity) are explained together with the results. The experimental loads are compared to some of the most random strings to produce a quantitative estimate of the random intensity. As a result, processes that use random functions and the entirety of their approach are recommended in mathematical modelling for further research

Effect of Compaction Energy on Selected Physical and Hydraulic Properties of Soils Amended With Different Sources of Organic Matter

Soil compaction has been recognized as a severe problem in mechanized agriculture and influences soil properties and processes. A study evaluated the effect of different energy levels on selected properties of Alfisols treated with different sources of organic amendments. The treatments consisted of soils with compost (10 pots), cow dung (10 pots), and control. These were laid out in a completely randomized design and replicated two times. All pots (soil ± amendment) were saturated and allowed to drain freely for 24 hours and 48 hours, respectively, and compacted to 0, 75, 150, 225, and 300 Joules of energy. Bulk density (BD), penetration resistance (PR), saturated hydraulic conductivity (Ksat), particle size distribution (PSD), gravimetric moisture content (GMC), and moisture retention (MR) was determined from treated plots. Results obtained indicated that the soil is sandy. BD and PR were highest in control, with mean values of 1.803 g cm-3 and 1.762 kg F cm-2, respectively. Treatment with compost improved the BD and PR with lower mean values of 1.320 g cm-3 and 1.283 kg F cm-2 respectively, compared to cow dung and untreated control. With increasing energy inputs, there was a highly significant difference amongst the studied soil properties at all the energies at p<0.0001. Minimum tillage is recommended to reduce the stress caused by heavy energy inputs on these soil properties. The organic matter will directly contribute to plant nutrients such as nitrogen, phosphorus, and micronutrients.

Effects of rainfall, sediment source–sink landscape, and hydrological connectivity on runoff more than sediment in a karst basin

AbstractUnderstanding the mechanisms underlying soil and water loss in karst basins is beneficial for water resources management and soil and water loss conservation. However, the effects of rainfall, sediment source–sink landscape, and hydrological connectivity on runoff sediment characteristics in karst basins are unclear. This study used sediment source–sink landscape and hydrological connectivity theories and a generalized additive model to analyze the changes and combined effects of sediment source–sink landscape patterns, hydrological connectivity, and rainfall on runoff sediment from 2000 to 2020 in the Yeji River basin in the karst region of southwest China. The results indicated that the average sediment transport modulus and runoff modulus in the Yeji River basin during 2000–2020 were 144 t·km−2·a−1 and 15 L·s−1·km−2, respectively. The karst surface and subsurface double‐layer hydrological structure resulted in a lower sediment transport modulus than in non‐karst areas. The sediment‐source landscape area decreased, sediment‐sink landscape area increased, and sediment source–sink landscape load ratio index slightly increased. Hydrological connectivity exhibited a decreasing trend over time, but the overall change was small. Changes in source–sink landscape patterns significantly affected hydrological connectivity. As the main affecting factor, rainfall and its combined effects with sediment source–sink landscape patterns and hydrological connectivity explained 85% and 95% of the variances in runoff, and 40% and 63% of the variances in sediment, respectively. These results suggest that a rational layout of the sediment source–sink landscape can effectively improve hydrological connectivity and regulate the soil and water loss process. Our findings have important implications for karst basin ecological restoration and protection.

Modification of Land Cultivation Techniques in Cultivating Tomato Plants (Solanum lycopersicum)

Tomato (Solanum lycopersicum) is one of the horticultural crops that has high economic value and is widely cultivated throughout the world. Tomato cultivation requires special attention, especially on tillage techniques to achieve maximum results. The purpose of this study was to determine soil processing techniques in the cultivation of tomato plants (Solanum Lycopersicum) in Claket village, Mojokerto Regency. The method used is observation with discrimination. The results of the study were that the land processing technique is with No Tillage (TOT) / Zero Tillage, Minimum Tillage and Maximum Tillage. The tillage technique applied by the Farmer Group in Claket village, Mojokerto regency is a maximum tillage technique, where the tillage process is carried out from the initial stage to the end and the land is ready for planting, so that the tomato plants produced are very good and of high quality.

DYNAMICS OF FERTILITY INDICATORS OF LIGHT-CHESTNUT SOIL AND OIL FLAX PRODUCTIVITY UNDER BOGARIAN CONDITIONS OF SOUTHEAST KAZAKHSTAN

The suitable research aims to ascertain the optimum dose of mineral fertilizers and methods of soil processing and preparation for successful flax (Linum usitatissimum L.) cultivation in the semi-arid conditions of the Almaty Region, Kazakhstan, focusing on achieving high crop productivity with good seed quality. Agrochemical investigations also employed modern devices and widely accepted methods. Studying parameters, such as total humus, labile humus, nitrate nitrogen, mobile phosphorus, exchangeable potassium, soil composition density, structural-aggregate composition, and moisture supply, ensued using specific techniques. The study observed an enhancement in nitrate nitrogen content in the soil, from an initial level of 11–19 mg/kg to 36–91 mg/kg during flax harvest in all experimental variants. On the contrary, the mobile phosphorus exhibited a decline in the soil from the beginning of crop vegetation until harvest; however, determining the available phosphorus in different practices showed medium, high, higher, and very high. Moreover, a decline in exchangeable potassium content (from 344–446 mg/kg to 175–215 mg/kg) emerged during the flax crop across all the experimental variants. The application of mineral fertilizers NPK at the rate of 60:60:30, with the application of a growth regulator Ecorost at the rate of 2 liters per ton of seeds, and employing a flatcut treatment (10–12 cm) on light chestnut soil in the semi-arid zone with super dry season of Almaty Region, resulted in the highest flax yield in cv. Karabalykskaya (410 kg/ha

Soil processes in the Aeolian Litoral Sheet of Doñana National Park (Huelva, SW Spain): the catena of Colón small-lake ecosystem

The wetlands on the quartz sands aeolian sheet make up one of the ecosystems most recognized and important of the Doñana National Park and Doñana Biological Reserve (South Spain). More than 650 temporal small-lakes have been surveyed in the abundant sand depressions of the aeolian sheet, the most are a hydro-geomorphological dune-small-lake system. This paper studies the pedological processes around Colón small-lake ecosystem wetland (COL), one of the more interesting temporal small-lakes. The movement of fine particles through sand dunes ("sand washing") and their subsequent accumulation in depth is the process responsible for the formation of a large part of the small and medium small-lakes in the Eolian Litoral Sheet of Doñana. Their bodies of water are supported by these clay layers generated corresponding sometimes to ancient soil horizons formed under previous different ecological conditions. The vegetation, the soil morphology and the evolution of the physical-chemical processes studied in this geosystem small-lake of Colón allow understand this phenomenon of chronologies very recent.

SOIL MINIMUM TILLAGE SYSTEM IMPACT UPON ARIDITY HINDERED LAND IN TELEORMAN COUNTY

Two land bodies in Teleorman County were characterized in order to identify aridity affected areas. The country's agricultural and edaphic potential were taken into account on one hand, and the negative consequences determined by years long application of classical technology which contributes in the long run to the enhancement of degradation processes of fine textured soils through compaction, cleaving, and waterlogging on the other. In the Traian Administration and Territorial Unit (ATU) a pronounced soils settlement process was noted due to ploughing execution at the same depth and equipment passage on the soil in inappropriate conditions. In the Mavrodin ATU the soils have a high clay content which favors soil compaction and waterproofing raising issues of air capacity. Rape crop output was 3,700 kg/ha on the Calcic Chernozem of the Traian ATU, and 3,000 kg/ha on the Mavrodin Chromic Luvisol in the same soil works system. These soils suitability for soil minimum tillage is low due to specific intrinsically characteristics. Preserving soil covered with vegetation for an as long as possible period is recommended.

Development of the information model of the soil cutting process spatially oriented knife of dynamic action

The results of the construction of an information model of the process of soil cutting with straight-furrow oriented knives of dynamic action are given. Bulldozer equipment and its main tasks are considered. A working hypothesis of the movement of the scraper and the vertically oriented knife has been formed. The working hypothesis is based on the fact that the movement of the spatially oriented knife will be carried out longitudinally - translationally, perpendicular to the trajectory of the movement of the working body. The dynamic movement of the knife will be carried out with the help of a self-oscillating hydraulic vibrator, the development of such a solution was implemented at the Department of Construction Machinery of KNUСA, the prerequisites were the work of the team, in particular, prof. Smirnov V.M. regarding the structure of the working body and prof. Baladinsky V.M. regarding the regularities of creating dynamic movements of cutting elements of earth-moving machines. And also, based on the works of Khmara L.A., candidate in connection with the intensification of the mechanization of earthworks in construction. Their vector movement and determination of the angles of application of the main cutting force to the corresponding angle α are presented. After constructing the movement vectors of the working body and the spatially oriented knife, a method of calculating the direction of the cutting force and the deflection angle α was developed. Using vector sums and speed ratios ranging from 10:1, where the spatially oriented knife moves ten times faster than the blade, to 1:10, where the spatially oriented knife moves ten times slower. A graph of the determination of the angle α is plotted depending on the ratio of the blade feeding speeds and the displacement of the spatially oriented knife. The speed ratio is calculated and entered in the speed ratio table according to the angle α and the bulldozer's gear ratio.

Effect of fire and post-fire management on soil microbial communities in a lower subtropical forest ecosystem after a mountain fire

Wildfires and post-fire management exert profound effects on soil properties and microbial communities in forest ecosystems. Understanding microbial community recovery from fire and what the best post-fire management should be is very important but needs to be sufficiently studied. In light of these gaps in our understanding, this study aimed to assess the short-term effects of wildfire and post-fire management on both bacteria and fungi community composition, diversity, structure, and co-occurrence networks, and to identify the principal determinants of soil processes influencing the restoration of these communities. Specifically, we investigated soil bacterial and fungal community composition, diversity, structure, and co-occurrence networks in lower subtropical forests during a short-term (<3 years) post-fire recovery period at four main sites in Guangdong Province, southern China. Our results revealed significant effects of wildfires on fungal community composition, diversity, and co-occurrence patterns. Network analysis indicated reduced bacterial network complexity and connectivity post-fire, while the same features were enhanced in fungal networks. However, post-fire management effects on microbial communities were negligible. Bacterial diversity correlated positively with soil microbial biomass nitrogen, soil organic carbon, and soil total nitrogen. Conversely, based on the best random forest model, fungal community dynamics were negatively linked to nitrate-nitrogen and soil water content. Spearman's correlation analysis suggested positive associations between bacterial networks and soil factors, whereas fungal networks exhibited predominantly negative associations. This study elucidates the pivotal role of post-fire management in shaping ecological outcomes. Additionally, it accentuates the discernible distinctions between bacterial and fungal responses to fire throughout a short-term recovery period. These findings contribute novel insights that bear significance in evaluating the efficacy of environmental management strategies.

Identification of calculated parameters of the Hardening Soil model based on laboratory soil tests

The modern soil model Hardening Soil, which is used in many software complexes intended for solving geotechnical problems, is considered. The model makes it possible to take into account changes in deformation parameters of soils depending on the level of applied stresses and to describe the deformation processes of cohesive soils under complex loading/unloading trajectories.&#x0D; The paper also presents tables and graphs obtained during laboratory studies of semi-hard clay "Kyiv marl" in a triaxial system and an oedometer. Based on these data, the soil strength parameters с' and φ', as well as the stiffens modules , , were determined.&#x0D; To correlate the results of numerical simulation with the real behavior of clay soil in the Plaxis software complex, using the SoilTest virtual laboratory, a test in a triaxial compression device was simulated and soil parameters were identified. This approach makes it possible to increase the accuracy and quality of calculation results.&#x0D; During identification, the parameters that most affect it were analyzed, which made it possible to better understand which parameters and in which ranges to vary in order to achieve the desired result.&#x0D; It was determined that the most sensitive parameters are the section modulus of rigidity and the coefficient of destruction Rf. Their percentage sensitivity is 65.9% and 32%, respectively.&#x0D; By varying the c' and φ' characteristics during the tests in the virtual laboratory, the destruction of the sample was simulated in accordance with real soil studies. Therefore, it is very important to correctly determine these parameters, because this can lead to an underestimation or, on the contrary, an overestimation of the strength of the soil base.

Spatial Distribution of Ammonia Concentrations and Modeled Dry Deposition in an Intensive Dairy Production Region.

Agriculture generates ~83% of total US ammonia (NH3) emissions, potentially adversely impacting sensitive ecosystems through wet and dry deposition. Regions with intense livestock production, such as the dairy region of south-central Idaho, generate hotspots of NH3 emissions. Our objective was to measure the spatial and temporal variability of NH3 across this region and estimate its dry deposition. Ambient NH3 was measured using diffusive passive samplers at 8 sites in two transects across the region from 2018-2020. NH3 fluxes were estimated using the Surface Tiled Aerosol and Gaseous Exchange (STAGE) model. Peak NH3 concentrations were 4-5 times greater at a high-density dairy site compared to mixed agriculture/dairy or agricultural sites, and 26 times greater than non-agricultural sites with prominent seasonal trends driven by temperature. Annual estimated dry deposition rates in areas of intensive dairy production can approach 45 kg N ha-1 y-1, compared to <1 kg N ha-1 y-1 in natural landscapes. Our results suggest that the natural sagebrush steppe landscapes interspersed within and surrounding agricultural areas in southern Idaho receive NH3 dry deposition rates within and above the range of nitrogen critical loads for North American deserts. Finally, our results highlight a need for improved understanding of the role of soil processes in NH3 dry deposition to arid and sparsely vegetated natural ecosystems across the western US.