Soil Archives Research Articles

Long‐term soil change in the US Great Plains: An evaluation of the Haas Soil Archive

AbstractDiverse patterns of climate and edaphic factors challenge detection of soil property change in the US Great Plains. Because detectable soil change can take decades, insights into the trajectory of soil properties frequently require long‐term site monitoring and, where available, associated soil archives to enable comparisons with initial or baseline states. Unfortunately, few multi‐decadal soil change investigations have been conducted in this region. Here, we document effects of dryland cropping on a suite of soil properties by comparing matched historic (1947) and contemporary (2018) soil samples from the Haas Soil Archive at three sites in the US Great Plains: Moccasin, MT, Akron, CO, and Big Spring, TX. Current analytical methods were used to provide insight into changes in soil texture, pH, carbon, and micronutrients at 0‐ to 15.2‐cm and 15.2‐ to 30.5‐cm depths. Changes in direction and magnitude of soil properties over 71 years were site specific. Changes in textural class occurred at all sites, with Moccasin and Akron transitioning from loam to clay loam and Big Spring from sandy clay loam to sandy loam. The soil pH reaction class changed from slightly alkaline to moderately acid at Akron and slightly alkaline to moderately alkaline at Big Spring. At 0–15.2 cm, soil organic carbon decreased by 15% and 36% at Moccasin and Big Spring, respectively, but increased by 15% at Akron. Soil micronutrients generally declined at all sites. Weather‐related variables derived from air temperature and precipitation records were not correlated with soil change. Inferred factors contributing to soil change included on‐site management, inherent soil features, weather metrics not evaluated, or a combination thereof.

Evaluating consistency across multiple NeoSpectra (compact Fourier transform near‐infrared) spectrometers for estimating common soil properties

AbstractRapid and cost‐effective techniques for soil analysis are essential to guide sustainable land management and production agriculture. This study aimed at evaluating the performance and consistency of portable handheld Fourier‐transform near‐infrared spectrometers and the NeoSpectra scanners in estimating 12 common soil physical and chemical properties including pH; organic carbon (OC); inorganic carbon (IC); total nitrogen (TN); cation exchange capacity (CEC); clay, silt, and sand fractions; and exchangeable potassium (K), phosphorus (P), calcium (Ca), and magnesium (Mg). A diverse set of samples (n = 600) were retrieved from a national‐scale soil archive of the Kellogg Soil Survey Laboratory of USDA‐NRCS and scanned with five NeoSpectra scanners. Predictive models for the soil properties were developed using partial least squares regression (PLSR), Cubist, and memory‐based learning (MBL). Cubist outperformed PLSR and MBL, with the best prediction performance for clay, OC, and CEC (R2 > 0.7), followed by IC, sand, silt, and Mg (R2 > 0.6), and then pH, TN, and Ca (R2 > 0.5). K and P were predicted somewhat poorly with R2 of 0.48 and 0.22. All five NeoSpectra yielded comparable near‐infrared (NIR) spectral data and the PLSR models for the soil properties (in terms of model regression coefficients). However, the consistency assessment showed that the model performance was significantly decreased when the training and testing spectra were from different NeoSpectra scanners. It is concluded that NeoSpectra scanners could be rapid and cost effective for estimating certain soil properties, and calibration transfer should be considered for applications where multiple devices are involved and high estimation accuracy from NIR data is required.

Exploring the past through lynchet landscapes in the Vosges Mountains and the Lorraine Plateau (France)

AbstractLynchets are ridges formed by erosion and sediment accumulation downstream of agricultural plots and offer valuable insights into past agricultural activity. These microtopographies cover vast areas and serve as indicators of historical changes in land use. As a result, their ubiquity across Europe makes them particularly interesting. In this study, we propose a geoarchaeological approach to analyze six lynchets, four in the Vosges Mountains and two on the Lorraine Plateau (France). The lynchets can be considered soil archives with no stratigraphic organization or chronological sequence from bottom to top, making it difficult to determine the age of the lynchets and identify changes in land use over time. To this end, we propose the analysis of historical and geo‐historical archives combined with the “pedosedimentary” archives of lynchets through charcoal identification and dating combined with near‐infrared spectroscopy to determine the age, vegetation, and past land use changes associated with lynchet landscapes. By combining these multiple data sources, we are better able to show the chronological development of these ancient agricultural systems and uncover valuable information on landscape history. Charcoal dating suggests a higher frequency of fires from the Middle Ages. The dating aligns with the regional dynamics of anthropogenic fires, indicating a potential use of fire for cultural purposes. We also demonstrate the difficulty of extrapolating the dating of a lynchet to the entire lynchet system. Our results highlight the difficulties of interpreting the formation and dating of lynchets and the lynchet system on the sole basis of charcoal analysis. However, we highlight the value of applying pedoanthracology to lynchets to determine the dynamics of land use change in former fields.

Optimised use of data fusion and memory‐based learning with an Austrian soil library for predictions with infrared data

AbstractInfrared spectroscopy in the visible to near‐infrared (vis–NIR) and mid‐infrared (MIR) regions is a well‐established approach for the prediction of soil properties. Different data fusion and training approaches exist, and the optimal procedures are yet undefined and may depend on the heterogeneity present in the set and on the considered scale. The objectives were to test the usefulness of partial least squares regressions (PLSRs) for soil organic carbon (SOC), total carbon (Ct), total nitrogen (Nt) and pH using vis–NIR and MIR spectroscopy for an independent validation after standard calibration (use of a general PLSR model) or using memory‐based learning (MBL) with and without spiking for a national spectral database. Data fusion approaches were simple concatenation of spectra, outer product analysis (OPA) and model averaging. In total, 481 soils from an Austrian forest soil archive were measured in the vis–NIR and MIR regions, and regressions were calculated. Fivefold calibration‐validation approaches were carried out with a region‐related split of spectra to implement independent validations with n ranging from 47 to 99 soils in different folds. MIR predictions were generally superior over vis–NIR predictions. For all properties, optimal predictions were obtained with data fusion, with OPA and spectra concatenation outperforming model averaging. The greatest robustness of performance was found for OPA and MBL with spiking with R2 ≥ 0.77 (N), 0.85 (SOC), 0.86 (pH) and 0.88 (Ct) in the validations of all folds. Overall, the results indicate that the combination of OPA for vis–NIR and MIR spectra with MBL and spiking has a high potential to accurately estimate properties when using large‐scale soil spectral libraries as reference data. However, the reduction of cost‐effectiveness using two spectrometers needs to be weighed against the potential increase in accuracy compared to a single MIR spectroscopy approach.

The preservation of bacterial community legacies in archived agricultural soils

The preservation of bacterial community legacies in archived agricultural soils

Dynamics of Diversity of Woody Species Taxa under Human Impact in the Upper Volga Region (NW Russia) According to Pedoanthracological Data

We studied charcoal from several types of natural soil archives, including cultural layers of archaeological sites (hillforts), surrounding forest and arable soils, and sediments in lower parts of the slopes associated with hillforts and moraine hills. The stratigraphy of the charcoals was described, and 41 samples were radiocarbon-dated. Analysis of 2277 charcoals showed the presence of 13 taxa of woody species; Pinus and Picea charcoals dominated. Charcoals older than 300 BC were found only in sediment and in several pits formed after treefalls with uprooting. The greatest diversity of woody species was found in the hillforts’ cultural layers composed of Anthropogenic Dark Earth soils formed between 300 BC and 300 cal. AD (Early Iron Age). All charcoals from ancient arable soils were younger than charcoals from the hillforts. Charcoals indicated that burning for arable farming started in the study region in the 6th century AD. Woody taxa exhibited a decrease in number of species and a decrease in the proportion of nemoral (broadleaved) species from the Early Iron Age to the Middle Ages and to the present. Quercus, Tilia, and Corylus have become relatively rare, although they still occur in the study region. Ulmus and Acer are now rare in the Upper Volga region and were not found in the vicinity of the study sites.

Sub-sampling a large physical soil archive for additional analyses to support spatial mapping; a pre-registered experiment in the Southern Nations, Nationalities, and Peoples Region (SNNPR) of Ethiopia

The value of physical archives of soil material from field sampling activities has been widely recognized. If we want to use archive material for new destructive analyses to support a task, such as spatial mapping, then an efficient sub-sampling strategy is needed, both to manage analytical costs and to conserve the archive material. In this paper we present an approach to this problem when the objective is spatial mapping by ordinary kriging. Our objective was to subsample the physical archive from the Ethiopia Soil Information System (EthioSIS) survey of the Southern Nations, Nationalities and Peoples Region (SNNPR) for spatial mapping of two variables, concentrations of particular fractions of selenium and iodine in the soil, which had not been measured there. We used data from cognate parts of surrounding regions of Ethiopia to estimate variograms of these properties, and then computed prediction error variances for maps in SNNPR based on proposed subsets of the archive of different size, selected to optimize a spatial coverage criterion (with some close sample pairs included). On this basis a subsample was selected.This is a preregistered experiment in that we have proposed criteria for evaluating the success of our approach, and are publishing that in advance of receiving analytical data on the subsampled material from the laboratories where they are being processed. A subsequent short report will publish the outcome. The use of preregistered trials is widely recommended and used in areas of science including public health, and we believe that it is a sound strategy to promote reproducible research in soil science.

Holocene vegetation reconstruction in the forest–steppe of Mongolia based on leaf waxes and macro-charcoals in soils

Abstract. Vegetation and climate reconstruction in the forest–steppe of Mongolia is still challenging regarding the pattern of forest and grassland distribution during the Holocene. Different sediments containing paleosols and humic layers provide geomorphological archives for landscape development in Mongolia. n-Alkane and macro-charcoal ratios represent specific indicators to distinguish the share between grasses and trees. In a preliminary study, we investigated the applicability of these two paleo-proxies from soils for vegetation reconstruction comparing different relief positions and site conditions in the northern Khangai Mountains of Mongolia. n-Alkanes that are deposited from leaf waxes in the soil have the potential to indicate vegetation composition on a local scale. Depending on site-specific environmental conditions, n-alkanes are subjected to different degrees of microbiological decomposition, which is more intensive in soils of dry steppe than of forests. Mongolian forests are often underlain by permafrost that may reduce microbiological activity. In steppe soils, the decomposition of n-alkanes increases the quantity of mid-chain n-alkanes that adulterate the biomarker proxy signal to indicate more forest share. Macro-charcoals in soils have a site-specific component, but additional eolian input of macro-charcoals from long-distance transport can provide a distinct proportion in sediments. Thus, eolian influx of wood-derived macro-charcoal can dominate the proxy signal at sites where trees were few or had never existed. Radiometric dating of several paleosols and humic layers has shown that both proxies coincide as evidence for high grassland-to-forest ratios during the Early Holocene. By contrast, the proxy signals diverge for the Late Holocene. For this period, n-alkanes generally indicate more grassland, whereas macro-charcoals show increased wood-derived proportions. We imply that this difference is caused by increased forest fires and simultaneously spreading steppe area. A main portion of leaf waxes and charcoal particles in soils directly derive from the covering and nearby vegetation, whereas large lakes and glacier may receive these biomarkers from a larger catchment area. Thus, we conclude that soil archives provide proxies on a more local and site-specific scale than other archives do. Although the temporal resolution of soil archives is lower than for the other ones, biomarker proxies for paleosols and humic layer can be related to periods of distinct geomorphological processes. Further investigations comparing the multi-proxy data of different geomorphological archives are necessary to improve the paleo-ecological reconstruction for landscape development in Mongolia.

‘Winter camp’ 1917: integrated conflict archaeology on the Messines Ridge 1914-1918 (Belgium)

ABSTRACT Integrated research using aerial photography, proximal soil sensing, historical research and excavations of an unusual First World War site in Flanders (Belgium) is presented. Aerial photography revealed a grid of 5x6 huts unusually close to the front line. Geophysical research indicates good preservation of these structures. A targeted excavation was carried out. The results give insight into the structure of a military camp built in autumn 1917, used until the German offensive of April 1918. Research on excavated objects and historical sources revealed the camp was as the winter quarters for British and Australian pioneers. The unusual location and the fact that the pioneers occupied the camp themselves means that the huts found were not standard and dug in to provide extra protection. This research shows that barracks camps can be well preserved in the soil archives and have the potential to uncover stories from everyday life behind the front.

A global soil spectral calibration library and estimation service

A global soil spectral calibration library and estimation service

Environmental Difference and Spatial Distance Affect the Fidelity of Variation Source of Microbial Community Structure in Air-Dried Soils.

Air-dried soil archives are important for microbial ecology research, although the process of air-drying preservation inevitably destroys the original microbial information in soils. Only upon fully understanding the limitations of air-dried soil can it play a greater role. The value of air-dried soil depends on the fidelity of microbial community structure information in the air-dried soil relative to that in fresh soil. To evaluate this, high-throughput sequencing was applied to investigate the microbial community of fresh soils and 227 days air-dried archives from typical farmland under a large spatial scale, and PERMANOVA was used to analyze the explanation proportion (EP) of the spatial factor on the microbial community structure in any paired-fresh or air-dried soils. The results show that for any paired soils, the value of EP ranged from 42.4% to 97.9% (p < 0.001). Importantly, taking fresh soil as a reference, the value of EP declined in air-dried soils (effect size r = 0.79, p < 0.001). Furthermore, the standardized difference in EP between fresh and air-dried soil (NDEP) was used to characterize the fidelity of variance source of microbial community structure in air-dried soils, and correlation tests showed that NDEP was negatively correlated with spatial distance (r = −0.21, p < 0.01) and with environmental difference (r = −0.37, p < 0.001). Further analyses show that larger NDEP was observed at a spatial distance <25 km or an environmental difference <0.58. Variance partitioning analysis showed that 28.0% of the variation in NDEP could be explained, with environmental difference constituting 14.0% and the interaction between the environmental difference and spatial distance constituting the remaining 14.0%. Soil texture was the most important factor for predicting NDEP, followed by soil pH and annual average temperature. This study not only emphasizes the possible decline in EP when using air-dried soils to reveal microbial community patterns, but also implies that air-dried soil is more suitable for addressing scientific questions under a large spatial scale or environmental differences.

Soil Archives Ripe for Researching Long‐Term Changes

CSA NewsEarly View SOCIETY SCIENCE Soil Archives Ripe for Researching Long-Term Changes First published: 01 March 2022 https://doi.org/10.1002/csan.20698Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Early ViewOnline Version of Record before inclusion in an issue RelatedInformation

Time in a bottle: Use of soil archives for understanding long‐term soil change

AbstractSoil archives preserve a snapshot of soils from a specific time and location, allowing researchers to re‐evaluate soils of the past in the context of the present for an improved understanding of long‐term soil change. To date, the extent of soil archive use in the peer‐reviewed literature is poorly inventoried. Here, we document the characteristics and distribution of global soil archive use, as found in 245 publications, following an exhaustive search of English language journals. Soil archive use has increased substantially since 1980, reaching 59 publications between 2016 and 2020. The age of soil archives across the compilation ranged from 5 to 160 yr, with mean and median archive ages of 48 and 37 yr, respectively. Publications using soil archives originated mostly from countries in the northern hemisphere, with the top five reporting countries including the United States (61), United Kingdom (52), New Zealand (21), Canada (18), and China (14). Land uses associated with soil archive publications were dominated by agroecosystems, specifically land planted to annual crops. Forty‐seven percent of investigations focused on changes in soil C, N, or organic matter, whereas investigations of other subjects did not exceed 20% each. The compilation is publicly available online. As demands on soils increase, archives will serve as an invaluable tool for understanding long‐term soil change in the Anthropocene era. Multiregional coordination and increased investment in curation and retention of soil archives are recommended to preserve these irreplaceable resources.

The Askov long‐term field experiment (1894–2021) represents a unique research platform#

AbstractLong‐term agricultural field experiments are essential for quantifying changes in soil properties and associated crop productivity that occur slowly but continue over long periods. Initiated in 1894 in the South of Denmark, the Askov long‐term experiment (LTE) is among the few LTEs in the world that continued for more than 125 years. The experiment compares different rates of nitrogen, phosphorus, and potassium applied in mineral fertilizers or animal manure with abundant treatment replicates. With well‐managed treatments, detailed yield records, and a soil archive dating back to 1923, today the Askov‐LTE represents a unique platform for research not envisioned at the start of experiments. Here, we provide a short description of site characteristics and experimental layout, examples of historic crop yields and changes in soil carbon (C) content. We provide short overviews of some of the studies that have used the Askov‐LTE as a research platform. These include crop yield‐related research; models simulating changes in soil C; availability of soil P reserves; indicators of biological, chemical, and physical soil quality; and studies related to prehistoric archaeology. Finally, we offer some reflections on long‐term field experimentation.

Transformation of n-alkanes from plant to soil: a review

Abstract. Despite the importance of soil organic matter (SOM) in the global carbon cycle, there remain many open questions regarding its formation and preservation. The study of individual organic compound classes that make up SOM, such as lipid biomarkers including n-alkanes, can provide insight into the cycling of bulk SOM. While studies of lipid biomarkers, particularly n-alkanes, have increased in number in the past few decades, only a limited number have focused on the transformation of these compounds following deposition in soil archives. We performed a systematic review to consolidate the available information on plant-derived n-alkanes and their transformation from plant to soil. Our major findings were (1) a nearly ubiquitous trend of decreased total concentration of n-alkanes either with time in litterbag experiments or with depth in open plant–soil systems and (2) preferential degradation of odd-chain length and shorter chain length n-alkanes represented by a decrease in either carbon preference index (CPI) or odd-over-even predominance (OEP) with depth, indicating degradation of the n-alkane signal or a shift in vegetation composition over time. The review also highlighted a lack of data transparency and standardization across studies of lipid biomarkers, making analysis and synthesis of published data time-consuming and difficult. We recommend that the community move towards more uniform and systematic reporting of biomarker data. Furthermore, as the number of studies examining the complete leaf–litter–soil continuum is very limited as well as unevenly distributed over geographical regions, climate zones, and soil types, future data collection should focus on underrepresented areas as well as quantifying the transformation of n-alkanes through the complete continuum from plant to soil.

Soil phosphorus over a period of agricultural change in Scotland

AbstractYield increases by use of phosphorus (P) fertiliser has been a defining aspect of last century's agriculture, but in many countries P inputs are now being regulated to avoid ecological damage and improve agricultural sustainability. We tested the hypothesis that P forms and functions in agricultural soils have changed over a period of 50–70 years of agricultural change using topsoils from 35 agricultural sites in North East Scotland compared at ‘original’ and ‘resampled’ timepoints. The original dried and archived samples were collected between 1951 and 1981, and resampling took place in the autumn of 2017 with all samples reanalysed at the same time and by same methods. A range of soil extractants, from labile (water soluble) P, carbon (C) and nitrogen (N) forms, to surface exchangeable P (acid ammonium oxalate extraction), to complexed P (NaOH‐EDTA extraction), were compared with agronomic soil test P (modified Morgan; MM‐P), soil pH, and, on a subset of five time pairs (n = 10), specific P compounds using 31P NMR spectroscopy. Whilst MM‐P had declined significantly in time, all soils were originally and remained at high soil P status. In contrast, no change in labile P pools, nor in the more refractory P pools that replenish labile P, were observed. In the subset analysed by NMR, orthophosphate P consistently increased in concentration. This suggests that soil P shows a slow (multidecadal) response to the documented reductions in fertiliser P for the study region. Significantly greater soil pH (by 0.4 units) over time and reduced water‐soluble C and N forms suggests that labile P in contemporary soils exists in a biogeochemical environment of enhanced solubility and in excess to other available macronutrients that control its microbial cycling. This study represents a long and important period of changing drivers acting on soil P change with potential to improve understanding future soil P trajectories. The value of archived historical soils samples is shown, if care in interpretation of storage implications is made.Highlights Phosphorus fractions in agricultural soil were compared at two timepoints 50–70 years apart. Whilst soil test P declined with time, other labile and refractory P pools did not change. The readjustment of P pools is slow even to substantial change in fertiliser inputs. The investigation of long‐term land use to inform future policy is enabled by soil archives.

Soils in Karst Sinkholes Record the Holocene History of Local Forest Fires at the North of European Russia

Despite the abundance of charcoal material entrapped in soils, they remain relatively less studied pyrogenic archives in comparison to the sedimentary paleofire records (e.g., lacustrine and peat deposits), and that is especially the case in most of Russia’s territory. We report here on the deep soil archives of the Holocene forest fires from the Pinega District of the Arkhangelsk region (64.747° N, 43.387° E). Series of buried soil profiles separated by charcoal layers and clusters were revealed in specific geomorphological traps represented by the active and paleokarst subsidence sinkholes on sulfate rocks overlaid by glacial and fluvial deposits. We combine the study of soil morphology and stratigraphy with a set of radiocarbon data on charcoal and soil organic matter, as well as the anthracomass analysis, to extract a set of paleoenvironmental data. A total of 45 radiocarbon dates were obtained for the macrocharcoal material and the soil organic matter. The maximum temporal “depth” of archives estimated from the radiocarbon dating of macrocharcoal reached 10,260 ± 35 cal yr BP. Soil formation with Podzols established at the inter-pyrogenic stages repeatedly reproduced within the period of ten thousand years, while the dominant tree species was Pinus sp. According to the macrocharcoal data, the intervals between fires have shortened in the last thousand years. Dendrochronological estimates suggest the occurrence of fires in almost every decade of the 20th and early 21st centuries. This is the first study of the millennia-scale soil record of forest fires in this particular region of Russia.

Testate Amoeba Functional Traits and Their Use in Paleoecology

This review provides a synthesis of current knowledge on the morphological and functional traits of testate amoebae, a polyphyletic group of protists commonly used as proxies of past hydrological changes in paleoecological investigations from peatland, lake sediment and soil archives. A trait-based approach to understanding testate amoebae ecology and paleoecology has gained in popularity in recent years, with research showing that morphological characteristics provide complementary information to the commonly used environmental inferences based on testate amoebae (morpho-)species data. We provide a broad overview of testate amoebae morphological and functional traits and trait-environment relationships in the context of ecology, evolution, genetics, biogeography, and paleoecology. As examples we report upon previous ecological and paleoecological studies that used trait-based approaches, and describe key testate amoebae traits that can be used to improve the interpretation of environmental studies. We also highlight knowledge gaps and speculate on potential future directions for the application of trait-based approaches in testate amoebae research.

Patient propagules: Do soil archives preserve the legacy of fungal and prokaryotic communities?

Soil archives are an important resource in agronomic and ecosystem sciences. If microbial communities could be reconstructed from archived soil DNA, as prehistoric plant communities are reconstructed via pollen data, soil archive resources would assume even greater value for reconstructing land-use history, forensic science, and biosphere modelling. Yet, the effects of long-term soil archival on the preservation of microbial DNA is still largely unknown. To address this, we assessed the capacity of high-throughput sequencing (Illumina MiSeq) of ITS (internal transcribed spacer) and prokaryotic 16S rRNA genes for reconstructing soil microbial communities across a 20 years time-series. We studied air-dried soil archives and fresh soil samples taken from Populus bioenergy and deciduous forest research plots at the Kellogg Biological Station. Habitat and archival time explained significant amounts of variation in soil microbial α- and β-diversity both in fungal and prokaryotic communities. We found that microbial richness, diversity, and abundance generally decreased with storage time, but varied between habitat and taxonomic groups. The high relative abundance of ectomycorrhizal species including Hebeloma and Cortinarius detected in older soil archives raises questions regarding traits such as long-term persistence and viability of ectomycorrhizal propagules in soils, with relevance to forest health and ecosystem succession. Talaromyces, Paecilomyces and Epicoccum spp. were detected in fresh and across 20-year-old archived soils and were also cultured from these soils demonstrating their long-term spore viability. In summary, we found that microbial DNA in air-dried soils archived over the past 20 years degraded with time, in a manner that differed between soil types and phylogenetic groups of microbes.

Repeated aeolian deflation during the Allerød/GI-1a-c in the coversand lowland of NW Belgium

Repeated aeolian deflation during the Allerød/GI-1a-c in the coversand lowland of NW Belgium