Soil Science最新文献

{"title":"Potential of natural language processing for metadata extraction from environmental scientific publications","authors":"G. Blanchy, Lukas Albrecht, J. Koestel, S. Garré","doi":"10.5194/soil-9-155-2023","DOIUrl":"https://doi.org/10.5194/soil-9-155-2023","url":null,"abstract":"Abstract. Summarizing information from large bodies of scientific literature is an\u0000essential but work-intensive task. This is especially true in environmental\u0000studies where multiple factors (e.g., soil, climate, vegetation) can\u0000contribute to the effects observed. Meta-analyses, studies that\u0000quantitatively summarize findings of a large body of literature, rely on\u0000manually curated databases built upon primary publications. However, given\u0000the increasing amount of literature, this manual work is likely to require\u0000more and more effort in the future. Natural language processing (NLP)\u0000facilitates this task, but it is not clear yet to which extent the\u0000extraction process is reliable or complete. In this work, we explore three\u0000NLP techniques that can help support this task: topic modeling, tailored\u0000regular expressions and the shortest dependency path method. We apply these\u0000techniques in a practical and reproducible workflow on two corpora of\u0000documents: the Open Tension-disk\u0000Infiltrometer Meta-database (OTIM) and the Meta corpus. The OTIM corpus contains the source\u0000publications of the entries of the OTIM database of near-saturated hydraulic\u0000conductivity from tension-disk infiltrometer measurements\u0000(https://github.com/climasoma/otim-db, last access: 1 March 2023). The Meta corpus is constituted of\u0000all primary studies from 36 selected meta-analyses on the impact of\u0000agricultural practices on sustainable water management in Europe. As a first\u0000step of our practical workflow, we identified different topics from the\u0000individual source publications of the Meta corpus using topic modeling.\u0000This enabled us to distinguish well-researched topics (e.g., conventional\u0000tillage, cover crops), where meta-analysis would be useful, from neglected\u0000topics (e.g., effect of irrigation on soil properties), showing potential\u0000knowledge gaps. Then, we used tailored regular expressions to extract\u0000coordinates, soil texture, soil type, rainfall, disk diameter and tensions\u0000from the OTIM corpus to build a quantitative database. We were able to\u0000retrieve the respective information with 56 % up to 100 % of all\u0000relevant information (recall) and with a precision between 83 % and\u0000100 %. Finally, we extracted relationships between a set of drivers\u0000corresponding to different soil management practices or amendments (e.g.,\u0000“biochar”, “zero tillage”) and target variables (e.g., “soil\u0000aggregate”, “hydraulic conductivity”, “crop yield”) from the\u0000source publications' abstracts of the Meta corpus using the shortest\u0000dependency path between them. These relationships were further classified\u0000according to positive, negative or absent correlations between the driver\u0000and the target variable. This quickly provided an overview of the different\u0000driver–variable relationships and their abundance for an entire body of\u0000literature. Overall, we found that all three tested NLP techniques were able\u0000to support evidence synthesis tasks. While human supervision remains\u0000essential, NLP methods have the potential to support auto","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85559305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wetting and drying cycles, organic amendments, and gypsum play a key role in structure formation and stability of sodic Vertisols","authors":"S. Niaz, J. Wehr, R. Dalal, P. Kopittke, N. Menzies","doi":"10.5194/soil-9-141-2023","DOIUrl":"https://doi.org/10.5194/soil-9-141-2023","url":null,"abstract":"Abstract. In the natural environment, soils undergo wetting and drying (WD) cycles due\u0000to precipitation and evapotranspiration. The WD cycles have a profound\u0000impact on soil physical, chemical, and biological properties and drive the\u0000development of structure in soils. Degraded soils are often lacking\u0000structure, and the effect of organic amendments and WD cycles on structure\u0000formation of these soils is poorly understood. The aim of this study was to\u0000evaluate the role of biotic and abiotic factors on aggregate formation and\u0000stabilization of sodic soils after the addition of gypsum and organic\u0000amendments (feedlot manure, chicken manure, lucerne pallets, and anionic\u0000poly acrylamide). Amended soils were incubated at 25 ∘C over four\u0000WD cycles, with assessment of soil microbial respiration, electrical\u0000conductivity, pH, sodium adsorption ratio (SAR), aggregate stability in\u0000water (ASWAT), aggregate size distribution, and mean weight diameter. Our\u0000results demonstrate that WD cycles can improve aggregate stability after the\u0000addition of amendments in sodic Vertisols, but this process depends on the\u0000type of organic amendment. Lucerne pellets resulted in highest soil\u0000microbial respiration, proportions of large macroaggregates (>2000 µm), and mean weight diameter. In contrast, dispersion was\u0000significantly reduced when soils were treated with chicken manure, whilst\u0000anionic polyacrylamide only had a transient effect on aggregate stability.\u0000When these organic amendments were applied together with gypsum, the\u0000stability of aggregates was further enhanced, and dispersion became\u0000negligible after the second WD cycle. The formation and stability of small\u0000macroaggregates (2000–250 µm) was less dependent on the type of\u0000organic amendments and more dependent on WD cycles as the proportion of\u0000small macroaggregates also increased in control soils after four WD cycles,\u0000highlighting the role of WD cycles as one of the key factors that improves\u0000aggregation and stability of sodic Vertisols.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79300285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quality assessment of meta-analyses on soil organic carbon","authors":"Julia Fohrafellner, S. Zechmeister-Boltenstern, Rajasekaran Murugan, Elena Valkama","doi":"10.5194/soil-9-117-2023","DOIUrl":"https://doi.org/10.5194/soil-9-117-2023","url":null,"abstract":"Abstract. Soil organic carbon (SOC) plays a vital role in the\u0000global carbon cycle and is a potential sink for carbon dioxide. Agricultural\u0000management practices can support carbon sequestration and, therefore, offer\u0000potential removal strategies whilst also improving overall soil quality.\u0000Meta-analysis allows one to summarize results from primary articles by\u0000calculating an overall effect size and to reveal the source of variation\u0000across studies. The number of meta-analyses published in the field of\u0000agriculture is continuously rising. At the same time, more and more articles\u0000refer to their synthesis work as a meta-analysis, despite applying less than\u0000rigorous methodologies. As a result, poor-quality meta-analyses are\u0000published and may lead to questionable conclusions and recommendations to\u0000scientists, policymakers, and farmers. This study aims at quantitatively analyzing 31 meta-analyses, published\u0000between the years of 2005 and 2020, studying the effects of different management\u0000practices on SOC. We compiled a set of quality criteria suitable for soil and\u0000agricultural sciences by adapting existing meta-analytical guidelines from\u0000other disciplines. The set is supported by a scoring scheme that allows for a\u0000quantitative analysis. The retrieved meta-analyses were structured according\u0000to 11 management categories, such as tillage, cover crops, crop residue\u0000management, and biochar application, which allowed us to assess the\u0000state of knowledge on these categories. Major deficiencies were found in the\u0000use of standard metrics for effect size calculation, independence of effect\u0000sizes, standard deviation extraction for each study, and study weighting by\u0000the inverse of variance. Only 1 out of 31 SOC meta-analyses, which studied\u0000the effects of no tillage/reduced tillage compared with conventional tillage, was\u0000found to be of high quality. Therefore, improved meta-analyses on the\u0000effects of organic agriculture, biochar, fertilization, or crop\u0000diversification on SOC are urgently needed. We conclude that, despite efforts over the last 15 years, the quality of\u0000meta-analyses on SOC research is still low. Thus, in order for the scientific\u0000community to provide high-quality synthesis work and to make advancements in\u0000the sustainable management of agricultural soils, we need to adapt rigorous\u0000methodologies of meta-analysis as quickly as possible.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74569773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of long-term mineral and manure fertilization on P species accumulation and phosphate-solubilizing microorganisms in paddy red soils","authors":"Shuiqing Chen, Ju-sheng Gao, Huaihai Chen, Zeyuan Zhang, Jing Huang, Lefu Lv, Jinfang Tan, Xiaoqian Jiang","doi":"10.5194/soil-9-101-2023","DOIUrl":"https://doi.org/10.5194/soil-9-101-2023","url":null,"abstract":"Abstract. Understanding soil phosphorus (P) transformation and turnover under various fertilization managements is important for evaluating sustainable P fertility and potential bioavailability in agriculture managements. Thus, long-term fertilization experiments (∼ 38 years) with the application of different inorganic and organic fertilizers in paddy red soils were\u0000conducted to determine the effect of different fertilizer applications on P\u0000pool accumulation and microbial communities, especially for phosphate-solubilizing microorganisms (PSMs). Long-term inorganic P (IP) fertilization increased the concentrations of total P (TP) (∼ 479 mg kg−1), available P (AP) (∼ 417 mg kg−1) and\u0000inorganic P (∼ 18 mg kg−1), but manure\u0000fertilization accelerated the accumulation of organic P, especially for\u0000orthophosphate monoesters (e.g., myo-IHP, ∼ 12 mg kg−1). Long-term mineral fertilization decreased bacterial richness,\u0000evenness and complexation of bacterial networks. In contrast, long-term\u0000manure fertilization and rhizosphere accumulated more amounts of total\u0000carbon, total nitrogen, and organic carbon, as well as regulated the soil\u0000pH, thus improving the separation of bacterial communities. Furthermore, PSM compositions were greatly influenced by fertilization managements and\u0000rhizosphere. For example, inorganic P fertilization increased the abundance\u0000of Thiobacillus (i.e., the most abundant phosphate-solubilizing bacteria (PSB) in this study) and shifted the community structure of PSB. Correspondingly, the concentrations of inorganic and total P were the key factors for the variation of the PSB community structure. These findings are beneficial for understanding the variation of inorganic and organic P pools and the microbial community, especially for PSMs under long-term inorganic and/or organic fertilization.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88431322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semantics about soil organic carbon storage: DATA4C+, a comprehensive thesaurus and classification of management practices in agriculture and forestry","authors":"K. Fujisaki, T. Chevallier, A. Bispo, J. Laurent, François Thevenin, L. Chapuis-Lardy, R. Cardinael, C. Le Bas, V. Freycon, F. Bénédet, V. Blanfort, Michel Brossard, M. Tella, J. Demenois","doi":"10.5194/soil-9-89-2023","DOIUrl":"https://doi.org/10.5194/soil-9-89-2023","url":null,"abstract":"Abstract. Identifying the drivers of soil organic carbon (SOC) stock changes is of the\u0000utmost importance to contribute to global challenges like climate change,\u0000land degradation, biodiversity loss, or food security. Evaluating the impacts\u0000of land use and management practices in agriculture and forestry on SOC is\u0000still challenging. Merging datasets or making databases interoperable is a\u0000promising way, but still has several semantic challenges. So far, a\u0000comprehensive thesaurus and classification of management practices in\u0000agriculture and forestry has been lacking, especially while focusing on SOC\u0000storage. Therefore, the aim of this paper is to present a first\u0000comprehensive thesaurus for management practices driving SOC storage\u0000(DATA4C+). The DATA4C+ thesaurus contains 224 classified and defined\u0000terms related to land management practices in agriculture and forestry. It\u0000is organized as a hierarchical tree reflecting the drivers of SOC storage.\u0000It is oriented to be used by scientists in agronomy, forestry, and soil\u0000sciences with the aim of uniformizing the description of practices\u0000influencing SOC in their original research. It is accessible in Agroportal\u0000(http://agroportal.lirmm.fr/ontologies/DATA4CPLUS, last access: 24 March 2022) to enhance\u0000its findability, accessibility, interoperability, and reuse by scientists\u0000and others such as laboratories or land managers. Future uses of the\u0000DATA4C+ thesaurus will be crucial to improve and enrich it, but also to\u0000raise the quality of meta-analyses on SOC, and ultimately help policymakers\u0000to identify efficient agricultural and forest management practices to\u0000enhance SOC storage.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89426459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does soil thinning change soil erodibility? An exploration of long-term erosion feedback systems","authors":"P. Batista, D. Evans, B. Cândido, P. Fiener","doi":"10.5194/soil-9-71-2023","DOIUrl":"https://doi.org/10.5194/soil-9-71-2023","url":null,"abstract":"Abstract. Soil erosion rates on arable land frequently exceed the pace at\u0000which new soil is formed. This imbalance leads to soil thinning (i.e.\u0000truncation), whereby subsoil horizons and their underlying parent material\u0000become progressively closer to the land surface. As soil erosion is a\u0000selective process and subsurface horizons often have contrasting properties\u0000to the original topsoil, truncation-induced changes to soil properties might affect erosion rates and runoff formation through a soil erosion feedback system. However, the potential interactions between soil erosion and soil truncation are poorly understood due to a lack of empirical data and the neglection of long-term erodibility dynamics in erosion simulation models. Here, we present a novel model-based exploration of the soil erosion feedback system over a period of 500 years using measured soil properties from a diversified database of 265 agricultural soil profiles in the UK. For this, we adapted the Modified Morgan–Morgan–Finney model (MMMF) to perform a modelling experiment in which topography, climate, land cover, and crop management parameters were held constant throughout the simulation period. As selective soil erosion processes removed topsoil layers, the model gradually mixed subsurface soil horizons into a 0.2 m plough layer and updated soil properties using mass-balance mixing models. Further, we estimated the uncertainty in model simulations with a forward error assessment. We found that modelled erosion rates in 99 % of the soil profiles were sensitive to truncation-induced changes in soil properties. The soil losses in all except one of the truncation-sensitive profiles displayed a decelerating trend, which depicted an exponential decay in erosion rates over the simulation period. This was largely explained by decreasing silt contents in the soil surface due to selective removal of this more erodible particle size fraction and the presence of clayey or sandy substrata. Moreover, the soil profiles displayed an increased residual stone cover, which armoured the land surface and reduced soil detachment. Contrastingly, the soils with siltier subsurface horizons continuously replenished the plough layer with readily erodible material, which prevented the decline of soil loss rates over time. Although our results are limited by the edaphoclimatic conditions represented in our data, as by our modelling assumptions, we have demonstrated how modelled soil losses can be sensitive to erosion-induced changes in soil properties. These findings are likely to affect how we calculate soil lifespans and make long-term\u0000projections of land degradation.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75927453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forest liming in the face of climate change: the implications of restorative liming for soil organic carbon in mature German forests","authors":"O. van Straaten, L. Kulp, Guntars O. Martinson, D. P. Zederer, U. Talkner","doi":"10.5194/soil-9-39-2023","DOIUrl":"https://doi.org/10.5194/soil-9-39-2023","url":null,"abstract":"Abstract. Forest liming is a management tool that has and continues to be used\u0000extensively across northern Europe to counteract acidification processes\u0000from anthropogenic sulfur and nitrogen (N) deposition. In this study, we\u0000quantified how liming affects soil organic carbon (SOC) stocks and attempt\u0000to disentangle the mechanisms responsible for the often contrasting\u0000processes that regulate net soil carbon (C) fluxes. Using a paired plot\u0000experimental design we compared SOC stocks in limed plots with adjacent\u0000unlimed control plots at 28 experimental sites to 60 cm soil depth in mature\u0000broadleaf and coniferous forests across Germany. Historical soil data from a\u0000subset of the paired experiment plots were analyzed to assess how SOC stocks\u0000in both control and limed plots changed between 1990 and 2019. Overall, we found that forest floor C stocks have been accumulating over\u0000time in the control plots. Liming however largely offset organic layer\u0000buildup in the L/Of layer, and forest floor C stocks remained unchanged\u0000over time in the limed plots. This, in turn, meant that nutrients remained\u0000mobile and were not bound in soil organic matter complexes. Results from the\u0000paired plot analysis showed that forest floor C stocks were significantly\u0000lower in limed plots than the control (−34 %, −8.4 ± 1.7 Mg C ha−1) but did not significantly affect SOC stocks in the\u0000mineral soil, when all sites are pooled together. In the forest floor\u0000layers, SOC stocks exhibited an exponential decrease with increasing pH,\u0000highlighting how lime-induced improvements in the biochemical environment\u0000stimulate organic matter (OM) decomposition. Nevertheless, for both forest\u0000floor and mineral soils, the magnitude and direction of the belowground C\u0000changes hinged directly on the inherent site characteristics, namely, forest\u0000type (conifer versus broadleaf), soil pH, soil texture, and the soil SOC\u0000stocks. On the other hand, SOC stock decreases were often offset by other\u0000processes that fostered C accumulation, such as improved forest productivity\u0000or increased carbon stabilization, which correspondingly translated to an\u0000overall variable response by SOC stocks, particularly in the mineral soil. Lastly, we measured soil carbon dioxide (CO2) and soil methane\u0000(CH4) flux immediately after a re-liming event at three of the\u0000experimental sites. Here, we found that (1) liming doubles CH4 uptake\u0000in the long-term; (2) soil organic matter mineralization\u0000processes respond quickly to liming, even though the duration and size of\u0000the CO2 flush varied between sites; and (3) lime-derived CO2\u0000contributed very little to total CO2 emissions over the measurement\u0000period (determined using stable isotope approaches).\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80275471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil depth as a driver of microbial and carbon dynamics in a planted forest (Pinus radiata) pumice soil","authors":"Alexa-Kate Byers, L. Garrett, C. Armstrong, F. Dean, S. Wakelin","doi":"10.5194/soil-9-55-2023","DOIUrl":"https://doi.org/10.5194/soil-9-55-2023","url":null,"abstract":"Abstract. Forest soils are fundamental in regulating the global carbon (C)\u0000cycle; their capacity to accumulate large stores of C means they form a\u0000vital role in mitigating the effects of climate change. Understanding the\u0000processes that regulate forest soil C dynamics and stabilisation is\u0000important to maximise the capacity and longevity of C sequestration.\u0000Compared with surface soil layers, little is known about soil C dynamics in\u0000subsoil layers, sensu those below 30 cm depth. This knowledge gap creates large\u0000uncertainties when estimating the distribution of global soil C stocks and\u0000assessing the vulnerability of soil C reserves to climate change. This study\u0000aimed to dive deep into the subsoils of Puruki Experimental Forest (New\u0000Zealand) and characterise the changes in soil C dynamics and the soil\u0000microbiome down to 1 m soil depth. ITS and 16S rRNA sequencing and\u0000quantitative real-time PCR were used to measure changes in soil microbial\u0000diversity, composition, and abundance. Stable (δ13C) and\u0000radioactive (14C) C analyses were performed to assess depth-driven\u0000changes in the stability and age of soil C. Our research identified large\u0000declines in microbial diversity and abundance with soil depth, alongside\u0000significant structural shifts in community membership. Importantly, we\u0000conservatively estimate that more than 35 % of soil C stocks are present in\u0000subsoil layers below 30 cm. Although the age of soil C steadily increased\u0000with depth, reaching a mean radiocarbon age of 1571 yr BP (years before\u0000present) in the deepest soil layers, the stability of soil C varied between\u0000different subsoil depth increments. These research findings highlight the\u0000importance of quantifying subsoil C stocks for accurate C accounting. By\u0000performing a broad range of analytical measures, this research has\u0000comprehensively characterised the abiotic and biotic properties of a subsoil\u0000environment – a frequently understudied but significant component of forest\u0000ecosystems.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"616 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85442371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shapley values reveal the drivers of soil organic carbon stock prediction","authors":"A. Wadoux, N. Saby, M. Martin","doi":"10.5194/soil-9-21-2023","DOIUrl":"https://doi.org/10.5194/soil-9-21-2023","url":null,"abstract":"Abstract. Insights into the controlling factors of soil organic carbon (SOC) stock variation are necessary both for our scientific understanding of the terrestrial carbon balance and to support policies that intend to promote carbon storage in soils to mitigate climate change. In recent years, complex statistical and algorithmic tools from the field of machine learning have become popular for modelling and mapping SOC stocks over large areas. In this paper, we report on the development of a statistical method for interpreting complex models, which we implemented for the study of SOC stock variation. We fitted a random forest machine learning model with 2206 measurements of SOC stocks for the 0–50 cm depth interval from mainland France and used a set of environmental covariates as explanatory variables. We introduce Shapley values, a method from coalitional game theory, and use them to understand how environmental factors influence SOC stock prediction: what is the functional form of the association in the model between SOC stocks and environmental covariates, and how does the covariate importance vary locally from one location to another and between carbon-landscape zones? Results were validated both in light of the existing and well-described soil processes mediating soil carbon storage and with regards to previous studies in the same area. We found that vegetation and topography were overall the most important drivers of SOC stock variation in mainland France but that the set of most important covariates varied greatly among locations and carbon-landscape zones. In two spatial locations with equivalent SOC stocks, there was nearly an opposite pattern in the individual covariate contribution that yielded the prediction – in one case climate variables contributed positively, whereas in the second case climate variables contributed negatively – and this effect was mitigated by land use. We demonstrate that Shapley values are a methodological development that yield useful insights into the importance of factors controlling SOC stock variation in space. This may provide valuable information to understand whether complex empirical models are predicting a property of interest for the right reasons and to formulate hypotheses on the mechanisms driving the carbon sequestration potential of a soil.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73014253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil and crop management practices and the water regulation functions of soils: a qualitative synthesis of meta-analyses relevant to European agriculture","authors":"G. Blanchy, G. Bragato, C. Di Bene, N. Jarvis, M. Larsbo, Katharina H. E. Meurer, S. Garré","doi":"10.5194/soil-9-1-2023","DOIUrl":"https://doi.org/10.5194/soil-9-1-2023","url":null,"abstract":"Abstract. Adopting soil and crop management practices that conserve or enhance soil structure is critical for supporting the sustainable adaptation of agriculture to climate change, as it should help maintain agricultural production in the face of increasing drought or water excess without impairing environmental quality. In this paper, we evaluate the evidence for this assertion by synthesizing the results of 34 published meta-analyses of the effects of such practices on soil physical and hydraulic properties relevant for climate change adaptation in European agriculture. We also review an additional 127 meta-analyses that investigated synergies and trade-offs or help to explain the effects of soil and crop management in terms of the underlying processes and mechanisms. Finally, we identify how responses to alternative soil–crop management systems vary under contrasting agro-environmental conditions across Europe. This information may help practitioners and policymakers to draw context-specific conclusions concerning the efficacy of management practices as climate adaptation tools. Our synthesis demonstrates that organic soil amendments and the adoption of practices that maintain “continuous living cover” result in significant benefits for the water regulation function of soils, mostly arising from the additional carbon inputs to soil and the stimulation of biological processes. These effects are clearly related to improved soil aggregation and enhanced bio-porosity, both of which reduce surface runoff and increase infiltration. One potentially negative consequence of these systems is a reduction in soil water storage and groundwater recharge, which may be problematic in dry climates. Some important synergies are reductions in nitrate leaching to groundwater and greenhouse gas emissions for nonleguminous cover crop systems. The benefits of reducing tillage intensity appear much less clear-cut. Increases in soil bulk density due to traffic compaction are commonly reported. However, biological activity is enhanced under reduced tillage intensity, which should improve soil structure and infiltration capacity and reduce surface runoff and the losses of agro-chemicals to surface water. However, the evidence for these beneficial effects is inconclusive, while significant trade-offs include yield penalties and increases in greenhouse gas emissions and the risks of leaching of pesticides and nitrate. Our synthesis also highlights important knowledge gaps on the effects of management practices on root growth and transpiration. Thus, conclusions related to the impacts of management on the crop water supply and other water regulation functions are necessarily based on inferences derived from proxy variables. Based on these knowledge gaps, we outlined several key avenues for future research on this topic.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83875106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}