Geoderma Regional最新文献

{"title":"Comparison of soil exchangeable calcium estimated using five extractants and near-infrared spectroscopy","authors":"Zhufeng Wang ,&nbsp;Yugang Wang ,&nbsp;Fei Peng ,&nbsp;Dengchun Xing ,&nbsp;Litao Lin ,&nbsp;Wenting Feng","doi":"10.1016/j.geodrs.2024.e00911","DOIUrl":"10.1016/j.geodrs.2024.e00911","url":null,"abstract":"<div><div>Soil exchangeable Ca (Ca_ex) regulates multiple functions, including nutrient provision for plant growth, soil structure maintenance, and carbon sequestration. However, various chemical extraction methods are currently used worldwide to determine soil Ca_ex, each with different mechanisms and purposes. The inconsistency in assessment methods complicates comparisons and predictions regarding soil Ca_ex functions across different environments. To address this issue, we developed equations to convert soil Ca_ex concentrations obtained from five different methods in arid regions. Furthermore, we evaluated the accuracy of predicting five soil Ca_ex proxies and cation exchange capacity (CEC) using near-infrared reflectance (NIR) spectroscopy. The chemical extractants (<em>i.e</em>., sodium acetate (NaOAc), potassium chloride (KCl), sodium sulfate (Na₂SO₄), ethylenediaminetetraacetic acid (EDTA), and copper chloride (CuCl₂)) were used on 308 soil samples representing a wide range of soil Ca_ex, climate, and edaphic properties in arid regions. Our findings reveal that compared to the commonly used NaOAc extraction, Na₂SO₄ extracted a similar amount of soil Ca_ex. In contrast, KCl extraction underestimated soil Ca_ex, whereas EDTA and CuCl₂ extractions overestimated it. Such discrepancies suggest that EDTA and CuCl₂ are inappropriate for soils with Ca-bearing minerals, such as Ca carbonate. Moreover, the quantitative correlation among soil Ca_ex values obtained through five different extractants highlights the need for careful selection based on specific environmental factors (<em>i.e</em>., soil pH and humidity). Notably, NIR-driven partial least squares regression outperformed support vector machine models for the estimation of soil Ca_ex measured by five extractants (0.78 &lt; <em>R</em>² &lt; 0.90) and CEC (<em>R</em>² = 0.96). This capability positions NIR spectroscopy as an efficient and reliable tool for rapid assessment of soil Ca_ex and CEC, particularly in arid regions. In conclusion, the quantitative relationships derived from various extraction methods provide a robust framework for comparing soil Ca_ex values and enhancing our ability to predict changes in its functions under differing environmental conditions.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00911"},"PeriodicalIF":3.1,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing agroecosystem sustainability: Integrative soil health strategies in regenerative organic soybean production on Andosol in Japan","authors":"Ratih Kemala Dewi ,&nbsp;Qiliang Huang ,&nbsp;Rahmatullah Hashimi ,&nbsp;Masakazu Komatsuzaki","doi":"10.1016/j.geodrs.2024.e00910","DOIUrl":"10.1016/j.geodrs.2024.e00910","url":null,"abstract":"<div><div>Regenerative agriculture prioritizes soil health to enhance ecosystems and crop production. No-tillage organic farming with cover crop rotation improves sustainability. However, economic barriers must be considered. This study evaluated the involvement of biochar into long-term no-tillage combined with cover crop as a regenerative organic approach on soil health and carbon sequestration as well as to assess the economic viability of this farming system. The field experiment was designed as a randomized complete block with a split–split plot arrangement consisting of different tillage practices (no-tillage, rotary cultivator, and moldboard plowing), cover crop (rye, hairy vetch, and fallow), and biochar applications (with and without biochar), in four replications. The study also included two farming scenarios, soybean and soybean + rice production, for economic analysis. Results showed that incorporating biochar into the continuous no-tillage with cover crop rotation increased soil organic carbon and its stock in the topsoil profile (0–30 cm), improved soil health indicators by reducing soil bulk density and penetration resistance, and increased microbial activity, thereby promoting nutrient cycling. Soybean yield varied under the no-tillage system, resulting in a low benefit–cost ratio; however, the integration of soybean with rice production improved this ratio in organic farming–based no-tillage management. Compared with moldboard plowing, no-tillage with rye resulted in the lowest cost of soil organic carbon production. Given these findings, integrating biochar into long-term no-tillage management centered on regenerative organic farming would improve environmental quality and provide economic advantages, strengthening the resilience of natural system, specifically in Andosol, Japan.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00910"},"PeriodicalIF":3.1,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring phosphorous dynamics within soil aggregate after 17 years long-term manuring in lateritic Inceptisols in rice paddies","authors":"Nafid Cheekilote ,&nbsp;Prasanna Kumar Samant ,&nbsp;Sanat Kumar Dwibedi ,&nbsp;Bandita Jena ,&nbsp;Kiran Kumar Mohapatra ,&nbsp;Hari Sankar Nayak ,&nbsp;Saheed Garnaik","doi":"10.1016/j.geodrs.2024.e00908","DOIUrl":"10.1016/j.geodrs.2024.e00908","url":null,"abstract":"<div><div>Understanding phosphorous dynamics can provide valuable insights for sustainable nutrient management and long-term fertilizer experiments are better source for elucidating such mechanism. In this study, eight distinct nutrient management treatments (combination of N, P, K fertilizer along with FYM and lime) were evaluated in an ongoing long-term fertilizer experiment. The experiment investigated the prolonged effects of both balanced and imbalanced fertilizer applications, the combined use of organic manure and inorganic fertilizers, and the application of liming material in a rice-rice cropping system on yield attributes and changes in soil properties. Integrated use of organic manure with NPK fertilizers and lime application (100% NPK + FYM + Lime) positively influenced soil properties and significantly increased yield by 41.4% and P-uptake by 88.4% compared to sole NPK application. The long-term fertilization contributed to significant relative accumulation of Ca<img>P fraction (∼240% increase) in 100% NPK + FYM + Lime in comparison to initial Ca<img>P fraction. The distribution pattern of inorganic phosphorus fractions varied with following sequence: Fe-P &gt; Red-P &gt; Al-P &gt; Ca-P &gt; Occl-P &gt; Sal-P. Among these fractions, Ca<img>P (<em>r</em> = 0.949**), Occl-P (<em>r</em> = 0.884**), and Sal-P (<em>r</em> = 0.866**) were correlated with available P. The mean weight diameter (MWD) exhibited the strongest correlation with Occl-P (<em>r</em> = 0.936**), whereas the geometric mean diameter (GMD) and water stable aggregate (WSA) had the strongest correlation with Ca<img>P (0.893** and 0.875**, respectively). The adjusted R² values indicated that the total contribution of all inorganic P fractions accounted for 99.9% of the variability in available P, 80.6 % in P uptakes, and 67.9% in grain yield. This study underscores the critical relationship among soil structure, crop yield, and P availability, emphasizing that macroaggregates play a crucial role in improving soil health and enhancing P retention and availability.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00908"},"PeriodicalIF":3.1,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 carbon benchmarks and cropland management effects: Insights from the Bavarian soil organic matter monitoring","authors":"Manuel Sümmerer ,&nbsp;Christopher Just ,&nbsp;Martin Wiesmeier","doi":"10.1016/j.geodrs.2024.e00909","DOIUrl":"10.1016/j.geodrs.2024.e00909","url":null,"abstract":"<div><div>Soil organic carbon (SOC) is a key property for soil productivity and functionality. According to the Federal Soil Protection Act in Germany, site-specific SOC contents need to be maintained in the course of agricultural land use in order to ensure soil fertility and the performance of soils as a natural resource. In this study, representative SOC benchmarks have been derived for arable mineral soils in Bavaria on the basis of a comprehensive soil organic matter (SOM) monitoring program as reference values for farmers and other stakeholders. Data from 283 representative study sites across Bavaria has been stratified according to the most influential site factors on SOC, particularly clay content and the elevation above sea level as a proxy for climate (temperature and precipitation). Due to an evaluation of the study sites in terms of agricultural management according to the principles of good agricultural practice combined with statistical exclusion of 25 % of extreme SOC contents, the benchmarks presented here can be regarded as representative reference values under specific environmental conditions. However, different management measures within the principles of good agricultural practice also influenced SOC, as organic fertilization and the cultivation of perennial forage crops positively affected SOC contents. In contrast, the cultivation of root crops negatively influenced SOC contents, while the proportion of corn within the crop rotation of up to 50 % did not affect SOC negatively. We further evaluated the suitability of the SOC/clay ratio as alternative SOC and soil structure indicator. However, the SOC/clay ratio seems to be inappropriate due to a high number of degraded sites and a systematic bias towards degradation with high clay contents. The SOC benchmarks presented here provide valuable reference values for farmers policymakers and agricultural stakeholders in optimizing cropland management practices for sustainable soil health and fertility in Bavaria and beyond. However, further research is required regarding the stratification approach and the calculation method for a widespread implementation of SOC benchmarks. Furthermore, the shifting baseline syndrome has to accounted for, so up to date SOC benchmarks remain within a range in which soils are considered healthy and fertile.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00909"},"PeriodicalIF":3.1,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sources of soil organic carbon under Eucalyptus silvopastures and other land-use systems in Brazilian Oxisols","authors":"Felipe M. Pinheiro ,&nbsp;P.K. Ramachandran Nair ,&nbsp;Vimala D. Nair ,&nbsp;Rafael G. Tonucci ,&nbsp;Regis P. Venturin","doi":"10.1016/j.geodrs.2024.e00907","DOIUrl":"10.1016/j.geodrs.2024.e00907","url":null,"abstract":"<div><div>Silvopastoral systems (SPS) incorporating non-native tree species such as Eucalyptus are increasingly being adopted in the Cerrado region of Brazil. The climate-change mitigation potential of the practice, although hypothesized, has not been assessed vigorously. The objective of this research was to measure the extent of SOC accumulation under SPS involving C3 and C4 plants and other prevalent land-use systems in an Oxisol-dominated location in Minas Gerais, Brazil. We determined the overall δ13C in three soil fraction-size groups within six land-use systems. These systems consisted of 8-year-old planted forests, native forest, managed pastures, and three variations of 8-year-old SPS with diverse tree-planting layouts. In the SPS and planted forest treatments, the tree species was Eucalyptus hybrid, and <em>Urochloa decumbens</em> was the grass species in the SPS and pasture treatments. For each treatment, soil samples were collected at depths of 0–10, 10–30, 30–60, and 60–100 cm. These samples were fractionated into three size classes (2000-250 μm, 250-53 μm, and &lt;53 μm) and analyzed for δ13C. The native forest had higher C3 contribution in the topsoil layers. The highest C3 derived SOC stock up to 1 m depth was in the pasture (137 Mg ha^-1), and the lowest in the forest (74 Mg ha^-1). The pasture also had the highest C4 derived SOC stock and the forest the lowest, but not significantly. The SPS had intermediate values. We infer that the study site had a mixed vegetation in the past, and after the conversion of the land to planted forest/SPS/pasture, the “native” SOC stock could be maintained better in a well-managed pasture than in a degraded native forest. The higher C3-derived SOC stock in the pasture treatment suggests that managed SPS could help retain more soil C in a stable form than in degraded forests.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00907"},"PeriodicalIF":3.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superior nutrient recovery and release by chicken manure-derived biochar over hydrochar and compost for soil fertilization","authors":"Mahmudul Islam Piash ,&nbsp;Takanori Itoh ,&nbsp;Kazusa Abe ,&nbsp;Kazunori Iwabuchi","doi":"10.1016/j.geodrs.2024.e00906","DOIUrl":"10.1016/j.geodrs.2024.e00906","url":null,"abstract":"<div><div>Recycling nutrient-rich organic waste materials in agriculture is increasingly recognized for its potential to establish sustainable systems, especially considering the diminishing availability of chemical fertilizers. However, appropriate pretreatment methods are essential for safe and efficient utilization in soil systems. In this study, we compared conventional composting (compost) with low-temperature pyrolysis (biochar) and hydrothermal carbonization (hydrochar) for conserving nutrients from chicken manure (CM) and producing stable organic fertilizer. Biochar exhibited superior nutrient recovery, with 76.4 % of N retrieved from CM compared to 37.4 % for hydrochar and 36.2 % for compost. The escape of NH₃ gas from deaminated hydrochar slurry and volatilization loss during composting might have caused such low N recovery in hydrochar and compost, respectively. When applied to soil, biochar released nearly 100 % of its nitrogen in phyto-available form and may satisfy 88.5 % of the N requirements for optimum sweetcorn production. Decomposition of pyridinic- and pyrrolic-N in low-temperature CM biochar might have contributed to this high N release. In contrast, compost released 85 % of its N, and hydrochar released only 33 %. Biochar also preserved the highest amount of carbon (67.6 %) during production, with a significantly higher fixed carbon content (19.2 %). Over a 140-day incubation period, while 26.6 % of compost‑carbon was emitted as CO₂ from soil, biochar remained significantly stable (11.5 %). These findings underscore manure biochar's potential as an effective tool for soil fertilization and carbon sequestration, surpassing compost and hydrochar in nitrogen recovery, nitrogen release, and carbon stability in soil.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00906"},"PeriodicalIF":3.1,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping soil parent materials in a previously glaciated landscape: Potential for a machine learning approach for detailed nationwide mapping","authors":"Yiqi Lin ,&nbsp;William Lidberg ,&nbsp;Cecilia Karlsson ,&nbsp;Gustav Sohlenius ,&nbsp;Florian Westphal ,&nbsp;Johannes Larson ,&nbsp;Anneli M. Ågren","doi":"10.1016/j.geodrs.2024.e00905","DOIUrl":"10.1016/j.geodrs.2024.e00905","url":null,"abstract":"<div><div>Reliable information on soil-forming parent materials is crucial for informed decision-making in infrastructure planning, land-use management, environmental assessments, and geohazard mitigation. In the northern landscapes previously affected by glacial processes, these parent materials are predominantly Quaternary deposits. This study explored the potential of machine learning to expedite soil parent material mapping in Sweden. Two Extreme Gradient Boosting models were trained, one using terrain and hydrological indices derived from Light Detection and Ranging data, and the other incorporating additional ancillary map data. Both models were trained on 29,588 soil observations and evaluated against a separate hold-out set of 3500 observations. As a baseline, the existing most detailed maps achieved a Matthews Correlation Coefficient of 0.36. The Extreme Gradient Boosting models achieved higher MCC values of 0.45 and 0.56, respectively. To understand spatial variations in model performance, the second model was evaluated across 28 physiographic regions in Sweden. The results revealed that model performance varied across regions and deposit types, with till and peat exhibiting better performance than sorted sediments. These findings underscore the need for region-specific analyses to optimize the application of machine learning in digital soil mapping.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00905"},"PeriodicalIF":3.1,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How to site grassed areas to reduce agricultural erosion efficiently? A computational analysis in Finland","authors":"M. Tähtikarhu,&nbsp;T.A. Räsänen,&nbsp;J. Uusi-Kämppä,&nbsp;J. Hyväluoma","doi":"10.1016/j.geodrs.2024.e00904","DOIUrl":"10.1016/j.geodrs.2024.e00904","url":null,"abstract":"<div><div>Spatial patterns of land-cover and agricultural operations have clear impacts on soil erosion. Allocating a portion of cultivated area for grass is a widely applied strategy to control erosion. However, it is still unclear how much and where grassed area should be spatially targeted in different landscapes to control erosion efficiently. To address this challenge, we estimate the potential of high-resolution RUSLE-based spatial targeting of grassed areas to improve erosion mitigation in two topographically different catchments in southern Finland. Erosion reductions of 1) policy-based targeting (buffer strips along main streams according to current CAP strategy) were compared with 2) RUSLE-targeted grassed areas (based on the highest computed erosion values within field parcels and sub-catchments). Furthermore, we computationally explored 3) how different rates of optimally located grass areas affected erosion and 4) how the areas could be computationally processed to continuous entities. The erosion reductions were estimated with 2 × 2 m² resolution RUSLE computations in all the scenarios. The RUSLE-targeted grassed areas demonstrated greater erosion reductions compared to the policy-based siting of grass areas along riparian fields. With optimal targeting, erosion risks could potentially be reduced up to 24 percentage points (up to 46 % erosion reduction), compared to the buffer strips. Increasing optimally targeted grassed area gradually from 0 to 100 % decreased erosion non-linearly. The largest share of erosion was generated in disproportionally small land areas (∼20 % of the land area). The location of the hotspots in relation to the streams varied between the sub-catchments and field parcels. These quantifications demonstrate the potential value of models for targeted landscape scale spatial erosion management. A more comprehensive assessment of erosion mitigation could benefit of improved empirical validation and consideration of other aspects of erosion and sediment transport, such as local drainage efficiency and reduction of erosion during flooding of rivers.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00904"},"PeriodicalIF":3.1,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial necromass as a critical driver of soil organic carbon accumulation in Qinghai-Tibet Plateau under climate warming: A meta-analysis","authors":"Yunduo Zhao ,&nbsp;Dongsheng Li ,&nbsp;Jinxing Zhou","doi":"10.1016/j.geodrs.2024.e00903","DOIUrl":"10.1016/j.geodrs.2024.e00903","url":null,"abstract":"<div><div>Microbial necromass plays a significant role in soil carbon storage under climate warming, as it is considered a crucial component of the stable carbon pool in soils. However, how the warming, including various warming patterns, affects microbial necromass and its contribution to the organic carbon pool in alpine regions remains largely unexplored. A meta-analysis was conducted utilizing data from ten publications to assess the effects of warming on microbial necromass on the Qinghai-Tibet Plateau. The findings indicated that the soil organic carbon (SOC) content did not exhibit significant changes after warming; however, microbial necromass carbon (MNC) and its ratio to SOC experienced significantly increases of 17.7 % and 52.0 %, respectively. The effect size of warming on fungal necromass carbon (FNC; +19.5 %) was larger than that of bacterial necromass carbon (BNC; +9.2 %). Furthermore, the warming patterns influenced the accumulation of microbial necromass and its ratio to SOC. The accumulation of microbial necromass and its ratio to SOC were increased (19.8 % and 63.9 %) under the low-magnitude warming and slowed down (14.0 % and 20.3 %) under the high-magnitude warming. The MNC and FNC were increased under both long-term warming (1.61 g/kg and 0.86 g/kg) and short-term warming (0.96 g/kg and 0.50 g/kg), but there was no significant change in BNC under long-term warming patterns. The effect sizes of warming on BNC, FNC and MNC were larger in the subsoil (16.3 %, 25.1 % and 24.2 %) than that in the topsoil (7.8 %, 19.1 % and 17.5 %). These results highlight the importance of warming patterns as predictors of microbial necromass. Nonetheless, these conclusions may be restricted by the insufficient sample size, and future researches should expand the sample size to reveal the threshold and mechanism underlying the effect of warming patterns on microbial necromass.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00903"},"PeriodicalIF":3.1,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparison of country-scale subsoil predictions between a numeric and a taxonomic soil classification system","authors":"Trevan Flynn ,&nbsp;Catherine Clarke ,&nbsp;Rosana Kostecki ,&nbsp;Ansa Rebi","doi":"10.1016/j.geodrs.2024.e00902","DOIUrl":"10.1016/j.geodrs.2024.e00902","url":null,"abstract":"<div><div>Traditional soil classification systems are designed to communicate information; however, surveyor biases and tacit knowledge can lead to subjective soil class designations. Consequently, different soil scientists may classify the same soil differently. This becomes a critical issue when mapping soil classes, as there could be multiple interpretations for the same observation. To address this problem, numerical soil classification systems have been developed. However, little is known about how well they compare to taxonomic systems when spatially predicted on a national scale. This study aimed to compare a previously developed, unsupervised numeric classification system and South Africa's taxonomic soil classification system in terms of their spatial predictions across the country. The taxonomic system of South Africa has 19 defined subsoil horizons, which were aggregated into eight horizons and compared to a nine horizon numeric classification as well as South Africa's profile (soil form) classification comprising of 73 different soil groupings, which was used as a control. The comparison was conducted from predictions through gradient tree boosting in Google Earth Engine at a 30 m resolution. The numerical system (kappa = 0.30, accuracy = 0.57) exhibited poor spatial predictions, with a kappa 22% lower and accuracy 2% lower than the control (kappa = 0.52, accuracy = 59%). On the other hand, the taxonomic system performed well, with a kappa of 0.57 and an accuracy of 67%, exhibiting a 5% increase in kappa and an 8% increase in accuracy compared to the control. It was hypothesized that the overpredictions of the predominant horizon contributed to the numeric system's poor performance. Nevertheless, both systems showed the highest maximum entropy in arid regions of the Karoo and savannah biomes, albeit in spatially distinct ecoregions. It was thought that the divergence in the two systems' maximum entropy was due to their association with precipitation differences (amount and seasonality) as well as vegetation type and cover (woodlands vs. shrublands). To map the country in more detail, further soil sampling should be conducted in arid regions and optimisation of the predictive algorithm for each soil category should be performed.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00902"},"PeriodicalIF":3.1,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}