Pub Date : 2024-02-20DOI: 10.1134/s1064229323602548
Wenqi Zhang, Lu Wang, Jinhong Chen, Yinghu Zhang
Abstract
Rapid and unstable preferential flow has a significant impact on soil carbon cycle. This review aims to explore the effects of preferential flow on the soil carbon cycle and indicate its characteristics and ecological responses in different ecosystems. This study concluded that preferential flow influences soil carbon cycle through various mechanisms, such as facilitating rapid transport of dissolved organic matter, shaping the distribution and aggregation patterns of soil organic carbon, and enhancing soil microbial activity and organic matter decomposition. The characteristics of preferential flow include surrounding characteristics, rapid non-equilibrium infiltration characteristics, fluctuating characteristics, universal characteristics, lateral infiltration characteristics. Those characteristics could also affect the spatial distribution of soil organic carbon. In addition, this review examines the phenomenon of preferential flow in farmland, forest, wetland, desert, and permafrost ecosystems. Finally, we provide insightful perspectives on future research directions, emphasizing the importance of advancing our understanding of preferential flow mechanisms. It also serves as a valuable resource for future research aimed at unraveling the underlying mechanisms of preferential flow and developing effective soil carbon management strategies.
{"title":"Preferential Flow in Soils: Review of Role in Soil Carbon Dynamics, Assessment of Characteristics, and Performance in Ecosystems","authors":"Wenqi Zhang, Lu Wang, Jinhong Chen, Yinghu Zhang","doi":"10.1134/s1064229323602548","DOIUrl":"https://doi.org/10.1134/s1064229323602548","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Rapid and unstable preferential flow has a significant impact on soil carbon cycle. This review aims to explore the effects of preferential flow on the soil carbon cycle and indicate its characteristics and ecological responses in different ecosystems. This study concluded that preferential flow influences soil carbon cycle through various mechanisms, such as facilitating rapid transport of dissolved organic matter, shaping the distribution and aggregation patterns of soil organic carbon, and enhancing soil microbial activity and organic matter decomposition. The characteristics of preferential flow include surrounding characteristics, rapid non-equilibrium infiltration characteristics, fluctuating characteristics, universal characteristics, lateral infiltration characteristics. Those characteristics could also affect the spatial distribution of soil organic carbon. In addition, this review examines the phenomenon of preferential flow in farmland, forest, wetland, desert, and permafrost ecosystems. Finally, we provide insightful perspectives on future research directions, emphasizing the importance of advancing our understanding of preferential flow mechanisms. It also serves as a valuable resource for future research aimed at unraveling the underlying mechanisms of preferential flow and developing effective soil carbon management strategies.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"286 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139918183","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}
Pub Date : 2024-02-20DOI: 10.1134/s106422932360344x
F. Fekrache, K. Boudeffa, L. Zaoui, M. Djemli, S. Cedah
Abstract
Soil pollution by heavy metals is a frequently encountered issue at many hazardous waste sites. Mining operations generate a significant volume of inert materials and waste, which are then deposited on the surface. The abandoned mine of Sidi Kambar could pose a major problem due to the potentially high concentrations of potentially toxic elements present in its discharges. To assess the level of soil contamination near the abandoned Pb-Zn mine in Sidi Kambar, heavy metal concentrations were determined in soil samples taken from the Essouk River. The results of the monitoring of the spatial evolution of metal trace elements (Zn, Pb, and Fe) during the month of February 2023 in the soil of this watercourse show that metal content is growing in the order: Pb > Zn > Fe. They also exhibit variations across the ten (10) study stations, ranging from 102.7 to 141.2 for Zn, 1918.8 to 3150.4 for Fe, and 115.5 to 134.5 for Pb. The degree and sources of contamination were determined by calculating metal contamination indices: the geoaccumulation index, the contamination factor, the degree of contamination, and the pollution load index. High levels of contamination have been observed around spills of mining waste, resulting in high levels of contamination. However, no cases of extremely high or ultra-high contamination were found in the mining fields of the studied area. Therefore, human activities could be the main factor in abandoned Pb/Zn mining areas.
{"title":"Assessment of Soil Contamination by Mining Discharges in the Essouk River (Northeast Algeria)","authors":"F. Fekrache, K. Boudeffa, L. Zaoui, M. Djemli, S. Cedah","doi":"10.1134/s106422932360344x","DOIUrl":"https://doi.org/10.1134/s106422932360344x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Soil pollution by heavy metals is a frequently encountered issue at many hazardous waste sites. Mining operations generate a significant volume of inert materials and waste, which are then deposited on the surface. The abandoned mine of Sidi Kambar could pose a major problem due to the potentially high concentrations of potentially toxic elements present in its discharges. To assess the level of soil contamination near the abandoned Pb-Zn mine in Sidi Kambar, heavy metal concentrations were determined in soil samples taken from the Essouk River. The results of the monitoring of the spatial evolution of metal trace elements (Zn, Pb, and Fe) during the month of February 2023 in the soil of this watercourse show that metal content is growing in the order: Pb > Zn > Fe. They also exhibit variations across the ten (10) study stations, ranging from 102.7 to 141.2 for Zn, 1918.8 to 3150.4 for Fe, and 115.5 to 134.5 for Pb. The degree and sources of contamination were determined by calculating metal contamination indices: the geoaccumulation index, the contamination factor, the degree of contamination, and the pollution load index. High levels of contamination have been observed around spills of mining waste, resulting in high levels of contamination. However, no cases of extremely high or ultra-high contamination were found in the mining fields of the studied area. Therefore, human activities could be the main factor in abandoned Pb/Zn mining areas.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"134 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139918267","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}
Pub Date : 2024-02-20DOI: 10.1134/s1064229323602846
Abstract
Soil nutrient storage and sequestration effects are closely related to the stability of alpine grassland ecosystems, and the study of soil nutrient storage and sequestration effects in alpine grasslands with different degradation levels is of great significance to the recovery of alpine grassland vegetation. On this basis, four alpine grasslands with different degrees of degradation (non-degraded, lightly degraded, moderately degraded, and heavily degraded) were selected in Maqu County, Gannan, and soil samples were collected from 0–10, 10–20, 20–40, and 40–60 cm, respectively, and analyzed for nutrients in terms of storage and sequestration effects. The results showed that soil water content decreased with increasing degradation, while soil pH, bulk density, and conductivity tended to increase. The storage and sequestration effects of soil organic carbon decreased with increasing degradation. And the storage and sequestration effects of soil total nitrogen and total phosphorus were smallest for moderately degraded soils in the 10–60 cm soil layer. Soil water content and soil bulk density were co-influences on soil organic carbon, total nitrogen, and total phosphorus storage. For the soil organic carbon sequestration effect, soil total nitrogen sequestration effect and soil pH were the two most important influencing factors, and the soil total nitrogen and total phosphorus sequestration effect were greatly influenced by soil organic carbon sequestration effect. In addition, soil bulk density was also the main influencing factor of soil total nitrogen sequestration effect, and the impact of soil total nitrogen sequestration on soil total phosphorus sequestration was also greatly influenced.
{"title":"Analysis of Soil Carbon, Nitrogen and Phosphorus Storage and Sequestration Effects in Alpine Grassland with Different Degradation Levels in Maqu County, China","authors":"","doi":"10.1134/s1064229323602846","DOIUrl":"https://doi.org/10.1134/s1064229323602846","url":null,"abstract":"<span> <h3>Abstract</h3> <p>Soil nutrient storage and sequestration effects are closely related to the stability of alpine grassland ecosystems, and the study of soil nutrient storage and sequestration effects in alpine grasslands with different degradation levels is of great significance to the recovery of alpine grassland vegetation. On this basis, four alpine grasslands with different degrees of degradation (non-degraded, lightly degraded, moderately degraded, and heavily degraded) were selected in Maqu County, Gannan, and soil samples were collected from 0–10, 10–20, 20–40, and 40–60 cm, respectively, and analyzed for nutrients in terms of storage and sequestration effects. The results showed that soil water content decreased with increasing degradation, while soil pH, bulk density, and conductivity tended to increase. The storage and sequestration effects of soil organic carbon decreased with increasing degradation. And the storage and sequestration effects of soil total nitrogen and total phosphorus were smallest for moderately degraded soils in the 10–60 cm soil layer. Soil water content and soil bulk density were co-influences on soil organic carbon, total nitrogen, and total phosphorus storage. For the soil organic carbon sequestration effect, soil total nitrogen sequestration effect and soil pH were the two most important influencing factors, and the soil total nitrogen and total phosphorus sequestration effect were greatly influenced by soil organic carbon sequestration effect. In addition, soil bulk density was also the main influencing factor of soil total nitrogen sequestration effect, and the impact of soil total nitrogen sequestration on soil total phosphorus sequestration was also greatly influenced.</p> </span>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"22 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139918268","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}
Pub Date : 2024-02-20DOI: 10.1134/s1064229323603220
Abstract
Soils play an important role in the balance of carbon on the global scale. The study of the carbon cycle in Calcareous soils has received less attention, while Calcareous soils cover a third of the world’s soils and most croplands of Iran. The aim of this study was to investigate soil organic carbon fractions and the relationship of soil organic carbon (SOC) with soil properties in 30 wheat farms of Calcisols of Alborz, Iran. To study the effects of soil geochemical properties, the data were subjected to cluster analysis to select samples with similar texture and low salinity. We applied a densimetric method using sodium iodide (NaI) to isolate light fraction (LF < 1.6 g/cm3), occluded fraction (OF < 1.8 g/cm3), and mineral-associated organic matter (MAOM > 1.8 g/cm3) of selected soils. Results showed that SOC decreased up to 61% throughout the soil profile. Mineral-associated organic matter had the highest proportion (more than 75%) of SOC in agricultural soils. The mean value of C/N reduced in mineral-associated organic matter compared to that of bulk soil, which indicates nitrogen concentration in this fraction. The study of soil properties suggested that calcium carbonate equivalent (CCE) could explain SOC content in calcareous soils, while extracted metals (iron, magnesium, and calcium) had a significant relationship with the organic carbon content of heavy fraction.
{"title":"Soil Organic Carbon Fractions in Cultivated Calcareous Soils","authors":"","doi":"10.1134/s1064229323603220","DOIUrl":"https://doi.org/10.1134/s1064229323603220","url":null,"abstract":"<span> <h3>Abstract</h3> <p>Soils play an important role in the balance of carbon on the global scale. The study of the carbon cycle in Calcareous soils has received less attention, while Calcareous soils cover a third of the world’s soils and most croplands of Iran. The aim of this study was to investigate soil organic carbon fractions and the relationship of soil organic carbon (SOC) with soil properties in 30 wheat farms of Calcisols of Alborz, Iran. To study the effects of soil geochemical properties, the data were subjected to cluster analysis to select samples with similar texture and low salinity. We applied a densimetric method using sodium iodide (NaI) to isolate light fraction (LF < 1.6 g/cm<sup>3</sup>), occluded fraction (OF < 1.8 g/cm<sup>3</sup>), and mineral-associated organic matter (MAOM > 1.8 g/cm<sup>3</sup>) of selected soils. Results showed that SOC decreased up to 61% throughout the soil profile. Mineral-associated organic matter had the highest proportion (more than 75%) of SOC in agricultural soils. The mean value of C/N reduced in mineral-associated organic matter compared to that of bulk soil, which indicates nitrogen concentration in this fraction. The study of soil properties suggested that calcium carbonate equivalent (CCE) could explain SOC content in calcareous soils, while extracted metals (iron, magnesium, and calcium) had a significant relationship with the organic carbon content of heavy fraction.</p> </span>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"35 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139918207","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}
Pub Date : 2024-02-01DOI: 10.1134/s1064229323602822
Abstract
Humic substances influence a number of soil properties: structure, cation exchange capacity, water retention capacity, etc. At the same time, in soils and solutions, humic substances exist not in the form of individual molecules, but in the form of supramolecular formations having a fractal cluster organization (F-clusters). Consequently, F-clusters should exert their influence on soil properties. As F-clusters are tightly interconnected, to assess their influence on soil properties it is necessary to separate them. This can be done by mechanical activation—increasing the reactivity (activity) of substances during their mechanical treatment. We studied the influence of mechanical activation on some soil properties and on the development of plants in activated soils. It has been shown that the water retention capacity of soil samples from the main types of zonal soils increases by up to 35% of the initial value under the impact of mechanical activation. This can be explained from the standpoint of a decrease in the mobility of gravitational water by F-clusters in macrocapillaries. The optical density of water extracts from chernozem increased by 75% and the viscosity of soil pastes increased by 57% due to an increase in the number of F-clusters in the soil solution. Activated soils stimulated the germination of wheat seeds by 26%. This effect may be associated with the formation of films of F-clusters on the surface of seeds, which fix soil allelotoxins that slow down seed development.
摘要 腐殖质对土壤的一些特性有影响：结构、阳离子交换能力、保水能力等。同时，在土壤和溶液中，腐殖质不是以单个分子的形式存在，而是以具有分形簇组织（F-clusters）的超分子形式存在。因此，分形簇会对土壤性质产生影响。由于 F 簇紧密相连，要评估它们对土壤性质的影响，就必须将它们分开。这可以通过机械活化来实现--在机械处理过程中提高物质的反应性（活性）。我们研究了机械活化对一些土壤特性和活化土壤中植物生长的影响。结果表明，在机械活化作用下，主要地带土壤样本的保水能力比初始值提高了 35%。这可以从大毛细管中 F 簇的重力水流动性降低的角度来解释。由于土壤溶液中 F 簇的数量增加，从切尔诺泽姆提取的水的光密度增加了 75%，土壤糊的粘度增加了 57%。活化土壤可促进小麦种子发芽 26%。这种效果可能与种子表面形成的 F 簇膜有关，F 簇膜能固定土壤中的等位毒素，从而减缓种子的发育。
{"title":"Influence of Mechanical Activation on Soil Properties and Plant Development","authors":"","doi":"10.1134/s1064229323602822","DOIUrl":"https://doi.org/10.1134/s1064229323602822","url":null,"abstract":"<span> <h3>Abstract</h3> <p>Humic substances influence a number of soil properties: structure, cation exchange capacity, water retention capacity, etc. At the same time, in soils and solutions, humic substances exist not in the form of individual molecules, but in the form of supramolecular formations having a fractal cluster organization (F-clusters). Consequently, F-clusters should exert their influence on soil properties. As F-clusters are tightly interconnected, to assess their influence on soil properties it is necessary to separate them. This can be done by mechanical activation—increasing the reactivity (activity) of substances during their mechanical treatment. We studied the influence of mechanical activation on some soil properties and on the development of plants in activated soils. It has been shown that the water retention capacity of soil samples from the main types of zonal soils increases by up to 35% of the initial value under the impact of mechanical activation. This can be explained from the standpoint of a decrease in the mobility of gravitational water by F-clusters in macrocapillaries. The optical density of water extracts from chernozem increased by 75% and the viscosity of soil pastes increased by 57% due to an increase in the number of F-clusters in the soil solution. Activated soils stimulated the germination of wheat seeds by 26%. This effect may be associated with the formation of films of F-clusters on the surface of seeds, which fix soil allelotoxins that slow down seed development.</p> </span>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140032396","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}
Pub Date : 2024-02-01DOI: 10.1134/s1064229323602883
Abstract
The structural and functional state of microbial communities of different-aged buried ancient soloids (soil-like bodies lacking genetically distinct horizons) have been comprehensively assessed in open archaeological pits of ancient human sites in the middle reaches of the Mzymta River on the Sochi Black Sea coast in the Akhtsu grotto and Akhshtyrskaya cave. A number of changes in the functional biodiversity of ancient soloids as compared with the background soils (alluvial soils formed immediately near the studied soloids with similar mesomorphological properties) are observed. They include a 1.2-fold decrease in the specific metabolic activity of microbial communities assessed by multisubstrate testing and an increased instability of paleomicrobial systems according to the coefficient of rank distribution of the range of substrate consumption d > 1, which is typical of irreversibly damaged systems. The microbial community of ancient soloids has undergone a number of changes associated with anthropogenic activity. According to the analysis of the main range of consumed substrates (multisubstrate testing), the microbial community of the Akhtsu grotto soloid displays a more intensive consumption of alcohols and amino acids, which suggests the supply of the organic matter of an animal origin to the cultural layer of ancient human site. Lactococci and bifidobacteria are identified in the Akhshtyrskaya cave soloid; they are extremely rare in soil and develop under conditions of excess carbohydrates on rich complex media, such as fermented meat and plant residues. In addition, an increased content of keratinolytic fungi capable of decomposing the keratin of hair, wool, feathers, and so on has been found in the cultural layer of the cave site. A comparative analysis of the prokaryotic taxonomy demonstrates the prevalence of the members of the Thermoleophilia class, family Gaiellaceae, order Solirubrobacterales in all the studied soils and soloids. These microorganisms require only positive temperatures for their development, suggesting a mild climate during the soil formation. The Akhtsu grotto paleosols are a promising source of bacteria (genera Janthinobacterium, Lysobacter, and Chitinophaga) that may possess biotechnological potential and useful properties.
{"title":"Structural and Functional State of the Microbial Communities in the Ancient Soloids of Archaeological Monuments on the Russian Black Sea Coast","authors":"","doi":"10.1134/s1064229323602883","DOIUrl":"https://doi.org/10.1134/s1064229323602883","url":null,"abstract":"<span> <h3>Abstract</h3> <p>The structural and functional state of microbial communities of different-aged buried ancient soloids (soil-like bodies lacking genetically distinct horizons) have been comprehensively assessed in open archaeological pits of ancient human sites in the middle reaches of the Mzymta River on the Sochi Black Sea coast in the Akhtsu grotto and Akhshtyrskaya cave. A number of changes in the functional biodiversity of ancient soloids as compared with the background soils (alluvial soils formed immediately near the studied soloids with similar mesomorphological properties) are observed. They include a 1.2-fold decrease in the specific metabolic activity of microbial communities assessed by multisubstrate testing and an increased instability of paleomicrobial systems according to the coefficient of rank distribution of the range of substrate consumption <em>d</em> > 1, which is typical of irreversibly damaged systems. The microbial community of ancient soloids has undergone a number of changes associated with anthropogenic activity. According to the analysis of the main range of consumed substrates (multisubstrate testing), the microbial community of the Akhtsu grotto soloid displays a more intensive consumption of alcohols and amino acids, which suggests the supply of the organic matter of an animal origin to the cultural layer of ancient human site. Lactococci and bifidobacteria are identified in the Akhshtyrskaya cave soloid; they are extremely rare in soil and develop under conditions of excess carbohydrates on rich complex media, such as fermented meat and plant residues. In addition, an increased content of keratinolytic fungi capable of decomposing the keratin of hair, wool, feathers, and so on has been found in the cultural layer of the cave site. A comparative analysis of the prokaryotic taxonomy demonstrates the prevalence of the members of the Thermoleophilia class, family Gaiellaceae, order Solirubrobacterales in all the studied soils and soloids. These microorganisms require only positive temperatures for their development, suggesting a mild climate during the soil formation. The Akhtsu grotto paleosols are a promising source of bacteria (genera <em>Janthinobacterium, Lysobacter,</em> and <em>Chitinophaga</em>) that may possess biotechnological potential and useful properties.</p> </span>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"7 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140032628","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}
Pub Date : 2024-01-31DOI: 10.1134/s1064229323601920
T. Assami, H. Chenchouni, S. Hadj-Miloud
Abstract
The presence of the petrogypsic horizon is an impediment to developing agriculture in the Sahara. It hinders the soil’s ability to store water and root development of crops. The petrogypsic horizon is commonly difficult to map due to its location either on the surface or at depth. This study used logistic regression-kriging and logistic regression models to map the petrogypsic horizon occurrence probability using 466 observations over an area of 22 573 ha in the Sahara Desert of Algeria. The models included remote sensing indices and topographic variables as environmental covariates. The accuracy of models was verified by the area under the curve (AUC). A binary map was produced by applying a threshold of 0.7 on the most performant probability map. Our results showed that logistic regression-kriging performed the best (AUC = 0.88), due to the consideration of residual spatial correlation in the model. The grain size index covariate was the most relevant compared to topographic variables, which showed the usefulness of spectral indices. Based on the binary map, the risk associated with the presence of the petrogypsic horizon was limited, representing 26% of the study area. In the Sahara Desert, though the petrogypsic horizon was weakly correlated with the tested environmental covariates, the use of satellite images and residual autocorrelation in a predictive modelling approach improved the mapping and thus risk assessment of the petrogypsic horizon.
{"title":"Mapping the Petrogypsic Horizon Occurrence Probability in the Sahara Desert Using Predictive Models","authors":"T. Assami, H. Chenchouni, S. Hadj-Miloud","doi":"10.1134/s1064229323601920","DOIUrl":"https://doi.org/10.1134/s1064229323601920","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The presence of the petrogypsic horizon is an impediment to developing agriculture in the Sahara. It hinders the soil’s ability to store water and root development of crops. The petrogypsic horizon is commonly difficult to map due to its location either on the surface or at depth. This study used logistic regression-kriging and logistic regression models to map the petrogypsic horizon occurrence probability using 466 observations over an area of 22 573 ha in the Sahara Desert of Algeria. The models included remote sensing indices and topographic variables as environmental covariates. The accuracy of models was verified by the area under the curve (AUC). A binary map was produced by applying a threshold of 0.7 on the most performant probability map. Our results showed that logistic regression-kriging performed the best (AUC = 0.88), due to the consideration of residual spatial correlation in the model. The grain size index covariate was the most relevant compared to topographic variables, which showed the usefulness of spectral indices. Based on the binary map, the risk associated with the presence of the petrogypsic horizon was limited, representing 26% of the study area. In the Sahara Desert, though the petrogypsic horizon was weakly correlated with the tested environmental covariates, the use of satellite images and residual autocorrelation in a predictive modelling approach improved the mapping and thus risk assessment of the petrogypsic horizon.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"4 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139647636","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}
Pub Date : 2024-01-31DOI: 10.1134/s1064229323602718
Yuanyuan Cui, Xiaohui Song, Liu Bai, Zhongwu Wang
Abstract
The subject of this study was to understand how grazing and precipitation affect the carbon cycle of grassland ecosystem. The experiment was carried out in a desert steppe of Siziwang Banner, Inner Mongolia, China, and measured CO2 flux and abiotic factors twice a month during the growing season (July to October in 2016, May to October in 2017). The experiment used a completely randomized block design, involving four different stocking rate treatments [CK, no grazing, (0 sheep unit hm –2 half year–1), light stocking rate (LG, 0.93 sheep unit hm–2 half year–1), moderate stocking rate (MG, 1.82 sheep unit hm–2 half year–1) and heavy stocking rate (HG, 2.71 sheep unit hm–2 half year–1)] with three replicates, and four precipitation treatments [50% reduced precipitation (P1), natural precipitation (P2), 50% increased precipitation (P3) and 100% increased precipitation (P4)] were set up in each stocking rate treatment plot. Results indicated that increased precipitation treatments significantly increased soil water content (SWC) and soil respiration (Rs), and significantly reduced soil temperature (Ts), grazing treatments significantly reduced Ts, the interaction between precipitation and stocking rate had no significant impact on the above indicators; Rs increased with increasing precipitation in the order: P4 > P3 > P2 > P1, Rs exhibited the following order under different stocking rates: CK > LG > MG > HG. There was a strong positive correlation between Rs and SWC, and a negative relationship between Rs and Ts. Our results demonstrate that SWC is the dominant factor affecting Rs, as SWC explained 87.12% of the variation in Rs.
{"title":"Effects of Stocking Rates and Simulated Precipitation on Soil Respiration in a Stipa breviflora Desert Steppe, Inner Mongolia, China","authors":"Yuanyuan Cui, Xiaohui Song, Liu Bai, Zhongwu Wang","doi":"10.1134/s1064229323602718","DOIUrl":"https://doi.org/10.1134/s1064229323602718","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The subject of this study was to understand how grazing and precipitation affect the carbon cycle of grassland ecosystem. The experiment was carried out in a desert steppe of Siziwang Banner, Inner Mongolia, China, and measured CO<sub>2</sub> flux and abiotic factors twice a month during the growing season (July to October in 2016, May to October in 2017). The experiment used a completely randomized block design, involving four different stocking rate treatments [CK, no grazing, (0 sheep unit hm <sup>–2</sup> half year<sup>–1</sup>), light stocking rate (LG, 0.93 sheep unit hm<sup>–2</sup> half year<sup>–1</sup>), moderate stocking rate (MG, 1.82 sheep unit hm<sup>–2</sup> half year<sup>–1</sup>) and heavy stocking rate (HG, 2.71 sheep unit hm<sup>–2</sup> half year<sup>–1</sup>)] with three replicates, and four precipitation treatments [50% reduced precipitation (P1), natural precipitation (P2), 50% increased precipitation (P3) and 100% increased precipitation (P4)] were set up in each stocking rate treatment plot. Results indicated that increased precipitation treatments significantly increased soil water content (SWC) and soil respiration (<i>Rs</i>), and significantly reduced soil temperature (<i>Ts</i>), grazing treatments significantly reduced <i>Ts</i>, the interaction between precipitation and stocking rate had no significant impact on the above indicators; <i>Rs</i> increased with increasing precipitation in the order: P4 > P3 > P2 > P1, <i>Rs</i> exhibited the following order under different stocking rates: CK > LG > MG > HG. There was a strong positive correlation between <i>Rs</i> and SWC, and a negative relationship between <i>Rs</i> and <i>Ts</i>. Our results demonstrate that SWC is the dominant factor affecting <i>Rs</i>, as SWC explained 87.12% of the variation in <i>Rs</i>.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"2 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139649592","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}
Soil enzyme activities are closely associated with soil organic carbon (SOC) or microbial biomass carbon (MBC). High correlation between SOC and MBC masks their individual effects on enzyme activities. Expressing soil enzymes activity relative to soil organic carbon (SOC) or Microbial Biomass Carbon (MBC) would normalize the differences in SOC/MBC. A long term subtropical rice-wheat system was selected to study the variation in soil-specific enzyme activity (per unit SOC and MBC) in soil aggregates under integrated nutrient management. Soil organic carbon, microbial biomass carbon and the enzyme activities like acid phosphatase (ACP), alkaline phosphatase (AKP), dehydrogenase (DHA), fluorescien diacetate hydrolysing capacity (FDA) and urease were measured in three aggregate size fractions viz., >2000, 2000–250 and <250 µm. Integrated nutrient management practices significantly increased the specific enzyme activities expressed in relation to SOC and MBC. Aggregate size fractions of 2000–250 µm size exhibited higher specific enzyme activities, when expressed in terms of SOC. Enzyme activity (per unit MBC) in aggregates also followed the same pattern with an exception to dehydrogenase activity which was almost uniform across all the aggregates size fractions. Aggregates of larger size do not always possess higher enzymes activity; even smaller macroaggregates were able to retain stable extracellular enzyme activity per unit of SOC or MBC. This study opens an alley to express soil enzymatic activities relative to SOC or MBC level in the soils, rather than expressing absolute activities.
{"title":"Assessment of Soil Specific Enzyme Activities in Aggregates Size Fractions: a Case Study from Subtropical Agro-ecosystem","authors":"Pallavi Bharti, Anupam Das, Sanjay Kumar, Rajiv Rakshit","doi":"10.1134/s1064229323602627","DOIUrl":"https://doi.org/10.1134/s1064229323602627","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Soil enzyme activities are closely associated with soil organic carbon (SOC) or microbial biomass carbon (MBC). High correlation between SOC and MBC masks their individual effects on enzyme activities. Expressing soil enzymes activity relative to soil organic carbon (SOC) or Microbial Biomass Carbon (MBC) would normalize the differences in SOC/MBC. A long term subtropical rice-wheat system was selected to study the variation in soil-specific enzyme activity (per unit SOC and MBC) in soil aggregates under integrated nutrient management. Soil organic carbon, microbial biomass carbon and the enzyme activities like acid phosphatase (ACP), alkaline phosphatase (AKP), dehydrogenase (DHA), fluorescien diacetate hydrolysing capacity (FDA) and urease were measured in three aggregate size fractions viz., >2000, 2000–250 and <250 µm. Integrated nutrient management practices significantly increased the specific enzyme activities expressed in relation to SOC and MBC. Aggregate size fractions of 2000–250 µm size exhibited higher specific enzyme activities, when expressed in terms of SOC. Enzyme activity (per unit MBC) in aggregates also followed the same pattern with an exception to dehydrogenase activity which was almost uniform across all the aggregates size fractions. Aggregates of larger size do not always possess higher enzymes activity; even smaller macroaggregates were able to retain stable extracellular enzyme activity per unit of SOC or MBC. This study opens an alley to express soil enzymatic activities relative to SOC or MBC level in the soils, rather than expressing absolute activities.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"60 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139649604","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}
Pub Date : 2024-01-31DOI: 10.1134/s1064229323602664
Abstract
In the past, the Hur al-Azim marshland served as a natural absorber of dust particles owing to its water content. However, due to a reduction in its expanse, it has transformed into a notable source of dust production in the region. The mitigation of wind erosion necessitates a comprehensive understanding of the quantity and influential factors of wind erodibility. This research endeavors to assess the impact of the drying process of the Hur al-Azim marshland on the wind erodibility. A total of 44 sampling points were strategically chosen along a perpendicular transect to the marshland, specifically in its desiccated segments, with intervals of approximately 5 km. The evaluation of wind erodibility and wind threshold velocity was carried out through a portable wind tunnel, while pertinent soil physical and chemical characteristics were analyzed in the laboratory. The diverse land uses, encompassing Oil Exploitation Lands (OEL), Marshland Fringe Lands (MFL), Marshland Neighboring Lands (MNL), cultivated lands, and virgin lands, were scrutinized for the variability in soil physical and chemical parameters. Subsequently, the influence of these characteristics on wind erodibility and wind threshold velocity was investigated. Leveraging the R software and employing the multiple linear regression (MLR) method, a robust combination of independent variables (physical and chemical properties) was determined and utilized to predict the dependent variables (wind threshold velocity and wind erodibility). Cultivated land exhibited the highest wind erodibility, coupled with the lowest organic matter content. The maximum wind threshold velocity was observed in virgin land, MFL, and MNL land uses, reaching 12 m/s, while the minimum was recorded in MFL and cultivated land at 2.4 m/s, attributed to the soil moisture exceeding 24.83% in MNL and MFL land uses. The findings indicate a linear and inverse correlation between wind erodibility and soil moisture (R2 = 0.42). Notably, the correlation coefficients between soil parameters and erodibility are considerably low, suggesting a lack of statistically significant relationships. The desiccation of the Hur al-Azim marshland emerges as the predominant factor influencing wind erodibility in this region. Consequently, augmenting soil moisture and reinstating marshland water proves instrumental in mitigating wind erodibility.
{"title":"Effects of Land Use Change on Soil Wind Erodibility in the Horul Azim Marshland","authors":"","doi":"10.1134/s1064229323602664","DOIUrl":"https://doi.org/10.1134/s1064229323602664","url":null,"abstract":"<span> <h3>Abstract</h3> <p>In the past, the Hur al-Azim marshland served as a natural absorber of dust particles owing to its water content. However, due to a reduction in its expanse, it has transformed into a notable source of dust production in the region. The mitigation of wind erosion necessitates a comprehensive understanding of the quantity and influential factors of wind erodibility. This research endeavors to assess the impact of the drying process of the Hur al-Azim marshland on the wind erodibility. A total of 44 sampling points were strategically chosen along a perpendicular transect to the marshland, specifically in its desiccated segments, with intervals of approximately 5 km. The evaluation of wind erodibility and wind threshold velocity was carried out through a portable wind tunnel, while pertinent soil physical and chemical characteristics were analyzed in the laboratory. The diverse land uses, encompassing Oil Exploitation Lands (OEL), Marshland Fringe Lands (MFL), Marshland Neighboring Lands (MNL), cultivated lands, and virgin lands, were scrutinized for the variability in soil physical and chemical parameters. Subsequently, the influence of these characteristics on wind erodibility and wind threshold velocity was investigated. Leveraging the R software and employing the multiple linear regression (MLR) method, a robust combination of independent variables (physical and chemical properties) was determined and utilized to predict the dependent variables (wind threshold velocity and wind erodibility). Cultivated land exhibited the highest wind erodibility, coupled with the lowest organic matter content. The maximum wind threshold velocity was observed in virgin land, MFL, and MNL land uses, reaching 12 m/s, while the minimum was recorded in MFL and cultivated land at 2.4 m/s, attributed to the soil moisture exceeding 24.83% in MNL and MFL land uses. The findings indicate a linear and inverse correlation between wind erodibility and soil moisture (<em>R</em><sup>2</sup> = 0.42). Notably, the correlation coefficients between soil parameters and erodibility are considerably low, suggesting a lack of statistically significant relationships. The desiccation of the Hur al-Azim marshland emerges as the predominant factor influencing wind erodibility in this region. Consequently, augmenting soil moisture and reinstating marshland water proves instrumental in mitigating wind erodibility.</p> </span>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":"5 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139647572","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}
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