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Predicting soil depth in a large and complex area using machine learning and environmental correlations

Journal of Integrative Agriculture 2022年第8期21卷 2422-2434页

作者： LIU Feng YANG Fei ZHAO Yu-guo ZHANG Gan-lin LI De-cheng State Key Laboratory of soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008P.R.China University of the Chinese Academy of Sciences Beijing 100049P.R.China Key Laboratory of Watershed Geographic Science Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008P.R.China

soil depth is critical for eco-hydrological modeling,carbon storage calculation and land ***,its spatial variation is poorly understood and rarely *** a limited number of sparse samples,how to predict soil depth in a large area of complex landscapes is still an *** study constructed an ensemble machine learning model,i.e.,quantile regression forest,to quantify the relationship between soil depth and environmental *** model was then combined with a rich set of environmental covariates to predict spatial variation of soil depth and straightforwardly estimate the associated predictive uncertainty in the 140000 km^(2)Heihe River basin of northwestern China.A total of 275 soil depth observation points and 26 covariates were *** results showed a model predictive accuracy with coefficient of determination(R)of 0.587 and root mean square error(RMSE)of 2.98 cm(square root scale),i.e.,almost 60% of soil depth variation *** resulting soil depth map clearly exhibited regional patterns as well as local *** deep soils occurred in low lying landscape positions such as valley bottoms and plains while shallow soils occurred in high and steep landscape positions such as hillslopes,ridges and *** oases had much deeper soils than outside semi-desert areas,the middle of an alluvial plain had deeper soils than its margins,and the middle of a lacustrine plain had shallower soils than its *** predictive uncertainty mainly occurred in areas with a lack of soil survey *** pedogenic and geomorphic processes contributed to the shaping of soil depth pattern of this basin but the latter was *** findings may be applicable to other similar basins in cold and arid regions around the world.

关键词： digital soil mapping spatial variation uncertainty machine learning soil-landscape model soil depth

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Three-source partitioning of soil respiration by ^(13)C natural abundance and its variation with soil depth in a plantation

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Journal of Forestry Research 2016年第3期27卷 533-540页

作者： Wenchen Song Xiaojuan Tong Jinsong Zhang Ping Meng College of Forestry Beijing Forestry University Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration Research Institute of ForestryChinese Academy of Forestry

Partitioning soil respiration into three components is vital to identify CO_2 sink or source and can help us better understand soil carbon dynamics. However, knowledge about the influences of soil depth and the priming effect on soil respiration components under field has been limited. Three components of soil respiration（root respiration, rhizomicrobial respiration and basal respiration） in a plantation in the hilly area of the North China were separated by the 13 C natural abundance method. The results showed that the average proportions of rhizomicrobial respiration, root respiration and basal respiration at the 25-65 cm depths were about 14, 23 and 63 %, respectively. Three components of soil respiration varied with soil depth, and root respiration was the main component of soil respiration in deeper soil. The priming effect was obvious for the deep soil respiration, especially at the 40-50 cm depth. Thus, depth and priming effect should be taken into account to increase the accuracy of estimations of soil carbon flux.

关键词： soil respirationRhizomicrobial respiration abundance soil depth Rhizosphere respiration Root respiration 13C natural

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soil Carbon Sequestrations in Forest soils in Relation to Parent Material and soil depth in South-Eastern Nigeria

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American Journal of Climate Change 2020年第4期9卷 400-409页

作者： Chinonso Millicent Chris-Emenyonu Emmanuel Uzoma Onweremadu John Didacus Njoku Chioma Mildred Ahukaemere Benarden Ngozi Aririguzo Department of soil Science and Technology Federal University of Technology Owerri Nigeria Department of Environmental Management Federal University of Technology Owerri Nigeria

There has been increased interest in soil organic carbon in recent times because of its role in carbon sequestration. Different parent materials affect soil properties and hence will influence how much carbon is sequestered by soil. The study was conducted in June 2019 to investigate soil carbon stock in forest soils with respect to their parent materials in three States in South-eastern Nigeria. Sampling was aided by the location map of the area and free soil survey method was used to locate sampling points. 0ne profile was dug in each location and described using the Food and Agricultural Organization guideline. A total of twelve soil samples were collected and analyzed for selected properties. Results showed that sand content was significantly higher in soils under coastal plain sands (851.96 g·kg−1) and was lowest in soils of Imo clay shale (605.60 g·kg−1). Clay content was higher in soils of Imo clay shale (277.34 g·kg−1) and was lowest in coastal plain sand (118.80 g·kg−1). Silt and clay had moderate variation in coastal plain sand (>15 ≤ 35%) and high variations in Asu River and Imo clay shale (CV > 35%). The soils studied were generally acidic with values ranging (3.52) in soils formed from coastal plain sand, followed by forest soils of Imo clay shale (3.64) and Asu river group (3.85). soil organic carbon

关键词： Carbon Sequestration Forest soils Parent material soil depth

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Effects of soil moisture and soil depth on nitrogen mineralization process under Mongolian pine plantations in Zhanggutai sandy land, P. R. China

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Journal of Forestry Research 2005年第2期16卷 101-104页

作者： CHENFu-sheng ZENGDe-hui SINGHAnandNarain CHENGuang-sheng DaqinggouEcologicalStation InstituteofAppliedEcologyChineseAcademyofSciencesShenyang110016P.R.China DaqinggouEcologicalStation InstituteofAppliedEcologyChineseAcademyofSciencesShenyang110016P.R.China／／GraduateSchoolofChineseAcademyofSciencesBeijing100039PR.China DaqinggouEcologicalStation InstituteofAppliedEcologyChineseAcademyofSciencesShenyang110016P.R.China／／SchoolofForestryandWddlifeSciencesAuburnUniversityAL36830U.S.A

The rates of soil N mineralization at soil depths of 0-15, 15-30, 30-45 and45-60 cm and moisture regimes were measured at three sand-fixation plantations of Pinus sylvestrisvar. mongolica by laboratory aerobic incubation method. The results showed that average rates ofsoil net N-mineralization across soil depth varied from 1.06 to 7.52 mg · kg^(-1)·month^(-1) atsoil depths from 0 to 60 cm. Statistical analyses indicated that the effects of different soildepths, moistures and their interactions on net N-mineralization rates were significant (P soil depths and at depth 0-15cm accounted for 60.52% of that at depth of 0-60 cm. There was no difference in soil netN-mineralization rates between half and fully-saturated water treatments, however these rates weresubstantially higher than that without water treatment (P < 0.05). The factors influencing Nmineralization process have to be studied further in these semiarid pine ecosystems.

关键词： laboratory aerobic incubation method nitrogen mineralization managementpractices sand-fixation forest semiarid region pinus sylvestris var· mongolica soil depth

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soil bacterial depth distribution controlled by soil orders and soil forms

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soil Ecology Letters 2022年第1期4卷 69-77页

作者： Peipei Xue Alex B.McBratney Budiman Minasny Tony O'Donnell Vanessa Pino Mario Fajardo Wartini Ng Neil Wilson Rosalind Deaker School of Life and Environmental Sciences The University of SydneyNSW 2015Australia Sydney Institute of Agriculture NSW 2006Australia Faculty of Science The University of Western AustraliaWA 6009Australia

Human disturbances to soils can lead to dramatic changes in soil physical,chemical,and biological *** influence of agricultural activities on the bacterial community over different orders of soil and at depth is still not well *** used the concept of genoform and phenoform to investigate the vertical(down to 1 m depth)soil bacterial community structure in paired genosoils(undisturbed forests)and phenosoils(cultivated vineyards)in different soil *** study was conducted in the Hunter Valley area,New South Wales,Australia,where samples were collected from 3 different soil orders(Calcarosol,Chromosol,and Kurosol),and each soil order consists of a pair of genosoil and *** bacterial community structure was analyzed using highthroughput sequencing of 16S *** showed that bacterial-diversity decreased with depth in phenosoils,however,the trend is less obvious in genoform *** diversity was greater in phenosoils than genosoils,but the trend was reversed in ***,cropping not only affected topsoil bacteria community but also decreased its diversity in the *** community in topsoils was influenced by both soil orders and soil forms,however,in subsoils it was more impacted by soil *** Analysis of Principal Coordinates revealed that cropping increased the similarity of bacterial structures of different soil *** study highlighted the strong influence of agricultural activities on soil microbial distribution with depth,which is controlled by soil order.

关键词： Bacterial distribution soil depth soil forms/land use Genosoil and phenosoil soil type/soil order

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Responses of N_2O reductase gene(nosZ)-denitrifier communities to long-term fertilization follow a depth pattern in calcareous purplish paddy soil

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Journal of Integrative Agriculture 2017年第11期16卷 2597-2611页

作者： WANG Ying-yan LU Sheng-e XIANG Quan-ju YU Xiu-mei ZHAO Ke ZHANG Xiao-ping TU Shi-hua GU Yun-fu Department of Microbiology College of ResourceSichuan Agricultural University soil and Fertilizer Institute Sichuan Academy of Agricultural Sciences

The effect of long-term fertilization on soil denitrifying communities was analysed by measuring the abundance and diversity of the nitrous oxide （N2O） reductase gene, nosZ. soil samples were collected from plots of a long-term fertilization experiment established in 1982 in Suining City, China. The fertilizer treatments were no fertilizer （CK）, three chemical fertilizer （CF） treatments （N, NP, NPK）, manure （M） alone, and manure with chemical fertilizers （NM, NPM, NPKM）. The abundance and diversity of the denitrifying bacteria were assessed by real-time quantitative PCR, terminal restriction fragment length polymorphism （T-RFLP）, and cloning and sequencing of nosZ genes. The diversity and abundance of nosZ-denitrifiers was higher in soil amended with manure and chemical fertilizers （CFM） than in soil amended with CF alone, and the highest in topsoil （0-20 cm）. The nosZ-denitrifier community composition was more complex in CFM soil than in CF soil： Specific species were detected only in the CFM soil. The abundance of nosZ-denitrifier in the NPKM treatment was approximately two times higher than that in the CK, N, and NPK treatments. Most of the cloned nosZ sequences were closely related to nosZ sequences from Bradyrhizobiaceae and Rhodospirillaceae in Alphaproteobacteria. Of the measured abiotic factors, soil organic matter correlated significantly with the abundance （P〈0.01）; available phosphorus correlated significantly with the topsoil community composition （P〈0.01）, whereas soil organic matter correlated significantly with the subsoil （20-90 cm） community composition （P〈0.01）. This study demonstrated that long-term CFM fertilization affected both the abundance and composition of the nosZ-denitrifier community.

关键词： fertilization community abundance denitrifiers soil depth

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Effects of degradation succession of alpine wetland on soil organic carbon and total nitrogen in the Yellow River source zone,west China

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Journal of Mountain Science 2021年第3期18卷 694-705页

作者： LIN Chun-ying LI Xi-lai ZHANG Jing SUN Hua-fang ZHANG Juan HAN Hui-bang WANG Qi-hua MA Cheng-biao LI Cheng-yi ZHANG Yu-xing MA Xue-qian State Key Laboratory of Plateau Ecology and Agriculture Qinghai UniversityXining 810016China Qinghai Province Weather Modification Office Xining 810001China College of Agriculture and Animal Husbandry Qinghai UniversityXining 810016China Meteorological Institute of Qinghai Province Xining 810001China Qinghai Province geographic situation monitoring Institute Xining 810001China

Wetland is an important carbon pool,and the degradation of wetlands causes the loss of organic carbon and total *** study aims to explore how wetland degradation succession affects soil organic carbon(SOC)and total nitrogen(TN)contents in alpine wetland.A field survey of 180 soilsampling profiles was conducted in an alpine wetland that has been classified into three degradation succession *** SOC and TN contents of soil layers from 0 to 200 cm depth were studied,including their distribution characteristics and the relationship between *** results showed that SOC and TN of different degradation succession gradients followed the ranked order of Non Degradation(ND)>Light Degradation(LD)>Heavy Degradation(HD).SWC was positively correlated with SOC and TN(psoil(0-30 cm).This result showed that SWC was an important indicator of SOC/TN in alpine *** is highly recommended to strengthen water injection into the wetland as a means of effective restoration to reverse alpine meadow back to marsh alpine wetland.

关键词： Degradation succession soil organic carbon(SOC) Total nitrogen(TN) soil water content(SWC) Microtopography soil depth

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Factors Affecting the Performance of Single-Chamber soil Microbial Fuel Cells for Power Generation

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Pedosphere 2014年第3期24卷 330-338页

作者： DENG Huan WU Yi-Cheng ZHANG Fan HUANG Zong-Chuan CHEN Zheng XU Hui-Juan ZHAO Feng Key Laboratory of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Department of Environmental Science and Engineering Nanjing Normal University

There is limited information about the factors that affect the power generation of single-chamber microbial fuel cells （MFCs） using soil organic matter as a fuel source. We examined the effect of soil and water depths, and temperature on the performance of soil MFCs with anode being embedded in the flooded soil and cathode in the overlaying water. Results showed that the MFC with 5 cm deep soil and 3 cm overlaying water exhibited the highest open circuit voltage of 562 mV and a power density of 0.72 mW m-2. The ohmic resistance increased with more soil and water. The polarization resistance of cathode increased with more soil while that of anode increased with more water. During the 30 d operation, the cell voltage positively correlated with temperature and reached a maximum of 162 mV with a 500 ft external load. After the operation, the bacterial 16S rRNA gene from the soil and anode was sequenced. The bacteria in the soil were more diverse than those adhere to the anode where the bacteria were mainly affiliated to Eseherichia coli and Deltaproteobacteria. In summary, the two bacterial groups may generate electricity and the electrical properties were affected by temperature and the depth of soil and water.

关键词： electrogenic bacteria impedance soil depth soil organic matter voltage

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Variation in glomalin in soil profiles and its association with climatic conditions,shelterbelt characteristics,and soil properties in poplar shelterbelts of Northeast China

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Journal of Forestry Research 2020年第1期31卷 279-290页

作者： Qiong Wang Wenjie Wang Zhaoliang Zhong Huimei Wang Yujie Fu Northeast Forestry University Harbin 150040People’s Republic of China Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Glomalin-related soil protein(GRSP)sequesters large amounts of carbon and plays important roles in maintaining terrestrial soil ecosystem functions and ecological restoration;however,little is known about GRSP variation in 1-m soil profiles and its association with stand characteristics,soil properties,and climatic conditions,hindering GRSP-related degraded soil improvement and GRSP *** this study,we sampled soils from 1-m profiles from poplar(Populus spp.)shelterbelts in Northeast *** contents were 1.8–2.0 times higher in the upper 40 cm soil layers than at 40–100 ***-related soil organic carbon(SOC)sequestration in deeper soil layers was*1.2 times higher than in surface *** amounts of GRSP-related nutrients were similar throughout the soil profile.A redundancy analysis showed that in both surface and deeper layers,soil properties(pH,electrical conductivity,water,SOC,and soil nutrients)explained the majority of the GRSP variation(59.5–84.2%);the second-most-important factor in GRSP regulation was climatic conditions(temperature,precipitation,and altitude),while specific shelterbelt characteristics had negligible effects(soil depth and climate indirectly affected GRSP features via soil properties,as manifested by structural equation model *** findings demonstrate that GRSP is important for carbon storage in deep soils,regardless of shelterbelt *** glomalin assessments should consider these vertical patterns and possible regulating mechanisms that are related to soil properties and climatic changes.

关键词： soil depth Glomalin-related soil protein(GRSP) soil organic carbon storage Climate change soil improvement

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Effects of sustainable land management interventions on selected soil properties in Geda watershed,central highlands of Ethiopia

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Ecological Processes 2020年第1期9卷 161-171页

作者： Hailu Terefe Mekuria Argaw Lulseged Tamene Kindu Mekonnen John Recha Dawit Solomon Center for Environmental Science College of Natural ScienceAddis Ababa UniversityP.O.Box 1176Addis AbabaEthiopia International Center for Tropical Agriculture(CIAT) P.O.Box 5689Addis AbabaEthiopia International Livestock Research Institute(ILRI) P.O.Box 5689Addis AbabaEthiopia International Livestock Research Institute(ILRI) P.O.Box 30709Nairobi 00100Kenya

Background:Land degradation through soil erosion by water is severe in the highlands of *** order to curb this problem,the government initiated sustainable land management interventions in different parts of the country since 2008,and in Geda watershed since ***,the impacts of the interventions on soil properties were not assessed so ***,this study investigated the impacts of sustainable land management interventions on selected soil properties in Geda *** samples were collected from treated and untreated subwatersheds at the upper and lower landscape positions,from cropland and grazing lands at two soil depths(0-15 cm and 15-30 cm).Selected soil physicochemical properties were assessed with respect to landscape position,land-use type,and soil depth in both treated and untreated ***:Generally,most of the soil physicochemical properties differed greatly across sub-watersheds,land-use types,and soil ***,electrical conductivity,total N,available P,exchangeable K,and organic carbon were higher in the treated sub-watershed,whereas sand,silt,bulk density,and pH were higher in the untreated *** higher sand,silt,and bulk density could be attributed to erosion,while the higher pH could be due to the higher exchangeable Na in the untreated *** of the selected soil chemical properties were not affected by landscape position,but land-use type affected available P and organic carbon with higher mean values at croplands than at grazing lands,which could be ascribed to the conservation structure and tillage of the soils in that conservation structures trap and accumulate transported organic materials from the upper slope,while tillage facilitates aeration and decomposition ***:Sustainable land management interventions improved soil physicochemical properties and brought a positive restoration of the soil *** the soil conservation measures and enhancing communi

关键词： Crop–livestock system Land degradation Land-use type Sub-watershed soil depth

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