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Land use effects on the dynamics of soil C,n and microbes in the water-wind erosion crisscross region of the northern Loess Plateau,China

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Pedosphere 2024年第1期34卷 181-190页

作者： Yi WAnG Chunyue LI Shunjin HU State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China Department of Entomology&Plant Pathology North Carolina State UniversityRaleigh 27695USA

The water-wind erosion crisscross region of the northern Loess Plateau in China is under constant pressure from severe erosion due to its windy and dry climate and intensive human activities. Identifying sustainable land use patterns is key to maintaining ecosystem sustainability in the area. Our aim was to appraise the impacts of different land use regimes on the dynamics of soil total organic C(TOC), total n(Tn), and microbes in a typical watershed in the northern Loess Plateau to identify suitable land use types that can maintain soil fertility and sustainability. A field experiment was performed in Liudaogou watershed in Shenmu City, Shaanxi Province, China, where the dynamics of soil TOC and Tn, microbial biomass C and n, microbial respiration, and net n mineralization in six typical land use types, dam land, rainfed slope land, deciduous broadleaf forest, evergreen coniferous forest, shrubland, and grassland,were measured in three different growing seasons. Land use type and season significantly affected TOC, Tn, and the dynamics of microbial biomass and activity. As the most anthropogenically disturbed land use pattern, dam land was an optimal land use pattern for TOC sequestration due to its higher TOC and Tn, but lower microbial activity. Soil TOC, Tn, and microbial properties demonstrated a decreasing trend after natural grassland was converted to shrubland,forest, and rainfed slope land. Shrubland with exotic n-fixing Korshinsk peashrub(Caragana korshinskii Kom.) can maintain TOC, Tn, and microbial properties similar to those in grassland. Soil TOC, nH_(4+)^(-)n, Tn, moisture, and extractable C were the principal indexes for soil microbial biomass and activity and explained 88.90% of the total variance. Thus, grassland was the optimal land use pattern in the water-wind erosion crisscross region of the northern Loess Plateau to maintain ecosystem stability and sustainability.

关键词： grassland microbial activity microbial biomass total organic C total n watershed

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total n,total P and organic matters content in floodplain soils of Xianghai nature Reserve

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Journal of Geographical Sciences 2002年第1期12卷 58-64页

作者： DEnG Wei, ZHAI Jin-liang, HE Yan (Changchun Institute of Geography, CAS, Changchun 130021, China) Changchun Institute of Geography CAS Changchun 130021

Soil sediment samples of 10 layers with a spacing of 10 cm each were collected in different floodplain zones adjacent to Huolin River in the Xianghai nature Reserve, and contents of total n, total P and organic matters were analyzed. The results showed that contents of total n, total P and organic matters were generally decreasing with the increase of distance from sample locations to the river channel, and contents of the three items were generally higher in the upper soil layer than that in the lower soil layer. The content variations displayed how flooding functions influenced nutrient matter content variations in floodplain soils since the flood inundation frequencies of the sample locations varied. The correlation analysis displayed that there were remarkable relativities between total n, total P and organic matters within definite spatial distance from the Huolin River channel.

关键词： floodplain wetland total n total P organic matter correlation analysis

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^(137)Cs tracing of the spatial patterns in soil redistribution,organic carbon and total nitrogen in the southeastern Tibetan Plateau

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International Soil and Water Conservation Research 2023年第1期11卷 86-96页

作者： Zhengan Su Lijuan Wang Yihan Liu Bin Fu Jjianhui Zhang Zuo Wu Tao Zhou Junjie Wang Key Laboratory of Mountain Environment Evolution and Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610041PR China University of Chinese Academy of Science Beijing100049PR China College of Geography and Resources Science Sichuan Normal UniversityChengdu610101PR China College of Water Conservancy and Hydropower Engineering Sichuan Agricultural UniversityYa'an625014.PR China

The southeastern Tibetan Plateau,which profoundly affects East Asia by helping to maintain the stability of climate systems,biological diversity and clean water,is one of the regions most vulnerable to water erosion,wind erosion,tillage erosion,freeze-thaw erosion and overgrazing under global climate changes and intensive human activities.Spatial variations in soil erosion in terraced farmland(TL),sloping farmland(SL)and grassland(GL)were determined by the^(137)Cs tracing method and compared with spatial variations in soil organic carbon(SOC)and total nitrogen(total n).The^(137)Cs concentration in the GL was higher in the 0-0.03 m soil layer than in the other soil layers due to weak migration and diffusion under low precipitation and temperature conditions,while the^(137)Cs concentration in the soil layer of the SL was generally uniform in the 0-0.18 m soil layer due to tillage-induced mixing.Low^(137)Cs inventories appeared at the summit and toe slope positions in the SL due to soil loss by tillage erosion and water erosion,respectively,while the highest^(137)Cs inventories appeared at the middle slope posi-tions due to soil accumulation under relatively flat landform conditions.In the GL,the^(137)Cs data showed that higher soil erosion rates appeared at the summit due to freeze-thaw erosion and steep slope gradients and at the toe slope position due to wind erosion,gully erosion,freeze-thaw erosion and overgrazing.The^(137)Cs inventory generally increased from upper to lower slope positions within each terrace(except the lowest terrace).The^(137)Cs data along the terrace toposequence showed abrupt changes in soil erosion rates between the lower part of the upper terrace and the upper part of the immediate terrace over a short distance and net deposition on the lower and toe terraces.Hence,tillage erosion played an important role in the soil loss at the summit slope positions of each terrace,while water erosion dominantly transported soil from the upper terrace to the lower terrace and resulted in net soil depos

关键词： Southeastern Tibetanplateau ^(137)Cs SOC total n Soil erosion

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Contaminant Removal of Domestic Wastewater by Constructed Wetlands： Effects of Plant Species

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Journal of Integrative Plant Biology 2007年第4期49卷 437-446页

作者： Qiong Yang Zhang-He Chen Jian-Gang Zhao Bin-He Gu College of Life Sciences South China Normal University Guangzhou 510631 China Everglades Division South Florida Water Management District West Palm Beach Florida 33406 USA

A comparative study of the efficiency of contaminant removal between five emergent plant species and between vegetated and unvegetated wetlands was conducted in small-scale （2.0 m×1.0 m×0.7 m, lengthxwidthxdepth） constructed wetlands for domestic wastewater treatment in order to evaluate the decontaminated effects of different wetland plants. There was generally a significant difference in the removal of total nitrogen （Tn） and total phosphorus （TP）, but no significant difference in the removal of organic matter between vegetated and unvegetated wetlands. Wetlands planted with Canna indica Linn., Pennisetum purpureum Schum., and Phragmites communis Trin. had generally higher removal rates for Tn and TP than wetlands planted with other species. Plant growth and fine root （root diameter ≤ 3 mm） biomass were related to removal efficiency. Fine root biomass rather than the mass of the entire root system played an important role in wastewater treatment. Removal efficiency varied with season and plant growth. Wetlands vegetated by P. purpureum significantly outperformed wetlands with other plants in May and June, whereas wetlands vegetated by P. communis and C. indica demonstrated higher removal efficiency from August to December. These findings suggest that abundance of fine roots is an important factor to consider in selecting for highly effective wetland plants. It also suggested that a plant community consisting of multiple plant species with different seasonal growth patterns and root characteristics may be able to enhance wetland performance.

关键词： constructed wetlands contaminants domestic wastewater plant species removal efficiency total n total P.

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Predictions of soil and nutrient losses using a modified SWAT model in a large hilly-gully watershed of the Chinese Loess Plateau

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International Soil and Water Conservation Research 2021年第2期9卷 291-304页

作者： Wenhai Shi Mingbin Huang The State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYanglingShaanxi Province712100China School of Water and Environment Chang’an UniversityXian710054China CAS Center for Excellence in Quaternary Science and Global Change XianShaanxi710061China University of Chinese Academy of Sciences Beijing100049China

Hydrological models are effective tools for assessing the effects of soil and nutrient losses on land degradation.SWAT(Soil and Water Assessment Tool)model is widely used to simulate soil and nutrient losses caused by various management regimes.However,its performance of predicting nutrient loss has not been assessed adequately on the Loess Plateau.This study proposed a modified SWAT model by incorporating the modified Soil Conservation Service curve number method,the storm-based Chinese soil loss equation and the nutrient loss model.The observed daily data of runoff and sediment over 16 years and the monthly soluble phosphorus(P)and nitrate losses over 9 years and 4 years,respectively at the outlet of the upper Beiluo river(UBR)basin were used to assess the model performances.Global sensitivity and uncertainty analyses of parameters to runoff,sediment,soluble P and nitrate in the modified SWAT were conducted.The findings during calibration and validation showed that the modified SWAT was highly accurate in terms of model efficiency(calibration:0.83,0.83,0.48,and 0.49;validation:0.58,0.57,0.53,and 0.65)for runoff,sediment,soluble P loss and nitrate loss,respectively.High model efficiency indicated that the modified SWAT could accurately predict soil and nutrient losses at the river basin scale for the Loess Plateau.Moreover,the temporal variations from month to year and the spatial variations at the sub-basin scale for soil loss and the total n and P losses were analysed using the data simulated by the modified SWAT.The results indicated that the critical loss period occurred in July and August,and the Grain for Green project significantly affected the hydrological behaviour and reduced the soil and nutrient losses in the UBR basin.

关键词： Sediment Runoff total n total P

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Discrepancy in Response of Rice Yield and Soil Fertility to Long-Term Chemical Fertilization and Organic Amendments in Paddy Soils Cultivated from Infertile Upland in Subtropical China

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Agricultural Sciences in China 2011年第2期10卷 259-266页

作者： LIU Ming LI Zhong-pei ZHAnG Tao-lin JIAnG Chun-yu CHE Yu-ping State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008P.R.China Graduate University Chinese Academy of SciencesBeijing 100049P.R.China

From 1990,over 17 years field experiment was carried out in paddy field cultivated from infertile upland to evaluate the response of rice productivity,soil organic carbon（SOC）,and total n to long-term nPK fertilization or nPK combined with organic amendments.The field trials included nPK（n,P,K fertilizer）,nPKRS（nPK combined with rice straw）,nPK2RS（nPK combined with double amount of rice straw）,nPKPM（nPK combined with pig manure） and nPKGM（nPK combined with green manure） and the cropping system was rice-rice（Oryza sativa L.） rotation.Annual rice yield,straw biomass,and harvesting index increased steadily with cultivation time in all treatments.Average annual rice yield from 1991 to 2006 was ranged from 7 795 to 8 572 kg ha-1 among treatments.Rice yields in treatments with organic amendments were usually higher than that in treatment with nPK.Contents of SOC and total n also increased gradually in the cultivation years and reached the level of 7.82 to 9.45 and 0.85 to 1.03 g kg-1,respectively,in 2006.Soil fertilities in treatments with chemical fertilization combined with organic amendments were relatively appropriate than those in treatment with nPK.There was obvious discrepancy between cumulative characters of rice yield and soil organic fertility in newly formed paddy field.Compared with relatively high rate of crop productivity improvement,cumulative rates of SOC and total n were much lower in our study.SOC and total n contents were still less than half of those in local highly productive paddy soils after 17 years cultivation in subtropical China.Present work helps to better understand the development of infertile paddy soils and to estimate the potential of yield improvement in this region.

关键词： paddy field rice yield SOC total n long-term field experiment

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Characterization of Amino Acid Composition in Fruits of Three Rosa roxburghii Genotypes

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Horticultural Plant Journal 2017年第6期3卷 232-236页

作者： LU Min An Huaming WAnG Daoping Agricultural College Guizhou University Guizhou Engineering Research Center for Fruit Crops Key Laboratory of Chemistry for natural Products of Guizhou Province and Chinese Academy of Sciences

Rosa roxburghii Tratt., is an important commercial horticultural crop in China due to its nutritional and medicinal value. To date, the economic production of a single predominant cultivar of R. roxburghii(‘Guinong 5') consumes 30 000 hm^2 in China. Here, we characterize the amino acid composition of ‘Guinong 5' and two novel genotypes(AL11, GP6) that prove valuable and deserve wide application. Here, 17 amino acids(acid hydrolysis of proteins) were detected in ‘Guinong 5', AL11 and GP6 fruits, with Glutamine and Asparagine being abundant, and L-cystine being absent. The essential amino acids and total amino acids were the highest in AL11, while Asparagine was most abundant in GP6. For the free amino acid, 18 amino acids and 9 metabolites were detected in ‘Guinong 5', AL11 and GP6 fruits. γ-aminobutyric acid, L-arginine and ornithine were the most abundant in ‘Guinong 5', while phosphoserine and taurine were the highest in AL11. In comparison, GP6 had the highest levels of L-asparagine, an essential amino acid, and the highest total n containing compounds.

关键词： Rosa roxburghii fruits amino acid essential amino acid total n

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