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Effect of Rotational Tillage on soil Aggregates, Organic Carbon and Nitrogen in the Loess Plateau Area of China

Pedosphere 2013年第4期23卷 542-548页

作者： HOU Xian-Qing LI Rong JIA Zhi-Kuan HAN Qing-Fang Chinese inst.tute of water-Saving Agriculture Northwest A&F University Key Laboratory of Crop Physi-Ecology and Tillage Science in northwestern Loess Plateau Ministry of Agriculture Northwest A&F University School of Agriculture Ningxia University

In rain-fed semi-arid agroecosystems, continuous conventional tillage can cause serious problems in soil quality and crop production, whereas rotational tillage （no-tillage and subsoiling） could decrease soil bulk density, and increase soil aggregates and organic carbon in the 0-40 cm soil layer. A 3-year field study was conducted to determine the effect of tillage practices on soil organic carbon （SOC）, total nitrogen （TN）, water-stable aggregate size distribution and aggregate C and N sequestration from 0 to 40 cm soil in semi-arid areas of southern Ningxia. Three tillage treatments were tested： no-tillage in year 1, subsoiling in year 2, and no-tillage in year 3 （NT-ST-NT）; subsoiling in year 1, no-tillage in year 2, and subsoiling in year 3 （ST-NT-ST）; and conventional tillage over years 1-3 （CT）. Mean values of soil bulk density in 0-40 cm under NT-ST-NT and ST-NT-ST were significantly decreased by 3.3% and 6.5%, respectively, compared with CT, while soil total porosity was greatly improved. Rotational tillage increased SOC, TN, and water-stable aggregates in the 0-40 cm soil, with the greatest effect under ST-NT-ST. In 0-20 and 2（}-40 cm soils, the tillage effect was confined to the 2-0.25 mm size fraction of soil aggregates, and rotational tillage treatments obtained significantly higher SOC and TN contents than conventional tillage. No significant differences were detected in SOC and TN contents in the 〉 2 mm and 〈 0.25 mm aggregates among all treatments. In conclusion, rotational tillage practices could significantly increase SOC and TN levels, due to a fundamental change in soil structure, and maintain agroecosystem sustainability in the Loess Plateau area of China.

关键词： semi-arid region SOC sorage soil bulk density tillage practice water-stable aggregates

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Multi-Source Characteristics of Atmospheric Deposition in Nanjing,China,as Controlled by East Asia Monsoons and Urban Activities

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Pedosphere 2016年第3期26卷 374-385页

作者： LI Shanquan ZHANG Ganlin YANG Jinling JIA Nan State Key Laboratory of soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 (China) University of Chinese Academy of Sciences Beijing 100049 (China)

Atmospheric deposition, a major pathway of metals entering into soils, plays an important role in soil environment, especially in urban regions where a large amount of pollutants are emitted into atmosphere through various sources. In order to understand the characteristics of atmospheric deposition in urban area and its relation with natural and anthropogenic sources, a three-year study of atmospheric deposition at three typical sites, industrial zone(IN), urban residential area(RZ) and suburban forested scenic area(FA),was carried out in Nanjing, a metropolitan city in eastern China from 2005 to 2007. The bulk deposition rate and element composition of atmospheric deposition varied spatio-temporally in the urban zones of Nanjing. The concentrations of Cu, Zn, Pb and Ca in the atmospheric deposits were strongly enriched in the whole Nanjing region; however, anthropogenic pollutants in atmospheric deposits were diluted by the input of external mineral dust transported from northwestern China. Source apportionment through principal component analysis(PCA) showed that the background atmospheric deposition at the FA site was the combination of external aerosol and local emission sources. The input of long-range transported Asian dust had an important influence on the urban background deposition, especially in spring when the continental dust from the northwestern China prevailed. Marine aerosol source was observed in summer and autumn, the seasons dominated by summer monsoon in Nanjing. In contrast, the contribution of local anthropogenic emission source was constant regardless of seasons. At the RZ and IN sites, the atmospheric deposition was more significantly affected by the nearby human activities than at the FA site. In addition, different urban activities and both the winter and summer Asian monsoons had substantial impacts on the characteristics of dust deposition in urban Nanjing.

关键词： aerosol anthropogenic pollutants Asian dust metals source apportionment urban environment

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FREEZE/THAW EFFECTS ON RILL AND GULLY EROSION IN THE northwestern WHEAT AND RANGE REGION

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International Journal of Sediment Research 2005年第3期20卷 48-56页

作者： D. K. MCCOOL,J. D. WILLIAMS Supervisory Agricultural Engineer Land Management and water conservation Research USDA-ARS Pullman WA USA Hydrologist Columbia Plateau conservation Research Center USDA-ARS Pendleton OR.

Hydrology of the northwestern Wheat and Range Region (NWRR) of the Pacific Northwest USA is dominated by winter events. Fifty-five to sixty-five percent of the precipitation occurs from November through March, and formation of impermeable frost, intensified by excessive tillage and tillage pans, has long been a major factor in rill and gully formation in the region. Saturated zones can form above tillage pans, freeze solid, and significantly reduce infiltration. Frost heaved surface soils thaw and weaken with warming temperatures or rain. Under these conditions, runoff from rain or snowmelt or a combination of the two is inevitable, concentrating in rills and channels, and carrying with it the loosened soil. Slopes are frequently quite steep and there may be little deposition above the toe slope. Classical over-fall head-cut gullies are uncommon. Concentrated flow channels form because of collection of water from impervious areas such as conventionally tilled fall seeded small grains and bare grass seed fields. In some soils, gullies are created by seepage from saturated layers above permanent restrictive layers in the soil. Gullies can also result from terrace failures due to rodent burrows and low compaction at the time of construction. In naturally unconsolidated soil, rodent activity can lead to piping failures that remove large quantities of subsurface soil and can become gullies. Rill measurements on conventionally tilled fields in Oregon, Washington, and Idaho were used to determine coefficients for relationships between slope length and steepness and size of rills. This paper describes these studies and the results as well as analysis of long-term erosion and weather records from southeastern Washington.

关键词： Erosion Slope length Slope steepness Topography Pacific Northwest Frozen soil Thawing soil

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Biological perspectives in geotechnics:Application and monitoring

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2854-2878页

作者： Partha Narayan Mishra Surabhi Jain Thierry Bore Ilhan Chang Yeong-Man Kwon Yijie Wang Hirak Ranjan Dash Ashutosh Kumar Satyam Tiwari Ningjun Jiang Sarat Kumar Das Alexander Scheuermann Department of Civil Engineering Indian Institute of Technology KanpurKanpur208016India School of Civil Engineering University of QueenslandSt LuciaQLD4072Australia Department of Civil Engineering Indian Institute of Technology DhanbadDhanbad826004India Department of Civil System Engineering Ajou UniversitySuwon-si16499Republic of Korea School of Engineering and IT University of New South WalesCanberraACT2600Australia Department of Civil and Environmental Engineering Northwestern UniversityEvanstonIL60208USA Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong KongChina National Forensic Sciences University New Delhi110085India Southeast University Nanjing211189China

This paper builds on exploring the applications of biomediated pathways to solve geotechnical ***,the state of the art of biological remediation strategies including microbial remediation and phytoremediation have been introduced and critically reviewed in the context of decontaminating the ***,biopolymerisation,biomineralisation and bioneutralisation processes have been depicted with a special emphasis on the applications including but not limited to soil stabilisation,soil erosion prevention,anti-desertification and pH *** of these methods have their own limitations and bottlenecks while scaling up,and these challenges have been summarised and some possible paths to overcome the challenges have also been *** state of the art of electromagnetic(EM)monitoring methods to capture the effects of biomediation on spatio-temporal soil properties are then highlighted as a non-invasive and rapid pathway to track the progress of biomediated soil ***,each of the technologies discussed have been evaluated for their maturity level using the principles of technology readiness level(TRL).A majority of the technologies amounting to around 77%are still in the TRL 4e7,*** the valley of *** is thus evident that development of these technologies needs to be supported with appropriate funding for improving their maturity to a level of industrial deployment.

关键词： Biogeotechnics Bioremediation Phytoremediation Biopolymers Biomineralisation Electromagnetic(EM)methods technology readiness level(TRL)

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Holocene loess and its deposition dynamics in the upper reaches of the Huaihe River

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Journal of Geographical Sciences 2011年第3期21卷 561-573页

作者： HE Zhong HUANG Chunchang ZHENG Hongbo ZHOU Jie PANG Jiangli LI Xinyan WANG Lijun inst.tute of Surficial Geochemistry School of Earth Science and Engineering Nanjing University Nanjing 210093 China College of Tourism and Environmental Sciences Shaanxi Normal University Xi'an 710062 China inst.tute of soil and water conservation CAS Yangling 712100 Shaanxi China Nanjing inst.tute of Geography & Limnology CAS Nanjing 210008 China

The dust source and transporting system are two indispensable aspects in the process of Ioess-palaeosol accumulation. It has been proved that the dust of the Loess Plateau mainly comes from the northwestern inland gobi and desert, transported by the East Asia monsoon systems and westerlies. However, there are little researches with respect to the dust source and deposition dynamics of the upper reaches of the Huaihe River. In the present study, we investigated and collected the YPC section with high resolution in the upper reaches of the Huaihe River. The chronological frame was reconstructed by optically stimulated luminescence （QSL） dating and correlated with the published loess time series. By comparison of the magnetic susceptibility （MS） and grain size （GS） of loess-soil profile among YPC profile, XJN profile （western Loess Plateau） and the JYC profile （southern Loess Plateau）, we find similar climate change and pedogenic process between the upper reaches of the Huaihe River and the Loess Plateau, both experienced an extreme dry and the weakest pedogenesis during the last glacial, followed by a transitional episodes from the cold-dry last glacial to the warm-humid mid-Holocene and increased pedogenesis in the early Holocene, then a most humid-warm and strong pedogenesis in the mid-Holocene, and climate deterioration and decreased pedogenesis occurred during the late Holocene. But the MS of loess-soil profile sequences in the upper reaches of the Huaihe River was much lower than those in the Loess Plateau, and the GS was much coarser than those in the Loess Plateau. Comparison of GS for these three profiles revealed that there were different dust sources, which belonged to different aeolian transporting systems. The loess in the upper reaches of the Huaihe River was a wind blown deposition of near source, while the coarser dust mainly came from loose alluvial deposits of alluvial and proluvial fans of the Yellow River. The yield- ing and carrying dynamics of the

关键词： aeolian dust dust source transporting system upper reaches of the Huaihe River

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Mass Balance of Major Elements in Relation to Weathering in soils Developed on Igneous Rocks in a Semiarid Region,northwestern Iran

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Journal of Mountain Science 2012年第1期9卷 41-58页

作者： Maryam YOUSEFIFARD Shamsollah AYOUBI Ahmad JALALIAN Hossein KHADEMI Mohammad Ali MAKKIZADEH Department of soil Science College of AgricultureIsfahan University of Technology84156-83111IsfahanIran Department of soil Science College of AgricultureIslamic Azad UniversityKhorasgan BranchIsfahanIran

This study was conducted to evaluate the weathering intensity of the major soils developed on igneous rocks in semiarid region of northwestern *** parent materials were selected including monzodiorite,alkali granite,granodiorite,syenite,pyroxene diorite,hornblende andesite,pyroxene andesite,and *** soil profiles were described and soil samples were collected and analyzed for selected chemical and physical properties and total concentrations of major elements and Zr,V,Ti and *** densities as well as Ti,Zr and V concentrations were used to estimate the strain factors and mass balance equations were used to quantify the net result of pedogenic weathering,*** loss and *** results of clay content and pedogenic iron variability as well as index of compositional variability(ICV),chemical index of alteration(CIA) and,A-CN-K and MFW ternary plots showed that the soils developed on volcanic rocks(hornblende andesite> pyroxene andesite> dacite) were more weathered than those on the plutonic parent rocks(alkali granite,granodiorite,monzodiorite,syenite,pyroxene diorite).The results of mass balance calculations based on the strain factors revealed that the Ca and Na depleted during weathering progress mostly from plagioclase *** the semiarid regions Ca is precipitated as pedogenic calcite in the soil horizons.K and Mg depletion is less than Ca and Na especially in the profiles on the hornblende andesite with the highest clay and LOI *** results of this study clearly suggest that the behavior of K and Mg during the weathering cannot only be explained by the disintegration of the primary minerals,since they are fixed on the secondary clay *** did not change in the soils compared to the parent material and was precipitated as the pedogenic iron and conserved in the soil ***,the results on the weathering indicators and major elements mass balance enrichment/depletion in the study area confirmed that the

关键词： Major elements Mass balance weathering intensity Igneous rocks Plutonic Volcanic

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Comparison of biochar properties from 5 kinds of halophyte produced by slow pyrolysis at 500℃

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Biochar 2022年第1期4卷 1003-1012页

作者： Hongyang Xiao Qimei Lin Guitong Li Xiaorong Zhao Jianzhong Li Erzhen Li Department of soil and water Science College of Land Science and TechnologyChina Agricultural UniversityBeijing 100193China Agricultural and Animal Husbandry Technology Extension and Service Center of Wuyuan County Bayannur 015100Inner MongoliaChina

Glycophyte biomass-derived biochars are currently concerned in most ***,little attention is given to the char-acteristics of halophyte-derived *** this study,five typical halophytes of euhalophytes(Suaeda altissima,Suaeda salsa,and Kalidium foliatum),recretohalophytes(Phragmites australis),and pseudohalophytes(Tamarix chinensis)which are widely distributed in the arid and semiarid regions of northwestern China were selected for producing biochars with a slow pyrolysis process at 500℃for 1 *** harvested biochars were characterized in elemental content,pores,surface area,and surface charges,and then their potential value as a soil conditioner was *** results showed that the halophyte-derived biochars had variable ash and Na+contents,ranging from 7.26 to 23.64%and 1.06 to 33.93 g kg^(−1)*** EC value of the biochars ranged from 1.76 to 23.45 mS cm^(−1).The biochar derived from Suaeda altissima had a very low specific surface area(SSA),3.50 m^(2)g^(−1),while that derived from Phragmites australis(BPA)had a very high SSA,344.02 m^(2)g^(−1).All the biochars carried both positive and negative *** foliatum biochar(BKF)possessed more nega-tive charges,while Suaeda altissima biochar(BSA)contained more positive *** general,the halophyte biochars had a higher ash content and lower point of zero net charge(PZNC)value,compared with the biochars derived from glycophytes,which would imply their higher potential value as an acidic soil conditioner.

关键词： Halophyte Biochar Structural elements Mineral elements Surface charges

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High basal defense gene expression determines sorghum resistance to the whorl-feeding insect southwestern corn borer

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Insect Science 2013年第3期20卷 307-317页

作者： Wei-Ning Cheng Jia-Xin Lei William L. Rooney Tong-Xian Liu Keyan Zhu-Salzman Key Laboratory of Integrated Pest Management on Crops in northwestern Loess Plateau Ministry of Agriculture Northwest A&F Uni- versity Yangling Shaanxi China Department of Entomology Department of soil and Crop Sciences Vegetable & Fruit Improvement Center Texas A&M University College Station Texas United States

Southwestern corn borer （SWCB, Diatraea grandiosella） and fall armyworm （FAW, Spodopterafrugiperda） are major pests of sorghum in the southern United States. Host plant resistance is a desirable means for reducing plant damage and yield losses from both insects. In this study, we evaluated 12 sorghum lines for whorl-stage resistance to leaf-feeding SWCB and FAW in greenhouse and laboratory bioassays. Differential plant responses were detected against.the two insects. Among 12 lines tested, CM1821, Della and PI196583 were resistant to both insects, while BTx2752 was largely susceptible. Line R.09110 was resistant to SWCB, but susceptible to FAW, whereas Redbine-60 was suscep- tible to SWCB, but not to FAW. In addition, we quantified various chemical components in the plants and determined their association with insect resistance. Tannin and chloro- phyll in leaves did not show any significant correlation with resistance to either insects, but contents of soluble protein in general were negatively correlated with resistance to both insects. Endogenous soluble sugar and dhurrin were only positively correlated with resistance to SWCB, but not with FAW resistance. To gain some molecular insight into resistance mechanism of sorghum to SWCB, we performed qPCR reactions for key genes encoding enzymes involved in dhurrin and jasmonic acid （JA） biosynthesis on selected resistant or susceptible lines. Although these genes were rapidly and strongly induced by insect feeding in all lines, the observed resistance is likely explained by higher constitutive dhurrin contents in some resistant lines and higher basal JA biosynthesis in others. Our results suggest that sorghum utilizes multiple strategies to defend itself against.SWCB.

关键词： Diatraea grandiosella host plant resistance resistance mechanism sorghum,Spodoptera frugiperda

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Evaluation of ecological risk and primary empirical research on heavy metals in polluted soil over Xiaoqinling gold mining region,Shaanxi,China

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Transactions of Nonferrous Metals Society of China 2010年第4期20卷 688-694页

作者：吴耀国徐友宁张江华胡思海 Department of Applied Chemistry Northwestern Polytechnical University Xi'an inst.tute of Geology and Mineral Resources

soil,crop and residents'hair over Xiaoqinling gold mining region,China,which was selected as a case study,were sampled and analyzed for Hg,Cd,Pb,Cu,Cr,As and Zn *** concentrations of heavy metals in soil or crop and hair samples were used to assess their potential ecological risks,or to find the responses to these metals as evidences to prove the potential risk was coming down to observed harm,*** results showed that,these metals in soil were ranked by severity of ecological risk as Hg>Cd>Pb>Cu>Cr>As>Zn,based on their single-element *** the view of the potential ecological risk indexes,of all soil samples,about half had significantly high or high potential ecological risk,which covered more than 74%of the studied *** of the risks were 97.41%from Hg,Pb and Cd,especially,84.37%from *** the single-element and potential ecological risk indexes indicated that,the ecological risk grades had a special spatial characteristic,and increased from northwest to southeast *** was agreed with the spatial distribution of the strength in gold mining activities over the studied *** concentrations of Hg and Pb were higher than their relative backgrounds in the corps,and were even 9.48 and 25.09 times higher than their relative backgrounds in residents'hair,*** these showed that the heavy metals in the soil had a high potential ecological risk,especially,had been affecting these crops'growing and yield,and even the residents'health through food ***,these metals'potential ecological harm had been coming down to observed harm to the ecology.

关键词： gold mining activity soil pollution heavy metal potential ecological risk

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Interaction between Cd and Pb in the soil-plant system: a case study of an arid oasis soil-cole system

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Journal of Arid Land 2014年第1期6卷 59-68页

作者： ZhuanJun ZHAO ZhongRen NAN ZhaoWei WANG YiMing YANG Masayuki SHIMIZU College of Resource & Environment Lanzhou University Department of soil and Crop Science Colorado State University

The Hexi Corridor,our study area,is located in Northwest China and is also the most developed area of oasis farming in arid regions of northwestern ***,the rapid development of metallurgy and chemical industries in this region poses a great threat to the accumulation of heavy metals in *** objectives of this study are(1)to determine the influence of heavy metals on plant growth;(2)to assess the translocation capability of heavy metals in soil-plant system;and(3)to investigate the interaction between heavy *** experiments were conducted on cole(Brassica campestris L.)grown in the arid oasis soils singly and jointly treated with cadmium(Cd)and lead(Pb).Nine treatments were applied into the *** the same planting conditions,three scenarios of Cd,Pb and Cd–Pb were designed to compare the interaction between Cd and *** results showed that the response of cole weights to Cd,Pb and Cd–Pb treatments was slight,while Cd and Pb uptakes in cole were more sensitive to the single effects of Cd and Pb concentration in soils from the lower treatment *** the influence of the single Cd,Pb and joint Cd–Pb treatments,Cd concentrations were lower in the cole roots than in the shoots,while for Pb,the results were *** studies revealed that the interaction of Cd and Pb could weaken the cole’s ability to uptake,concentrate and translocate heavy metals in arid oasis soils.

关键词： heavy metals interaction vegetables oasis soils arid regions Brassica campestris L.

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