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Attribution of explanatory factors for change in soil organic carbon density in the native grasslands of Inner Mongolia,China

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Journal of Arid Land 2018年第3期10卷 375-387页

作者： JIN Dongyan Phil J MURRAY XIN Xiaoping QIN Yifei CHEN Baorui QING Gele ZHANG Zhao YAN Ruirui Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences department of sustainable soils and grassland systems Rothamsted Research North Wyke department of grassland Ecology and Animal Husbandry Xilingol Vocational College

The variation in soil organic carbon density（SOCD） has been widely documented at various spatial and temporal scales. However, an accurate method for examining the attribution of explanatory factors for change in SOCD is still lacking. This study aims to attribute and quantify the key climatic factors, anthropogenic activities, and soil properties associated with SOCD change in the native grasslands of Inner Mongolia, China, by comparing data between the 1960s and the 2010s. In 2007 and 2011, we resampled 142 soil profiles which were originally sampled during 1963–1964 in the native grasslands of Inner Mongolia. SOCD was determined in A horizon（eluvial horizon） of the soil. We selected the explanatory factors based on a random forest method, and explored the relationships between SOCD change and each of the explanatory factors using a linear mixed model. Our results indicated that the change in SOCD varied from the east to the west of Inner Mongolia, and SOCD was 18% lower in the 2010s than in the 1960s. The lower SOCD in the 2010s may primarily be attributed to the increasing in mean annual water surface evaporation, which explained approximately 10% and 50% of the total variation and explainable variation in the change in SOCD, respectively. The sand content of the soil is also a significant explanatory factor for the decrease in SOCD, which explained about 4% and 21% of the total variation and explainable variation in the change in SOCD, respectively. Furthermore, the collection of quantitative information on grazing frequency and duration may also help to improve our understanding of the anthropogenic factors that govern the change in SOCD.

关键词： soil organic carbon climate change soil texture mixed linear model effect isolation native grasslands

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Soil CO_2 and N_2O Emissions in Maize Growing Season Under Different Fertilizer Regimes in an Upland Red Soil Region of South China

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Journal of Integrative Agriculture 2014年第3期13卷 604-614页

作者： ZHANG Xu-bo WU Lian-hai SUN Nan DING Xue-shan LI Jian-wei WANG Bo-ren LI Dong-chu Key Laboratory of Crop Nutrition and Fertilization Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences sustainable soils and grassland systems department Rothamsted Research department of Botany and Microbiology University of Oklahoma

Upland red soils have been identified as major CO2 and N2O sources induced by human activities such as fertilization. To monitor characteristics of soil surface CO2 and N2O fluxes in cropland ecosystems after continuous fertilizer applications over decades and to separate the respective contributions of root and heterotrophic respiration to the total soil CO2 and N2O fluxes, the measurements of soil surface CO2 and N2O fluxes throughout the maize growing season in 2009 were carried out based on a fertilization experiment （from 1990） through of the maize （Zea mays L.） growing season in red soil in southern China. Five fertilization treatments were chosen from the experiment for study： zero-fertilizer application （CK）, nitrogen-phosphorus- potassium （NPK） fertilizer application only, pig manure （M）, NPK plus pig manure （NPKM） and NPK with straw （NPKS）. Six chambers were installed in each plot. Three of them are in the inter-row soil （NR） and the others are in the soil within the row （R）. Each fertilizer treatment received the same amount of N （300 kg ha-1 yr-1）. Results showed that cumulative soil CO2 fluxes in NR or R were both following the order： NPKS〉M, NPKM〉NPK〉CK. The contributions of root respiration to soil CO2 fluxes was 40, 44, 50, 47 and 35% in CK, NPK, NPKM, M and NPKS treatments, respectively, with the mean value of 43%. Cumulative soil N2O fluxes in NR or R were both following the order： NPKS, NPKM〉M〉NPK〉CK, and soil N2O fluxes in R were 18, 20 and 30% higher than that in NR in NPKM, M and NPKS treatments, respectively, but with no difference between NR and R in NPK treatment. Furthermore, combine with soil temperature at -5 cm depth and soil moisWxe （0-20 cm） together could explain 55-70% and 42-59% of soil CO2 and N2O emissions with root interference and 62- 78% and 44-63% of that without root interference, respectively. In addition, soil CO2 and N2O flUXeS per unit yield in NPKM （0.55 and 0.10 kg C t^-1） and M （0.65 and 0.13 g N t^-1） treatments were

关键词： greenhouse gas emissions carbon dioxide nitrous oxide manure mineral fertilizers straw return South China

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Soil Characteristics Overwhelm Cultivar Effects on the Structure and Assembly of Root-Associated Microbiomes of Modern Maize

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Pedosphere 2019年第3期29卷 360-373页

作者： CHEN Lin XIN Xiuli ZHANG Jiabao Marc REDMILE-GORDON NIE Guangsen WANG Qingyun State Key Laboratory of Soil and sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 (China) department of sustainable soils and grassland systems Rothamsted Research Harpenden Herts AL5 2JQ (UK) School of Resources and Environment Anhui Agricultural University Hefei 230036 (China)

Modern breeding primarily targets crop yield traits and is likely to influence root-associated microbiomes, which play significant roles in plant growth and health. The relative importance of soil and cultivar factors in shaping root-associated microbiomes of modern maize (Zea mays L.) remains uncertain. We conducted a pot experiment in a controlled environment using three soils (Mollisol, Inceptisol, and Ultisol) and four contrasting cultivars, Denghai 605, Nonghua 816, Qiaoyu 8, and Zhengdan 958, which are widely planted in China. We used 16S rRNA gene amplicon sequencing to characterize the bacterial communities in the bulk soil, rhizosphere, and endosphere. Our results showed that the four cultivars had different shoot biomass and root exudate total organic carbon and organic acid contents. The microbiomes in the bulk soil, rhizosphere, and endosphere were different. We observed apparent community divergence between soils rather than cultivars, within which edaphic factors substantially contributed to microbiome variation. Moreover, permutational multivariate analysis of variance corroborated significant contributions of soil type but not cultivar on the root-associated microbiome structure. Differential abundance analysis confirmed that each soil presented a distinct root microbiome, while network analysis indicated different co-occurrence patterns of the root microbiome among the three soils. The core root microbiome members are implicated in plant growth promotion and nutrient acquisition in the roots. In conclusion, root-associated microbiomes of modern maize are much more controlled by soil characteristics than by cultivar root exudation. Our study is anticipated to help improve breeding strategies through integrative interactions of soils, cultivars, and their associated microbiomes.

关键词： amplicon sequencing edaphic properties endosphere indigenous microbes rhizosphere root exudation

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Influence of Accompanying Anions on Potassium Retention and Leaching in Potato Growing Alluvial soils

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Pedosphere 2013年第4期23卷 464-471页

作者： V.SHARMA K.N.SHARMA department of soils Punjab Agricultural University

A column study was carried out to assess the influence of accompanying anions on potassium （K） leaching at potato growing sites with different soil textures （sandy loam and clay loam） in northwestern India. Potassium was applied in the top 15 cm layer of soil column at 30 and 60 mg K kg-1 through different sources having different accompanying anions （CI-, SO^-, NO3 and H2PO4-）. Maximum K was retained in the top 0-15 cm layer with a sharp decrease in K content occurring in 15 30 cm layer of the soil column. The trend was similar for both levels of applied K as well as frequency of leaching and soil type. The decrease of K content in soil column after four leaching events was maximum in case of Khanaura sandy loam, while only minor decrease was observed in Hundowal clay loam when K was applied at 60 mg K kg-1, indicating higher potential of clay rich soil to adsorb K. In general, the K leaching in presence of the accompanying anions followed the order of SO4^2-≤ H2PO42- 〈 NO3 = Cl-. Highest 1 mol·L^-1 CH3COONH4-extractable K was retained when K was applied along with SO4^2- and H2PO4 anions, and the least was retained when accompanying anion was Cl-. The influence of anions was more pronounced in the light textured soil and at high amounts of K application. Higher levels of K application resulted in higher losses of K, especially in sandy loam soil as observed from the leachate concentration. Among the different K sources, the maximum amount of K leaching was noticed in the soil column amended with KC1. After four leachings, the maximum amount of K leached out was 6.40 mg L-1 in Hundowal clay loam and 9.29 mg L-1 in Khanaura sandy loam at 60 mg K kg-1 of soil application through KC1. These concentrations were lower than the recommended guideline of the World Health Organisation （12.00 mg L-1）.

关键词： column study leaching events potassium application potassium sources soil texture

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The Generalized Thermodynamic Temperature and the New Expressions of the First and the Second Law of Thermodynamics

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Journal of Thermal Science 2016年第1期25卷 1-6页

作者： HU Yacai CHEN Qi HU Yayuan department of Energy Engineering Institute of Thermal Science and Power Systems Zhejiang University The MOE Key Laboratory of Soft soils and Geoenvironmental Engineering Zhejiang University

The classical thermodynamics reflects the significant relationship between the heat and the temperature. On the basis of the relationships, according to the mathematical derivation, this paper structures the conceptions of generalized heat, generalized thermodynamic temperature, generalized entropy and so on. The series of conceptions in the classical thermodynamics is merely a special case of the generalized thermodynamics. Based on these conceptions of generalized thermodynamics, this paper presents the new expressions of the first law and the second law of thermodynamics. In other words, these expressions are endued with new explanations. The Eq. LZ = kTS given by this paper provides theoretical basis for these new expressions.

关键词： Generalized thermodynamic temperature First law of thermodynamics Second law of thermodynamics Generalized Carnot cycle Generalized Clausius inequality

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A proposed surface resistance model for the Penman-Monteith formula to estimate evapotranspiration in a solar greenhouse

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Journal of Arid Land 2017年第4期9卷 530-546页

作者： GONG Xuewen LIU Hao SUN Jingsheng GAO Yang ZHANG Xiaoxian Shiva K JHA ZHANG Hao MA Xiaojian WANG Wanning Key Laboratory of Crop Water Use and Regulation Ministry of AgricultureFarmland Irrigation Research InstituteChineseAcademy of Agricultural SciencesXinxiang 453003China Graduate School of Chinese Academy of Agricultural Sciences Beijing 100081China department of sustainable soils and grassland systems Rothamsted ResearchHarpendenHertfordshire AL5 2JQUnited Kingdom National Maize Research Program Nepal Agricultural Research CouncilChitwan 44209Nepal

Greenhousing is a technique to bridge season gap in vegetable production and has been widely used worldwide. Calculation of water requirement of crops grown in greenhouse and determination of their irrigation schedules in arid and semi-arid regions are essential for greenhouse maintenance and have thus attracted increased attention over the past decades. The most common method used in the literature to estimate crop evapotranspiration（ET） is the Penman-Monteith（PM） formula. When applied to greenhouse, however, it often uses canopy resistance instead of surface resistance. It is understood that the surface resistance in greenhouse is the result of a combined effect of canopy restriction and soil-surface restriction to water vapor flow, and the relative dominance of one restriction over another depends on crop canopy. In this paper, we developed a surface resistance model in a way similar to two parallel resistances in an electrical circuit to account for both restrictions. Also, considering that wind speed in greenhouse is normally rather small, we compared three methods available in the literature to calculate the aerodynamic resistance, which are the r_a^1 method proposed by Perrier（1975a, b）, the r_a^2 method proposed by Thom and Oliver（1977）, and the r_a^3 method proposed by Zhang and Lemeu（1992）. We validated the model against ET of tomatoes in a greenhouse measured from sap flow system combined with micro-lysimeter in 2015 and with weighing lysimeter in 2016. The results showed that the proposed surface resistance model improved the accuracy of the PM model, especially when the leaf area index was low and the greenhouse was being irrigated. We also found that the aerodynamic resistance calculated from the r_a^1 and r_a^3 methods is applicable to the greenhouse although the latter is slightly more accurate than the former. The proposed surface resistance model, together with the r_a^3 method for aerodynamic resistance, offers an improved approach to estimate ET

关键词： canopy resistance surface resistance aerodynamic resistance sap flow system micro-lysimeter weighing lysimeter

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Interpreting sedimentation dynamics at Longxi catchment in the Three Gorges Area,China,using Cs-137 activity,particle size and rainfall erosivity

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Journal of Mountain Science 2016年第5期13卷 857-869页

作者： GAO Jin-zhang LONG Yi ZHANG Xin-bao Collins Adrian L HE Xiu-bin ZHANG Yun-qi SHI Zhong-lin Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China sustainable soils and grassland systems department Rothamsted ResearchNorth WykeOkehamptonDevon EX20 2SBUK Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection Linyi UniversityLinyi 276005China

Reservoir sedimentation dynamics were interpreted using Cs-137 activity, particle size and rainfall erosivity analysis in conjunetion with sediment profile coring. Two sediment cores were retrieved from the Changshou reservoir of Chongqing, which was dammed in 1956 at the outlet of Longxi catchment in the Three Gorges Area using a gravity corer equipped with an aerylie tube with an inner diameter of 6 em. The extracted cores were sectioned at 2 cm intervals. All sediment core samples were dried, sieved （〈2 mm） and weighed. 137Cs activity was measured by y-ray spectrometry. The particle size of the core samples was measured using laser particle size granulometry. Rainfall erosivity was calculated using daily rainfall data from meteorological records and information on soil conservation history was collated to help interpret temporal sedimentation trends. The peak fallout of 137Cs in 1963 appeared at a depth of 84 cm in core A and 56 cm in core B. The peaks of sand contents were related to the peaks of rainfall erosivity which were recorded in 1982, 1989, 1998 and 2005, respectively. Sedimentation rates were calculated according to the sediment profile chronological controls of 1956, 1963, 1982, 1989, 1998 and 2oo5. The highest sedimentation rate was around 2.0 cm·a^-1 between 1982 and 1988 when the Chinese national reform and the Household Responsibility System were implemented, leading to accelerated soil erosion in the Longxi catchment. Since 1990s, and particularly since 2005, sedimentation rates clearly decreased, since a number of soil conservation programs have been carried out in the catchment. The combined use of ^137Cs chronology, particle size and rainfall erosivity provided a simple basis for reconstructing reservoir sedimentation dynamics in the context of both physical processes and soil restoration. Its advantages include avoiding the need for full blown sediment yield reconstruction and the concomitant consideration of core correlation and corrections

关键词： Sedimentation Cesium-137 Particle size Rainfall erosivity Soil erosion Three Gorges Area

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Simulation of the relationship between porosity and tortuosity in porous media with cubic particles

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Chinese Physics B 2012年第10期21卷 1-8页

作者：唐晓武孙祖峰程冠初 MOE Key Laboratory of Soft soils and Geoenvironmental Engineering Department of Civil EngineeringZhejiang University

Tortuosity is an important parameter used in areas such as vascular medicine,neurobiology,and the field of soil permeability and diffusion to express the mass transport in porous *** is a function of the porosity and the shape and distribution of *** this paper,the tortuosity of cubic particles is *** the assumption that the porous medium is homogeneous,the problem is converted to the micro-level over a unit cell,and geometry models of flow paths are *** three-dimensional（3D） cells,the flow paths are too complicated to ***,the 3D models are converted to two-dimensional（2D） models to simplify the calculation *** is noticed that the path in the 2D model is shorter than that in the 3D *** a result,triangular particles and the interaction are also taken into consideration to account for the longer distance *** have proposed quadrate particle and interaction（QI） and quadrate and triangular particle（QT） models with cubic *** models have shown good agreement with the experimental *** is also found that they can predict the toruosities of some kinds of porous media,like freshwater sediment and Negev chalk.

关键词： tortuosity porosity porous media cubic particles

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Stress and immunological response of heifers divergently ranked for residual feed intake following an adrenocorticotropic hormone challenge

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Journal of Animal Science and Biotechnology 2018年第1期9卷 111-118页

作者： A.K.Kelly P.Lawrence B.Earley D.A.Kenny M.McGee School of Agriculture and Food Science College of Health and Agricultural SciencesUniversity College Dublin Livestock systems Research department Teagasc Animal&Grassland Research and Innovation CentreGrangeDunsanyCo. Animal and Bioscience Research department Animal&Grassland Research and Innovation CentreTeagascDunsanyCo.

Background： When an animal is exposed to a stressor, metabolic rate, energy consumption and utilisation increase primarily through activation of the hypothalamic-pituitary-adrenal（HPA） axis. Changes to partitioning of energy by an animal are likely to influence the efficiency with which it is utilised. Therefore, this study aimed to determine the physiological stress response to an exogenous adrenocorticotropic hormone（ACTH） challenge in beef heifers divergently ranked on phenotypic residual feed intake（RFI）.Results： Data were collected on 34 Simmental weaning beef heifers the progeny of a well characterized and divergently bred RFI suckler beef herd. Residual feed intake was determined on each animal during the postweaning stage over a 91-day feed intake measurement period during which they were individually offered adlibitum grass silage and 2 kg of concentrate per head once daily. The 12 highest [0.34 kg DM/d] and 12 lowest[-0.48 kg DM/d] ranking animals on RFI were selected for use in this study. For the physiological stress challenge heifers（mean age 605 ± 13 d; mean BW 518 ± 31.4 kg） were fitted aseptically with indwelling jugular catheters to facilitate intensive blood collection. The response of the adrenal cortex to a standardised dose of ACTH（1.98 IU/kg metabolic BW^（0.75）） was examined. Serial blood samples were analysed for plasma cortisol, ACTH and haematology variables. Heifers differing in RFI did not differ（P = 0.59） in ACTH concentrations. Concentration of ACTH peaked（P 〈 0.001） in both RFI groups at 20 min post-ACTH administration, following which concentration declined to baseline levels by 150 min. Similarly, cortisol systemic profile peaked at 60 min and concentrations remained continuously elevated for 150 min. A RFI × time interaction was detected for cortisol concentrations（P = 0.06） with high RFI heifers had a greater cortisol response than Low RFI from 40 min to 150 min relative to ACTH administration. Cortisol response was positively assoc

关键词： Beef cattle Cortisol Feed efficiency Residual feed intake Stress response

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Nitric oxide, g-aminobutyric acid, and mannose pretreatment influence metabolic profiles in white clover under water stress

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Journal of Integrative Plant Biology 2019年第12期61卷 1255-1273页

作者： Zhou Li Bin Yong Bizhen Cheng Xing Wu Yan Zhang Xinquan Zhang Yan Peng department of grassland Science College of Animal Science and Technology Sichuan Agricultural University

Nitric oxide(NO),γ-aminobutyric acid(GABA),and mannose(MAS)could be important regulators of plant growth and adaptation to water *** application of sodium nitroprusside(SNP,a NO donor),GABA,and MAS improved plant growth under watersufficient conditions and effectively mitigated water stress damage to white *** metabonomic analysis showed that both SNP and GABA application resulted in a significant increase in myo-inositol content;the accumulation of mannose was commonly regulated by SNP and MAS;GABA and MAS induced the accumulation of aspartic acid,quinic acid,trehalose,and glycerol under water *** addition,citric acid was uniquely up-regulated by SNP associated with tricarboxylic acid(TCA)cycle under water *** induced the accumulation of GABA,glycine,methionine,and aconitic acid related to GABA shunt,amino acids metabolism,and TCA cycle in response to water *** uniquely enhanced the accumulation of asparagine,galactose,and D-pinitol in association with amino acids and sugars metabolism under water ***-,GABA-,and MAS-induced changes of metabolic profiles and associated metabolic pathways could contribute to enhanced stress tolerance via involvement in the TCA cycle for energy supply,osmotic adjustment,antioxidant defense,and signal transduction for stress defense in white clover.

关键词： uniquely donor sugar

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