Determination of Metal Content in Soil and Wheat Plant by Inductively Coupled Plasma Mass Spectrometry

This study aims to investigate the level of soil pollution and the grade of accumulation of metals and heavy metals by wheat plants from the soil in different parts of the crop: root, stem, leaf, spike and grain. Sampling campaigns took place in February, April and July when wheat plants were at different growth stages. A number of eight soil samples and eight wheat plant samples were collected. The sampled wheat plant was taken at the same time and from the same place as the soil. Concentrations of Al (aluminium), Cr (chromium), Mn (manganese), Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Zn (zinc), Sr (strontium), Cd (cadmium) and Pb (lead) were determined by inductively coupled plasma mass spectrometry. Bioconcentration and translocation factors were calculated for the samples analysed.

Heavy metal concentrations in plants and soils at roadside locations and parks of urban Guangzhou

Levels ofCu, Ni, Zn, Pb and Cr were measured in soils and trees in urban Guangzhou, China. Tree and soil samples were collected from the roadside, urban parks and a university campus. Mean concentrations of Cu, Ni, Zn, Pb and Cr in tree leaves were 28.3, 7.7, 142.1, 23.4, and 195.1 mg/kg respectively. In a comparison of heavy metal concentrations in tree leaves between roads and park locations, only Pb concentrations were significantly higher in the former. Heavy metal concentrations were lower in the roots compared to leaves. It indicated that heavy metal pollution of trees is mainly from air pollution, For all top soil samples the mean concentrations of Cu, Ni, Zn, Pb and Cr were 24.3, 17.3, 121.5, 63.9 and 88.7 mg/kg, respectively. Heavy metal concentrations in roadside soils were higher and their coefficient of variation was higher than those in urban parks. Comparing heavy metal concentrations in trees and soil between urban Guangzhou and Hainan Island, China, Cu, Ni, Zn, Pb and Cr levels in soils and plants in urban Guangzhou were evidently affected by the human impact. However the heavy metal content in the soil compared to some international standards do not give cause for concern. Some observations on the implications of the data for environmental monitoring are made.

Analysis on the Main Nutrient State of Tobacco Planting Soil in Fuquan City

[Objective] The research aimed to provide the reference for the precise formula and balanced fertilization of tobacco production in Fuquan City, Guizhou Province. [Method] 180 soil samples were gathered from Fuquan City by Global Position System （GPS） fixed position. The main nutrient contents and pH value were analyzed. [Result] The average contents of organic matter, available nitrogen, available phosphorus, available potassium in tobacco planting soil were 26.8 g/kg, 134.1 mg/kg, 35.9 mg/kg, and 222.1 mg/kg respectively, and the coefficient of vari- ation were 25.8%, 21.4%, 72.1%, and 55.3% respectively. The pH value of tobacco planting soil was 6.2, and the pH value coefficient of variation was 15.3%. [Conclu. sien] The organic matter, available nitrogen, available phosphorus, available potassi- um contents were abundant in the mass, but there were big difference among dif- ferent towns. The precise fertility types and precise fertility dosage should be deter- mined according to the main nutdent state and pH value of tobacco planting soil in Fuquan city.

Effects of seven different companion plants on cucumber productivity, soil chemical characteristics and Pseudomonas community

Companion cropping can influence cucumber productivity by altering soil chemical characteristics and microbial communities. However, how these alterations affect the growth of cucumber is still unknown. In this study, seven different plant species were selected as companion plants for testing their effects on cucumber productivity. The effects of different companion plants on changes in soil chemical properties such as electrical conductivity （EC） and contents of essential nutrients as well as the structure and abundance of the soil Pseudomonas community were evaluated. The results showed a higher cucumber yield in the wheat/cucumber companion system than that in the cucumber monocultured and other companion cropping systems. The lowest phosphorus （P） and potassium （K） contents in the soil were found in the cucumber monocultured system, and the highest NO3＋-N and NH4＊-N contents were observed in the rye/cucumber companion system. PCR-denaturing gradient gel electrophoresis （DGGE） and real-time PCR analysis showed that the trifolium/cucumber companion system increased the diversity of the soil Pseudomonas community, while the chrysanthemum/cucumber companion system increased its abundance. Interestingly, plant-soil feedback trials revealed that inoculating the soil of the wheat/cucumber companion system increased the growth of cucumber seedlings. In conclusion, the effects of different companion plants on cucumber productivity, soil chemical characteristics and the soil Pseudomonas community were different, and wheat was a more suitable companion plant for increasing cucumber productivity. In addition, the altered microbial community caused by companion cropping with wheat contributed to increased cucumber productivity.

Compound pollution of Cd,Pb,Cu,Zn,As in plant-soil system and its prevention

By means of both pot and field tests,this paper studied the contents of Cd,Pb,Cu,Zn and As and their ecological effects on plant-soil system.in tissues of crops and soil microorganisms.It was found that there exist synergistic effect among these five elements,especially for Cd in combination.The reclaniation of soil polluted by these elements in combination is rather difficult to be carried out.The distinctive ecological and chemical behaviors between Cd and As make various reclamation measures less applicable,and thus,further research measures are necessary.

Research on soil multi-media environmental pollution around a Pb-Zn mining and smelting plant in the karst area of Guangxi Zhuang Autonomous Region,Southwest China

The method of principal component analysis was applied to systematical research on the soil multi-media environment, including soil, surface water, ground water, waterbody sediment and agricultural crops, as well as pollution-inducing wastewater, mullock (or waste ore) and slag in the periphery of a large-sized Pb-Zn mining and smelting plant in a karst area of Guangxi Zhuang Autonomous Region. The results revealed that soils in the area studied have been heavily polluted by Cd, Zn, Pb and Hg, and the levels of these metals in the samples of agricultural crop greatly exceed the standards. The above-mentioned pollutants exist in all soil-multi-media environments. The mullock, slag, wastewater, surface water, ground water, soil, and agricultural crops constitute a composite ecological chain. Therefore, the improper disposal of mullock and slag, and the use of polluted wastewater for agricultural irrigation are the main causes of soil pollution. Heavy metals in the soil have three transition progresses: point (improved soil with slag, ground water inflow plot), linear (river transition) and non-point transition (regional pollution by slag) patterns, and the tailing yard is the most important locus for heavy metals to release into the environment.

Effects of grazing on carbon and nitrogen in plants and soils in a semiarid desert grassland,China

Grazing can modulate the feedback between vegetation and soil nutrient dynamics（carbon and nitrogen）,altering the cycles of these elements in grassland ecosystems.For clarifying the impact of grazing on the C and N in plants and soils in the desert grassland of Ningxia,China,we examined the plant biomass,SOC（soil organic carbon）,total soil N and stable isotope signatures of plants and soils from both the grazed and ungrazed sites.Significantly lower aboveground biomass,root biomass,litter biomass and vegetation coverage were found in the grazed site compared to the ungrazed site,with decreases of 42.0%,16.2%,59.4% and 30.0%,respectively.The effects of grazing on plant carbon,nitrogen,？15N and ？13C values were uniform among species.The levels of plant carbon and nitrogen in grasses were greater than those in the forbs（except for the carbon of Cynanchum komarovii and Euphorbia esula）.Root 15 N and 13 C values increased with grazing,while the responses of root carbon and nitrogen to grazing showed no consistent patterns.Root 15 N and 13 C were increased by 79.0% and 22.4% in the grazed site compared to the ungrazed site,respectively.The values of SOC and total N were significantly lower in the grazed than in the ungrazed sites for all sampling depths（0–10 and 10–20 cm）,and values of SOC and total N at the surface（0–10 cm） were lower than those in the deeper soils（10–20 cm）.Soil ？15N values were not affected by grazing at any sampling depth,whereas soil ？13C values were significantly affected by grazing and increased by 19.3% and 8.6% in the soils at 0–10 and 10–20 cm,respectively.The soil ？13C values（–8.3‰ to –6.7‰） were higher than those for roots（–20.2‰ to –15.6‰） and plant tissues（–27.9‰ to –13.3‰）.Our study suggests that grazing could greatly affect soil organic carbon and nitrogen in contrast to ungrazed grassland and that grazing appears to exert a negative effect on soil carbon and nitrogen in desert grassland.

Covariation between plant biodiversity and soil systems in a European beech forest and a black pine plantation:the case of Mount Faito,(Campania,Southern Italy)

Both climate and land-use changes,including the introduction and spread of allochthonous species,are forecast to affect forest ecosystems.Accordingly,forests will be affected in terms of species composition as well as their soil chemical and biological characteristics.The possible changes in both tree cover and soil system might impact the amount of carbon that is stored in living plants and dead biomass and within the soil itself.Additionally,such alterations can have a strong impact on the detrital food web that is linked to litter decomposition.Although there are studies on the infuence of plant diversity on soil physical and chemical characteristics,the effects on soil biological activity and carbon storage processes remain largely unknown.The aim of this study was to investigate and compare chemical and biological variables in covariation with plant communities in an autochthonous beech forest(Fagus sylvatica L.)and a black pine plantation(Pinus nigra J.F.Arnold subsp.nigra).Our results confirmed that the two communities were considerably different,with the old-growth beech community having a lower number of plant species and the pine community was in development as a consequence of anthropogenic activities.These aspects of the two communities were also refected in the soil,with the beech soil having higher nitrogen levels and a more specialized microbial community compared to the pine soil,with most extracellular enzymes(such as peroxidase and chitinase)showing lower activity in the pine soil.

Study on Soil Improvement Measure of Plant Landscape Construction in Saline and Alkaline Area in Tianjin

A detailed research in soil improving measure was conducted during the process of plants that were cultivated in Tianjin saline and alkaline area. The results showed that the commonly used measures could improve the soil, and also we got some useful advices and suggestions for plants cultivating in Tianiin saline and alkaline areas.

Soil Microbial Community and Enzyme Activity Responses to Herbaceous Plant Expansion in the Changbai Mountains Tundra, China

As one of the most sensitive regions to global climate change, alpine tundra in many places around the world has been undergoing dramatic changes in vegetation communities over the past few decades.Herbaceous plant species in the Changbai Mountains area have significantly expanded into tundra shrub communities over the past 30 yr.Soil microbial communities, enzyme activities, and soil nutrients are intertwined with this expansion process.In order to understand the responses of the soil microbial communities to such an expansion, we analyzed soil microbial community structures and enzyme activities in shrub tundra as well as areas with three different levels of herbaceous plant expansion.Our investigation was based on phospholipid fatty acid(PLFA) analysis and 96-well microtiter plates.The results showed that herbs have expanded greatly in the tundra, and they have become the dominant species in herbaceous plant expansion areas.There were differences for community composition and appearance among the shrub tundra and the mild expansion, moderate expansion, and severe expansion areas.Except for soil organic matter, soil nutrients were increased in herbaceous plant expansion areas, and the total nitrogen(TN), total phosphorus(TP), available nitrogen(AN), and available phosphorus(AP) were greatest in moderate expansion areas(MOE), while soil organic matter levels were highest in the non-expanded areas(CK).The total soil PLFAs in the three levels of herbaceous plant expansion areas were significantly higher than those in the non-expanded areas, and total soil PLFAs were highest in the moderately expanded area and lowest in the severely expanded area(SEE).Bacteria increased significantly more than fungi and actinomycetes with herbaceous plant expansion.Soil hydrolase activities(β-1,4-glucosidase(βG) activity, β-1, 4-N-acetylglucosaminidase(NAG) activity, and acid phosphatase(aP) activity) were highest in MOE and lowest in the CK treatment.Soil oxidase activities(polyphenol oxidase(PPO) activities and peroxidase(PER) activities) were also highest in MOE, but they were lowest in the SEE treatment.The variations in total soil PLFAs with herbaceous plant expansion were mostly correlated with soil organic matter and available phosphorus concentrations, while soil enzyme activities were mostly correlated with the total soil nitrogen concentration.Our results suggest that herbaceous plant expansion increase the total soil PLFAs and soil enzyme activities and improved soil nutrients.However, soil microorganisms, enzyme activity, and nutrients responded differently to levels of herbaceous plant expansion.The soil conditions in mild and moderate expansion areas are more favorable than those in severe expansion areas.

Accumulation and migration of elements-pollutants in “soil-plant” system within urban territory

In the urbanized territory (the Irkutsk city), the content of sulfur and heavy metals (lead, cadmium, copper, zinc) in soil profile horizons and leaves (needles) arboreal plants were studied. High accumulation of polluting elements in pine and larch needles, birch and poplar leaves, as well as in all genetic horizons of the city soils was shown. There were revealed elements disbalance in city trees assimilation organs showing in the increase of the polluting elements quota with the parallel decrease of the quota of nitrogen, phosphorus, calcium, magnesium, potassium, manganese. Pollutants concentration in trees needles (leaves) was shown to be closely related to their content in soil horizons. The results speak in favor of high migration ability of polluting elements in soil profile and about possibility their entrance in trees root system and further to assimilation organs from all city soils horizons. It can be concluded that data on accumulation and migration of polluting elements in soils and arboreal trees assimilation organs contribute to adequate assessment of technogenic load on urban ecosystems.

Responses of Plant Community and Soil Properties to Inter-Annual Precipitation Variability and Grazing Durations in a Desert Steppe in Inner Mongolia

Grazing can dramatically affect arid grassland communities that are very vulnerable to environmental changes due to its relatively short and sparse ground coverage, low biomass, sandy soil and inter-annual precipitation found in the desert steppe. The study investigates the effects of different grazing durations on vegetation and soil properties of a desert steppe community. The experiment was conducted in Xisu Banner in Inner Mongolia with ifve treatments：CG （continuous grazing）, 40UG （40 d ungrazed）, 50UG （50 d ungrazed）, 60UG （60 d ungrazed） and UG （ungrazed）. The biomass of both shrub and annual-biennial plant communities were signiifcantly decreased by CG. Continuous grazing and 40UG signiifcantly reduced the ANPP （aboveground net primary productivity） by the end of the three year study. 60UG treatment increased soil organic carbon （OC）, total nitrogen concentration （TN） and total phosphorus concentration （TP） concentrations and 50UG increased the TN and total phosphorus concentration （TK） concentrations, whereas CG, 40UG and 50UG decreased soil OC, TP and available phosphorus concentration （AP） concentrations. The perennial plant species of the desert steppe were generally tolerant for grazing. The annual-biennial plant species had large variability in ANPP because of the inter-annual precipitation. Our results highlight that inter-annual precipitation variations could strongly modify the community responses to grazing in arid ecosystems.

Using a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to Study the Sensitivity of Land Surface and Boundary Layer Processes to Soil and Vegetation Conditions

A series of sensitivity tests are performed to test the stability and sensibility of the Modified Soil-Plant-Atmosphere Scheme (MSPAS), which was wholly introduced in a previous paper. The numerical simulation results from the experiments show good agreement with physical reality. Besides, some of the results are illuminating. Together with the first paper, it is concluded that MSPAS is a simple but effective model, and it is practically valuable in the research work of desertification control and reforestation in China.

Distribution of Crystal Organic Fertilizer-N in Soil-plant System

The distribution of crystal organic fertilizer, urea and compound fertilizer-N in soil and plant system was researched with 15N-trace under tobacco pot experiment. The results showed that the leaf yield of tobacco used crystal organic fertilizer was 23.1% and 14.6% higher than that of urea and compound fertilizer treatments respectively. Compound fertilizer also resulted in higher yield of 8.5 % comparing with the urea treatment. Nitrogen content of the plant from the crystal organic fertilizer treatment was 138. 6% and 145.7% as high as that of the compound fertilizer and urea treatments respectively. The absorbed N from the organic fertilizer was 25.1% and 27.9% more than that from the compound fertilizer and urea respectively. However, the absorbed N from the soil with the organic fertilizer was 47.4% and 58.3% more than that with compound fertilizer and urea respectively. The N use efficiency of the organic fertilizer was 9.4% and 10.1% higher than that of the compound fertilizer and urea. It indicated that the crystal organic fertilizer not only had high N use efficiency, but also stimulated tobacco taking up more N from soil.

Identification of candidate soil microbes responsible for small-scale heterogeneity in strawberry plant vigour

Studies were conducted to identify candidate soil microbes responsible for observed differences in strawberry vigour at a small spatial scale, which was not associated with visual disease symptoms. Samples were obtained from the soils close to the rhizosphere of ‘big＇ and ‘small＇ plants from small plots which exhibited large local heterogeneity in plant vigour. A metabarcoding approach was used to profile bacterial and fungal compositions, using two primer pairs for 16 S ribosomal RNA genes（16S r DNA） and one for the fungal internal transcribed spacer（ITS） region. Of the two 16 S r DNA primer sets, the 341F/805 R resulted in sequences of better quality. A total 28 operational taxonomic units（OTUs） had differential relative abundance between samples from ‘big＇ and ‘small＇ plants. However, plausible biological explanation was only possible for three fungal OTUs. Two were possible phytopathogens： Verticillium spp. and Alternaria alternata although the latter has never been considered as a main pathogen of strawberry in the UK. For samples from ‘small＇ plants, the abundance of these OTUs was much greater than from ‘big＇ plants. The opposite was true for a mycorrhizal OTU. These results suggest that soil microbes related to crop production can be identified using metabarcoding technique. Further research is needed to assess whether A. alternata and Verticillium spp. could affect strawberry growth in the field.

Diversity of endophytes across the soil-plant continuum for Atriplex spp. in arid environments

Endophytes are hypothesized to be transferred across the soil-plant continuum, suggesting both the transfers of endophytes from environment to plant and from plant to soil. To verify this hypothesis and to assess the role of locality, we evaluated the similarity of microbial communities commonly found both in soils and endophytic communities in three arid regions, i.e. the Jornada LTER （Long Term Ecological Research） site in New Mexico, USA, and the research station of Jordan University of Science and Technology （JUST） and Khanasd research station in Badia region of Jordan. Rhizosphere and non-rhizosphere soils, leaves and seeds of Atriplex spp. were sampled. Diversity and distribution of bacteria and fungi across the soil-plant continuums were assessed by tag-encoded FLX amplicon pyrosequencing and sequence alignment. Of the total bacterial OTUs （operational taxonomic units）, 0.17% in Khanasri research station, 0.16% in research station of JUST, and 0.42% in Jornada LTER site were commonly found across all the plant and soil compartments. The same was true for fungi in two regions, i.e. 1.56% in research station of JUST and 0.86% in Jornada LTER site. However, in Khanasri research station, 12.08% of total fungi OTUs were found in at least one soil compartment and one plant compartment. Putative Arthrobacter, Sporosarcina, Cladosporium and members of Proteobacteria and Actinobacteria were found across all the soil-plant continuums. Ascomycota, mainly including Didymellaceae, Pleosporaceae and Davidiellaceae were present across all the soil-plant continuums. Microbial communities in two regions of Jordan were similar to each other, but both of them were different from the Jornada LTER site of USA. SIMPER （similarity percentage） analysis of bacterial and fungal taxa for both soil and endophyte communities revealed that dissimilarities of two bacterial genera （Arthrobacter and Sporosarcina） and two fungal genera （Cladosporium and Alternaria） are very high, so they play key roles in the soil-plant continuums. A weighed Pearson correlation analysis for the specific bacterial OTUs in the soil-plant continuums only showed high similarity between the two regions of Jordan. However, fungal groups showed higher similarities among all regions. This research supports the hypothesis of continuity of certain bacterial and fungal communities across the soil-plant continuums, and also explores the influences of plant species and geographic specificity on diversity and distribution of bacteria and fungi.

Accumulation of cadmium and copper by female Oxya chinensis (Orthopera: Acridoidea) in soil-plant-insect system

One purpose of this research is to present accumulation of cadmium （Cd） and copper （Cu） by female Oxya chinensis （Orthopera： Acridoidea） in a simulated soil-plant-insect ecosystem treated with Cd. Fourth-instar nymphs of O. chinensis had been fed on wheat （Triticurn aestivum） seedlings contaminated with Cd and Cu for one month. In the ecosystem, the Cd concentration in wheat seedlings rose greatly with the increasing of Cd in the soil, but the Cu concentration in wheat seedlings was not found elevated. There was a highly significant difference（P〈0.05） in Cd concentrations of wheat seedlings and not any significant difference（P〉0.05） in Cu concentrations of wheat seedlings. The Cd and Cu concentration in different body part-head, thorax, abdomen, and hind femur, varied under different Cd concentrations in soil. There were significant differences （P〈0.05） in the four parts of Cd and Cu accumulations with all treatments. The order of Cd accumulation was thorax 〉abdomen 〉head 〉hind femur and the Cu was abdomen 〉thorax 〉 head〉hind femur. The results indicated that Cd and Cu were accumulated from the soil to grasshoppers through the plant; that is to say, Cd and Cu in environment could be transported to animal or human via food chain.

Multimedia model of atrazine in plant-soil-groundwater system with a fugacity approach

The application of atrazine in China during the last ten years has led to some environmental problems. In this paper, the multimedia model of atrazine in soil-plant-groundwater system at Baiyangdian Lake area in Northern China was established using a fugacity approach, and verified with observed values. The model involved 7 environmental compartments which are air, groundwater, soil, corn roots, corn stem, corn leaf and kernel of corn. The results showed that the relative errors between calculated and observed values have a mean value of 24.7%, the highest value is 48% and the lowest value is 1.4%. All these values indicated that this multimedia model can be used to simulate the environmental fate of atrazine. Both the calculated and observed values of concentrations of atrazine in plant compartments are in the following order: in corn roots > in corn stem > in kernel of corn > in corn leaf, it exhibited a good regularity. The prediction results indicated that concentrations of atrazine in the groundwater and kernel of corn will override the limitation of 3 μg/L and 0.05 mg/kg respectively.

Effects of Different Cultivation Time of Garden Plants on Soil Chemical Properties and Soil Enzyme Activities

Garden soil test was used to study the effects of different cultivation time of garden plants on soil chemical properties and soil enzyme activities in the garden. The results showed that with the extension of cultivation time,the activity of protease,urease and catalase in Ginkgo biloba soil increased significantly,while the activity of protease in other garden plants showed a certain degree of decline,and the activity of urease increased significantly in the soil cultivated Lagerstroemia indica for over 3 years. However,in the soil cultivated the garden plants for less than 3 years,the difference in the activity of urease was relatively small,and the difference in the activity of catalase was relatively significant.

Using a Modified Soil-Plant-Atmosphere Scheme(MSPAS)to Simulate the Interaction between Land Surface Processes and Atmospheric Boundary Layer in Semi-Arid Regions

This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary layer processes and land surface processes. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feasibility of the model is well proved in this paper. The numerical simulation results from MSPAS show good agreement with reality. The scheme is used to obtain reasonable simulations for diurnal variations of heat balance, potential temperature of boundary layer, and wind field, and spatial distributions of temperature, specific humidity, vertical velocity, turbulence kinetic energy, and turbulence exchange coefficient over desert and oasis. In addition, MSPAS is used to simulate the interaction between desert and oasis at night, and again it obtains reasonable results. This indicates that MSPAS can be used to study the interaction between land surface processes and the atmospheric boundary layer over various underlying surfaces and can be extended for regional climate and numerical weather prediction study.