The Effects of Fungicide, Soil Fumigant, Bio-Organic Fertilizer and Their Combined Application on Chrysanthemum Fusarium Wilt Controlling, Soil Enzyme Activities and Microbial Properties

Directory of Open Access Journals (Sweden)

Shuang Zhao

2016-04-01

Full Text Available Sustained monoculture often leads to a decline in soil quality, in particular to the build-up of pathogen populations, a problem that is conventionally addressed by the use of either fungicide and/or soil fumigation. This practice is no longer considered to be either environmentally sustainable or safe. While the application of organic fertilizer is seen as a means of combating declining soil fertility, it has also been suggested as providing some control over certain soil-borne plant pathogens. Here, a greenhouse comparison was made of the Fusarium wilt control efficacy of various treatments given to a soil in which chrysanthemum had been produced continuously for many years. The treatments comprised the fungicide carbendazim (MBC, the soil fumigant dazomet (DAZ, the incorporation of a Paenibacillus polymyxa SQR21 (P. polymyxa SQR21, fungal antagonist enhanced bio-organic fertilizer (BOF, and applications of BOF combined with either MBC or DAZ. Data suggest that all the treatments evaluated show good control over Fusarium wilt. The MBC and DAZ treatments were effective in suppressing the disease, but led to significant decrease in urease activity and no enhancement of catalase activity in the rhizosphere soils. BOF including treatments showed significant enhancement in soil enzyme activities and microbial communities compared to the MBC and DAZ, evidenced by differences in bacterial/fungi (B/F ratios, Shannon–Wiener indexes and urease, catalase and sucrase activities in the rhizosphere soil of chrysanthemum. Of all the treatments evaluated, DAZ/BOF application not only greatly suppressed Fusarium wilt and enhanced soil enzyme activities and microbial communities but also promoted the quality of chrysanthemum obviously. Our findings suggest that combined BOF with DAZ could more effectively control Fusarium wilt disease of chrysanthemum.

Soil Fumigant Labels - Chloropicrin

Science.gov (United States)

Search by EPA registration number, product name, or company name, and follow the link to the Pesticide Product Label System (PPLS) for details on each fumigant. Updated labels include new safety requirements for buffer zones and related measures.

Totally impermeable film (TIF reduces emissions in perennial crop fumigation

Directory of Open Access Journals (Sweden)

Suduan Gao

2013-10-01

Full Text Available Many perennial nursery fields and replanted orchards and vineyards in California are treated with preplant soil fumigants to control soilborne pests. In annual crops, such as strawberry, covering fumigated fields with totally impermeable film (TIF has shown promise in controlling emissions and improving fumigant distribution in soil. The objective of this research was to optimize the use of TIF for perennial crops via three field trials. TIF reduced peak emission flux and cumulative emissions by > 90% relative to polyethylene tarp during a 2-week covering period. After the TIF was cut, emissions were greatly reduced compared to when tarps were cut after 6 days. TIF maintained higher fumigant concentrations under tarp and in the soil than polyethylene film. The results indicate that TIF can increase fumigation efficiency for perennial crop growers.

Measurement and characteristics of microbial biomass in forest soils

International Nuclear Information System (INIS)

Vance, E.D.

1986-01-01

The soil microbial biomass is the primary agent responsible for the breakdown and mineralization of soil organic matter and plays a major role in regulating nutrient availability to plants. In this study, methods for measuring biomass in soil were compared and tested in forest soils ranging in pH from 3.2 to 7.2. A good relationship between biomass C measured using the chloroform fumigation-incubation method and soil ATP or microbial biomass C by direct microscopy was found in soils at or above pH 4.2. The fumigation-incubation method consistently underestimated biomass C in soils below pH 4.2, however. Hypotheses for the breakdown of the fumigation-incubation method in strongly acid soils were tested by using an alterative fumigant, measuring the proportion of added 14 C labelled fungi and bacteria decomposed in fumigated soils (k/sub C/), and by studying the effect of large, non-fumigated soil inocula on the flush of respiration following fumigation. These studies indicated that the failure of the method in strongly acid soils was due to inhibited decomposition of non-microbial soil organic matter by the microbial recolonizing population following fumigation. A modified method for measuring biomass C by fumigation-incubation in acid soils is proposed

Atmospheric emissions of methyl isothiocyanate and chloropicrin following soil fumigation and surface containment treatment in bare-root forest nurseries

Science.gov (United States)

D. Wang; J. Juzwik; S.W. Fraedrich; K. Spokas; Y. Zhang; W.C. Koskinen

2005-01-01

Methylisothiocyanate (MITC) and chloropicrin (CP) are alternatives to methyl bromide for soil fumigation. However, surface transport of MITC emission has been cited as the cause for seedling damage in adjacent fields at several bare-root forest-tree nurseries. Field experiments were conducted at nurseries to measure air emissions of MITC and CP after fumigation....

Legacy effects of continuous chloropicrin-fumigation for 3-years on soil microbial community composition and metabolic activity

NARCIS (Netherlands)

Zhang, Shuting; Liu, Xiaojiao; Jiang, Qipeng; Shen, Guihua; Ding, Wei

2017-01-01

Chloropicrin is widely used to control ginger wilt in China, which have an enormous impact on soil microbial diversity. However, little is known on the possible legacy effects on soil microbial community composition with continuous fumigation over different years. In this report, we used high

Effects of soil type, moisture content, redox potential and methyl bromide fumigation on Kd values of radio-selenium in soil

International Nuclear Information System (INIS)

Ashworth, D.J.; Moore, J.; Shaw, G.

2008-01-01

Understanding the processes that determine the solid-liquid partitioning (K d value) of Se is of fundamental importance in assessing the risk associated with the disposal of radio-selenium-containing waste. Using a mini-column (rather than batch) approach, K d values for 75 Se were determined over time in relation to soil moisture content (field capacity or saturated), redox potential and methyl bromide fumigation (used to disrupt the soil microbial population) in three contrasting soil types: clay loam, organic and sandy loam. The K d values were generally in the range 50-500 L kg -1 , with mean soil K d increasing with increasing organic matter content. Saturation with water lowered the measured redox potentials in the soils. However, only in the sandy loam soil did redox potential become negative, and this led to an increase in 75 Se K d value in this soil. Comparison of the data with the Eh-pH stability diagram for Se suggested that such strong reduction may have been consistent with the formation of the insoluble Se species, selenide. These findings, coupled with the fact that methyl bromide fumigation had no discernible effect on 75 Se K d value in the sandy loam soil, suggest that geochemical, rather than microbial, processes controlled 75 Se partitioning. The inter-relations between soil moisture content, redox potential and Se speciation should be considered in the modelling and assessment of radioactive Se fate and transport in the environment

Catalytic degradation of the soil fumigant 1,3-dichloropropene in aqueous biochar slurry

Energy Technology Data Exchange (ETDEWEB)

Qin, Jiaolong [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Cheng, Yuxiao; Sun, Mingxing [Shanghai Entry–Exit Inspection and Quarantine Bureau, Shanghai 200135 (China); Yan, Lili [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Shen, Guoqing, E-mail: gqsh@sjtu.edu.cn [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

2016-11-01

Biochar has been explored as a cost-effective sorbent of contaminants, such as soil fumigant. However, contaminant-loaded biochar probably becomes a source of secondary air pollution. In this study, biochars developed from cow manure and rice husk at 300 °C or 700 °C were used to investigate the catalytic degradation of the soil fumigant 1,3-dichloropropene (1,3-D) in aqueous biochar slurry. Results showed that the adsorption of 1,3-D on the biochars was influenced by Langmuir surface monolayer adsorption. The maximum adsorption capacity of cow manure was greater than that of rice husk at the same pyrolysis temperature. Batch experiments revealed that 1,3-D degradation was improved in aqueous biochar slurry. The most rapid 1,3-D degradation occurred on cow manure-derived biochar produced at 300 °C (C-300), with t{sub 1/2} = 3.47 days. The degradation efficiency of 1,3-D on C-300 was 95.52%. Environmentally persistent free radicals (EPFRs) in biochars were detected via electron paramagnetic resonance (EPR) techniques. Dissolved organic matter (DOM) and hydroxyl radical (·OH) in biochars were detected by using a fluorescence spectrophotometer coupled with a terephthalic acid trapping method. The improvement of 1,3-D degradation efficiency may be attributed to EPFRs and DOM in aqueous biochar slurry. Our results may pose implications in the development of effective reduction strategies for soil fumigant emission with biochar. - Highlights: • Hydrolysis of 1,3-D was accelerated in aqueous biochar slurry. • 1,3-D adsorption kinetics on biochars fitted well with Langmuir model. • Cow manure biochar showed higher catalytic degradation activity for 1,3-D than rice husk biochar did. • EPFRs and DOM have potential roles in 1,3-D degradation on biochar.

Catalytic degradation of the soil fumigant 1,3-dichloropropene in aqueous biochar slurry

International Nuclear Information System (INIS)

Qin, Jiaolong; Cheng, Yuxiao; Sun, Mingxing; Yan, Lili; Shen, Guoqing

2016-01-01

Biochar has been explored as a cost-effective sorbent of contaminants, such as soil fumigant. However, contaminant-loaded biochar probably becomes a source of secondary air pollution. In this study, biochars developed from cow manure and rice husk at 300 °C or 700 °C were used to investigate the catalytic degradation of the soil fumigant 1,3-dichloropropene (1,3-D) in aqueous biochar slurry. Results showed that the adsorption of 1,3-D on the biochars was influenced by Langmuir surface monolayer adsorption. The maximum adsorption capacity of cow manure was greater than that of rice husk at the same pyrolysis temperature. Batch experiments revealed that 1,3-D degradation was improved in aqueous biochar slurry. The most rapid 1,3-D degradation occurred on cow manure-derived biochar produced at 300 °C (C-300), with t 1/2 = 3.47 days. The degradation efficiency of 1,3-D on C-300 was 95.52%. Environmentally persistent free radicals (EPFRs) in biochars were detected via electron paramagnetic resonance (EPR) techniques. Dissolved organic matter (DOM) and hydroxyl radical (·OH) in biochars were detected by using a fluorescence spectrophotometer coupled with a terephthalic acid trapping method. The improvement of 1,3-D degradation efficiency may be attributed to EPFRs and DOM in aqueous biochar slurry. Our results may pose implications in the development of effective reduction strategies for soil fumigant emission with biochar. - Highlights: • Hydrolysis of 1,3-D was accelerated in aqueous biochar slurry. • 1,3-D adsorption kinetics on biochars fitted well with Langmuir model. • Cow manure biochar showed higher catalytic degradation activity for 1,3-D than rice husk biochar did. • EPFRs and DOM have potential roles in 1,3-D degradation on biochar.

Soil resilience and yield performance in a vineyard established after intense pre-planting earthworks

Science.gov (United States)

Costantini, Edoardo; Valboa, Giuseppe; Gagnarli, Elena; Mocali, Stefano; Fabiani, Arturo; Priori, Simone; Simoni, Sauro; Storchi, Paolo; Perria, Rita; Vignozzi, Nadia; Agnelli, Alessandro

2017-04-01

Conventional earthworks undertaken before vine plantation may severely compromise soil functions and vine production, as a consequence of a decline of soil fertility caused by loss of organic matter and biological activity, along with changes in chemical and physical features of the topsoil due to the upset of the soil profile. This research was aimed at assessing the effects of conventional pre-planting earthworks on soil fertility and vine yield performance under organic farming. To this purpose, grape yield and quality along with soil chemical, physical and biological properties, were monitored over seven years in a young vineyard established in 2010 after soil leveling and deep ploughing, and in parallel in an older vineyard planted in 2000 after similar earthworks under the same soil and environment conditions. The vineyards (Vitis vinifera L., cv. Sangiovese) were located in the Chianti Classico district (Tuscany, Italy) on a stony calcareous soil classified as Cambic Skeletic Calcisol (loamic, aric) (WRB, 2014). Fertilization was based on annual applications of compost and shredded plant residues. According to the ordinary farming system, the older vineyard was kept free from grass covering during the first four years of growth by periodic tillage, in order to prevent nutritional competition, while in the following years it was managed by natural grass covering on alternate inter-rows. In the younger vineyard, grass covering needed to be postponed because of a delay in the vine development and grape yield induced by poor soil fertility. The results showed significant differences between the two vineyard, with the younger exhibiting lower total organic carbon (0.4 - 0.6 % vs 0.6 - 1.1 %), lower total nitrogen (0.07 - 0.11 % vs 0.10 - 0.15 %) and higher carbonate contents (32 - 38 % vs 21 -30 % total CaCO3), with no clear trend of recovery over time. Pre-planting earthworks also affected the structure and diversity of microbial and microarthropod communities

Toxicity of pesticides associated with potato production, including soil fumigants, to snapping turtle eggs (Chelydra serpentina).

Science.gov (United States)

de Solla, Shane Raymond; Palonen, Kimberley Elizabeth; Martin, Pamela Anne

2014-01-01

Turtles frequently oviposit in soils associated with agriculture and, thus, may be exposed to pesticides or fertilizers. The toxicity of a pesticide regime that is used for potato production in Ontario on the survivorship of snapping turtle (Chelydra serpentina) eggs was evaluated. The following treatments were applied to clean soil: 1) a mixture of the pesticides chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos, and 2) the soil fumigant metam sodium. Turtle eggs were incubated in soil in outdoor plots in which these mixtures were applied at typical and higher field application rates, where the eggs were subject to ambient temperature and weather conditions. The pesticide mixture consisting of chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos did not affect survivorship, deformities, or body size at applications up to 10 times the typical field application rates. Hatching success ranged between 87% and 100% for these treatments. Metam sodium was applied at 0.1¯ times, 0.3¯ times, 1 times, and 3 times field application rates. Eggs exposed to any application of metam sodium had 100% mortality. At typical field application rates, the chemical regime associated with potato production does not appear to have any detrimental impacts on turtle egg development, except for the use of the soil fumigant metam sodium, which is highly toxic to turtle eggs at the lowest recommended application rate. © 2013 SETAC.

Buffer Zone Requirements for Soil Fumigant Applications

Science.gov (United States)

Updated pesticide product labels require fumigant users to establish a buffer zone around treated fields to reduce risks to bystanders. Useful information includes tarp testing guidance and a buffer zone calculator.

Fumigant toxicity and acetylcholinesterase inhibitory activity of 4 Asteraceae plant essential oils and their constituents against Japanese termite (Reticulitermes speratus Kolbe).

Science.gov (United States)

Seo, Seon-Mi; Kim, Junheon; Kang, Jaesoon; Koh, Sang-Hyun; Ahn, Young-Joon; Kang, Kyu-Suk; Park, Il-Kwon

2014-07-01

This study investigated the fumigant toxicity of 4 Asteraceae plant essential oils and their constituents against the Japanese termite Reticulitermes speratus Kolbe. Fumigant toxicity varied with plant essential oils or constituents, exposure time, and concentration. Among the tested essential oils, those from Chamaemelum nobile exhibited the strongest fumigant toxicity, followed by those from Santolina chamaecyparissus, Ormenis multicaulis, and Eriocephalus punctulatus at 2 days after treatment. In all, 15, 24, 19, and 9 compounds were identified in the essential oils from C. nobile, E. punctulatus, O. multicaulis, and S. chamaecyparissus, respectively, by using gas chromatography, gas chromatography-mass spectrometry, or open-column chromatography. The identified compounds were tested individually for their fumigant toxicity against Japanese termites. Among the test compounds, trans-pinocarveol, caryophyllene oxide, sabinene hydrate, and santolina alcohol showed strong fumigant toxicity against Japanese termites. Acetylcholinesterase (AChE) inhibition activity of the identified compounds from C. nobile, E. punctulatus, O. multicaulis, and S. chamaecyparissus essential oils were tested to determine the mode of their action. The IC50 values of (+)-α-pinene, (-)-limonene, (-)-α-pinene, β-pinene, and β-phellandrene against Japanese termite AChE were 0.03, 0.13, 0.41, 0.42, and 0.67mg/mL, respectively. Further studies are warranted to determine the potential of these essential oils and their constituents as fumigants for termite control. Copyright © 2014 Elsevier Inc. All rights reserved.

Midas® Fumigant Safe Handling Guide

Science.gov (United States)

Handlers or applicators should wear personal protective equipment including respirator and chemical-resistant gloves when working with this soil fumigant, be trained according to the Worker Protection Standard (WPS), and know signs of pesticide exposure.

Defining a realistic control for the chloroform fumigation-incubation method using microscopic counting and 14C-substrates

International Nuclear Information System (INIS)

Horwath, W.R.; Paul, E.A.; Harris, D.; Norton, J.; Jagger, L.; National Science Foundation, Logan, UT; Horton, K.A.

1996-01-01

Chloroform fumigation-incubation (CFI) has made possible the extensive characterization of soil microbial biomass carbon (C) (MBC). Defining the non-microbial C mineralized in soils following fumigation remains the major limitation of CFI. The mineralization of non-microbial C during CFI was examined by adding 14 C-maize to soil before incubation. The decomposition of the 14 C-maize during a 10-d incubation after fumigation was 22.5% that in non-fumigated control soils. Re-inoculation of the fumigated soil raised 14 C-maize decomposition to 77% that of the unfumigated control. A method was developed which varies the proportion of mineralized C from the unfumigated soil (UF c ) that is subtracted in calculating CFI biomass C. The proportion subtracted (P) varies according to a linear function of the ratio of C mineralized in the fumigated (F c ) and unfumigated samples (F c /UF c ) with two parameters K 1 and K 2 (P = K 1 F c /UF c ) + K 2 ). These parameters were estimated by regression of CFI biomass C, calculated according to the equation MBC = (F c - PUF c )/0.41, against that derived by direct microscopy in a series of California soils. Parameter values which gave the best estimate of microscopic biomass from the fumigation data were K 1 = 0.29 and K 2 = 0.23 (R 2 = 0.87). Substituting these parameter values, the equation can be simplified to MBC = 1.73F c - 0.56UF c . The equation was applied to other CFI data to determine its effect on the measurement of MBC. The use of this approach corrected data that were previously difficult to interpret and helped to reveal temporal trends and changes in MBC associated with soil depth. (author). 40 refs., 4 tabs., 3 figs

Changes in transpiration rate of SO/sub 2/-resistant and -sensitive plants with SO/sub 2/ fumigation and the participation of abscisic acid

Energy Technology Data Exchange (ETDEWEB)

Kondo, N.; Sugahara, K.

1978-01-01

Peanut and tomato plants were resistant to 2.0 ppm SO/sub 2/, while radish, perilla and spinach plants were sensitive. The amounts of SO/sub 2/ absorbed by peanut and tomato were obviously less than those absorbed by radish, perilla and spinach. Transpiration rates of peanut and tomato began to decrease within 5 min after the commencement of SO/sub 2/ fumigation and reached minimum levels, i.e., 10 and 50% for the initial levels, respectively, after initiation of fumigation, then declined. Those of radish and spinach did not change for about 20 and 30 min, then decreased gradually. The content of abscisic acid (ABA) was highest in peanut. The content in tomato was also high, but low in radish, perilla and spinach. Radish supplied with exogenous ABA began to decrease its transpiration rate immediately after SO/sub 2/ fumigation and was markedly resistant to SO/sub 2/. ABA in leaves may control the rapid stomatal closure following SO/sub 2/ fumigation. 26 references.

The effects of soil fumigation on the growth and mineral nutrition of weeds and crops=Efeito da fumigação do solo no crescimento e nutrição mineral de plantas daninhas e culturas

Directory of Open Access Journals (Sweden)

Marliane de Cássia Soares da Silva

2012-04-01

Full Text Available Weeds and soil microorganisms interact with each other in the soil/root interface, promoting the development and establishment of both. The objective of this study was to evaluate the growth and nutrient accumulation in eight species of weeds (Ageratum conyzoides L., Bidens pilosa L., Cenchrus echinatus L., Conyza bonariensis L., Echinochloa crus-galli L., Eleusine indica L. Ipomoea grandifolia L. and Lolium multiflorum L. and in bean and corn crops grown for 50 days in a substrate fumigated with methyl bromide. Assessments relating to the height, leaf area, leaf number, dry weight of shoots and roots and relative content of nutrients were carried out 50 days after seedling emergence. A positive effect of soil fumigation was observed on the growth, leaf number, leaf area, plant height and accumulation of nutrients in monocot weeds in relation to dicots. Conyza bonariensis was the most affected by soil fumigation, with levels of dry matter, leaf number, leaf area, height and accumulation of nutrients approximately 50% lower than plants grown in normal soil. Fumigation also influenced the growth cycle of the plants, which was lower for B. pilosa, E. indica and C. echinatus. We also observed a 20 and 30% lower phosphorus accumulation in Bidens pilosa and Conyza bonariensis, respectively, when grown in the sterilized soil. Overall, the bean and corn crops were less affected by soil fumigation than the weeds.Plantas daninhas e microrganismos do solo se interagem na interface solo/raiz promovendo vantagens para o desenvolvimento e estabelecimento de ambos. Objetivou-se com este trabalho avaliar o crescimento e o acúmulo de nutrientes em oito espécies de plantas daninhas (Ageratum conyzoides L., Bidens pilosa L., Cenchrus echinatus L., Conyza bonariensis L., Echinochloa crus-galli L., Eleusine indica L., Ipomoea grandifolia L. e Lolium multiflorum L. e nas culturas de feijão e milho, cultivadas, por 50 dias, em substrato fumigado com brometo de

Herbicidal Activity of Coumarin When Applied as a Pre-plant Incorporated into Soil

Directory of Open Access Journals (Sweden)

Amir-Hossein NAZEMI

2015-06-01

Full Text Available Due to having a short half-life and novel site of action, the herbicidal potential of natural compounds are lionized. Coumarin is a secondary metabolite from Lavandula sp., family Lamiacae. The impact of eight concentrations of coumarin (0, 100, 200, 400, 800, 1600, 3200 and 6400 ppm were separately used as a pre-plant incorporated into soil on six plant species under greenhouse conditions. Generally, coumarin had phytotoxic effect against all plant species. The phytotoxic effect was concentration-dependent. The high concentrations could inhibit the emergence of seedlings (probably by stopping germination of seeds. Based on ED50 parameter, the ranking of plant species for tolerance to coumarin was S. halepense > Z. mays > C. album > A. retroflexus > E. cruss-gali > P. oleracea. Based on selectivity index, coumarin at a concentration of 365.69 ppm can control P. oleracea without damaging Z. mays, whereas any concentration it cannot control other weeds without damaging Z. mays.

Fumigant Management Plan Templates - Phase 2 Files Listed by Chemical

Science.gov (United States)

FMP templates are in PDF and Word formats for each type of soil fumigant pesticide, with samples of filled out plans. Types are by active ingredient chemical: Chloropicrin, dazomet, dimethyl disulfide, metam sodium/potassium, and methyl bromide.

Regulations and control of in-transit fumigated containers as well as of fumigated cargo ships.

Science.gov (United States)

Low, Anthony; Hüsing, Ulf-Peter; Preisser, Alexandra; Baur, Xaver

2003-01-01

According to IMO's international regulations, e.g. "Recommendations on the safe use of pesticides in ships", fumigated containers and ship cargoes must be labeled giving specifications about dates of fumigation and the fumigation gas used. Furthermore, appropriate certificates are necessary and these records have to be forwarded to the Port Health Authorities without their explicitly asking for them. According to IMO (DSC/Circ.8.24.7.2001) a recent inspection of containers unloaded in ports showed that some were under fumigation, but not declared as such and in a few cases these ventilated containers arrive with "Degas Certificates" stating that fumigant has been removed, but still have a high fumigant concentration inside when opened. There are similar reports from The Netherlands, where 21% of the fumigated containers had missing or false declarations and contained measurable amounts of toxic gas. In England 6% were mentioned to be allegedly false. Reports exist of a number of other incidents with containers under fumigation arriving in English ports with no accompanying documents on the ship or at the port of discharge as to the type of cargo. In one case several people were hospitalized after exposure to phosphine gas because the fumigant tablets were not yet totally decomposed before the ship arrived at its destination port. In Bavaria, Germany, a bad accident recently occurred through a non declared fumigated container (see press release). Our sample: a large container ship in the Port of Hamburg where 27 of the cargo's containers were found fumigated with 27 non/incomplete/false declarations. These examples show that missing/false labelling is frequent. Clearance of in-transit fumigated containers in ports is complicated and time-consuming for the captain and shipping company. The above mentioned accident and also the results of our spot check prove, as do the experiences in The Netherlands and England, that false declarations of fumigated containers seem

Management of the potato cyst nematode (Globodera pallida) with bio-fumigants/stimulants.

Science.gov (United States)

Martin, T J G; Turner, S J; Fleming, C C

2007-01-01

Field trials evaluated the effect of four plant-based bio-fumigants/stimulants on population levels of G. pallida and the resulting potato yields and quality. Three formulations contained seaweed biostimulants (Algifol, Nutridip and Metastim) and one bio-fumigant containing mustard and chilli pepper extracts (Dazitol). These were compared with the fumigant nematicide Nemathorin and untreated control plots. The effect of G. pallida on growing potato crops was assessed by recording haulm characteristics which indicated that the nematicide treatment gave most protection. Levels of PCN juveniles and migratory nematodes were assessed during the trial. Plots treated with Nemathorin and Dazitol had fewest PCN, whilst the highest number of migratory nematodes occurred in fallow plots. Sixteen weeks after planting the nematicide treatment produced highest yield and tuber numbers. Dazitol treatment produced a lower yield but the largest tubers.

Exposure to methyl bromide during greenhouse fumigation on Crete, Greece

NARCIS (Netherlands)

Vreede, J.A.F. de; Boeft, J. den; Hemmen, J.J. van

1998-01-01

In agricultural areas where greenhouses and dwellings are intermixed, the general population as well as the professional applicators may be exposed to pesticides. In a field study on Crete, exposure to methyl bromide during soil fumigation was assessed. Exposure of applicators (both contractors and

Rice weevil response to basil oil fumigation

Science.gov (United States)

Basil oil, Ocimum basilicum L., is a volatile plant essential oil that is known to have insecticidal activity against stored product pests such as rice weevil, Sitophilus oryzae (L.). Basil oil was diluted in acetone and applied to a sponge held inside a tea strainer for fumigations in containers wi...

Effects of Fumigant Alternatives to Methyl Bromide on Pest Control in Open Field Nursery Production of Perennial Fruit and Nut Plants

Science.gov (United States)

Producers of deciduous fruit and nut trees and vines rely on preplant fumigation to meet regulatory requirements designed to ensure nematode free planting stock. In the past, preplant treatments with methyl bromide or high rates of 1,3-dichloropropene were the preferred treatments. However, the ph...

Response of Sitophilus granarius L. to fumigant toxicity of some plant volatile oils

Directory of Open Access Journals (Sweden)

Ali F. Hamza

2016-01-01

Full Text Available One-week-old adults of Sitophilus granarius (L. reared on wheat were subjected to pure plant volatile oils of Thuja, Eucalyptus and Peppermint. Volatile oil of Thuja was extracted from unripe fruits of Thuja orientalis plant by water distillation. The objective of the current study was to determine the fumigant toxicity of these volatile oils against adults of S. granarius. The fumigant toxicity of the volatile oils was tested against 1week old adults of S. granarius at 28±2 °C and 65±5% RH in darkness. The mortality of adults was tested at different concentrations ranging from 20 to 100 μl of Thuja, 10–30 μl of Eucalyptus and 3–15 μl of Peppermint at different exposure times (24, 48 and 72 h. The results demonstrated that the mortality increased with increases in concentration and exposure periods. The percent mortality of S. granarius reached 91.2, 95.0 and 91.2% when 1-w-old adult exposed to higher concentration of Thuja, Eucalyptus and Peppermint oils, respectively, comparing to 0% in the control after 24 h. After 72 h the percent mortality was 100% at the higher concentration of the three volatile oils. LC50 and LC90 were determined for each volatile oil and each exposure period. Data probit analysis demonstrated that concentrations of 70.71 μl Thuja, 16.95 μl Eucalyptus and 10.48 μl Peppermint, recorded 50% mortality after 24 h, however it reached 90% when concentrations increased to 104.04 μl Thuja, 25.48 μl Eucalyptus and 15.92 μl Peppermint after the same period. LC50 and LC90 values were decreased by increasing the exposure periods. These results showed that the three volatile oils could be applicable to the management of populations of S. granarius (L..

The importance of plant-soil interactions for N mineralisation in different soil types

Science.gov (United States)

Murphy, Conor; Paterson, Eric; Baggs, Elizabeth; Morley, Nicholas; Wall, David; Schulte, Rogier

2013-04-01

The last hundred years has seen major advancements in our knowledge of nitrogen mineralisation in soil, but key drivers and controls remain poorly understood. Due to an increase in the global population there is a higher demand on food production. To accommodate this demand agriculture has increased its use of N based fertilizers, but these pose risks for water quality and GHG emissions as N can be lost through nitrate leaching, ammonia volatilization, and denitrification processes (Velthof, et al., 2009). Therefore, understanding the underlying processes that determine the soils ability to supply N to the plant is vital for effective optimisation of N-fertilisation with crop demand. Carbon rich compounds exuded from plant roots to the rhizosphere, which are utilized by the microbial biomass and support activities including nutrient transformations, may be a key unaccounted for driver of N mineralisation. The main aim of this study was to study the impact of root exudates on turnover of C and N in soil, as mediated by the microbial community. Two soil types, known to contrast in N-mineralisation capacity, were used to determine relationships between C inputs, organic matter mineralisation (priming effects) and N fluxes. 15N and 13C stable isotope approaches were used to quantify the importance of rhizosphere processes on C and N mineralisation. Gross nitrogen mineralisation was measured using 15N pool dilution. Total soil CO2 efflux was measured and 13C isotope partitioning was applied to quantify SOM turnover and microbial biomass respiration. Also, 13C was traced through the microbial biomass (chloroform fumigation) to separate pool-substitution effects (apparent priming) from altered microbial utilisation of soil organic matter (real priming effects). Addition of labile carbon resulted in an increase in N-mineralisation from soil organic matter in both soils. Concurrent with this there was an increase in microbial biomass size, indicating that labile C elicited

Rhizosphere Microbiomes Modulated by Pre-crops Assisted Plants in Defense Against Plant-Parasitic Nematodes

Directory of Open Access Journals (Sweden)

Ahmed Elhady

2018-06-01

Full Text Available Plant-parasitic nematodes cause considerable damage to crop plants. The rhizosphere microbiome can affect invasion and reproductive success of plant-parasitic nematodes, thus affecting plant damage. In this study, we investigated how the transplanted rhizosphere microbiome from different crops affect plant-parasitic nematodes on soybean or tomato, and whether the plant’s own microbiome from the rhizosphere protects it better than the microbiome from fallow soil. Soybean plants growing in sterilized substrate were inoculated with the microbiome extracted from the rhizosphere of soybean, maize, or tomato. Controls were inoculated with extracts from bulk soil, or not inoculated. After the microbiome was established, the root lesion nematode Pratylenchus penetrans was added. Root invasion of P. penetrans was significantly reduced on soybean plants inoculated with the microbiome from maize or soybean compared to tomato or bulk soil, or the uninoculated control. In the analogous experiment with tomato plants inoculated with either P. penetrans or the root knot nematode Meloidogyne incognita, the rhizosphere microbiomes of maize and tomato reduced root invasion by P. penetrans and M. incognita compared to microbiomes from soybean or bulk soil. Reproduction of M. incognita on tomato followed the same trend, and it was best suppressed by the tomato rhizosphere microbiome. In split-root experiments with soybean and tomato plants, a systemic effect of the inoculated rhizosphere microbiomes on root invasion of P. penetrans was shown. Furthermore, some transplanted microbiomes slightly enhanced plant growth compared to uninoculated plants. The microbiomes from maize rhizosphere and bulk soil increased the fresh weights of roots and shoots of soybean plants, and microbiomes from soybean rhizosphere and bulk soil increased the fresh weights of roots and shoots of tomato plants. Nematode invasion did not affect plant growth in these short-term experiments. In

[Quality changes in Gastrodia Rhizoma of different origins and forms before and after sulfur fumigation].

Science.gov (United States)

Kang, Chuan-Zhi; Yang, Wan-Zhen; Zhou, Li; Jiang, Jing-Yi; Lv, Chao-Geng; Wang, Sheng; Zhou, Tao; Yang, Ye; Huang, Lu-Qi; Guo, Lan-Ping

2018-01-01

As Gastrodiae Rhizoma (GR) is one of the herbs more seriously affected by sulfur fumigation, so its quality has been always of a great concern. In this paper, GR samples collected from eight main producing areas and in three forms were fumigated with sulfur and quantitatively and qualitatively analyzed based on UPLC-Q-TOF-MS/MS. The results showed that the contents of gastrodin, parishin, parishin B and parishin C were decreased, while the content of parishin E was increased after sulfur fumigation treatment. Besides, a new sulfur marker named p-hydroxybenzyl hydrogen sulfite was produced in sulfur-fumigated GR samples. As compared with producing origins, forms had a greater impact on the quality of GR, especially in Hongtianma and Wutianma. Besides, the contents of gastrodins and parishins in Hongtianma from Jilin were lowest as compared with those in other producing areas. This might be correlated with planting patterns and environmental factors. In conclusion, sulfur fumigation has a more obvious impact on the quality of GR than origins and forms, which is attributed to the generation of new sulfur fumigated markers. Copyright© by the Chinese Pharmaceutical Association.

Effect of thermal pre-treatment on the availability of PAHs for successive chemical oxidation in contaminated soils.

Science.gov (United States)

Usman, M; Chaudhary, A; Biache, C; Faure, P; Hanna, K

2016-01-01

This is the premier study designed to evaluate the impact of thermal pre-treatment on the availability of polycyclic aromatic hydrocarbons (PAHs) for successive removal by chemical oxidation. Experiments were conducted in two soils having different PAH distribution originating from former coking plant sites (Homécourt, H, and Neuves Maisons, NM) located in northeast of France. Soil samples were pre-heated at 60, 100, and 150 °C for 1 week under inert atmosphere (N2). Pre-heating resulted in slight removal of PAHs (soil samples were subjected to Fenton-like oxidation (H2O2 and magnetite) at room temperature. Chemical oxidation in soil without any pre-treatment showed almost no PAH degradation underscoring the unavailability of PAHs. However, chemical oxidation in pre-heated soils showed significant PAH degradation (19, 29, and 43% in NM soil and 31, 36, and 47% in H soil pre-treated at 60, 100, and 150 °C, respectively). No preferential removal of PAHs was observed after chemical oxidation in both soils. These results indicated the significant impact of pre-heating temperature on the availability of PAHs in contaminated soils and therefore may have strong implications in the remediation of contaminated soils especially where pollutant availability is a limiting factor.

Study on the Influence of Sulfur Fumigation on Chemical ...

African Journals Online (AJOL)

Purpose: To study the influence of different sulfur fumigation time and ... after sulfur fumigation though sulfur fumigation time and dosage were at low levels – 2 h ... Conclusion: Sulfur fumigation is not a desirable method for field processing of ...

Tracking movement of Meloidogyne spp and R. reniformis in a plasticulture system

Science.gov (United States)

Soil fumigation and in-row treatments of nematicides have been the common protocol for pre-and in-season management of plant parasitic nematodes (PPN’s) in vegetable production. One issue not addressed is the depth at which the highest concentration of nematodes occur. In the United States, applicat...

Evaluation of anaerobic soil disinfestation amendments and rates for conventional tomato production in Florida

Science.gov (United States)

Methyl bromide and other soil fumigants have been heavily relied upon to control soilborne plant pathogens, nematodes, and weeds in polyethylene-mulched vegetable production in Florida. However, negative aspects of their use on the environment and human health have increased the interest in non-chem...

Effects of growth retardants and fumigations with ozone and sulfur dioxide on growth and flowering of Euphorbia pulcherrima Willd

Energy Technology Data Exchange (ETDEWEB)

Cathey, H.M.; Heggestad, H.E.

1973-01-01

Eight cultivars of poinsettia, Euphorbia pulcherrima Willd., were evaluated for sensitivity to ..cap alpha..-cyclopropyl-..cap alpha.. (4-methoxyphenyl)-5-pyrimidine methanol (ancymidol) and protection from ozone and sulfur dioxide injury afforded by applications of ancymidol and (2-chloroethyl) trimethyl ammonium chloride (chlormequat). Foliar sprays of ancymidol were at least 80 to 500 times and the soil drench 1000 times more active than chlormequat in retarding stem elongation. The diam of the bracts was reduced, but branching increased more on plants treated with ancymidol than on untreated plants. The cv. Annette Hegg (AH) was more sensitive to ozone fumigations than was Eckespoint C-1' (C-1). Sulfur dioxide also caused more injury to AH than to C-1. Ancymidol and chlormequat reduced visible injury induced by ozone and sulfur dioxide.

Procedures of Laboratory Fumigation for Pest Control with Nitric Oxide Gas.

Science.gov (United States)

Liu, Yong-Biao; Yang, Xiangbing; Masuda, Tiffany

2017-11-24

Nitric oxide (NO) is a newly discovered fumigant for postharvest pest control. This paper provides detailed protocols for conducting NO fumigation on fresh products and procedures for residue analysis and product quality evaluation. An airtight fumigation chamber containing fresh fruit and vegetables is first flushed with nitrogen (N2) to establish an ultralow oxygen (ULO) environment followed by injection of NO. The fumigation chamber is then kept at a low temperature of 2 - 5 °C for a specified time period necessary to kill a target pest to complete a fumigation treatment. At the end of a fumigation treatment, the fumigation chamber is flushed with N2 to dilute NO prior to opening the chamber to ambient air to prevent the reaction between NO and O2, which produces NO2 and may damage delicate fresh products. At different times after NO fumigation, NO2 in headspace and nitrate and nitrite in liquid samples were measured as residues. Product quality was evaluated after 2 weeks of post-treatment cold storage to determine effects of NO fumigation on product quality. Keeping O2 from reacting with NO is critical to NO fumigation and is an important part of the protocols. Measuring NO levels is challenging and a practical solution is provided. Possible protocol modifications are also suggested for measuring NO levels in the fumigation chambers as well as residues. NO fumigation has the potential to be a practical alternative to methyl bromide fumigation for postharvest pest control on fresh and stored products. This publication is intended to assist other researchers in conducting NO fumigation research for postharvest pest control and accelerating the development of NO fumigation for practical applications.

Insecticidal Activity of Melaleuca alternifolia Essential Oil and RNA-Seq Analysis of Sitophilus zeamais Transcriptome in Response to Oil Fumigation.

Science.gov (United States)

Liao, Min; Xiao, Jin-Jing; Zhou, Li-Jun; Liu, Yang; Wu, Xiang-Wei; Hua, Ri-Mao; Wang, Gui-Rong; Cao, Hai-Qun

2016-01-01

The cereal weevil, Sitophilus zeamais is one of the most destructive pests of stored cereals worldwide. Frequent use of fumigants for managing stored-product insects has led to the development of resistance in insects. Essential oils from aromatic plants including the tea oil plant, Melaleuca alternifolia may provide environmentally friendly alternatives to currently used pest control agents. However, little is known about molecular events involved in stored-product insects in response to plant essential oil fumigation. M. alternifolia essential oil was shown to possess the fumigant toxicity against S. zeamais. The constituent, terpinen-4-ol was the most effective compound for fumigant toxicity. M. alternifolia essential oil significantly inhibited the activity of three enzymes in S. zeamais, including two detoxifying enzymes, glutathione S-transferase (GST), and carboxylesterase (CarE), as well as a nerve conduction enzyme, acetylcholinesterase (AChE). Comparative transcriptome analysis of S. zeamais through RNA-Seq identified a total of 3,562 differentially expressed genes (DEGs), of which 2,836 and 726 were up-regulated and down-regulated in response to M. alternifolia essential oil fumigation, respectively. Based on gene ontology (GO) analysis, the majority of DEGs were involved in insecticide detoxification and mitochondrial function. Furthermore, an abundance of DEGs mapped into the metabolism pathway in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database were associated with respiration and metabolism of xenobiotics, including cytochrome P450s, CarEs, GSTs, and ATP-binding cassette transporters (ABC transporters). Some DEGs mapped into the proteasome and phagosome pathway were found to be significantly enriched. These results led us to propose a model of insecticide action that M. alternifolia essential oil likely directly affects the hydrogen carrier to block the electron flow and interfere energy synthesis in mitochondrial respiratory chain

Impact of sulphur fumigation on the chemistry of ginger.

Science.gov (United States)

Wu, Cheng-Ying; Kong, Ming; Zhang, Wei; Long, Fang; Zhou, Jing; Zhou, Shan-Shan; Xu, Jin-Di; Xu, Jun; Li, Song-Lin

2018-01-15

Ginger (Zingiberis Rhizoma), a commonly-consumed food supplement, is often sulphur-fumigated during post-harvest handling, but it remains unknown if sulphur fumigation induces chemical transformations in ginger. In this study, the effects of sulphur fumigation on ginger chemicals were investigated by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS/MS)-based metabolomics. The results showed that sulphur fumigation significantly altered the holistic chemical profile of ginger by triggering chemical transformations of certain original components. 6-Gingesulphonic acid, previously reported as a naturally-occurring component in ginger, was revealed to be a sulphur fumigation-induced artificial derivative, which was deduced to be generated by electrophilic addition of 6-shogaol to sulphurous acid. Using UHPLC-QTOF-MS/MS extracting ion analysis with 6-gingesulphonic acid as a characteristic chemical marker, all the commercial ginger samples inspected were determined to be sulphur-fumigated. The research outcomes provide a chemical basis for further comprehensive safety and efficacy evaluations of sulphur-fumigated ginger. Copyright © 2017 Elsevier Ltd. All rights reserved.

Managing for soil health can suppress pests

Directory of Open Access Journals (Sweden)

Amanda Hodson

2016-08-01

Full Text Available A “healthy” soil can be thought of as one that functions well, both agronomically and ecologically, and one in which soil biodiversity and crop management work in synergy to suppress pests and diseases. UC researchers have pioneered many ways of managing soil biology for pest management, including strategies such as soil solarization, steam treatment and anaerobic soil disinfestation, as well as improvements on traditional methods, such as reducing tillage, amending soil with organic materials, and cover cropping. As managing for soil health becomes more of an explicit focus due to restrictions on the use of soil fumigants, integrated soil health tests will be needed that are validated for use in California. Other research needs include breeding crops for disease resistance and pest suppressive microbial communities as well as knowledge of how beneficial organisms influence plant health.

Tracing in situ amino acid uptake in plants and microbes with¹⁵N¹³C labelled compounds

DEFF Research Database (Denmark)

Andresen, Louise Christoffersen; Michelsen, Anders; Jonasson, Sven Evert

amino acids. Furthermore, tannin addition tended to reduce plant uptake of label. By combining data on 15N recovery after 1 day in shoots and roots (fine and coarse) of the dominant heathland plants: the evergreen dwarf shrub Calluna vulgaris and the graminoid Deschampsia flexuosa, in soil...... microorganisms (chloroform fumigation extraction) and in soil water, we discuss the relative importance of free amino acids and ammonium as plant nutrients and microbial substrates in natural N-limited ecosystems with a high proportion of soil N held in tannin-N complexes. ...

Soil inoculation method determines the strength of plant-soil interactions

NARCIS (Netherlands)

Voorde, van de T.F.J.; Ruijten, M.; Putten, van der W.H.; Bezemer, T.M.

2012-01-01

There is increasing evidence that interactions between plants and biotic components of the soil influence plant productivity and plant community composition. Many plant–soil feedback experiments start from inoculating relatively small amounts of natural soil to sterilized bulk soil. These soil

Insecticidal Activity of Melaleuca alternifolia Essential Oil and RNA-Seq Analysis of Sitophilus zeamais Transcriptome in Response to Oil Fumigation.

Directory of Open Access Journals (Sweden)

Min Liao

Full Text Available The cereal weevil, Sitophilus zeamais is one of the most destructive pests of stored cereals worldwide. Frequent use of fumigants for managing stored-product insects has led to the development of resistance in insects. Essential oils from aromatic plants including the tea oil plant, Melaleuca alternifolia may provide environmentally friendly alternatives to currently used pest control agents. However, little is known about molecular events involved in stored-product insects in response to plant essential oil fumigation.M. alternifolia essential oil was shown to possess the fumigant toxicity against S. zeamais. The constituent, terpinen-4-ol was the most effective compound for fumigant toxicity. M. alternifolia essential oil significantly inhibited the activity of three enzymes in S. zeamais, including two detoxifying enzymes, glutathione S-transferase (GST, and carboxylesterase (CarE, as well as a nerve conduction enzyme, acetylcholinesterase (AChE. Comparative transcriptome analysis of S. zeamais through RNA-Seq identified a total of 3,562 differentially expressed genes (DEGs, of which 2,836 and 726 were up-regulated and down-regulated in response to M. alternifolia essential oil fumigation, respectively. Based on gene ontology (GO analysis, the majority of DEGs were involved in insecticide detoxification and mitochondrial function. Furthermore, an abundance of DEGs mapped into the metabolism pathway in the Kyoto Encyclopedia of Genes and Genomes (KEGG pathway database were associated with respiration and metabolism of xenobiotics, including cytochrome P450s, CarEs, GSTs, and ATP-binding cassette transporters (ABC transporters. Some DEGs mapped into the proteasome and phagosome pathway were found to be significantly enriched. These results led us to propose a model of insecticide action that M. alternifolia essential oil likely directly affects the hydrogen carrier to block the electron flow and interfere energy synthesis in mitochondrial

PIXE analysis of remaining bromine in fumigated old manuscripts and books

International Nuclear Information System (INIS)

Kohno, M.; Yoshida, K.; Moritani, K.; Naito, M.; Enami, K.; Kasajima, H.; Takada, J.; Matsushita, R.

1999-01-01

Buddhist scriptures in Reeky University Library have been fumigated regularly for protecting them from vermin. Methyl bromide (CH 3 Br) had been used there till 1985. In order to examine whether the chemical remains on the fumigated objects or not, paper fragments of old manuscripts and books, modern paper placed together with them, and non-fumigated ones were analyzed by PIXE. The bromine concentration of fumigated paper was more than from several tens to several hundreds times higher than non-fumigated ones. (author)

Efficacy of Nitric Oxide Fumigation for Controlling Codling Moth in Apples

Directory of Open Access Journals (Sweden)

Yong-Biao Liu

2016-12-01

Full Text Available Nitric oxide (NO fumigation under ultralow oxygen (ULO conditions was studied for its efficacy in controlling codling moth and effects on postharvest quality of apples. NO fumigation was effective against eggs and larvae of different sizes on artificial diet in 48 h treatments. Small larvae were more susceptible to nitric oxide than other stages at 0.5% NO concentration. There were no significant differences among life stages at 1.0% to 2.0% NO concentrations. In 24 h treatments of eggs, 3.0% NO fumigation at 2 °C achieved 100% egg mortality. Two 24 h fumigation treatments of infested apples containing medium and large larvae with 3.0% and 5.0% NO resulted in 98% and 100% mortalities respectively. Sound apples were also fumigated with 5.0% NO for 24 h at 2 °C to determine effects on apple quality. The fumigation treatment was terminated by flushing with nitrogen and had no negative impact on postharvest quality of apples as measured by firmness and color at 2 and 4 weeks after fumigation. This study demonstrated that NO fumigation was effective against codling moth and safe to apple quality, and therefore has potential to become a practical alternative to methyl bromide fumigation for control of codling moth in apples.

Efficacy of Nitric Oxide Fumigation for Controlling Codling Moth in Apples.

Science.gov (United States)

Liu, Yong-Biao; Yang, Xiangbing; Simmons, Gregory

2016-12-02

Nitric oxide (NO) fumigation under ultralow oxygen (ULO) conditions was studied for its efficacy in controlling codling moth and effects on postharvest quality of apples. NO fumigation was effective against eggs and larvae of different sizes on artificial diet in 48 h treatments. Small larvae were more susceptible to nitric oxide than other stages at 0.5% NO concentration. There were no significant differences among life stages at 1.0% to 2.0% NO concentrations. In 24 h treatments of eggs, 3.0% NO fumigation at 2 °C achieved 100% egg mortality. Two 24 h fumigation treatments of infested apples containing medium and large larvae with 3.0% and 5.0% NO resulted in 98% and 100% mortalities respectively. Sound apples were also fumigated with 5.0% NO for 24 h at 2 °C to determine effects on apple quality. The fumigation treatment was terminated by flushing with nitrogen and had no negative impact on postharvest quality of apples as measured by firmness and color at 2 and 4 weeks after fumigation. This study demonstrated that NO fumigation was effective against codling moth and safe to apple quality, and therefore has potential to become a practical alternative to methyl bromide fumigation for control of codling moth in apples.

Action spectrum of peroxyacetyl nitrate damage to bean plants

Energy Technology Data Exchange (ETDEWEB)

Dugger, W M; Taylor, O C; Klein, W H; Shropshire, W

1963-04-06

For plant damage from peroxyacetyl nitrate (PAN) there is absolute requirement for light prior to, during, and after fumigation of plants with the oxidant. Pinto beans were fumigated with PAN and exposed to a variety of light intensities and wavelengths. Maximum damage to plants was found when PAN fumigation was contemporaneous with incident light of 370, 419, 480, and 641 m..mu...

Chloropicrin Emission Reduction by Soil Amendment with Biochar

Science.gov (United States)

Wang, Qiuxia; Yan, Dongdong; Liu, Pengfei; Mao, Liangang; Wang, Dong; Fang, Wensheng; Li, Yuan; Ouyang, Canbin; Guo, Meixia; Cao, Aocheng

2015-01-01

Biochar has sorption capacity, and can be used to enhance the sequestration of volatile organic contaminants such as pesticides in soil. Chloropicrin (CP) is an important soil fumigant for the production of many fruit and vegetable crops, but its emissions must be minimized to reduce exposure risks and air pollution. The objective of this study was to determine the capacity of biochar to adsorb CP and the effect of biochar amendments to soil on CP emission, concentration in the soil gas phase, degradation in soil and CP bioactivity for controlling soil borne pests. CP emission and concentration in the soil air phase were measured from packed soil columns after fumigant injection at 20-cm depth and application of selected doses of biocharto the surface 5 cm soil. Laboratory incubation and fumigation experiments were conducted to determine the capacity of biochar to adsorb CP, the effects on CP degradation and, separately, CP’s bioactivity on soil borne pests in soil amended with biochar. Biochar amendment at 2% to 5% (w/w) greatly reduced total CP emission losses by 85.7% - 97.7% compared to fumigation without biochar. CP concentrations in the soil gas-phase, especially in the top 5 cm of soil, were reduced within 48 h following application. The half-life of CP decreased from 13.6 h to 6.4 h as the biochar rate increased from 0% to 5%. CP and its metabolite (dichloronitromethane) both degraded more rapidly in pure biochar than in soil. The biochar used in the present study had a maximum adsorption capacity for CP of less than 5 mg g-1. There were no negative effects on pathogen and nematode control when the biochar used in this study was less than 1% (on a weight basis) in soil. Biochar amendment to soil reduced the emissions of CP. CP concentrations in the top 5 cm of soil gas-phase were reduced. CP degradation was accelerated with the addition of biochar. The biochar used in the present study had a low adsorption capacity for CP. There were no negative effects

Soil pCO2, soil respiration, and root activity in CO2 - fumigated and nitrogen-fertilized ponderosa pine

Science.gov (United States)

Dale Johnson; Donn Geisinger; Roger Walker; John Newman; James Vose; Katherine Elliott; Timothy Ball

1994-01-01

The purpose of this paper is to describe the effects of C02 and N treatments on soil pC02, calculated CO2 efflux, root biomass and soil carbon in open-top chambers planted with Pinus ponderosa seedlings. Based upon the literature, it was hypothesized that both elevated CO...

Effectiveness of different pre-treatments in recovering pre-burial isotopic ratios of charred plants.

Science.gov (United States)

Brinkkemper, O; Braadbaart, F; van Os, B; van Hoesel, A; van Brussel, A A N; Fernandes, R

2018-02-15

Isotopic analysis of archaeological charred plant remains offers useful archaeological information. However, adequate sample pre-treatment protocols may be necessary to provide a contamination-free isotopic signal while limiting sample loss and achieving a high throughput. Under these constraints, research was undertaken to compare the performance of different pre-treatment protocols. Charred archaeological plant material was selected for isotopic analysis (δ 13 C and δ 15 N values) by isotope ratio mass spectrometry from a variety of plant species, time periods and soil conditions. Preservation conditions and the effectiveness of cleaning protocols were assessed through Fourier transform infrared spectroscopy and X-ray fluorescence (XRF) spectrometry. An acid-base-acid protocol, successfully employed in radiocarbon dating, was used to define a contamination-free isotopic reference. Acid-base-acid isotopic measurements were compared with those obtained from untreated material and an acid-only protocol. The isotopic signals of untreated material and the acid-only protocol typically did not differ more than 1‰ from those of the acid-base-acid reference. There were no significant isotopic offsets between acid-base-acid and acid-only or untreated samples. Sample losses in the acid-base-acid protocol were on average 50 ± 17% (maximum = 98.4%). Elemental XRF measurements showed promising results in the detection of more contaminated samples albeit with a high rate of false positives. For the large range of preservation conditions described in the study, untreated charred plant samples, water cleaned of sediments, provide reliable stable isotope ratios of carbon and nitrogen. The use of pre-treatments may be necessary under different preservation conditions or more conservative measurement uncertainties should be reported. Copyright © 2017 John Wiley & Sons, Ltd.

TIF film, substrates and nonfumigant soil disinfestation maintain fruit yields

Directory of Open Access Journals (Sweden)

Steven Fennimore

2013-07-01

Full Text Available A 5-year project to facilitate the adoption of strawberry production systems that do not use methyl bromide initially focused on fumigant alternatives and resulted in increased use of barrier films that reduce fumigant emissions. The focus shifted in year 3 to evaluating and demonstrating nonfumigant alternatives: soilless production, biofumigation, anaerobic soil disinfestation (ASD and disinfestation with steam. In the 2010–2011 strawberry production season, fruit yields on substrates were comparable to fruit yields using conventional methods. Anaerobic soil disinfestation and steam disinfestation also resulted in fruit yields that were comparable to those produced using conventionally fumigated soils. Additional work is in progress to evaluate their efficacy in larger-scale production systems in different strawberry production districts in California.

Active oxygen participation in chlorophyll destruction and lipid peroxidation in SO/sub 2/-fumigated leaves of spinach

Energy Technology Data Exchange (ETDEWEB)

Shimazaki, K; Sakaki, T; Sugahara, K

1980-01-01

Chlorophyll a and carotenoids of spinach plants began to be destroyed in 2 to 3 hr after the initiation of fumigation with 2.0 ppM sulfur dioxide (SO/sub 2/) in light, whereas chlorophyll b was apparently undamaged during 8 hr of exposure to SO/sub 2/. The content of pheophytin a, chromatographically determined, was not changed by SO/sub 2/ fumigation. When leaf disks (phi = 10 mm), excised from the leaves fumigated with SO/sub 2/ at 2.0 ppM for 2 hr, were illuminated, chlorophyll a and carotenoids were broken down, but they were not destroyed in darkness. The destruction of chlorophyll a and carotenoids was suppressed under a stream of nitrogen. Chlorophyll a destruction was inhibited by free radical scavengers, 1,2-dihydroxbenzene-3,5-disulfonate (tiron), hydroquinone and ascorbate. The singlet oxygen scavengers, 1,4-diazabicyclo-(2,2,2)-octane (DABCO), methionine and histidine, and hydroxyl radical scavengers, benzoate and formate were without effect on the destruction of chlorophyll a. Chlorophyll a destruction was inhibited by the addition of superoxide dismutase (SOD) to the homogenate of SO/sub 2/-fumigated leaves. SO/sub 2/ fumigation for 2 hr reduced the activity of superoxide dismutase to 40% without producing the significant loss of chlorophyll. From these results we concluded that chlorophyll a destruction by SO/sub 2/ was due to superoxide radicals. Moreover, malondialdehyde (MDA), an indicator of lipid peroxidation, was accumulated in SO/sub 2/-fumigated leaves in light. MDA formation was inhibited by tiron and hydroquinone, and by DABCO but was not inhibited by benzoate and formate. MDA formation was increased by D/sub 2/O. From these results it was concluded that /sup 1/O/sub 2/ was involved in lipid peroxidation in SO/sub 2/-fumigated leaves.

Role of soil, crop debris, and a plant pathogen in Salmonella enterica contamination of tomato plants.

Directory of Open Access Journals (Sweden)

Jeri D Barak

Full Text Available BACKGROUND: In the U.S., tomatoes have become the most implicated vehicle for produce-associated Salmonellosis with 12 outbreaks since 1998. Although unconfirmed, trace backs suggest pre-harvest contamination with Salmonella enterica. Routes of tomato crop contamination by S. enterica in the absence of direct artificial inoculation have not been investigated. METHODOLOGY/PRINCIPAL FINDINGS: This work examined the role of contaminated soil, the potential for crop debris to act as inoculum from one crop to the next, and any interaction between the seedbourne plant pathogen Xanthomonas campestris pv. vesicatoria and S. enterica on tomato plants. Our results show S. enterica can survive for up to six weeks in fallow soil with the ability to contaminate tomato plants. We found S. enterica can contaminate a subsequent crop via crop debris; however a fallow period between crop incorporation and subsequent seeding can affect contamination patterns. Throughout these studies, populations of S. enterica declined over time and there was no bacterial growth in either the phyllosphere or rhizoplane. The presence of X. campestris pv. vesicatoria on co-colonized tomato plants had no effect on the incidence of S. enterica tomato phyllosphere contamination. However, growth of S. enterica in the tomato phyllosphere occurred on co-colonized plants in the absence of plant disease. CONCLUSIONS/SIGNIFICANCE: S. enterica contaminated soil can lead to contamination of the tomato phyllosphere. A six week lag period between soil contamination and tomato seeding did not deter subsequent crop contamination. In the absence of plant disease, presence of the bacterial plant pathogen, X. campestris pv. vesicatoria was beneficial to S. enterica allowing multiplication of the human pathogen population. Any event leading to soil contamination with S. enterica could pose a public health risk with subsequent tomato production, especially in areas prone to bacterial spot disease.

Plant-plant competition outcomes are modulated by plant effects on the soil bacterial community.

Science.gov (United States)

Hortal, S; Lozano, Y M; Bastida, F; Armas, C; Moreno, J L; Garcia, C; Pugnaire, F I

2017-12-19

Competition is a key process that determines plant community structure and dynamics, often mediated by nutrients and water availability. However, the role of soil microorganisms on plant competition, and the links between above- and belowground processes, are not well understood. Here we show that the effects of interspecific plant competition on plant performance are mediated by feedbacks between plants and soil bacterial communities. Each plant species selects a singular community of soil microorganisms in its rhizosphere with a specific species composition, abundance and activity. When two plant species interact, the resulting soil bacterial community matches that of the most competitive plant species, suggesting strong competitive interactions between soil bacterial communities as well. We propose a novel mechanism by which changes in belowground bacterial communities promoted by the most competitive plant species influence plant performance and competition outcome. These findings emphasise the strong links between plant and soil communities, paving the way to a better understanding of plant community dynamics and the effects of soil bacterial communities on ecosystem functioning and services.

Plant diversity and plant identity influence Fusarium communities in soil.

Science.gov (United States)

LeBlanc, Nicholas; Kinkel, Linda; Kistler, H Corby

2017-01-01

Fusarium communities play important functional roles in soil and in plants as pathogens, endophytes, and saprotrophs. This study tests how rhizosphere Fusarium communities may vary with plant species, changes in the diversity of the surrounding plant community, and soil physiochemical characteristics. Fusarium communities in soil associated with the roots of two perennial prairie plant species maintained as monocultures or growing within polyculture plant communities were characterized using targeted metagenomics. Amplicon libraries targeting the RPB2 locus were generated from rhizosphere soil DNAs and sequenced using pyrosequencing. Sequences were clustered into operational taxonomic units (OTUs) and assigned a taxonomy using the Evolutionary Placement Algorithm. Fusarium community composition was differentiated between monoculture and polyculture plant communities, and by plant species in monoculture, but not in polyculture. Taxonomic classification of the Fusarium OTUs showed a predominance of F. tricinctum and F. oxysporum as well of the presence of a clade previously only found in the Southern Hemisphere. Total Fusarium richness was not affected by changes in plant community richness or correlated with soil physiochemical characteristics. However, OTU richness within two predominant phylogenetic lineages within the genus was positively or negatively correlated with soil physiochemical characteristics among samples within each lineage. This work shows that plant species, plant community richness, and soil physiochemical characteristics may all influence the composition and richness of Fusarium communities in soil.

Fact Sheet in English and Spanish: What Residents in Agricultural Communities Should Know About Soil Fumigants

Science.gov (United States)

Learn about fumigant gas from treated fields (often covered with plastic tarps), some chemical and trade names of these agricultural products, signs and symptoms of pesticide exposure, and how to avoid or report or treat pesticide illness.

Isotopes in soil-plant nutrition studies

International Nuclear Information System (INIS)

1962-01-01

Radioisotopes have greatly facilitated investigating the characteristics of plant nutrients in the soil, in measuring soil moisture, in studying the uptake of nutrients by plants and in devising efficient methods of fertilizer application, and are now being widely used in soil-plant nutrition research. A recent international symposium on the use of radioisotopes in soil-plant nutrition studies showed the varied ways in which isotopes can contribute to agricultural production by helping to investigate soil characteristics and soil-plant relationships. The symposium, jointly sponsored by the International Atomic Energy Agency and the Food and Agriculture Organization of the United Nations, was held in Bombay from 26 February to 2 March 1962, at the invitation of the Government of India

Oxygenated phosphine fumigation for control of Nasonovia ribisnigri (Homoptera: Aphididae) on harvested lettuce.

Science.gov (United States)

Liu, Yong-Biao

2012-06-01

Low temperature regular phosphine fumigations under the normal oxygen level and oxygenated phosphine fumigations under superatmospheric oxygen levels were compared for efficacy against the aphid, Nasonovia ribisnigri (Mosley), and effects on postharvest quality of romaine and head lettuce. Low temperature regular phosphine fumigation was effective against the aphid. However, a 3 d treatment with high phosphine concentrations of > or = 2,000 ppm was needed for complete control of the aphid. Oxygen greatly increased phosphine toxicity and significantly reduced both treatment time and phosphine concentration for control of N. ribisnigri. At 1,000 ppm phosphine, 72 h regular fumigations at 6 degrees C did not achieve 100% mortality of the aphid. The 1,000 ppm phosphine fumigation under 60% O2 killed all aphids in 30 h. Both a 72 h regular fumigation with 2,200 ppm phosphine and a 48 h oxygenated fumigation with 1,000 ppm phosphine under 60% O2 were tested on romaine and head lettuce at 3 degrees C. Both treatments achieved complete control of N. ribisnigri. However, the 72 h regular fumigation resulted in significantly higher percentages of lettuce with injuries and significantly lower lettuce internal quality scores than the 48 h oxygenated phosphine fumigation. Although the oxygenated phosphine fumigation also caused injuries to some treated lettuce, lettuce quality remained very good and the treatment is not expected to have a significant impact on marketability of the lettuce. This study demonstrated that oxygenated phosphine fumigation was more effective and less phytotoxic for controlling N. ribisnigri on harvested lettuce than regular phosphine fumigation and is promising for practical use.

Fumigation in Ayurveda: potential strategy for drug discovery and drug delivery.

Science.gov (United States)

Vishnuprasad, Chethala N; Pradeep, Nediyamparambu Sukumaran; Cho, Yong Woo; Gangadharan, Geethalayam Gopinathan; Han, Sung Soo

2013-09-16

Ayurveda has its unique perceptions and resultant methodologies for defining and treating human diseases. Fumigation therapy is one of the several treatment methods described in Ayurveda whereby fumes produced from defined drug formulations are inhaled by patients. This therapeutic procedure offers promising research opportunities from phytochemical and ethnopharmacological viewpoints, however, it remains under-noticed. Considering these facts, this review is primarily aimed at introducing said Ayurvedic fumigation therapy and discussing its scientific gaps and future challenges. A search of multiple bibliographical databases and traditional Ayurvedic text books was conducted and the articles analyzed under various key themes, e.g., Ayurvedic fumigation, fumigation therapy, medicinal fumigation, inhalation of drugs and aerosol therapy. Ayurveda recommends fumigation as a method of sterilization and therapeutic procedure for various human diseases including microbial infections and psychological disorders. However, it has not gained much attention as a prospective field with multiple research opportunities. It is necessary to have a more detailed and systematic investigation of the phytochemical and pharmacodynamic properties of Ayurvedic fumigation therapy in order to facilitate the identification of novel bioactive compounds and more effective drug administration methods. © 2013 Elsevier Ireland Ltd. All rights reserved.

Evaluating anaerobic soil disinfestation and other biological soil management methods for open-field tomato production in Florida

Science.gov (United States)

Anaerobic soil disinfestation (ASD), amending the soil with composted poultry litter (CPL) and molasses (M), has been shown to be a potential alternative to chemical soil fumigation for tomato production, however, optimization of ASD and the use of other biologically-based soil management practices ...

Soil availability, plant uptake and soil to plant transfer of 99Tc-- A review

International Nuclear Information System (INIS)

Bennett, Roy; Willey, Neil

2003-01-01

The fission yield of 99 Tc from 239 Pu and 235 U is similar to that of 137 Cs or 90 Sr and it is therefore an important component of nuclear weapons fall-out, nuclear waste and releases from nuclear facilities. There is particular current interest in 99 Tc transfer from soil to plants for: (a) environmental impact assessments for terrestrial nuclear waste repositories, and (b) assessments of the potential for phytoextraction of radionuclides from contaminated effluent and soil. Vascular plants have high 99 Tc uptake capacity, a strong tendency to transport it to shoot material and accumulate it in vegetative rather than reproductive structures. The mechanisms that control 99 Tc entry to plants have not been identified and there has been little discussion of the potential for phytoextraction of 99 Tc contaminated effluents or soil. Here we review soil availability, plant uptake mechanisms and soil to plant transfer of 99 Tc in the light of recent advances in soil science, plant molecular biology and phytoextraction technologies. We conclude that 99 Tc might not be highly available in the long term from up to 50% of soils worldwide, and that no single mechanism that might be easily targeted by recombinant DNA technologies controls 99 Tc uptake by plants. Overall, we suggest that Tc might be less available in terrestrial ecosystems than is often assumed but that nevertheless the potential of phytoextraction as a decontamination strategy is probably greater for 99 Tc than for any other nuclide of radioecological interest

Competition overwhelms the positive plant-soil feedback generated by an invasive plant.

Science.gov (United States)

Crawford, Kerri M; Knight, Tiffany M

2017-01-01

Invasive plant species can modify soils in a way that benefits their fitness more than the fitness of native species. However, it is unclear how competition among plant species alters the strength and direction of plant-soil feedbacks. We tested how community context altered plant-soil feedback between the non-native invasive forb Lespedeza cuneata and nine co-occurring native prairie species. In a series of greenhouse experiments, we grew plants individually and in communities with soils that differed in soil origin (invaded or uninvaded by L. cuneata) and in soils that were live vs. sterilized. In the absence of competition, L. cuneata produced over 60% more biomass in invaded than uninvaded soils, while native species performance was unaffected. The absence of a soil origin effect in sterile soil suggests that the positive plant-soil feedback was caused by differences in the soil biota. However, in the presence of competition, the positive effect of soil origin on L. cuneata growth disappeared. These results suggest that L. cuneata may benefit from positive plant-soil feedback when establishing populations in disturbed landscapes with few interspecific competitors, but does not support the hypothesis that plant-soil feedbacks influence competitive outcomes between L. cuneata and native plant species. These results highlight the importance of considering whether competition influences the outcome of interactions between plants and soils.

Effect of pre-sowing soil tillage for wheat on the crop structure and the yield components in Dobrudzha region

Directory of Open Access Journals (Sweden)

P. Yankov

2017-06-01

Full Text Available Abstract. The investigation was carried out in the trial field of Dobrudzha Agricultural Institute on slightly leached chernozem soil. In order to clarify the effect of some types of pre-sowing soil tillage for wheat on the crop structure and certain yield components, the following variants of a stationary field experiment were analyzed: double disking at depth 10-12 cm (check variant; ploughing at 14-16 cm + disking; no-tillage (direct sowing – pre-sowing treatment of the area with total herbicides. Wheat was sown after previous crop grain maize and was fertilized with N P K . Wheat cultivar Enola was planted at norm 550 germinating 140 120 80 2 seeds/m . The number of emerging wheat plants was read using square sampling frames sized 50 cm x 50 cm. Using the same sampling frames, the tillering in autumn prior to the wintering of the crops was followed, and in spring – prior to booting stage. The number of productive tillers was also read using these sampling frames. To determine the length of spike, the number of grains in it, and their weight, 30 spikes from 8 replications of each variant were analyzed. The emerging of the wheat plants, under the conditions of slightly leached chernozem soil in Dobrudzha region, was more uniform after sowing following disking, and after direct sowing. The minimal pre-sowing tillage and no-tillage for wheat ensured better autumn development of the crop and the plants. In these variants, higher number of overwintering plants and productive tillers per unit area were registered. Spike length was the highest after ploughing as pre-sowing tillage. Significant variations in the number of grains per spike of the investigated variants were not found. Grain weight per spike was the lowest under direct sowing.

Dynamics of Verticillium species microsclerotia in field soils in response to fumigation, cropping patterns, and flooding

Science.gov (United States)

Many soil-inhabiting fungi are capable of surviving the dynamic soil microenvironment through the formation of resilient resting structures, such as thick-walled spores, melanized hyphae, and sclerotia. Verticillium dahliae is a soil-inhabiting, economically significant plant pathogenic fungus that ...

Soil compaction and growth of woody plants

Energy Technology Data Exchange (ETDEWEB)

Kozlowski, T.T. [Univ. of California, Berkeley (United States). Dept. of Environmental Science, Policy and Management

1999-07-01

Although soil compaction in the field may benefit or inhibit the growth of plants, the harmful effects are much more common. This paper emphasizes the deleterious effects of predominantly high levels of soil compaction on plant growth and yield. High levels of soil compaction are common in heavily used recreation areas, construction sites, urban areas, timber harvesting sites, fruit orchards, agroforestry systems and tree nurseries. Compaction can occur naturally by settling or slumping of soil or may be induced by tillage tools, heavy machinery, pedestrian traffic, trampling by animals and fire. Compaction typically alters soil structure and hydrology by increasing soil bulk density; breaking down soil aggregates; decreasing soil porosity, aeration and infiltration capacity; and by increasing soil strength, water runoff and soil erosion. Appreciable compaction of soil leads to physiological dysfunctions in plants. Often, but not always, reduced water absorption and leaf water deficits develop. Soil compaction also induces changes in the amounts and balances of growth hormones in plants, especially increases in abscisic acid and ethylene. Absorption of the major mineral nutrients is reduced by compaction of both surface soils and subsoils. The rate of photosynthesis of plants growing in very compacted soil is decreased by both stomatal and non-stomatal inhibition. Total photosynthesis is reduced as a result of smaller leaf areas. As soils become increasingly compacted respiration of roots shifts toward an anaerobic state. Severe soil compaction adversely influences regeneration of forest stands by inhibiting seed germination and growth of seedlings, and by inducing seedling mortality. Growth of woody plants beyond the seedling stage and yields of harvestable plant products also are greatly decreased by soil compaction because of the combined effects of high soil strength, decreased infiltration of water and poor soil aeration, all of which lead to a decreased

Soil compaction and growth of woody plants

International Nuclear Information System (INIS)

Kozlowski, T.T.

1999-01-01

Although soil compaction in the field may benefit or inhibit the growth of plants, the harmful effects are much more common. This paper emphasizes the deleterious effects of predominantly high levels of soil compaction on plant growth and yield. High levels of soil compaction are common in heavily used recreation areas, construction sites, urban areas, timber harvesting sites, fruit orchards, agroforestry systems and tree nurseries. Compaction can occur naturally by settling or slumping of soil or may be induced by tillage tools, heavy machinery, pedestrian traffic, trampling by animals and fire. Compaction typically alters soil structure and hydrology by increasing soil bulk density; breaking down soil aggregates; decreasing soil porosity, aeration and infiltration capacity; and by increasing soil strength, water runoff and soil erosion. Appreciable compaction of soil leads to physiological dysfunctions in plants. Often, but not always, reduced water absorption and leaf water deficits develop. Soil compaction also induces changes in the amounts and balances of growth hormones in plants, especially increases in abscisic acid and ethylene. Absorption of the major mineral nutrients is reduced by compaction of both surface soils and subsoils. The rate of photosynthesis of plants growing in very compacted soil is decreased by both stomatal and non-stomatal inhibition. Total photosynthesis is reduced as a result of smaller leaf areas. As soils become increasingly compacted respiration of roots shifts toward an anaerobic state. Severe soil compaction adversely influences regeneration of forest stands by inhibiting seed germination and growth of seedlings, and by inducing seedling mortality. Growth of woody plants beyond the seedling stage and yields of harvestable plant products also are greatly decreased by soil compaction because of the combined effects of high soil strength, decreased infiltration of water and poor soil aeration, all of which lead to a decreased

Parameterization of radiocaesium soil-plant transfer using soil characteristics

International Nuclear Information System (INIS)

Konoplev, A. V.; Drissner, J.; Klemt, E.; Konopleva, I. V.; Zibold, G.

1996-01-01

A model of radionuclide soil-plant transfer is proposed to parameterize the transfer factor by soil and soil solution characteristics. The model is tested with experimental data on the aggregated transfer factor T ag and soil parameters for 8 forest sites in Baden-Wuerttemberg. It is shown that the integral soil-plant transfer factor can be parameterized through radiocaesium exchangeability, capacity of selective sorption sites and ion composition of the soil solution or the water extract. A modified technique of (FES) measurement for soils with interlayer collapse is proposed. (author)

Volatilization of iodine from soils and plants

International Nuclear Information System (INIS)

Wildung, R.E.; Cataldo, D.A.; Garland, T.R.

1985-04-01

Elevated levels of 129 I, a long-lived fission product, are present in the environment as a result of nuclear weapons testing and fuel reprocessing. To aid in understanding the anomalous behavior of this element, relative to natural I ( 127 I), in the vicinity of nuclear fuel reprocessing plants, preliminary laboratory-growth chamber studies were undertaken to examine the possible formation of volatile inorganic and organic I species in soil and plant systems. Inorganic 129 I added to soil was volatilized from both the soil and plant during plant growth, at average ratios of 2 x 10 -3 %/day soil and 9 x 10 -3 %/day foliage, respectively. Volatilization rates from soil were an order of magnitude less in the absence of growing roots. Less than 2% of soil or plant volatiles was subsequently retained by plant canopies. Volatile I, chemically characterized by selective sorption methods, consisted principally of alkyl iodides formed by both soil and plant processes. However, plants and soils containing actively growing roots produced a larger fraction of volatile inorganic I than soil alone. 14 refs., 1 fig., 3 tabs

Chlorine Dioxide Fumigation of Subway Materials ...

Science.gov (United States)

Report This bench scale study observed that a six (6) log reduction in viable spores of a suitable B. anthracis surrogate can be obtained for subway infrastructure materials by ClO2 fumigation if the temperature is at or above 24 °C combined with RH greater than 75%. No six log reduction in viable spores was observed at realistic (winter) temperatures in a subway environment (11-13 °C and 70-80% RH) for periods of fumigation that are otherwise efficacious at 24 °C/ 75% RH.

Chemical constituents and fumigant toxicity of essential oil from Carum copticum against two stored product beetles

Institute of Scientific and Technical Information of China (English)

BIBI ZAHRA SAHAF; SAEID MOHARRAMIPOUR; MOHAMMAD HADI MESHKATALSADAT

2007-01-01

Plant secondary metabolites play an important role in plant-insect interactions and therefore such compounds may have insecticidal or antifeedant activity against insects. Carum copticum C. B. Clarke (Apiaceae) is one of these plants that have medicinal effects on humans. The chemical composition of the essential oil from dry seeds of C. copticum was studied by gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS). Thymol (41.34%), α-terpinolene (17.46%) and ρ-cymene (11.76%) were found to be the major constituents of the oil. In fumigant toxicity tests with the essential oil against adults of Sitophilus oryzae (L.) and Tribolium castaneum (Herbst) at 27 +-1℃ and 60%+-5% RH, it was observed that S. oryzae (LC50= 0.91 μL/L) were significantly susceptible than T. castaneum (LC50= 33.14 μL/L). The mortalities of the insect species reached 100% at concentrations higher than 185.2 μL/L and 12-h exposure time. The findings indicate the strong insecticidal activity of C. copticum oil and its potential role as a fumigant for storedproduct insects.

Experimental studies on fumigation of ethanol in a small capacity Diesel engine

International Nuclear Information System (INIS)

Chauhan, Bhupendra Singh; Kumar, Naveen; Pal, Shyam Sunder; Du Jun, Yong

2011-01-01

To diversify the mix of domestic energy resources and to reduce dependence on imported oil, ethanol is widely investigated for applying in combination with Diesel fuel to reduce pollutants, including smoke and NO x . Present work aims at developing a fumigation system for introduction of ethanol in a small capacity Diesel engine and to determine its effects on emission. Fumigation was achieved by using a constant volume carburetor. Different percentages of ethanol fumes with air were then introduced in the Diesel engine, under various load conditions. Ethanol is an oxygenated fuel and lead to smooth and efficient combustion. Atomization of ethanol also results in lower combustion temperature. During the present study, gaseous emission has been found to be decreasing with ethanol fumigation. Results from the experiment suggest that ethanol fumigation can be effectively employed in existing compression ignition engine to achieve substantial saving of the limited Diesel oil. Results show that fumigated Diesel engine exhibit better engine performance with lower NOx, CO, CO 2 and exhaust temperature. Ethanol fumigation has resulted in increase of unburned hydrocarbon (HC) emission in the entire load range. Considering the parameters, the optimum percentage was found as 15% for ethanol fumigation. -- Research highlights: → To diversify energy resources and to reduce dependence on imported oil, ethanol is used in Diesel engine to reduce pollutants. → Developing a fumigation system to inject ethanol in a small capacity Diesel engine, to determine its effects on emissions. → Different percentages of ethanol fumes with air were introduced in Diesel engine, under various load conditions by using a constant volume carburetor. → Results show that fumigated Diesel engine exhibits better engine performance with lower NOx, CO, CO 2 and exhaust temperature. → Results show increase of unburned hydrocarbon emission in entire load range. Optimum percentage found as 15% for

[Primary investigation on fumigation and moxibustion in treatment ulcer and sore of yin syndrome].

Science.gov (United States)

Zhu, Chao-Jun; Zhang, Zhao-Hui; Ma, Jing; Li, Pin-Chuan; Liu, Xian-Zhou; Yin, Yue; Tian, Ying

2011-09-01

To explore the fumigation and moxibustion therapy in treatment of ulcer and sore of yin syndrome. The fumigation and moxibustion therapy is the combination of fumigation and moxibustion, in which, smoking fumigation is provided with warming effect and the actions as moxibustion. This therapy works on the efficacy of both fumigation and moxibustion. In treatment, different herbal medicines can be selected flexibly, acting on dispersing yin and rescuing yang. The fumigation and moxibustion therapy can drain toxin and remove ulcer and sore. It contributes to the treatment of boils and chronic sores of yin syndrome and promotes wound healing.

Transuranic element behavior in soils and plants

International Nuclear Information System (INIS)

Wildung, R.E.

1982-01-01

The principal objective of this study is to define soil, plant, and foliar interaction processes that influence the availability of transuranic elements to agricultural plants and animals as a basis for improved modeling and dose-assessment. Major areas of emphasis are: (1) soil and soil-microbial processes that influence the concentration and form of transuranic elements in soil solutions and availability to the plant root with time; (2) deposition and plant interception of airborne submicronic particles containing transuranic elements and their susceptibility to leaching; (3) plant processes that influence transport across plant root membrane and foliar surfaces, as well as the form and sites of deposition of transuranic elements in mature plants; and (4) the integrated effect of soil and plant processes on transuranic element availability to, and form in, animals that consume plants

Growth response of maize plants (Zea mays L.) to wheat and lentil pre-cropping and to indigenous mycorrhizal in field soil

Energy Technology Data Exchange (ETDEWEB)

Almaca, A.; Ortas, I.

2010-07-01

The presence of indigenous mycorrhizal fungi may have significant effects on the growth and on the root morphology of plants, under arid and semi arid soil conditions. Lentil and wheat are the traditional crops grown in Southeastern Turkey. In this study soil samples from the Harran plain were collected from the 0-15 cm surface layer under wheat or lentil crop residues and used in a pot experiment carried out under greenhouse conditions with four levels of P fertilization: 0, 20, 40 and 80 mg kg{sup -}1 soil as Ca(H{sub 2}PO{sub 4}){sub 2}. Half of the soil batches were submitted to a heating treatment (80 degree centigrade, 2 h). The maize variety PX-9540 was grown in the pots for 57 days. At harvest, plant dry weight, root length, P and Zn concentrations in plant tissues were measured and the extent of root colonization by arbuscular mycorrhizal fungi (AMF) was determined. Results showed that maize plants grown in soils where lentil had been previously cultivated grew better than those grown after wheat cultivation. In both cases, P concentration in plant tissues increased with increased P fertilization. There were no significant differences in root AMF colonization between soils with different crop sequences, nor with soils submitted to high temperature. Previous crops had a significant influence on the growth of plants that could be related to differences in the indigenous mycorrhizas inoculum potential and efficacy that can promote P uptake and benefit plant growth. (Author) 29 refs.

Behaviour of transuranic radionuclides in soils, plants and soil-plant system

International Nuclear Information System (INIS)

Vyas, B.N.; Mistry, K.B.

1996-01-01

The present paper reviews the investigations undertaken to elucidate the physicochemical, edaphic and physiological aspects of the behaviour of long-lived transuranic radionuclides 239 Pu and 241 Am in typical Indian soils and soil-plant systems. 23 refs

40 CFR 180.521 - Fumigants for grain-mill machinery; tolerances for residues.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Fumigants for grain-mill machinery... Tolerances § 180.521 Fumigants for grain-mill machinery; tolerances for residues. (a) General. Fumigants may be safely used in or on grain-mill machinery in accordance with the following prescribed conditions...

Assessment of the polytank for fumigation and storage of cowpea

International Nuclear Information System (INIS)

Ademang Korletey, Francis

2009-06-01

Insect infestation of cowpea (Vigna unguiculata) in storage is identified as a major constraint facing cowpea farmers in Ghana. The major insect pest causing losses to stored cowpea in West Africa is the cowpea weevil (Callosobruchus maculatus). Fumigation is the most effective control method against cowpea weevil considering its mode of infestation. The jute sack lined with a plastic film bag commonly used by farmers for fumigation and storage is very delicate to handle, not sufficiently airtight for fumigation and easily attacked by rodents. The objectives of the project were to (1) assess the polytank for fumigation and storage of cowpea, and (2) compare the storage qualities of stored cowpea using the polytank and jute sack lined with a plastic film bag. The cowpea was fumigated using aluminium phosphide tablets for a period of 7 days and stored for six mouths. Data was collected, analysed and compared between the two storage containers on seed germination, seed vigour, grain moisture content, insect infestation, percentage usable proportion by number and by weight before, mid-storage and after the trial. The levels of phosphine gas concentration in the polytank and the jute sack were assessed daily for 7 days. The results showed no significant differences (1% probability) between the two storage containers in their performance as storage containers in terms of grain moisture content, seed germination, seed vigour, insect infestation, percentage usable proportion by number and by weight. There was also significant difference (5%) in phosphine gas concentration between the two storage containers in their performance as fumigation containers except on day one. However, it was found that fumigation and storage using the polytank had a greater advantage over the jute sack lined with plastic film bag in terms of air tightness, handling and resistance to rodent attacks. (au)

Some plant extracts retarde nitrification in soil

Directory of Open Access Journals (Sweden)

Abdul–Mehdi S. AL-ANSARI

2015-12-01

Full Text Available An incubation experiment was conducted to evaluate the effect of aqueous extracts of 17 plant materials on nitrification inhibition of urea- N in soil as compared with chemical inhibitor Dicyandiamide (DCD. Plant materials used in study were collected from different areas of Basrah province, south of Iraq. Aqueous extracts were prepared at ratio of 1:10 (plant material: water and added at conc. of 0.05, 0.10 and 0.20 ml g– 1 soil to loamy sand soil. DCD was added to soil at rate of 50 µg g-1 soil . Soil received urea at rate of 1000 µg N g-1 soil. Treated soils were incubated at 30 OC for 40 days. Results showed that application of all plant extracts, except those of casuarina, date palm and eucalyptus to soil retarded nitrification in soil. Caper, Sowthistle ,bladygrass and pomegranate extracts showed highest inhibition percentage (51, 42, 40 and 40 %, respectively and were found to be more effective than DCD (33 %. Highest inhibition was achieved by using those extracts at conc. of 0.1 ml g-1 soil after 10 days of incubation . Data also revealed that treated soil with these plant extracts significantly increased amount of NH4+–N and decreased amount of NO3-–N accumulation in soil compared with DCD and control treatments. Results of the study suggested a possibility of using aqueous extracts of some studied plants as potent nitrification inhibitor in soil.

Variability of δ15N in soil and plants at a New Zealand hill country site: correlations with soil chemistry and nutrient inputs

International Nuclear Information System (INIS)

Hawke, D.J.

2000-01-01

This study investigated 15 N enrichment and nutrient cycling in hill country used for semi-extensive pastoral agriculture, at a site where pre-European seabird breeding occurred. Soil (>15 cm) and plant samples were taken from 18 ridgeline and sideslope transects. Three stock camps (locations which grazing animals frequent) were identified within the study area, two on the ridgeline and one on the sideslope. Soil 15 N enrichment was greatest at stock camps, and lowest where stock input was minimal. Soil natural abundance 15 N (815N) was therefore an index of stock nutrient inputs. Soil δ 15 N increased with decreasing C:N ratio, consistent with N loss through volatilisation and/or nitrate leaching from net mineralisation. Plant δ 15 N from stock camps was lower than its associated soil, implying that 15 N enrichment of plant-available N was lower than that of total soil N. However, the correlation between plant δ 15 N and soil δ 15 N varied between stock camps, indicating differences in N cycling. Olsen P was higher at stock camps, although again differences were found between stock camps. Total P and N were correlated neither with stock camps nor topography, but were higher than expected from parent material concentrations and literature results, respectively. It is postulated that significant contributions of both elements from former seabird breeding remain in the soil. Copyright (2000) CSIRO Publishing

Transuranic Behavior in Soils and Plants

International Nuclear Information System (INIS)

Wildung, R.E.; Garland, T.R.; Cataldo, D.A.; Rogers, J.E.; McFadden, K.M.; McNair, V.M.; Schreckhise, R.G.

1980-01-01

The principal objectives of these investigations are to determine (1) the potential for alteration of transuranic solubility through formation of transuranic complexes in soil and the role of the soil microflora in this process, (2) the extent of uptake nd translocation by plants and the sites of plant deposition of transuranics or their complexes, (3) the bond types and chemical forms of transuranics or their metabolites in microbes, plant tissues and soils, (4) the influence of soil properties, environmental conditions and cropping on these processes, and (5) the retention of airborne pollutants by plant foliage and their subsequent absorption by leaves and transport to seeds and roots

Plant species and functional group effects on abiotic and microbial soil properties and plant-soil feedback responses in two grasslands

NARCIS (Netherlands)

Bezemer, T.M.; Lawson, C.S.; Hedlund, K.; Edwards, A.R.; Brooks, A.J.; Igual, J.M.; Mortimer, S.R.; Putten, van der W.H.

2006-01-01

1 Plant species differ in their capacity to influence soil organic matter, soil nutrient availability and the composition of soil microbial communities. Their influences on soil properties result in net positive or negative feedback effects, which influence plant performance and plant community

THE EFFECT OF FUMIGATION TREATMENT TOWARDS AGAVE CANTALA ROXB FIBRE STRENGTH AND MORPHOLOGY

Directory of Open Access Journals (Sweden)

MUSA BONDARIS PALUNGAN

2017-05-01

Full Text Available The objective of this study is to reveal the morphology, physical properties and strength of the king pineapple leaf fibre (Agave Cantala Roxb after fumigation treatment. The king pineapple leaf fibres (KPLF before and after the fumigation treatment are then separated into groups. The fumigation treatment on KPLF is given in different durations, and the smoke comes from burning coconut shells. Before and after fumigation, the surface morphology, chemical content, and functional group character of KPLF were observed by SEM, XRD, and FTIR, respectively. While the physical characteristics were identified by measuring fibre density, moisture content and fibre strength were tested by a single fibre tensile strength test. The results show that chemical contents of KPLF were cellulose, hemicellulose and lignin, accounting for as much as 55.8%, 21.27%, and 7.66%, respectively. After fumigation, the KPLF surface morphology becomes rough and grooved, the fibre density increased, and the single fibre tensile strength increased notably at the base of the king pineapple leaf. With the tensile strength increase and a rough and grooved KPLF surface morphology due to fumigation, fumigated KPLF would have the potential to be used as a strengthened composite.

Do invasive plant species alter soil health?

Science.gov (United States)

Invasive species may alter soil characteristics or interact with the soil microbial community to yield a competitive advantage. Our objectives were to determine: if invasive plant species alter soil properties important to soil health; and the long-term effects of invasive plant species on soil pro...

Plant-soil feedbacks and the coexistence of competing plants

NARCIS (Netherlands)

Revilla Rimbach, Tomas; Veen, G. F. (Ciska); Eppinga, Maarten B.; Weissing, Franz J.

Plant-soil feedbacks can have important implications for the interactions among plants. Understanding these effects is a major challenge since it is inherently difficult to measure and manipulate highly diverse soil communities. Mathematical models may advance this understanding by making the

Plant species influence on soil C after afforestation of Mediterranean degraded soils

Science.gov (United States)

Dominguez, Maria T.; García-Vargas, Carlos; Madejón, Engracia; Marañón, Teodoro

2015-04-01

Increasing C sequestration in terrestrial ecosystems is one of the main current environmental challenges to mitigate climate change. Afforestation of degraded and contaminated lands is one of the key strategies to achieve an increase in C sequestration in ecosystems. Plant species differ in their mechanisms of C-fixation, C allocation into different plant organs, and interaction with soil microorganisms, all these factors influencing the dynamics of soil C following the afforestation of degraded soils. In this work we examine the influence of different woody plant species on soil C dynamics in degraded and afforested Mediterranean soils. The soils were former agricultural lands that were polluted by a mining accident and later afforested with different native plant species. We analysed the effect of four of these species (Olea europaea var. sylvestris Brot., Populus alba L., Pistacia lentiscus L. and Retama sphaerocarpa (L.) Boiss.) on different soil C fractions, soil nutrient availability, microbial activity (soil enzyme activities) and soil CO2 fluxes 15 years after the establishment of the plantations. Results suggest that the influence of the planted trees and shrubs is still limited, being more pronounced in the more acidic and nutrient-poor soils. Litter accumulation varied among species, with the highest C accumulated in the litter under the deciduous species (Populus alba L.). No differences were observed in the amount of total soil organic C among the studied species, or in the concentrations of phenols and sugars in the dissolved organic C (DOC), which might have indicated differences in the biodegradability of the DOC. Microbial biomass and activity was highly influenced by soil pH, and plant species had a significant influence on soil pH in the more acidic site. Soil CO2 fluxes were more influenced by the plant species than total soil C content. Our results suggest that changes in total soil C stocks after the afforestation of degraded Mediterranean

Tractor-mounted, GPS-based spot fumigation system manages Prunus replant disease

Directory of Open Access Journals (Sweden)

V. Udompetaikul

2013-10-01

Full Text Available Our research goal was to use recent advances in global positioning system (GPS and computer technology to apply just the right amount of fumigant where it is most needed (i.e., in a small target treatment zone in and around each tree replanting site to control Prunus replant disease (PRD. We developed and confirmed the function of (1 GPS-based software that can be used on cleared orchard land to flexibly plan and map all of an orchard's future tree sites and associated spot fumigation treatment zones and 2 a tractor-based GPS-controlled spot fumigation system to quickly and safely treat the targeted tree site treatment zones. In trials in two almond orchards and one peach orchard, our evaluations of the composite mapping and application system, which examined spatial accuracy of the spot treatments, delivery rate accuracy of the spot treatments, and tree growth responses to the spot treatments, all indicated that GPS spot fumigation has excellent potential to greatly reduce fumigant usage while adequately managing the PRD complex.

Gaseous and particle emissions from an ethanol fumigated compression ignition engine

International Nuclear Information System (INIS)

Surawski, Nicholas C.; Ristovski, Zoran D.; Brown, Richard J.; Situ, Rong

2012-01-01

Highlights: ► Ethanol fumigation system fitted on a direct injection compression ignition engine. ► Ethanol substitutions up to 40% (by energy) were achieved. ► Gaseous and particle emissions were measured at intermediate speed. ► PM and NO emissions significantly reduced, whilst CO and HC increased. ► The number of particles emitted generally higher with ethanol fumigation. - Abstract: A 4-cylinder Ford 2701C test engine was used in this study to explore the impact of ethanol fumigation on gaseous and particle emission concentrations. The fumigation technique delivered vaporised ethanol into the intake manifold of the engine, using an injector, a pump and pressure regulator, a heat exchanger for vaporising ethanol and a separate fuel tank and lines. Gaseous (Nitric oxide (NO), Carbon monoxide (CO) and hydrocarbons (HC)) and particulate emissions (particle mass (PM 2.5 ) and particle number) testing was conducted at intermediate speed (1700 rpm) using 4 load settings with ethanol substitution percentages ranging from 10% to 40% (by energy). With ethanol fumigation, NO and PM 2.5 emissions were reduced, whereas CO and HC emissions increased considerably and particle number emissions increased at most test settings. It was found that ethanol fumigation reduced the excess air factor for the engine and this led to increased emissions of CO and HC, but decreased emissions of NO. PM 2.5 emissions were reduced with ethanol fumigation, as ethanol has a very low “sooting” tendency. This is due to the higher hydrogen-to-carbon ratio of this fuel, and also because ethanol does not contain aromatics, both of which are known soot precursors. The use of a diesel oxidation catalyst (as an after-treatment device) is recommended to achieve a reduction in the four pollutants that are currently regulated for compression ignition engines. The increase in particle number emissions with ethanol fumigation was due to the formation of volatile (organic) particles

Effects of soil's properties on transfer of 137Cs to rice plants through plant uptake after soil deposition

International Nuclear Information System (INIS)

Keum, Dong-Kwon; Lee, Hansoo; Kang, Hee-Seok; Jun, In; Choi, Yong-Ho; Lee, Chang-Woo

2007-01-01

This paper presents a dynamic compartment model to appraise the concentration of 137 Cs in agricultural plants as a result of a soil deposition. The present model used the Absalom model as a module to account for the effects of a soil's properties (pH, soil clay content, organic matter content, and exchangeable potassium) on a plant uptake, and the leaching and fixation process of 137 Cs in a soil. The model was tested by comparing the model predictions of the 137 Cs aggregated transfer factors for rice plants with those obtained as results of simulated 137 Cs soil deposition experiments with seventeen paddy soils of different properties, all of which were performed before a transplanting of the rice. Predicted 137 Cs TF a values of the rice plants were found to be comparable with those observed. (author)

Testing of multistep soil washing for radiocesium-contaminated soil containing plant matter

International Nuclear Information System (INIS)

Funakawa, Masafumi; Tagawa, Akihiro; Okuda, Nobuyasu

2012-01-01

Decontamination work following radiocesium exposure requires a vast reduction in the amount of contaminated soil generated. The current study subjected 4 types of contaminated soil with different properties to multistep soil washing under the same conditions. This study also determined the effectiveness of radiocesium decontamination and the extent to which the amount of contaminated soil was reduced. In addition, the effectiveness of plant matter separation, adsorbent addition, and grinding as part of multistep soil washing was determined using the same contaminated soil. Results of testing indicated that the rate of radiocesium decontamination ranged from 73.6 to 89.2% and the recovery rate ranged from 51.5 to 84.2% for twice-treated soil, regardless of the soil properties or cesium level. Plant matter in soil had a high radiocesium level. However, there was little plant matter in our soil sample. Therefore, plant matter separation had little effect on the improvement in the percentage of radiocesium decontamination of twice-treated soil. Soil surface grinding improved the rate of radiocesium decontamination of twice-treated soil. However, radiocesium in soil tightly bound with minerals in the soil; thus, the addition of an adsorbent also failed to improve the rate of radiocesium decontamination. (author)

An experimental study of the 14C transfer from air to rice plant by photosynthesis

International Nuclear Information System (INIS)

Jun, In; Kang, Heeseok; Keum, Dongkweon; Choi, Yongho; Lee, Hansoo; Lee, Changwoo

2007-01-01

Experimental studies were performed under controlled environmental conditions to observe the deposition and subsequent allocation of 14 C following a short-term fumigation of a major Korean crop with 14 CO 2 . The fumigation of the rice plants was performed at five different times during their growth in a transparent box and the fumigation time was 40 minutes. The 14 C in the fumigation box was collected into collection vials every 5 minutes using an air sampler. A duplicate plant sampling was made immediately after the end of fumigation and another is going to be made at the normal harvest time. After the 2nd and 3rd fumigation experiments, plant sampling was made 3 times more till harvest. The samples will be ground into powder after removing the moisture completely and the trapped 14 C in the carbosorb vials by sample oxidizer will be analyzed by Liquid Scintillation Counter. This paper only shows the analysis results of air samples because no plant sample was analyzed yet. (author)

Nitrogen fractions in the microbial biomass in soils of southern Brazil

Directory of Open Access Journals (Sweden)

F. A.O. Camargo

1999-03-01

Full Text Available The reaction of nitrogen compounds with ninhydrin can be used as an indicator of cytoplasmic materials released from microbial cells killed by fumigation. Total-N, ninhydrin-reactive-N (NR-N, ammonium-N (A-N, and α-amino-N in the microbial biomass of soils from the State of Rio Grande do Sul, Brazil, were determined, in 1996, in 0.5 mol L-1 K2SO4 extracts of fumigated and non-fumigated soils. Total-N varied from 20.3 to 104.4 mg kg-1 and the ninhydrin-reactive-N corresponded, in average, to 27% of this. The ninhydrin-reactive-N was made up of 67% ammonium-N and 33% aminoacids with the amino group at the α-carbon position. It was concluded that colorimetric analysis of NR-N and A-N may be used as a direct measure of microbial N in soil. This simple and rapid procedure is adequate for routine analyses.

Pre-fire planning for nuclear power plants

International Nuclear Information System (INIS)

Talbert, J.H.

1980-01-01

Regardless of the fire prevention measures which are taken, plant experience indicates that fires will occur in a nuclear power plant. When a fire occurs, the plant staff must handle the fire emergency. Pre-fire planning is a method of developing detailed fire attack plans and salvage operations to protect equipment from damage due to fire and fire fighting operations. This paper describes the purpose and use of a pre-fire plan to achieve these goals in nuclear power plants

Pioneer plant species contributing to phytoestabilization of contaminated soils in mine areas

Science.gov (United States)

João Batista, Maria; Gonzalez-Fernandez, Oscar; Abreu, Maria Manuela; Carvalho, Luisa; Queralt, Ignasi

2013-04-01

Young and mature leaves from several plant species of the genus Cistus L. (C. crispus, C. ladanifer, C. monspeliensis, C. salviifolius), Erica australis L., and Lavandula sampaioana (Rozeira) Rivas Mart., T.E. Díaz& Fern. Gonz., as well as soils where plants grew, were sampled in various areas of São Domingos abandoned mine. The São Domingos mine, dating from pre-Roman times, is 60 km SE of Beja, Southeast Portugal. This mine belongs to the world class metallogenetic province of the Iberian Pyrite Belt. Sampling occurred throughout spring and winter to better understand plant behaviour and natural attenuation of contaminated soils. Multiple Correspondence Analysis (MCA) was used to synthesize the information and group characteristics that could justify different chemical concentrations. Soils are extremely acid (pH between 3.4 and 5.2) and present a wide range of Corganic concentrations (10.2-109 g/kg). Total nitrogen and extractable phosphorus concentrations are low to very low, but extractable potassium show medium to high concentrations. Chemical elements concentrations, analysed for total fraction, were great in soils, especially arsenic and lead that can attain 7.6 g/kg and 17.2 g/kg, respectively. However, only a small percentage (in general plants showed different behaviour on the trace-elements uptake and translocation. Winter and spring variations in most chemical elements concentrations in the plants leaves are not significantly different, except for arsenic, probably because plants were not exposed to important dry conditions during the sampling seasons. Nevertheless, MCA of the individuals makes a clear distinction between winter and spring leaves. Generally, mature leaves have higher concentrations of arsenic, copper, iron, lead, manganese and zinc than younger ones. However, in this study, sulfur concentrations show an opposite behaviour. Soil total and available fraction concentrations of the chemical elements have similar behaviour between sites

Plant-uptake of uranium: Hydroponic and soil system studies

Science.gov (United States)

Ramaswami, A.; Carr, P.; Burkhardt, M.

2001-01-01

Limited information is available on screening and selection of terrestrial plants for uptake and translocation of uranium from soil. This article evaluates the removal of uranium from water and soil by selected plants, comparing plant performance in hydroponic systems with that in two soil systems (a sandy-loam soil and an organic-rich soil). Plants selected for this study were Sunflower (Helianthus giganteus), Spring Vetch (Vicia sativa), Hairy Vetch (Vicia villosa), Juniper (Juniperus monosperma), Indian Mustard (Brassica juncea), and Bush Bean (Phaseolus nanus). Plant performance was evaluated both in terms of the percent uranium extracted from the three systems, as well as the biological absorption coefficient (BAC) that normalized uranium uptake to plant biomass. Study results indicate that uranium extraction efficiency decreased sharply across hydroponic, sandy and organic soil systems, indicating that soil organic matter sequestered uranium, rendering it largely unavailable for plant uptake. These results indicate that site-specific soils must be used to screen plants for uranium extraction capability; plant behavior in hydroponic systems does not correlate well with that in soil systems. One plant species, Juniper, exhibited consistent uranium extraction efficiencies and BACs in both sandy and organic soils, suggesting unique uranium extraction capabilities.

Experimental investigation of gasoline fumigation in a single cylinder direct injection (DI) diesel engine

International Nuclear Information System (INIS)

Sahin, Z.; Durgun, O.; Bayram, C.

2008-01-01

In the presented study, the effects of gasoline fumigation have been investigated experimentally in a single cylinder direct injection (DI) diesel engine. Gasoline has been introduced into the inlet air flow using an elementary carburetor and no other modification on the engine has been done. The effects of 2%, 4%, 6%, 8% and 10% (by vol.) gasoline fumigation have been investigated experimentally at the speeds of (900-1600) (rpm) and at the selected compression ratios of (18-23). From the experimental results it is determined that by application of gasoline fumigation effective power output increases at the levels of 4-9%, effective efficiency increases by approximately 1.5-4% and specific fuel consumption decreases by approximately 1.5-4%. It is also determined that 4-6% fumigation ratio range is the most favorable percentage interval of gasoline at the selected compression ratios for this engine. Because cost of gasoline is higher than diesel fuel in Turkey as well as in many of the other countries and the decrease ratio of specific fuel consumption is low, gasoline fumigation is not economic for this engine. In the presented study, heat balance tests have also been performed for 18 and 21 compression ratios. The heat balance has been investigated experimentally in respect of effective power, heat rejected to the cooling water, heat lost through exhaust, and other losses (unaccounted-for losses). Heat lost through exhaust decreases until 4-6% gasoline fumigation ratios and after these fumigation ratios it starts to increase because of increasing exhaust gas temperature. Heat rejected to the cooling water decreases at low fumigation ratios, but at high fumigation ratios it increases. Other losses generally exhibit an increasing tendency at low fumigation ratios

Bioelectric potentials in the soil-plant system

Science.gov (United States)

Pozdnyakov, A. I.

2013-07-01

A detailed study of the electric potentials in the soil-plant system was performed. It was found that the electric potential depends on the plant species and the soil properties. A theoretical interpretation of the obtained data was given. All the plants, independently from their species and their state, always had a negative electric potential relative to the soil. The electric potential of the herbaceous plants largely depended on the leaf area. In some plants, such as burdock ( Arctium lappa) and hogweed ( Heracleum sosnowskyi), the absolute values of the negative electric potential exceeded 100 mV. The electric potential was clearly differentiated by the plant organs: in the flowers, it was lower than in the leaves; in the leaves, it was usually lower than in the leaf rosettes and stems. The electric potentials displayed seasonal dynamics. As a rule, the higher the soil water content, the lower the electric potential of the plants. However, an inverse relationship was observed for dandelions ( Taraxacum officinale). It can be supposed that the electric potential between the soil and the plant characterizes the vital energy of the plant.

Soil-plant transfer factors in forest ecosystems

International Nuclear Information System (INIS)

Strebl, F.; Gerzabek, M.H.

1995-04-01

Within scope of an extended study about 137 Cs behaviour in forest ecosystems several parameters were found to influence soil-plant transfer factors. TF-values of different plant species cover a range of two magnitudes. This is partly due to variations in rooting depth of plants and specific physiological adaptations of nutrient supply. Perrenial plants like trees (Picea abies) and dwarf shrubs (Vaccinium myrtillus) showed a distinct age - dependency of 137 Cs - transfer factors. In young plant parts caesium concentration is higher than in old, more signified twigs. A correlation analysis of physico-chemical soil parameters and TF-values to forest vegetation showed, that soil organic matter, especially the degree of humification and the ratio between extractable fulvic to humic acids are important influencing factors of 137 Cs transfer from forest soils to plants. (author)

Enrichment planting without soil treatment

Energy Technology Data Exchange (ETDEWEB)

Hagner, Mats

1998-12-31

Where enrichment planting had been carried out with either of the two species Picea abies and Pinus contorta, the survival of the planted seedlings was at least as good as after planting in a normal clear cut area treated with soil scarification. This was in spite of the fact that the seedlings were placed shallow in the humus layer without any soil treatment. However, they were sheltered from insects by treatment before planting. Where enrichment planting was carried out with Pinus sylvestris the survival in dense forest was poor, but in open forest the survival was good. The growth of planted seedlings was enhanced by traditional clearing and soil treatment. However, this was for Pinus sylvestris not enough to compensate for the loss of time, 1-2 years, caused by arrangement of soil scarification. The growth of seedlings planted under crown cover was directly related to basal area of retained trees. However, the variation in height growth among individual seedlings was very big, which meant that some seedlings grow well also under a fairly dense forest cover. The pioneer species Pinus sylvestris reacted more strongly to basal area of retained trees than did the shade tolerant species Picea abies. Enrichment planting seems to be a necessary tool for preserving volume productivity, at places where fairly intensive harvest of mature trees has been carried out in stands of ordinary forest type in central Sweden. If double seedlings, with one Picea abies and one Pinus sylvestris, are used, the probability for long term establishment is enhanced 13 refs, 20 figs, 4 tabs

Seasonal changes in and relationship between soil microbial and ...

African Journals Online (AJOL)

In April, June and October 2010, soil samples were taken from an estuary of the Yellow River. We measured microbiomass (using the soil chloroform fumigation extraction method), substrate induced respiration (SIR), and phospholipid fatty acids (PLFA). Microbe community structure and soil nematode species richness ...

Negative plant-soil feedbacks increase with plant abundance, and are unchanged by competition.

Science.gov (United States)

Maron, John L; Laney Smith, Alyssa; Ortega, Yvette K; Pearson, Dean E; Callaway, Ragan M

2016-08-01

Plant-soil feedbacks and interspecific competition are ubiquitous interactions that strongly influence the performance of plants. Yet few studies have examined whether the strength of these interactions corresponds with the abundance of plant species in the field, or whether feedbacks and competition interact in ways that either ameliorate or exacerbate their effects in isolation. We sampled soil from two intermountain grassland communities where we also measured the relative abundance of plant species. In greenhouse experiments, we quantified the direction and magnitude of plant-soil feedbacks for 10 target species that spanned a range of abundances in the field. In soil from both sites, plant-soil feedbacks were mostly negative, with more abundant species suffering greater negative feedbacks than rare species. In contrast, the average response to competition for each species was unrelated with its abundance in the field. We also determined how competitive response varied among our target species when plants competed in live vs. sterile soil. Interspecific competition reduced plant size, but the strength of this negative effect was unchanged by plant-soil feedbacks. Finally, when plants competed interspecifically, we asked how conspecific-trained, heterospecific-trained, and sterile soil influenced the competitive responses of our target species and how this varied depending on whether target species were abundant or rare in the field. Here, we found that both abundant and rare species were not as harmed by competition when they grew in heterospecific-trained soil compared to when they grew in conspecific-cultured soil. Abundant species were also not as harmed by competition when growing in sterile vs. conspecific-trained soil, but this was not the case for rare species. Our results suggest that abundant plants accrue species-specific soil pathogens to a greater extent than rare species. Thus, negative feedbacks may be critical for preventing abundant species from

Study of the fumigation effect on pollutants over Inshas area

International Nuclear Information System (INIS)

Tawfik, F.S.; Ramadan, Abou Bakr. A.; Abdel El-Aal, M.M.

2004-01-01

This work aims to investigate the effect of morning fumigation event on the ground level pollutants concentration at inshas area. Monitoring stations for mesuring the hourly continues concetration of some pollutants such sulphur dioxide, carbon monoxide, and ozone were placed near the hot lab in nuclear research center for one complete year, At the same time the hourly averages meteorological parameters were measured continuously at different levels. A fortran computer program was developed to determine the relative relative concentration Assuming accident case in two cases, nonfumigation and morning fumigation. The processing and interpretation of the meteorological data and pollutants concentration revealed that these high pollution events occur almost on daily bassis, usually several hours between sunrise and before afternoon. The maximum fumigation peaks occur earlier in the summer than other seasons owing to theearlier sunrise in addition, ozone concentrations appear to reach their maximum a few hours after intense fumigation events. Maximum hourly concentrations of sulphur dioxide, carbon monoxide and ozone don't exceed threshold values that are considered to be phytotoxic. As sunset pollutant concentration is decrease due to lofting condition

Plant-soil feedbacks: role of plant functional group and plant traits

NARCIS (Netherlands)

Cortois, R.; Schröder-Georgi, T.; Weigelt, A.; van der Putten, W.H.; De Deyn, G.B.

2016-01-01

Plant-soil feedback (PSF), plant trait and functional group concepts advanced our understanding of plant community dynamics, but how they are interlinked is poorly known. To test how plant functional groups (FGs: graminoids, small herbs, tall herbs, legumes) and plant traits relate to PSF, we grew

Fumigant and repellent properties of sesquiterpene-rich essential oil from Teucrium polium subsp. capitatum (L.)

Institute of Scientific and Technical Information of China (English)

Abbas Khani; Monireh Heydarian

2014-01-01

Objective:To test fumigant and repellent properties of sesquiterpene-rich essential oil from Teucrium polium subsp.capitatum(L.).Methods:The fumigant toxicity test was performed at(27±1)℃,(65±5)% relative humidity, and under darkness condition and24 h exposure time.The chemical composition of the isolated oils was examined by gas chromatography-mass spectrometry.Results:The major compounds wereα-cadinol(46.2%), caryophyllene oxide(25.9%), α muurolol epi(8.1%), cadalene(3.7%) and longiverbenone(2.9%).In all cases, considerable differences in mortality of insect to essential oil vapor were observed in different concentrations and exposure times.Callosobruchus maculatus(C. maculates)(LC50=148.9 μL/L air) was more susceptible to the tested plant product thanTeucrium castaneum(T. castaneum) (LC50=360.2 μL/L air) based onLC50 values.In the present investigation, the concentration of3 μL /mL acetone showed60% and52% repellency againstT. casteneumandC. maculatus adults, respectively.Conclusions:The results suggests that sesquiterpene-rich essential oils from the tested plant could be used as a potential control agent for stored-product insects.

Physiological responses of lichens to factorial fumigations with nitric acid and ozone

International Nuclear Information System (INIS)

Riddell, J.; Padgett, P.E.; Nash, T.H.

2012-01-01

This paper addresses the effects of gaseous nitric acid (HNO 3 ) and ozone (O 3 ), two important air pollutants, on six lichen species with different morphological, ecological, and biological characteristics. The treatment chambers were set up in a factorial design consisting of control chambers, chambers fumigated with HNO 3 , with O 3 , and with HNO 3 and O 3 , together. Each species showed a different sensitivity to the fumigations, reflecting the physiological variation among species. Our results clearly indicate that HNO 3 is a strong phytotoxin to many lichens, and that O 3 alone has little effect on the measured parameters. The combined fumigation effects of HNO 3 and O 3 were not significantly different from HNO 3 alone. - Highlights: ► We fumigated 6 lichen species with factorial combinations of nitric acid (HNO 3 ) and ozone (O 3 ). ► Some species were highly sensitive to HNO 3 while others were tolerant. ► No species responded significantly to O 3 . ► The combined fumigation effects of HNO 3 and O 3 were not significantly different from HNO 3 alone. ► HNO 3 may play an important role in lichen community composition in areas with high HNO 3 pollution. - Nitric acid can be highly toxic to lichens through several physiological mechanisms. Ozone is relatively non-toxic to fumigated lichens.

Plant volatile aldehydes as natural insecticides against stored-product beetles.

Science.gov (United States)

Hubert, Jan; Münzbergová, Zuzana; Santino, Angelo

2008-01-01

Infestation by stored-product pests causes serious losses in food and feed commodities. Among possible strategies against these pests, which aim to reduce the use of synthetic insecticides, including fumigants, natural insecticides produced by plants represent one of the most promising approaches for their ecochemical control. Three six-carbon and nine-carbon aldehydes, natural plant volatiles produced by the plant lipoxygenase pathway, were tested for their insecticidal activity against five species of stored-product beetles in feeding, fumigation and combined bioassays. The compounds (2E,6Z)-nonadienal, (2E)-nonenal and (2E)-hexenal were incorporated into feeding discs in feeding bioassays or evaporated from filter paper in closed glass chambers in fumigation tests. Beetle sensitivity to aldehydes differed according to the different treatments. The highest activity was obtained by (2E)-hexenal in fumigation tests, with the LC(50) ranging from 4 to 26 mg L(-1), while (2E, 6Z)-nonadienal was the most effective in feeding tests, giving LD(50)s ranging from 0.44 to 2.76 mg g(-1) when applied to feeding discs. Fumigation tests in the presence of wheat grains confirmed that (2E)-hexenal was the most effective compound, with a calculated LC(99) ranging from 33 to 166 mg L(-1). The results of both feeding and fumigation tests indicated that natural plant aldehydes are potential candidates to control stored-product beetles.

Community-level plant-soil feedbacks explain landscape distribution of native and non-native plants.

Science.gov (United States)

Kulmatiski, Andrew

2018-02-01

Plant-soil feedbacks (PSFs) have gained attention for their potential role in explaining plant growth and invasion. While promising, most PSF research has measured plant monoculture growth on different soils in short-term, greenhouse experiments. Here, five soil types were conditioned by growing one native species, three non-native species, or a mixed plant community in different plots in a common-garden experiment. After 4 years, plants were removed and one native and one non-native plant community were planted into replicate plots of each soil type. After three additional years, the percentage cover of each of the three target species in each community was measured. These data were used to parameterize a plant community growth model. Model predictions were compared to native and non-native abundance on the landscape. Native community cover was lowest on soil conditioned by the dominant non-native, Centaurea diffusa , and non-native community cover was lowest on soil cultivated by the dominant native, Pseudoroegneria spicata . Consistent with plant growth on the landscape, the plant growth model predicted that the positive PSFs observed in the common-garden experiment would result in two distinct communities on the landscape: a native plant community on native soils and a non-native plant community on non-native soils. In contrast, when PSF effects were removed, the model predicted that non-native plants would dominate all soils, which was not consistent with plant growth on the landscape. Results provide an example where PSF effects were large enough to change the rank-order abundance of native and non-native plant communities and to explain plant distributions on the landscape. The positive PSFs that contributed to this effect reflected the ability of the two dominant plant species to suppress each other's growth. Results suggest that plant dominance, at least in this system, reflects the ability of a species to suppress the growth of dominant competitors

Soil Management Plan for the Y-12 Plant

International Nuclear Information System (INIS)

1993-01-01

Construction activities at the US Department of Energy (DOE) Y-12 Plant have often required the excavation or other management of soil within the facility. Because some of this soil may be contaminated, Martin Marietta Energy Systems, Inc. (Energy Systems) adopted specific policies to ensure the proper management of contaminated or potentially contaminated soil at the plant. Five types of contaminated or potentially contaminated soil are likely to be present at the Y-12 Plant: Soil that is within the boundaries of a Comprehensive Response, Compensation, and Liability Act (CERCLA) Area of Contamination (AOC) or Operable Unit (OU); Soil that contains listed hazardous wastes; Soil that is within the boundaries of a RCRA Solid Waste Management Unit (SWMU); Soil that contains polychlorinated biphenyls (PCBS); Soil that contains low-level radioactive materials. The regulatory requirements associated with the five types of contaminated soil listed above are complex and will vary according to site conditions. This Soil Management Plan provides a standardized method for managers to determine the options available for selecting soil management scenarios associated with construction activities at the Y-12 Plant

Fumigant toxicity of plant essential oils against Camptomyia corticalis (Diptera: Cecidomyiidae).

Science.gov (United States)

Kim, Jun-Ran; Haribalan, Perumalsamy; Son, Bong-Ki; Ahn, Young-Joon

2012-08-01

The toxicity of 98 plant essential oils against third instars of cecidomyiid gall midge Camptomyia corticalis (Loew) (Diptera: Cecidomyiidae) was examined using a vapor-phase mortality bioassay. Results were compared with that of a conventional insecticide dichlorvos. Based on 24-h LC50 values, all essential oils were less toxic than dichlorvos (LC50, 0.027 mg/cm3). The LC50 of caraway (Carum carvi L.) seed, armoise (Artemisia vulgaris L.), clary sage (Salvia sclarea L.), oregano (Origanum vulgare L.), lemongrass [Cymbopogon citratus (DC.) Stapf], niaouli (Melaleuca viridiflora Gaertner), spearmint (Mentha spicata L.), cassia especial (Cinnamomum cassia Nees ex Blume), Dalmatian sage (Salvia offcinalis L.), red thyme (Thymus vulgaris L.), bay [Pimenta racemosa (P. Mill.) J.W. Moore], garlic (Allium sativum L.), and pennyroyal (Mentha pulegium L.) oils is between 0.55 and 0.60 mg/cm3. The LC50 of cassia (C. cassia, pure and redistilled), white thyme (T. vulgaris), star anise (Illicium verum Hook.f.), peppermint (Mentha X piperita L.), wintergreen (Gaultheria procumbens L.), cinnamon (Cinnamomum zeylanicum Blume) bark, sweet marjoram (Origanum majorana L.), Roman chamomile [Chamaemelum nobile (L.) All.], eucalyptus (Eucalyptus globulus Labill.), rosemary (Rosmarinus officinalis L.),Virginian cedarwood (Juniperus virginiana L.), pimento berry [Pimenta dioica (L.) Merr.], summer savory (Satureja hortensis L.), lavender (Lavandula angustifolia Mill.), and coriander (Coriandrum sativum L.) oils is between 0.61 and 0.99 mg/cm3. All other essential oils tested exhibited low toxicity to the cecidomyiid larvae (LC50, >0.99 mg/cm3). Global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment justify further studies on the active essential oils as potential larvicides for the control of C. corticalis populations as fumigants with contact action.

Radioactive zinc in soil-plant relationship studies

International Nuclear Information System (INIS)

Karimian, N.

1986-01-01

Zinc is one of the elements whose essentiality for plant growth and development has been proved beyond any doubt. Plant life and consequently the crop yield is impossible without zinc. The results of chemical, greenhouse, and field experiments on soils of Shiraz show that their level of available zinc for some crops is inadequate, despite the fact that the total amount of zinc in these soils may be relatively high. Obtaining the maximum yield, therefore, requires that either supplemental zinc be applied as chemical fertilizers or make the endogenous zinc more available to plants through some management practices. One of the isotopes of zinc, i.e. 65 Zn, is radioactive and has a detectable radiation which makes it suitable for tracer studies of zinc in soil, water, plant and animal. These studies help in understanding the soil plant relationships of zinc which in turn help to determine the optimum conditions of obtaining maximum yield. This paper presents and analyzes the results of some selected experiments to show different techniques of using radioactive zinc in understanding the behavior of zinc in soil and plant. Suggestions are also made of using this radioisotope in understanding the reactions of zinc in soils of Iran

Radioiodine uptake by plants from soils

International Nuclear Information System (INIS)

Sabova, T.

1976-01-01

The uptake and accumulation of radioiodine by wheat, maize and peas from various types of soil have been studied. The uptake depends on the type of soil, on its content of organic matter and on the amount of fertilizer. Radioiodine is mainly accumulated in the roots. Accumulation in above-ground plant parts decreases in the following order: wheat, maize, peas. Uptake was highest from humus and clay soils and lowest from black and meadow soils. Application of chloride fertilizer or carrier iodine lead to an increase of radioiodine uptake in the whole plant. (author)

[Progress of sulfur fumigation and modern processing technology of Chinese traditional medicines].

Science.gov (United States)

Lu, Tu-Lin; Shan, Xin; Li, Lin; Mao, Chun-Qin; Ji, De; Yin, Fang-Zhou; Lang, Yong-Ying

2014-08-01

Infestation, moldy and other phenomenon in the processing and storage of Chinese herbal medicines is a problem that faced in the production of Chinese traditional medicine. The low productivity of traditional processing methods can not guarantee the quality of Chinese herbal medicines. Sulfur fumigation is the first choice of grassroots to process the Chinese herbal medicine with its low cost and easy operation. Sulfur fumigation can solve some problems in the processing and storage of Chinese herbal medicines, but modern pharmacological studies show that long-term use of Chinese traditional medicine which is fumigated by sulfur can cause some serious harm to human liver, kidney and other organs. This paper conducts a review about the application history of sulfur fumigation, its influence to the quality of Chinese herbal medicines as well as domestic and foreign limits to sulfur quantity, and a brief introduction of the status of modern processing technologies in the processing of food and some Chinese herbal medicines, the problems ex- isting in the Chinese herbal medicines processing, which can provide a reference basis for the further research, development and application of investigating alternative technologies of sulfur fumigation.

Plant selection and soil legacy enhance long-term biodiversity effects.

Science.gov (United States)

Zuppinger-Dingley, Debra; Flynn, Dan F B; De Deyn, Gerlinde B; Petermann, Jana S; Schmid, Bernhard

2016-04-01

Plant-plant and plant-soil interactions can help maintain plant diversity and ecosystem functions. Changes in these interactions may underlie experimentally observed increases in biodiversity effects over time via the selection of genotypes adapted to low or high plant diversity. Little is known, however, about such community-history effects and particularly the role of plant-soil interactions in this process. Soil-legacy effects may occur if co-evolved interactions with soil communities either positively or negatively modify plant biodiversity effects. We tested how plant selection and soil legacy influence biodiversity effects on productivity, and whether such effects increase the resistance of the communities to invasion by weeds. We used two plant selection treatments: parental plants growing in monoculture or in mixture over 8 yr in a grassland biodiversity experiment in the field, which we term monoculture types and mixture types. The two soil-legacy treatments used in this study were neutral soil inoculated with live or sterilized soil inocula collected from the same plots in the biodiversity experiment. For each of the four factorial combinations, seedlings of eight species were grown in monocultures or four-species mixtures in pots in an experimental garden over 15 weeks. Soil legacy (live inoculum) strongly increased biodiversity complementarity effects for communities of mixture types, and to a significantly weaker extent for communities of monoculture types. This may be attributed to negative plant-soil feedbacks suffered by mixture types in monocultures, whereas monoculture types had positive plant-soil feedbacks, in both monocultures and mixtures. Monocultures of mixture types were most strongly invaded by weeds, presumably due to increased pathogen susceptibility, reduced biomass, and altered plant-soil interactions of mixture types. These results show that biodiversity effects in experimental grassland communities can be modified by the evolution of

Formative pre-Hispanic agricultural soils in northwest Argentina

Science.gov (United States)

Sampietro Vattuone, María Marta; Roldán, Jimena; Neder, Liliana; Maldonado, Mario Gabriel; Vattuone, Marta Amelia

2011-01-01

Our study area is from an early agricultural archaeological site named "El Tolar" (1st to 9th century AD), located in Tafí Valley (Tucumán, northwest Argentina). The objective was to identify geochemical signatures generated by the sustained agrarian use of soils. Chemical and pedological studies were made in different archaeological contexts. Physical and chemical features, such as bulk density, pH, organic and inorganic phosphorus, and available copper, manganese and iron, were taken into account. The results suggested that a buried paleosol identified was contemporary with the occupation of the site. It also showed characteristics clearly related to pre-Hispanic agrarian production. The concentrations of organic phosphorus and iron in agricultural soils probably reflect the use of fertilizers. The application of geoscience techniques allowed us to obtain important information on their behaviour and socio-economic development. This paper constitutes the first pedogeochemical approach to the study of Argentinean pre-Hispanic agricultural soils.

Plant uptake of radiocaesium from artificially contaminated soil monoliths covering major European soil types

International Nuclear Information System (INIS)

Waegeneers, Nadia; Sauras-Yera, Teresa; Thiry, Yves; Vallejo, V. Ramon; Smolders, Erik; Madoz-Escande, Chantal; Brechignac, Francois

2009-01-01

Uptake of 137 Cs was measured in different agricultural plant species (beans, lettuce, barley and ryegrass) grown in 5 undisturbed soil monoliths covering major European soil types. The first cultivation was made three years after soil contamination and plants were grown during 3 successive years. The plant-soil 137 Cs transfer factors varied maximally 12-fold among soils and 35-fold among species when grown on the same soil. Single correlations between transfer factors and soil properties were found, but they varied widely with plant type and can hardly be used as a predictive tool because of the few soils used. The variation of 137 Cs concentrations in plants among soils was related to differences in soil solution 137 Cs and K concentrations, consistent with previous observations in hydroponics and pot trials. Absolute values of transfer factors could not be predicted based on a model validated for pot trials. The 137 Cs activity concentration in soil solution decreased significantly (11- to 250-fold) for most soils in the 1997-1999 period and is partly explained by decreasing K in soil solution. Transfer factors of lettuce showed both increasing and decreasing trends between 2 consecutive years depending on soil type. The trends could be explained by the variation in 137 Cs and K concentrations in soil solution. It is concluded that differences in 137 Cs transfer factors among soils and trends in transfer factors as a function of time can be explained from soil solution composition, as shown previously for pot trials, although absolute values of transfer factors could not be predicted.

Methylation of food commodities during fumigation with methyl bromide

International Nuclear Information System (INIS)

Starratt, A.N.; Bond, E.J.

1990-01-01

Sites of methylation in several commodities (wheat, oatmeal, peanuts, almonds, apples, oranges, maize, alfalfa and potatoes) during fumigation with 14 C-methyl bromide were studied. Differences were observed in levels of the major volatiles: methanol, dimethyl sulphide and methyl mercaptan, products of O- and S-methylation, resulting from treatment of the fumigated materials with 1N sodium hydroxide. In studies of maize and wheat, histidine was the amino acid which underwent the highest level of N-methylation. (author). 24 refs, 3 tabs

Effects of plant species identity, diversity and soil fertility on biodegradation of phenanthrene in soil

International Nuclear Information System (INIS)

Oyelami, Ayodeji O.; Okere, Uchechukwu V.; Orwin, Kate H.; De Deyn, Gerlinde B.; Jones, Kevin C.; Semple, Kirk T.

2013-01-01

The work presented in this paper investigated the effects of plant species composition, species diversity and soil fertility on biodegradation of 14 C-phenanthrene in soil. The two soils used were of contrasting fertility, taken from long term unfertilised and fertilised grassland, showing differences in total nitrogen content (%N). Plant communities consisted of six different plant species: two grasses, two forbs, and two legume species, and ranged in species richness from 1 to 6. The degradation of 14 C-phenanthrene was evaluated by measuring indigenous catabolic activity following the addition of the contaminant to soil using respirometry. Soil fertility was a driving factor in all aspects of 14 C-phenanthrene degradation; lag phase, maximum rates and total extents of 14 C-phenanthrene mineralisation were higher in improved soils compared to unimproved soils. Plant identity had a significant effect on the lag phase and extents of mineralisation. Soil fertility was the major influence also on abundance of microbial communities. - Highlights: ► Two grassland soils of contrasting fertility showing differences in total nitrogen content (%N) were used in this study. ► The effects of individual plant species and plant diversity on mineralisation of 14 C-phenanthrene in soil were investigated. ► Soil fertility was the major influence on mineralisation of 14 C-phenanthrene, and abundance of microbial community. ► The presence of a specific plant plays a role in the extent of mineralisation of phenanthrene in soil. - Soil management was the main driver for the mineralisation of 14 C-phenanthrene in soil.

Effect of fumigation methanol and ethanol on the gaseous and particulate emissions of a direct-injection diesel engine

Science.gov (United States)

Zhang, Z. H.; Tsang, K. S.; Cheung, C. S.; Chan, T. L.; Yao, C. D.

2011-02-01

Experiments were conducted on a four-cylinder direct-injection diesel engine with methanol or ethanol injected into the air intake of each cylinder, to compare their effect on the engine performance, gaseous emissions and particulate emissions of the engine under five engine loads at the maximum torque speed of 1800 rev/min. The methanol or ethanol was injected to top up 10% and 20% of the engine loads under different engine operating conditions. The experimental results show that both fumigation methanol and fumigation ethanol decrease the brake thermal efficiency (BTE) at low engine load but improves it at high engine load; however the fumigation methanol has higher influence on the BTE. Compared with Euro V diesel fuel, fumigation methanol or ethanol could lead to reduction of both NOx and particulate mass and number emissions of the diesel engine, with fumigation methanol being more effective than fumigation ethanol in particulate reduction. The NOx and particulate reduction is more effective with increasing level of fumigation. However, in general, fumigation fuels increase the HC, CO and NO 2 emissions, with fumigation methanol leading to higher increase of these pollutants. Compared with ethanol, the fumigation methanol has stronger influence on the in-cylinder gas temperature, the air/fuel ratio, the combustion processes and hence the emissions of the engine.

Cesium and potassium uptake by plants from soils

International Nuclear Information System (INIS)

Schaller, G.; Leising, C.; Krestel, R.; Wirth, E.

1990-11-01

The aim of the investigation was the reliable estimation of the Cs-137 root uptake by agricultural crops using the 'observed ratio model' (OR model) for the determination of transfer factors: Cs (plant)/K (plant) = OR x Cs (soil)/K (soil). For model validation representative soil (arable land, grass land, organic substrates from forests and peat) and plant samples from Bavaria were taken. These 4 parameters varied within a sufficiently wide range. In addition some samples from forest sites were taken. Soil and plant samples were taken at the same locations within 1 m 2 . (orig./HP) [de

Plant diversity surpasses plant functional groups and plant productivity as driver of soil biota in the long term.

Directory of Open Access Journals (Sweden)

Nico Eisenhauer

2011-01-01

Full Text Available One of the most significant consequences of contemporary global change is the rapid decline of biodiversity in many ecosystems. Knowledge of the consequences of biodiversity loss in terrestrial ecosystems is largely restricted to single ecosystem functions. Impacts of key plant functional groups on soil biota are considered to be more important than those of plant diversity; however, current knowledge mainly relies on short-term experiments.We studied changes in the impacts of plant diversity and presence of key functional groups on soil biota by investigating the performance of soil microorganisms and soil fauna two, four and six years after the establishment of model grasslands. The results indicate that temporal changes of plant community effects depend on the trophic affiliation of soil animals: plant diversity effects on decomposers only occurred after six years, changed little in herbivores, but occurred in predators after two years. The results suggest that plant diversity, in terms of species and functional group richness, is the most important plant community property affecting soil biota, exceeding the relevance of plant above- and belowground productivity and the presence of key plant functional groups, i.e. grasses and legumes, with the relevance of the latter decreasing in time.Plant diversity effects on biota are not only due to the presence of key plant functional groups or plant productivity highlighting the importance of diverse and high-quality plant derived resources, and supporting the validity of the singular hypothesis for soil biota. Our results demonstrate that in the long term plant diversity essentially drives the performance of soil biota questioning the paradigm that belowground communities are not affected by plant diversity and reinforcing the importance of biodiversity for ecosystem functioning.

The fate of arsenic in soil-plant systems.

Science.gov (United States)

Moreno-Jiménez, Eduardo; Esteban, Elvira; Peñalosa, Jesús M

2012-01-01

Arsenic is a natural trace element found in the environment. In some cases and places, human activities have increased the soil concentration of As to levels that exceed hazard thresholds. Amongst the main contributing sources of As contamination of soil and water are the following: geologic origin, pyriticmining, agriculture, and coal burning. Arsenic speciation in soils occurs and is relatively complex. Soils contain both organic and inorganic arsenic species. Inorganic As species include arsenite and arsenate, which are the most abundant forms found in the environment. The majority of As in aerated soils exists as H₂AsO₄- (acid soils) or HAsO₄²- (neutral species and basic). However, HA₃sO₃ is the predomiant anaerobic soils, where arsenic availability is higher and As(III) is more weakly retained in the soil matrix than is As(V). The availability of As in soils is usually driven by multiple factors. Among these factors is the presence of Fe-oxides and/or phosphorus, (co)precipitation in salts, pH, organic matter, clay content, rainfall amount, etc. The available and most labile As fraction can potentially be taken up by plant roots, although the concentration of this fraction is usually low. Arsenic has no known biological function in plants. Once inside root cells, As(V) is quickly reduced to As(III), and, in many plant species, becomes complexed. Phosphorus nutrition influences As(V) uptake and toxicity in plants, whilst silicon has similar influences on As(III). Plants cope with As contamination in their tissues by possessing detoxification mechanisms. Such mechanisms include complexation and compartmentalization. However, once these mechanisms are saturated, symptoms of phytotoxicity appear. Phytotoxic effects commonly observed from As exposure includes growth inhibition, chlorophyll degradation, nutrient depletion and oxidative stress. Plants vary in their ability to accumulate and tolerate As (from tolerant hyperaccumulators to sensitive

Understanding resistant effect of mosquito on fumigation strategy in dengue control program

Science.gov (United States)

Aldila, D.; Situngkir, N.; Nareswari, K.

2018-01-01

A mathematical model of dengue disease transmission will be introduced in this talk with involving fumigation intervention into mosquito population. Worsening effect of uncontrolled fumigation in the form of resistance of mosquito to fumigation chemicals will also be included into the model to capture the reality in the field. Deterministic approach in a 9 dimensional of ordinary differential equation will be used. Analytical result about the existence and local stability of the equilibrium points followed with the basic reproduction number will be discussed. Some numerical result will be performed for some scenario to give a better interpretation for the analytical results.

29 CFR 1917.25 - Fumigants, pesticides, insecticides and hazardous preservatives (see also § 1917.2 Hazardous...

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Fumigants, pesticides, insecticides and hazardous..., DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Marine Terminal Operations § 1917.25 Fumigants, pesticides... fumigants, pesticides or hazardous preservatives have created a hazardous atmosphere. These signs shall note...

Plant uptake of radiocaesium from artificially contaminated soil monoliths covering major European soil types

Energy Technology Data Exchange (ETDEWEB)

Waegeneers, Nadia [Laboratory for Soil and Water Management, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium)], E-mail: nadia.waegeneers@agr.kuleuven.ac.be; Sauras-Yera, Teresa [Departament de Biologia Vegetal, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona (Spain); Thiry, Yves [SCK.CEN, Radioecology Laboratory, Boeretang 200, B-2400 Mol (Belgium); Vallejo, V. Ramon [Departament de Biologia Vegetal, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona (Spain); CEAM, Parque Tecnologico, Charles Darwin 14, 46980 Parterna (Spain); Smolders, Erik [Laboratory for Soil and Water Management, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium); Madoz-Escande, Chantal; Brechignac, Francois [SERLAB, ISPN, Department for Environmental Protection, CE-Cadarache Batiment 159, Saint-Paul-lez-Durance Cedex 13108 (France)

2009-06-15

Uptake of {sup 137}Cs was measured in different agricultural plant species (beans, lettuce, barley and ryegrass) grown in 5 undisturbed soil monoliths covering major European soil types. The first cultivation was made three years after soil contamination and plants were grown during 3 successive years. The plant-soil {sup 137}Cs transfer factors varied maximally 12-fold among soils and 35-fold among species when grown on the same soil. Single correlations between transfer factors and soil properties were found, but they varied widely with plant type and can hardly be used as a predictive tool because of the few soils used. The variation of {sup 137}Cs concentrations in plants among soils was related to differences in soil solution {sup 137}Cs and K concentrations, consistent with previous observations in hydroponics and pot trials. Absolute values of transfer factors could not be predicted based on a model validated for pot trials. The {sup 137}Cs activity concentration in soil solution decreased significantly (11- to 250-fold) for most soils in the 1997-1999 period and is partly explained by decreasing K in soil solution. Transfer factors of lettuce showed both increasing and decreasing trends between 2 consecutive years depending on soil type. The trends could be explained by the variation in {sup 137}Cs and K concentrations in soil solution. It is concluded that differences in {sup 137}Cs transfer factors among soils and trends in transfer factors as a function of time can be explained from soil solution composition, as shown previously for pot trials, although absolute values of transfer factors could not be predicted.

Effects of plant species identity, diversity and soil fertility on biodegradation of phenanthrene in soil

Energy Technology Data Exchange (ETDEWEB)

Oyelami, Ayodeji O; Okere, Uchechukwu V; Orwin, Kate H; De Deyn, Gerlinde B; Jones, Kevin C [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Semple, Kirk T., E-mail: k.semple@lancaster.ac.uk [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

2013-02-15

The work presented in this paper investigated the effects of plant species composition, species diversity and soil fertility on biodegradation of {sup 14}C-phenanthrene in soil. The two soils used were of contrasting fertility, taken from long term unfertilised and fertilised grassland, showing differences in total nitrogen content (%N). Plant communities consisted of six different plant species: two grasses, two forbs, and two legume species, and ranged in species richness from 1 to 6. The degradation of {sup 14}C-phenanthrene was evaluated by measuring indigenous catabolic activity following the addition of the contaminant to soil using respirometry. Soil fertility was a driving factor in all aspects of {sup 14}C-phenanthrene degradation; lag phase, maximum rates and total extents of {sup 14}C-phenanthrene mineralisation were higher in improved soils compared to unimproved soils. Plant identity had a significant effect on the lag phase and extents of mineralisation. Soil fertility was the major influence also on abundance of microbial communities. - Highlights: Black-Right-Pointing-Pointer Two grassland soils of contrasting fertility showing differences in total nitrogen content (%N) were used in this study. Black-Right-Pointing-Pointer The effects of individual plant species and plant diversity on mineralisation of {sup 14}C-phenanthrene in soil were investigated. Black-Right-Pointing-Pointer Soil fertility was the major influence on mineralisation of {sup 14}C-phenanthrene, and abundance of microbial community. Black-Right-Pointing-Pointer The presence of a specific plant plays a role in the extent of mineralisation of phenanthrene in soil. - Soil management was the main driver for the mineralisation of {sup 14}C-phenanthrene in soil.

Total and bioavailable arsenic concentration in arid soils and its uptake by native plants from the pre-Andean zones in Chile.

Science.gov (United States)

Díaz, O; Tapia, Y; Pastene, R; Montes, S; Núñez, N; Vélez, D; Montoro, R

2011-06-01

Arsenic is the most important contaminant of the environment in northern Chile. Soil samples and plant organs from three native plant species, Pluchea absinthioides, Atriplex atacamensis and Lupinus microcarpus, were collected from arid zones in order to determine the total and bioavailable arsenic concentrations in soils and to assess the bioconcentration factor (BCF) and transport index (Ti) of arsenic in the plants. Total arsenic concentrations in soils (pH 8.3-8.5) where A. atacamensis and P. absinthioides were collected, reached levels considered to be contaminated (54.3 ± 15.4 and 52.9 ± 9.9 mg kg⁻¹, respectively), and these values were approximately ten times higher than in soils (pH 7.6) where L. microcarpus was collected. Bioavailable arsenic ranged from 0.18 to 0.42% of total arsenic concentration. In the three plant species, arsenic concentration in leaves were significantly (p ≤ 0.05) higher than in roots. L. microcarpus showed the highest arsenic concentration in its leaves (9.7 ± 1.6 mg kg⁻¹) and higher values of BCF (1.8) and Ti (6.1), indicating that this species has a greater capacity to accumulate and translocate the metalloid to the leaf than do the other species.

Plant uptake of radiocesium from contaminated soils

International Nuclear Information System (INIS)

Pipiska, M.; Lesny, J.; Hornik, M.; Augustin, J.

2004-01-01

Phytoextraction field experiments were conducted on soil contaminated with radiocesium to determine the capacity of autochthonous grasses and weeds to accumulate 137 Cs. The aim of the study was to evaluate the potential of spontaneously growing vegetation as a tool for decontamination of non-agricultural contaminated land. As a test field, the closed monitored area of the radioactive wastewater treatment plant of the Nuclear Power Plant in Jaslovskie Bohunice, Slovakia was used. contamination was irregularly distributed from the level of background to spots with maximal activity up to 900 Bq/g soil. Sequential extraction analysis of soil samples showed the following extractability of radiocesium (as percent of total): water 2 = 0.3-1.1%; 1M CH 3 COONa = 0.3-0.9%; 0.04 M NH 4 Cl (in 25% CH 3 COOH) = 0.9-1.4% and 30% H 2 O 2 - 0.02 M HNO 3 = 4.5-9.0%.Specific radioactivity of the most efficiently bioaccumulating plant species did not exceed 4.0 BqKg -1 (dry weight biomass). These correspond to the soil-to-plant transfer factor (TF) values up to 44.4x10 -4 BqKg -1 crop, d.w.)/(BqKg -1 soil d.w). Aggregated transfer factor (T ag ) of the average sample of the whole crop harvested from defined area was 0.5x10 -5 (Bqkg -1 d.w. crop)/(Bqm -2 soil). It can be concluded that low mobility of radiocesium in analysed soil type, confirmed by sequential extraction analyses, is the main hindrance for practical application for autochthonous plants as a phytoremediation tool for aged contaminated area of non-cultivated sites. Plant cover can efficiently serve only as a soil surface-stabilising layer, mitigating the migration of radiocesium into the surrounding environment. (author)

Study of solution speciation, soil retention and soil-plant transfer of zirconium

International Nuclear Information System (INIS)

Ferrand, E.

2005-12-01

Within the framework of the risks prevention policy of Andra, the radioactive zirconium introduction ( 93 Zr and 95 Zr) into the environment could be carried out starting from the nuclear waste whose storage is envisaged in deep geological layers. Thus, the goal of this study was to evaluate the parameters and phenomena influencing speciation (various chemical forms) and the soil-plant transfer of zirconium. Experiments of adsorption/desorption of zirconium with different ligands likely to be present in soils (goethite and humic acid) and with two soils, with contrasted characteristics, close to the underground research laboratory of Andra (Meuse) were carried out. These results of adsorption were then confronted with those obtained by the MUSIC and NICA-DONNAN models carried out using the computer code ECOSAT. Zr presents a strong affinity for the two types of soils and the soils constituents. Specific interactions of internal sphere type with the goethite were highlighted using the model. Soil-solution partition coefficients, or K d , values increase with pH and contact time. Various types of edible plants, pea (Pisum sativum L.) and tomato (Lycopersicon esculentum L cv. St Pierre) were cultivated in hydroponic conditions and in soils spiked with various sources of Zirconium. The maximum zirconium contents are mainly measured in the roots of the plants. The soil-plant transfer factors measured during these experiments show a weak bioavailability of zirconium. An influence of speciation on Zr bioavailability is however highlighted. Some chemical forms, such as oxychloride or acetate, are more easily mobilized than others by the plant. (author)

Soil fertility and plant diversity enhance microbial performance in metal-polluted soils.

Science.gov (United States)

Stefanowicz, Anna M; Kapusta, Paweł; Szarek-Łukaszewska, Grażyna; Grodzińska, Krystyna; Niklińska, Maria; Vogt, Rolf D

2012-11-15

This study examined the effects of soil physicochemical properties (including heavy metal pollution) and vegetation parameters on soil basal respiration, microbial biomass, and the activity and functional richness of culturable soil bacteria and fungi. In a zinc and lead mining area (S Poland), 49 sites were selected to represent all common plant communities and comprise the area's diverse soil types. Numerous variables describing habitat properties were reduced by PCA to 7 independent factors, mainly representing subsoil type (metal-rich mining waste vs. sand), soil fertility (exchangeable Ca, Mg and K, total C and N, organic C), plant species richness, phosphorus content, water-soluble heavy metals (Zn, Cd and Pb), clay content and plant functional diversity (based on graminoids, legumes and non-leguminous forbs). Multiple regression analysis including these factors explained much of the variation in most microbial parameters; in the case of microbial respiration and biomass, it was 86% and 71%, respectively. The activity of soil microbes was positively affected mainly by soil fertility and, apparently, by the presence of mining waste in the subsoil. The mining waste contained vast amounts of trace metals (total Zn, Cd and Pb), but it promoted microbial performance due to its inherently high content of macronutrients (total Ca, Mg, K and C). Plant species richness had a relatively strong positive effect on all microbial parameters, except for the fungal component. In contrast, plant functional diversity was practically negligible in its effect on microbes. Other explanatory variables had only a minor positive effect (clay content) or no significant influence (phosphorus content) on microbial communities. The main conclusion from this study is that high nutrient availability and plant species richness positively affected the soil microbes and that this apparently counteracted the toxic effects of metal contamination. Copyright © 2012 Elsevier B.V. All rights

Soil Oxidation-Reduction in Wetlands and Its Impact on Plant Functioning

Science.gov (United States)

Pezeshki, S. R.; DeLaune, R. D.

2012-01-01

Soil flooding in wetlands is accompanied by changes in soil physical and chemical characteristics. These changes include the lowering of soil redox potential (Eh) leading to increasing demand for oxygen within the soil profile as well as production of soil phytotoxins that are by-products of soil reduction and thus, imposing potentially severe stress on plant roots. Various methods are utilized for quantifying plant responses to reducing soil conditions that include measurement of radial oxygen transport, plant enzymatic responses, and assessment of anatomical/morphological changes. However, the chemical properties and reducing nature of soil environment in which plant roots are grown, including oxygen demand, and other associated processes that occur in wetland soils, pose a challenge to evaluation and comparison of plant responses that are reported in the literature. This review emphasizes soil-plant interactions in wetlands, drawing attention to the importance of quantifying the intensity and capacity of soil reduction for proper evaluation of wetland plant responses, particularly at the process and whole-plant levels. Furthermore, while root oxygen-deficiency may partially account for plant stress responses, the importance of soil phytotoxins, produced as by-products of low soil Eh conditions, is discussed and the need for development of methods to allow differentiation of plant responses to reduced or anaerobic soil conditions vs. soil phytotoxins is emphasized. PMID:24832223

Suppression of soil nitrification by plants.

Science.gov (United States)

Subbarao, Guntur Venkata; Yoshihashi, Tadashi; Worthington, Margaret; Nakahara, Kazuhiko; Ando, Yasuo; Sahrawat, Kanwar Lal; Rao, Idupulapati Madhusudhana; Lata, Jean-Christophe; Kishii, Masahiro; Braun, Hans-Joachim

2015-04-01

Nitrification, the biological oxidation of ammonium to nitrate, weakens the soil's ability to retain N and facilitates N-losses from production agriculture through nitrate-leaching and denitrification. This process has a profound influence on what form of mineral-N is absorbed, used by plants, and retained in the soil, or lost to the environment, which in turn affects N-cycling, N-use efficiency (NUE) and ecosystem health and services. As reactive-N is often the most limiting in natural ecosystems, plants have acquired a range of mechanisms that suppress soil-nitrifier activity to limit N-losses via N-leaching and denitrification. Plants' ability to produce and release nitrification inhibitors from roots and suppress soil-nitrifier activity is termed 'biological nitrification inhibition' (BNI). With recent developments in methodology for in-situ measurement of nitrification inhibition, it is now possible to characterize BNI function in plants. This review assesses the current status of our understanding of the production and release of biological nitrification inhibitors (BNIs) and their potential in improving NUE in agriculture. A suite of genetic, soil and environmental factors regulate BNI activity in plants. BNI-function can be genetically exploited to improve the BNI-capacity of major food- and feed-crops to develop next-generation production systems with reduced nitrification and N2O emission rates to benefit both agriculture and the environment. The feasibility of such an approach is discussed based on the progresses made. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Evaluation and development of soil values for the pathway 'soil to plant'. Significance of mercury evaporation for the burden of plants

International Nuclear Information System (INIS)

Gaeth, S.; Schlueter, K.

1998-05-01

In cooperation with the Ad-hoc working group 'Transfer of heavy metals from soil to plant' of the Laenderarbeitsgemeinschaft Bodenschutz (LABO) the significance of mercury evaporation for the deduction of threshold values in respect of the impact via the pathway soil to plant was investigated. Mercury contamination of food- and feeding stuff plants was examined with special emphasis. For these purposes a lab experiment including three different soils with varying initial mercury load (background level, geogenic and anthropogenic contamination) and two different plant species (parsely and spinach) was carried out under defined conditions in closed lysimeters. Mercury uptake via the roots was minimised since the plants grew in isolated customary substrate which showed a low concentration of mercury. Thus, only the surrounding soil evaporated mercury. The concentrations of mercury in the plants in the background level treatment (0.1 mg Hg/kg dry soil) were 0.15 mg/kg dry matter (spinach) and 0.44 mg/kg dry matter (parsely). The treatment with anthropogenic contaminated soil (111 mg Hg/kg dry soil) resulted in concentrations in the two plants of 2.0 and 2.6 mg/kg dry matter, respectively. A comparable order of magnitude was achieved in the geogenic contaminated treatment (34 mg Hg/kg dry soil) with 2.1 mg/kg dry matter. Experiments conducted with radioactive 203 Hg showed in each case recoveries of 20 to 34% in the leaves regarding the evaporated Hg-tracer. Also in the stem and in the roots Hg-tracer could be detected, indicating a translocation within the plant from leaf to root. By means of a comprehensive literature study the state of the art for Hg-evaporation and Hg-uptake of plants was compiled. Comparing the experimental results with data derived from literature, the Hg-concentrations found are confirmed by results of other authors. (orig.) [de

Soil ecosystem functioning under climate change: plant species and community effects

Energy Technology Data Exchange (ETDEWEB)

Kardol, Paul [ORNL; Cregger, Melissa [ORNL; Campany, Courtney E [ORNL; Classen, Aimee T [ORNL

2010-01-01

Feedbacks of terrestrial ecosystems to climate change depend on soil ecosystem dynamics. Soil ecosystems can directly and indirectly respond to climate change. For example, warming directly alters microbial communities by increasing their activity. Climate change may also alter plant community composition, thus indirectly altering the microbial communities that feed on their inputs. To better understand how climate change may directly and indirectly alter soil ecosystem functioning, we investigated old-field plant community and soil ecosystem responses to single and combined effects of elevated [CO2], warming, and water availability. Specifically, we collected soils at the plot level (plant community soils), and beneath dominant plant species (plant-specific soils). We used microbial enzyme activities and soil nematodes as indicators for soil ecosystem functioning. Our study resulted in two main findings: 1) Overall, while there were some interactions, water, relative to increases in [CO2] and warming, had the largest impact on plant community composition, soil enzyme activities, and soil nematodes. Multiple climate change factors can interact to shape ecosystems, but in this case, those interactions were largely driven by changes in water availability. 2) Indirect effects of climate change, via changes in plant communities, had a significant impact on soil ecosystem functioning and this impact was not obvious when looking at plant community soils. Climate change effects on enzyme activities and soil nematode abundance and community structure strongly differed between plant community soils and plant-specific soils, but also within plant-specific soils. In sum, these results indicate that accurate assessments of climate change impacts on soil ecosystem functioning require incorporating the concurrent changes in plant function and plant community composition. Climate change-induced shifts in plant community composition will likely modify or counteract the direct

Hg transfer from contaminated soils to plants and animals

NARCIS (Netherlands)

Rodrigues, S.M.; Henriques, B.; Reis, A.T.; Duarte, A.C.; Pereira, E.; Romkens, P.F.A.M.

2012-01-01

Understanding the transfer of mercury (Hg) from soil to crops is crucial due to Hg toxicity and Hg occurrence in terrestrial systems. Previous research has shown that available Hg in soils contributes to plant Hg levels. Plant Hg concentrations are related to soil conditions and plant

A soil washing pilot plant for removing petroleum hydrocarbons from contaminated soils

International Nuclear Information System (INIS)

Toor, I.A.; Roehrig, G.R.

1992-01-01

A soil washing pilot plant was built and tested for its ability to remove petroleum hydrocarbons from certain soils. The ITEX soil washing pilot plant is a trailer mountable mobile unit which has a washing capacity of two tons per hour of contaminated soils. A benchscale study was carried out prior to the fabrication of the pilot plant. The first sample was contaminated with diesel fuel while the second sample was contaminated with crude oil. Various nonionic, cationic and anionic cleaning agents were evaluated for their ability to remove petroleum hydrocarbons from these materials. The nonionic cleaning agents were more successful in cleaning the soils in general. The ultimate surfactant choice was based on several factors including cost, biodegradability, cleaning efficiency and other technical considerations. The soil samples were characterized in terms of their particle size distributions. Commercial diesel fuel was carefully mixed in this sand to prepare a representative sample for the pilot plant study. Two pilot runs were made using this material. A multistage washing study was also conducted in the laboratory which indicates that the contamination level can be reduced to 100 ppm using only four stages. Because the pilot plant washing efficiency is twice as high, it is believed that ultimate contamination levels can be reduced to lower levels using the same number of stages. However, this hypothesis has not been demonstrated to date

Photochemical oxidants injury in rice plants. III. Effect of ozone on physiological activities in rice plants

Energy Technology Data Exchange (ETDEWEB)

Nakamura, H; Saka, H

1978-01-01

Experiments were made to determine the effect of photochemical oxidants on physiological activities of rice plants. Rice plants were fumigated with ozone at concentrations of 0.12-0.20 ppm for 2-3 hr to investigate acute injury and at 0.05 and 0.09 ppm for daily exposure from 3.0 leaf stage to assess the effect of ozone on growth. It was observed that malondialdehyde produced by disruption of the components of the membrane increased in the leaves exposed to ozone. Ozone reduced the RuBP-carboxylase activity in both young and old leaves 12-24 hr after fumigation. In the young leaves the activity of this enzyme recovered to some extent after 48 hr, but it did not show any recovery in the old leaves. On the other hand, ozone remarkably increased the peroxidase activity and slightly increased acid phosphatase in all leaves. Abnormally high ethylene evolution and oxygen uptake were detected in leaves soon after ozone fumigation. In general, high molecular protein and chlorophyll contents in the detached leaves decreased with incubation in dark, particularly in the old ones. These phenomena were more accelerated by ozone fumigation. Kinetin and benzimidazole showed significant effects on chlorophyll retention in ozone-exposed leaves. Reduction of plant growth and photosynthetic rate was recognized even in low concentration of ozone in daily exposure at 0.05 and 0.09 ppm. From these results it was postulated that ozone may cause the senescence of leaves in rice plants.

Digital soil mapping: strategy for data pre-processing

Directory of Open Access Journals (Sweden)

Alexandre ten Caten

2012-08-01

Full Text Available The region of greatest variability on soil maps is along the edge of their polygons, causing disagreement among pedologists about the appropriate description of soil classes at these locations. The objective of this work was to propose a strategy for data pre-processing applied to digital soil mapping (DSM. Soil polygons on a training map were shrunk by 100 and 160 m. This strategy prevented the use of covariates located near the edge of the soil classes for the Decision Tree (DT models. Three DT models derived from eight predictive covariates, related to relief and organism factors sampled on the original polygons of a soil map and on polygons shrunk by 100 and 160 m were used to predict soil classes. The DT model derived from observations 160 m away from the edge of the polygons on the original map is less complex and has a better predictive performance.

Screening plant species native to Taiwan for remediation of 137Cs-contaminated soil and the effects of K addition and soil amendment on the transfer of 137Cs from soil to plants

International Nuclear Information System (INIS)

Chou, F.-I.; Chung, H.-P.; Teng, S.-P.; Sheu, S.-T.

2005-01-01

This study aims to screen plant species native to Taiwan that could be used to eliminate 137 Cs radionuclides from contaminated soil. Four kinds of vegetables and two kinds of plants known as green manures were used for the screening. The test plants were cultivated in 137 Cs-contaminated soil and amended soil which is a mixture of the contaminated one with a horticultural soil. The plant with the highest 137 Cs transfer factor was used for further examination on the effects of K addition on the transfer of 137 Cs from the soils to the plant. Experimental results revealed that plants cultivated in the amended soil produced more biomass than those in the contaminated soil. Rape exhibited the highest production of aboveground parts, and had the highest 137 Cs transfer factor among all the tested plants. The transfer of 137 Cs to the rape grown in the soil to which 100 ppm KCl commonly used in local fertilizers had been added, were restrained. Results of this study indicated that rape, a popular green manure in Taiwan, could remedy 137 Cs-contaminated soil

Soil Conditions Rather Than Long-Term Exposure to Elevated CO2 Affect Soil Microbial Communities Associated with N-Cycling

Directory of Open Access Journals (Sweden)

Kristof Brenzinger

2017-10-01

Full Text Available Continuously rising atmospheric CO2 concentrations may lead to an increased transfer of organic C from plants to the soil through rhizodeposition and may affect the interaction between the C- and N-cycle. For instance, fumigation of soils with elevated CO2 (eCO2 concentrations (20% higher compared to current atmospheric concentrations at the Giessen Free-Air Carbon Dioxide Enrichment (GiFACE sites resulted in a more than 2-fold increase of long-term N2O emissions and an increase in dissimilatory reduction of nitrate compared to ambient CO2 (aCO2. We hypothesized that the observed differences in soil functioning were based on differences in the abundance and composition of microbial communities in general and especially of those which are responsible for N-transformations in soil. We also expected eCO2 effects on soil parameters, such as on nitrate as previously reported. To explore the impact of long-term eCO2 on soil microbial communities, we applied a molecular approach (qPCR, T-RFLP, and 454 pyrosequencing. Microbial groups were analyzed in soil of three sets of two FACE plots (three replicate samples from each plot, which were fumigated with eCO2 and aCO2, respectively. N-fixers, denitrifiers, archaeal and bacterial ammonia oxidizers, and dissimilatory nitrate reducers producing ammonia were targeted by analysis of functional marker genes, and the overall archaeal community by 16S rRNA genes. Remarkably, soil parameters as well as the abundance and composition of microbial communities in the top soil under eCO2 differed only slightly from soil under aCO2. Wherever differences in microbial community abundance and composition were detected, they were not linked to CO2 level but rather determined by differences in soil parameters (e.g., soil moisture content due to the localization of the GiFACE sets in the experimental field. We concluded that +20% eCO2 had little to no effect on the overall microbial community involved in N-cycling in the

Soil Conditions Rather Than Long-Term Exposure to Elevated CO2 Affect Soil Microbial Communities Associated with N-Cycling.

Science.gov (United States)

Brenzinger, Kristof; Kujala, Katharina; Horn, Marcus A; Moser, Gerald; Guillet, Cécile; Kammann, Claudia; Müller, Christoph; Braker, Gesche

2017-01-01

Continuously rising atmospheric CO 2 concentrations may lead to an increased transfer of organic C from plants to the soil through rhizodeposition and may affect the interaction between the C- and N-cycle. For instance, fumigation of soils with elevated CO 2 ( e CO 2 ) concentrations (20% higher compared to current atmospheric concentrations) at the Giessen Free-Air Carbon Dioxide Enrichment (GiFACE) sites resulted in a more than 2-fold increase of long-term N 2 O emissions and an increase in dissimilatory reduction of nitrate compared to ambient CO 2 ( a CO 2 ). We hypothesized that the observed differences in soil functioning were based on differences in the abundance and composition of microbial communities in general and especially of those which are responsible for N-transformations in soil. We also expected e CO 2 effects on soil parameters, such as on nitrate as previously reported. To explore the impact of long-term e CO 2 on soil microbial communities, we applied a molecular approach (qPCR, T-RFLP, and 454 pyrosequencing). Microbial groups were analyzed in soil of three sets of two FACE plots (three replicate samples from each plot), which were fumigated with e CO 2 and a CO 2 , respectively. N-fixers, denitrifiers, archaeal and bacterial ammonia oxidizers, and dissimilatory nitrate reducers producing ammonia were targeted by analysis of functional marker genes, and the overall archaeal community by 16S rRNA genes. Remarkably, soil parameters as well as the abundance and composition of microbial communities in the top soil under e CO 2 differed only slightly from soil under a CO 2 . Wherever differences in microbial community abundance and composition were detected, they were not linked to CO 2 level but rather determined by differences in soil parameters (e.g., soil moisture content) due to the localization of the GiFACE sets in the experimental field. We concluded that +20% e CO 2 had little to no effect on the overall microbial community involved in N

Nuclear techniques used in soil fertility and plant nutrition

International Nuclear Information System (INIS)

Halitligil, M.B.; Kislal, H.; Sirin, H.; Sirin, C.; Kilicaslan, A.

2004-01-01

Full text: Nuclear techniques, which include the usage of radioactive and stable isotopes, had been used in soil fertility, plant nutrition, plant breeding, plant protection and food preservation research works after 1950s. Ultimately these nuclear techniques contributed greatly in increased plant production. In general, it is possible to separate the nuclear techniques used in soil fertility and plant nutrition into two groups. The first group is the use of radioactive and stable isotopes as a tracer in order to find out the optimum fertilization rate of plants precisely. The second group is the use of neutron probe in determining the soil moisture at different periods of the growing season and at various soil depths precisely without any difficulty. In research works where conventional techniques are used, it is not possible to identify how much of the nutrient taken up by the plant came from applied fertilizer or soil. However, when tracer techniques are used in research works it is possible to identify precisely which amount of the nutrient taken from fertilizer or from soil. Therefore, the nuclear techniques are very important in finding out which variety of fertilizer and how much of it must be used. The determination of the soil moisture is very important in finding the water needs of the plants for a good growth. Soil moisture contents changes often during the growth period, so it must be determined very frequently in order to determine the amount of irrigation that has to be done. Conventional soil moisture determination (gravimetric method) is very laborious especially when it has to be done frequently. However, by using neutron probe soil moisture determinations can be done very easily any time during the plant growth period

Nuclear techniques used in soil fertility and plant nutrition

International Nuclear Information System (INIS)

Halitligil, M.B.

2004-01-01

Nuclear techniques, which include the usage of radioactive and stable isotopes, had been used in soil fertility, plant nutrition, plant breeding, plant protection and food preservation research works after 1950s. Ultimately these nuclear techniques contributed greatly in increased plant production. In general, it is possible to separate the nuclear techniques used in soil fertility and plant nutrition into two groups. The first group is the use of radioactive and stable isotopes as a tracer in order to find out the optimum fertilization rate of plants precisely. The second group is the use of neutron probe in determining the soil moisture at different periods of the growing season and at various soil depths precisely without any difficulty. In research works where conventional techniques are used, it is not possible to identify how much of the nutrient taken up by the plant came from applied fertilizer or soil. However, when tracer techniques are used in research works it is possible to identify precisely which amount of the nutrient taken from fertilizer or from soil. Therefore, the nuclear techniques are very important in finding out which variety of fertilizer and how much of it must be used. The determination of the soil moisture is very important in finding the water needs of the plants for a good growth. Soil moisture contents changes often during the growth period, so it must be determined very frequently in order to determine the amount of irrigation that has to be done. Conventional soil moisture determination (gravimetric method) is very laborious especially when it has to be done frequently. However, by using neutron probe soil moisture determinations can be done very easily any time during the plant growth period. (author)

Importance of biotic and abiotic components in feedback between plants and soil

OpenAIRE

Hanzelková, Věra

2017-01-01

The plant-soil feedback affects the forming of a plant community. Plants affect their own species as well as other species. The plant-soil feedback can be both positive and negative. Plants affect soil, change its properties, and the soil affects the plants reciprocally. Soil components can be divided into biotic and abiotic ones. The abiotic component is represented by physical and chemical properties of the soil. The main properties are the soil structure, the soil moisture, the soil temper...

Local variation in conspecific plant density influences plant-soil feedback in a natural grassland

NARCIS (Netherlands)

Kos, M.; Veendrick, Johan; Bezemer, T.M.

2013-01-01

Several studies have argued that under field conditions plant–soil feedback may be related to the local density of a plant species, but plant–soil feedback is often studied by comparing conspecific and heterospecific soils or by using mixed soil samples collected from different locations and plant

Soil reclamation with turfing plant harvest

International Nuclear Information System (INIS)

Jouve, A.; Maubert, H.; Bon, P.; Barthe, P.

1992-01-01

This work performed within the European RESSAC Programme aims at providing efficient countermeasures to decontaminate agricultural soils. The evaluation of the admissible concentration of radionuclides in the soil is an important question in this topic. Two considerations may help to answer this question: the health aspect approaches with ICRP recommendations and the economical aspects which can widely interfere with the other. If the cleaning technique is inexpensive, it will be possible to enlarge its use beyond the low intervention levels. According to the frequently low migration rate of radionuclides in the soil profile after deposition on the soil surface, a method removing a thin layer of the soil surface entrapped by turfing plants will allow to limit the waste production. The method being tried in summer 1991 is inexpensive because it uses the power of the plants to convert sunlight energy into biomass. The method consist in sowing turfing plants able to develop a very dense root network entrapping the soil surface contaminated particles allowing their mechanical removal by means of existing machines: sod harvesters. This promising method, according to lab-experiments, can use the green techniques as well for hydro-seeding: a very fast tool for sowing by helicopter at the rate of 0,3 km sup 2 per day, as sod harvester able to remove a sod-soil layer thinner than 2 cm. (author)

Evaluation of methyl bromide alternatives efficacy against soil-borne pathogens, nematodes and soil microbial community.

Directory of Open Access Journals (Sweden)

Hongwei Xie

Full Text Available Methyl bromide (MB and other alternatives were evaluated for suppression of Fusarium spp., Phytophthora spp., and Meloidogyne spp. and their influence on soil microbial communities. Both Fusarium spp. and Phytophthora spp. were significantly reduced by the MB (30.74 mg kg-1, methyl iodide (MI: 45.58 mg kg-1, metham sodium (MS: 53.92 mg kg-1 treatments. MS exhibited comparable effectiveness to MB in controlling Meloidogyne spp. and total nematodes, followed by MI at the tested rate. By contrast, sulfuryl fluoride (SF: 33.04 mg kg-1 and chloroform (CF: 23.68 mg kg-1 showed low efficacy in controlling Fusarium spp., Phytophthora spp., and Meloidogyne spp. MB, MI and MS significantly lowered the abundance of different microbial populations and microbial biomass in soil, whereas SF and CF had limited influence on them compared with the control. Diversity indices in Biolog studies decreased in response to fumigation, but no significant difference was found among treatments in PLFA studies. Principal component and cluster analyses of Biolog and PLFA data sets revealed that MB and MI treatments greatly influenced the soil microbial community functional and structural diversity compared with SF treatment. These results suggest that fumigants with high effectiveness in suppressing soil-borne disease could significantly influence soil microbial community.

Density-dependency and plant-soil feedback: former plant abundance influences competitive interactions between two grassland plant species through plant-soil feedbacks

NARCIS (Netherlands)

Xue, W.; Bezemer, T.M.; Berendse, Frank

2018-01-01

Backgrounds and aims Negative plant-soil feedbacks (PSFs) are thought to promote species coexistence, but most evidence is derived from theoretical models and data from plant monoculture experiments. Methods We grew Anthoxanthum odoratum and Centaurea jacea in field plots in monocultures and in

Soil-to-plant halogens transfer studies 2. Root uptake of radiochlorine by plants

International Nuclear Information System (INIS)

Kashparov, V.; Colle, C.; Zvarich, S.; Yoschenko, V.; Levchuk, S.; Lundin, S.

2005-01-01

Long-term field experiments have been carried out in the Chernobyl exclusion zone in order to determine the parameters governing radiochlorine ( 36 Cl) transfer to plants from four types of soil, namely, podzoluvisol, greyzem, and typical and meadow chernozem. Radiochlorine concentration ratios (CR) in radish roots (15 ± 10), lettuce leaves (30 ± 15), bean pods (15 ± 11) and wheat seed (23 ± 11) and straw (210 ± 110) for fresh weight of plants were obtained. These values correlate well with stable chlorine values for the same plants. One year after injection, 36 Cl reached a quasi-equilibrium with stable chlorine in the agricultural soils and its behavior in the soil-plant system mimicked the behavior of stable chlorine (this behavior was determined by soil moisture transport in the investigated soils). In the absence of intensive vertical migration, more than half of 36 Cl activity in arable layer of soil passes into the radish, lettuce and the aboveground parts of wheat during a single vegetation period

Soil-to-plant halogens transfer studies 2. Root uptake of radiochlorine by plants

Energy Technology Data Exchange (ETDEWEB)

Kashparov, V. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine); Colle, C. [Institute for Radioprotection and Nuclear Safety (IRSN/DEI/SECRE), Cadarache bat 159, BP 3, 13115 Saint Paul-lez-Durance (France)]. E-mail: claude.colle@irsn.fr; Zvarich, S. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine); Yoschenko, V. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine); Levchuk, S. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine); Lundin, S. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine)

2005-07-01

Long-term field experiments have been carried out in the Chernobyl exclusion zone in order to determine the parameters governing radiochlorine ({sup 36}Cl) transfer to plants from four types of soil, namely, podzoluvisol, greyzem, and typical and meadow chernozem. Radiochlorine concentration ratios (CR) in radish roots (15 {+-} 10), lettuce leaves (30 {+-} 15), bean pods (15 {+-} 11) and wheat seed (23 {+-} 11) and straw (210 {+-} 110) for fresh weight of plants were obtained. These values correlate well with stable chlorine values for the same plants. One year after injection, {sup 36}Cl reached a quasi-equilibrium with stable chlorine in the agricultural soils and its behavior in the soil-plant system mimicked the behavior of stable chlorine (this behavior was determined by soil moisture transport in the investigated soils). In the absence of intensive vertical migration, more than half of {sup 36}Cl activity in arable layer of soil passes into the radish, lettuce and the aboveground parts of wheat during a single vegetation period.

Effect of growing plants on denitrification at high soil nitrate concentrations

International Nuclear Information System (INIS)

Haider, K.; Mosier, A.; Heinemeyer, O.

1987-01-01

The availability of plant rhizosphere C deposits and its influence on microbial denitrification is not clearly defined. Conflicting reports as to the influence of plants and root exudation on denitrification continue to appear in the literature. The results of the authors earlier phytotron study indicated that denitrification was not stimulated in soils planted with corn or wheat compared to unplanted soils. Lower nitrate concentrations in the planted soils, however, may have led to misinterpretation of this data. A second study was conducted, to evaluate the effect of actively growing plants on denitrification where the NO 3 7 content of planted soils was maintained similar to unplanted soils. Simultaneously the C fixed by corn (Zea mays) and the fate of fertilizer N applied to the soil during the growing season were quantified. The corn was grown in a phytotron under a continuous supply of 14 CO 2 in 15 N fertilized soils to which 15 N-NO 3 - was added periodically during the growing season. The results of these studies showed that denitrification was not stimulated in soils planted with corn during active plant growth phase even when soil NO 3 - was relatively high. Denitrification was, however, greater in corn planted than unplanted soil when the recoverable root biomass began to decrease. Less N was immobilized and net 15 N immobilization was lower in planted soils than in unplanted soils. As denitrification was lower in planted soils during the time of active plant growth, the study suggests that root exudates did not stimulate either process

Do we know how plants sense a drying soil?

Directory of Open Access Journals (Sweden)

Streck Nereu Augusto

2004-01-01

Full Text Available The reduction of crop growth and yield in dry areas is largely due to stomatal closure in response to dry soil, which decreases photosynthesis. However, the mechanism that causes stomatal closure in a drying soil is a controversial issue. Experienced and respected plant physiologists around the world have different views about the primary sensor of soil water shortage in plants. The goal of this review is to present a chronological synthesis about the evidence of the possible candidates for the mechanism by which plants sense a drying soil. Hydraulic signals in the leaves as the mechanism that causes stomatal closure dominated the view on how plants sense a drying soil during the 70?s and the early 80?s. In the middle 80?s, studies suggested that stomatal conductance is better correlated with soil and root water status than with leaf water status. Thus, chemical signals produced in the roots dominated the view on how plants sense a drying soil during the late 80?s and early 90?s. During the second half of the 90?s, however, studies provided evidence that hydraulic signals in the leaves are still better candidates for the mechanism by which plants sense a drying soil. After more than 60 years of studies in plant-water relations, the question raised in the title still has no unanimous answer. This controversial issue is a good research rationale for the current generation of plant physiologists.

Enhancing Elementary Pre-service Teachers' Plant Processes Conceptions

Science.gov (United States)

Thompson, Stephen L.; Lotter, Christine; Fann, Xumei; Taylor, Laurie

2016-06-01

Researchers examined how an inquiry-based instructional treatment emphasizing interrelated plant processes influenced 210 elementary pre-service teachers' (PTs) conceptions of three plant processes, photosynthesis, cellular respiration, and transpiration, and the interrelated nature of these processes. The instructional treatment required PTs to predict the fate of a healthy plant in a sealed terrarium (Plant-in-a-Jar), justify their predictions, observe the plant over a 5-week period, and complete guided inquiry activities centered on one of the targeted plant processes each week. Data sources included PTs' pre- and post-predictions with accompanying justifications, course artifacts such as weekly terrarium observations and science journal entries, and group models of the interrelated plant processes occurring within the sealed terraria. A subset of 33 volunteer PTs also completed interviews the week the Plant-in-a-Jar scenario was introduced and approximately 4 months after the instructional intervention ended. Pre- and post-predictions from all PTs as well as interview responses from the subgroup of PTs, were coded into categories based on key plant processes emphasized in the Next Generation Science Standards. Study findings revealed that PTs developed more accurate conceptions of plant processes and their interrelated nature as a result of the instructional intervention. Primary patterns of change in PTs' plant process conceptions included development of more accurate conceptions of how water is used by plants, more accurate conceptions of photosynthesis features, and more accurate conceptions of photosynthesis and cellular respiration as transformative processes.

Plant-soil feedbacks and the coexistence of competing plants

NARCIS (Netherlands)

Revilla, T.A.; Veen, G.F.; Eppinga, M.B.; Weissing, F.J.

2013-01-01

Plant–soil feedbacks can have important implications for the interactions among plants. Understanding these effects is a major challenge since it is inherently difficult to measure and manipulate highly diverse soil communities. Mathematical models may advance this understanding by making the

Plant-soil feedbacks and the coexistence of competing plants

NARCIS (Netherlands)

Revilla, T.A.; Veen, G.F.; Eppinga, M.B.; Weissing, F.J.

Plant–soil feedbacks can have important implications for the interactions among plants. Understanding these effects is a major challenge since it is inherently difficult to measure and manipulate highly diverse soil communities. Mathematical models may advance this understanding by making the

Salinity controls on plant transpiration and soil water balance

Science.gov (United States)

Perri, S.; Molini, A.; Suweis, S. S.; Viola, F.; Entekhabi, D.

2017-12-01

Soil salinization and aridification represent a major threat for the food security and sustainable development of drylands. The two problems are deeply connected, and their interplay is expected to be further enhanced by climate change and projected population growth. Salt-affected land is currently estimated to cover around 1.1 Gha, and is particularly widespread in semi-arid to hyper-arid climates. Over 900 Mha of these saline/sodic soils are potentially available for crop or biomass production. Salt-tolerant plants have been recently proposed as valid solution to exploit or even remediate salinized soils. However the effects of salinity on evapotranspiration, soil water balance and the long-term salt mass balance in the soil, are still largely unexplored. In this contribution we analyze the feedback of evapotranspiration on soil salinization, with particular emphasis on the role of vegetation and plant salt-tolerance. The goal is to introduce a simple modeling framework able to shed some light on how (a) soil salinity controls plant transpiration, and (b) salinization itself is favored/impeded by different vegetation feedback. We introduce at this goal a spatially lumped stochastic model of soil moisture and salt mass dynamics averaged over the active soil depth, and accounting for the effect of salinity on evapotranspiration. Here, the limiting effect of salinity on ET is modeled through a simple plant response function depending on both salt concentration in the soil and plant salt-tolerance. The coupled soil moisture and salt mass balance is hence used to obtain the conditional steady-state probability density function (pdf) of soil moisture for given salt tolerance and salinization level, Our results show that salinity imposes a limit in the soil water balance and this limit depends on plant salt-tolerance mainly through the control of the leaching occurrence (tolerant plants exploit water more efficiently than the sensitive ones). We also analyzed the

Interpretation of soil-to-plant transfer on the basis of soil solution chemical composition

International Nuclear Information System (INIS)

Lembrechts, J.F.; Van Loon, L.R.; Van Ginkel, J.H.; Desmet, G.M.

1988-01-01

Soil-to-plant translocation of a radionuclide depends on its availability on the one hand and on the efficiency of the uptake process on the other. Criticism on the use of transfer coefficients for the description of translocation mainly concerns the fact that the complex variety of processes, a.o. dependent on plant characteristics and soil type and treatment, is integrated in a single ratio. For the interpretation of the effect of counter-measures the static transfer coefficient proved to be hard to handle and knowledge of the separate underlying processes and their time dependence showed to be indispensible. Based upon translocation experiments with technetium, cobalt, strontium and zinc transfer was shown to be primarily related to the concentration of the plant available fraction in the soil solution as well as to the soil solution chemistry in general. The transfer factor of the first three elements expressed in the basis of soil solution activity (ml/g), was observed to decrease when the nutrient content of the soil solution -- reflected by its conductivity -- increased. The characteristics of the soil matrix (solid phase) furthermore showed to be of secondary importance for the explanation of the observed accumulation. Since the interstitial soil liquid phase mediates between solid phase and plant root, reliable interpretations of soil-to-plant transfer might as a rule be based on a separate study of the effect of soil properties on availability on the one hand of the uptake from nutrient solutions on the other

Influence of air pollution on cultivated plants

Energy Technology Data Exchange (ETDEWEB)

Spierings, F H.F.G.; Van Raay, A; Wolting, H G

1967-01-01

An investigation repeated for the third time on susceptibility for SO/sub 2/ of 7 varieties of lettuce resulted in a reliable difference between the most and least susceptible variety; the others produced differences between individual plants within the varieties. Ethylene fumigations of tomato plants during five to six hours at concentrations of 0.5 to 3 ppm caused no visible reaction. A fumigation with 3 ppm for 23 hours resulted in a strong epinastic reaction at the base of the leaf petioles and curling of the young growing leaves. An apparatus was constructed to fumigate herbaceous plants, shrubs and trees in their natural environment and under normal climatic conditions. With this apparatus daffodil, tulip and Ixia were fumigated for 3 hours with HF in a concentration of 0.030 ppm. The most susceptible varieties showed leaf tip damage to an extent of 2 to 4 cm. Some time after an aluminium factory came into operation, injury to trees and shrubs occurred in the neighborhood; farm crops were not affected. For some factories the opportunity was given to carry out measurements on the amount of air pollution in the neighborhood of these factories before production starts, to estimate how much extra air pollution may be caused by the new factory.

Arsenic-phosphorus interactions in the soil-plant-microbe system: Dynamics of uptake, suppression and toxicity to plants.

Science.gov (United States)

Anawar, Hossain M; Rengel, Zed; Damon, Paul; Tibbett, Mark

2018-02-01

High arsenic (As) concentrations in the soil, water and plant systems can pose a direct health risk to humans and ecosystems. Phosphate (Pi) ions strongly influence As availability in soil, its uptake and toxicity to plants. Better understanding of As(V)-Pi interactions in soils and plants will facilitate a potential remediation strategy for As contaminated soils, reducing As uptake by crop plants and toxicity to human populations via manipulation of soil Pi content. However, the As(V)-Pi interactions in soil-plant systems are complex, leading to contradictory findings among different studies. Therefore, this review investigates the role of soil type, soil properties, minerals, Pi levels in soil and plant, Pi transporters, mycorrhizal association and microbial activities on As-Pi interactions in soils and hydroponics, and uptake by plants, elucidate the key mechanisms, identify key knowledge gaps and recommend new research directions. Although Pi suppresses As uptake by plants in hydroponic systems, in soils it could either increase or decrease As availability and toxicity to plants depending on the soil types, properties and charge characteristics. In soil, As(V) availability is typically increased by the addition of Pi. At the root surface, the Pi transport system has high affinity for Pi over As(V). However, Pi concentration in plant influences the As transport from roots to shoots. Mycorrhizal association may reduce As uptake via a physiological shift to the mycorrhizal uptake pathway, which has a greater affinity for Pi over As(V) than the root epidermal uptake pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

Agriculture on Mars: Soils for Plant Growth

Science.gov (United States)

Ming, D. W.

2016-01-01

Robotic rovers and landers have enabled the mineralogical, chemical, and physical characterization of loose, unconsolidated materials on the surface of Mars. Planetary scientists refer to the regolith material as "soil." NASA is currently planning to send humans to Mars in the mid 2030s. Early missions may rely on the use of onsite resources to enable exploration and self-sufficient outposts on Mars. The martian "soil" and surface environment contain all essential plant growth elements. The study of martian surface materials and how they might react as agricultural soils opens a new frontier for researchers in the soil science community. Other potential applications for surface "soils" include (i) sources for extraction of essential plant-growth nutrients, (ii) sources of O2, H2, CO2, and H2O, (iii) substrates for microbial populations in the degradation of wastes, and (iv) shielding materials surrounding outpost structures to protect humans, plants, and microorganisms from radiation. There are many challenges that will have to be addressed by soil scientists prior to human exploration over the next two decades.

Oxygenated Phosphine Fumigation for Control of Light Brown Apple Moth (Lepidoptera: Tortricidae) Eggs on Cut-Flowers.

Science.gov (United States)

Liu, Samuel S; Liu, Yong-Biao; Simmons, Gregory S

2015-08-01

Light brown apple moth, Epiphyas postvittana (Walker), eggs were subjected to oxygenated phosphine fumigation treatments under 70% oxygen on cut flowers to determine efficacy and safety. Five cut flower species: roses, lilies, tulips, gerbera daisy, and pompon chrysanthemums, were fumigated in separate groups with 2,500 ppm phosphine for 72 h at 5°C. Egg mortality and postharvest quality of cut flowers were determined after fumigation. Egg mortalities of 99.7-100% were achieved among the cut flower species. The treatment was safe to all cut flowers except gerbera daisy. A 96-h fumigation treatment with 2,200 ppm phosphine of eggs on chrysanthemums cut flowers also did not achieve complete control of light brown apple moth eggs. A simulation of fumigation in hermetically sealed fumigation chambers with gerbera daisy showed significant accumulations of carbon dioxide and ethylene by the end of 72-h sealing. However, oxygenated phosphine fumigations with carbon dioxide and ethylene absorbents did not reduce the injury to gerbera daisy, indicating that it is likely that phosphine may directly cause the injury to gerbera daisy cut flowers. The study demonstrated that oxygenated phosphine fumigation is effective against light brown apple moth eggs. However, it may not be able to achieve the probit9 quarantine level of control and the treatment was safe to most of the cut flower species. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

Exposure of Brown Recluse and Brown Widow Spiders (Araneae: Sicariidae, Theridiidae) to a Commercial Sulfuryl Fluoride Fumigation.

Science.gov (United States)

Vetter, Richard S; Hoddle, Mark S; Choe, Dong-Hwan; Thoms, Ellen

2014-10-01

The body of pesticide research on spiders is sparse with most studies using topical or residual applications to assess efficacy. Data on the effects of fumigation on spider survivorship are scarce in the scientific literature. In this study, we exposed adult male and female brown recluse spiders, Loxosceles reclusa Gertsch & Mulaik, and female brown widow spiders, Latrodectus geometricus C. L. Koch, to a commercial fumigation event using sulfuryl fluoride directed at termite control. General consensus from the pest control industry is that fumigation is not always effective for control of spiders for a variety of reasons, including insufficient fumigant dosage, particularly, for contents of egg sacs that require a higher fumigant dosage for control. We demonstrated that a sulfuryl fluoride fumigation with an accumulated dosage of 162 oz-h per 1,000 ft(3) at 21°C over 25 h (≈1.7 × the drywood termite dosage) directed at termites was sufficient to kill adult brown recluse and brown widow spiders. The effectiveness of commercial fumigation practices to control spiders, and particularly their egg sacs, warrants further study. © 2014 Entomological Society of America.

Transfer of 137Cs from soil to plants in different types of soils

International Nuclear Information System (INIS)

Todorovic, D.; Radenkovic, M.; Popovic, D.; Djuric, G.

1998-01-01

The investigations were carried out in two mountainous regions in the West and South region of the country). Three main types of soils were examined: shale, limestone and the mixed type, and several plants: grass, meadow flora, pinewood, blueberries, an endemic species of Mt. Sara and the bioindicators: moss and lichen. The transfer factors lay in the range of 0.1 - 2.0 in dependence on the type of soil and plant (3.0 - 10.0 for the bioindicator plants). The vertical distribution of 13' 7Cs in the first 15 cm layer of the soil indicates a slow migration of Chernobyl cesium through soil, except on riversides where the wash-out effect plays a role. Generally, the concentration of 137 Cs in soils strongly depends on the configuration of the ground

Methods to Quantify Nickel in Soils and Plant Tissues

Directory of Open Access Journals (Sweden)

Bruna Wurr Rodak

2015-06-01

Full Text Available In comparison with other micronutrients, the levels of nickel (Ni available in soils and plant tissues are very low, making quantification very difficult. The objective of this paper is to present optimized determination methods of Ni availability in soils by extractants and total content in plant tissues for routine commercial laboratory analyses. Samples of natural and agricultural soils were processed and analyzed by Mehlich-1 extraction and by DTPA. To quantify Ni in the plant tissues, samples were digested with nitric acid in a closed system in a microwave oven. The measurement was performed by inductively coupled plasma/optical emission spectrometry (ICP-OES. There was a positive and significant correlation between the levels of available Ni in the soils subjected to Mehlich-1 and DTPA extraction, while for plant tissue samples the Ni levels recovered were high and similar to the reference materials. The availability of Ni in some of the natural soil and plant tissue samples were lower than the limits of quantification. Concentrations of this micronutrient were higher in the soil samples in which Ni had been applied. Nickel concentration differed in the plant parts analyzed, with highest levels in the grains of soybean. The grain, in comparison with the shoot and leaf concentrations, were better correlated with the soil available levels for both extractants. The methods described in this article were efficient in quantifying Ni and can be used for routine laboratory analysis of soils and plant tissues.

Diffusion and adsorption of the nematicide 1,3-dichloropropene in soil

NARCIS (Netherlands)

Leistra, M.

1972-01-01

After soil fumigation the concentration of the nematicidal compounds cis and trans 1,3-dichloropropene at various depths in the soil was estimated by electron-capture gas-chromatography. The coefficients for the distribution of the compounds over

Transfer of technetium in the soil-rice plant system

International Nuclear Information System (INIS)

Yanagisawa, K.; Muramatsu, Y.

1995-01-01

In order to assess the behavior of Tc in flooded soil-plant systems, laboratory experiments have been done using 95m Tc as a tracer. Two common soil types in Japan, Andosol and Gray lowland soils, were used. Soil-plant transfer factors of Tc in rice grain were very low, i.e. 5 x 10 -5 for Andosol and 6 x 10 -4 for Gray lowland soil. It was found that the Tc concentrations in rice plants were influenced by those in soil solutions. Concentrations of 95m Tc in both soil solutions decreased rapidly in the early period of cultivation. It was observed that redox-potential (Eh) also decreased markedly following flooding. A relationship was found between the decrease of the 95m Tc concentrations in soil solutions and the drop of Eh in the soils. The Tc (VII) added to soil was transformed to insoluble Tc (IV) under the reduced conditions existing in flooded soil. (author). 10 refs., 2 figs., 4 tabs

Impacts of soil incorporation of pre-incubated silica-rich rice residue on soil biogeochemistry and greenhouse gas fluxes under flooding and drying.

Science.gov (United States)

Gutekunst, Madison Y; Vargas, Rodrigo; Seyfferth, Angelia L

2017-09-01

Incorporation of silica-rich rice husk residue into flooded paddy soil decreases arsenic uptake by rice. However, the impact of this practice on soil greenhouse gas (GHG) emissions and elemental cycling is unresolved particularly as amended soils experience recurrent flooding and drying cycles. We evaluated the impact of pre-incubated silica-rich rice residue incorporation to soils on pore water chemistry and soil GHG fluxes (i.e., CO 2 , CH 4 , N 2 O) over a flooding and drying cycle typical of flooded rice cultivation. Soils pre-incubated with rice husk had 4-fold higher pore water Si than control and 2-fold higher than soils pre-incubated with rice straw, whereas the pore water As and Fe concentrations in soils amended with pre-incubated straw and husk were unexpectedly similar (maximum ~0.85μM and ~450μM levels, respectively). Pre-incubation of residues did not affect Si but did affect the pore water levels of As and Fe compared to previous studies using fresh residues where straw amended soils had higher As and Fe in pore water. The global warming potential (GWP) of soil GHG emissions decreased in the order straw (612±76g CO 2 -eqm -2 )>husk (367±42gCO 2 -eqm -2 )>ashed husk=ashed straw (251±26 and 278±28gCO 2 -eqm -2 )>control (186±23gCO 2 -eqm -2 ). The GWP increase due to pre-incubated straw amendment was due to: a) larger N 2 O fluxes during re-flooding; b) smaller contributions from larger CH 4 fluxes during flooded periods; and c) higher CH 4 and CO 2 fluxes at the onset of drainage. In contrast, the GWP of the husk amendment was dominated by CO 2 and CH 4 emissions during flooded and drainage periods, while ashed amendments increased CO 2 emissions particularly during drainage. This experiment shows that ashed residues and husk addition minimizes GWP of flooded soils and enhances pore water Si compared to straw addition even after pre-incubation. Copyright © 2017 Elsevier B.V. All rights reserved.

Distribution modelling of pre-Columbian California grasslands with soil phytoliths: New insights for prehistoric grassland ecology and restoration.

Science.gov (United States)

Fick, Stephen E; Evett, Rand R

2018-01-01

Historical reconstructions of plant community distributions are useful for biogeographic studies and restoration planning, but the quality of insights gained depends on the depth and reliability of historical information available. For the Central Valley of California, one of the most altered terrestrial ecosystems on the planet, this task is particularly difficult given poor historical documentation and sparse relict assemblages of pre-invasion plant species. Coastal and interior prairies were long assumed to have been dominated by perennial bunchgrasses, but this hypothesis has recently been challenged. We evaluated this hypothesis by creating species distribution models (SDMs) using a novel approach based on the abundance of soil phytoliths (microscopic particles of biogenic silica used as a proxy for long-term grass presence) extracted from soil samples at locations statewide. Modeled historical grass abundance was consistently high along the coast and to a lesser extent in higher elevation foothills surrounding the Central Valley. SDMs found strong associations with mean temperature, temperature variability, and precipitation variability, with higher predicted abundance in regions with cooler, equable temperatures and moderated rainfall, mirroring the pattern for modern perennial grass distribution across the state. The results of this study strongly suggest that the pre-Columbian Central Valley of California was not dominated by grasses. Using soil phytolith data as input for SDMs is a promising new method for predicting the extent of prehistoric grass distributions where alternative historical datasets are lacking.

Plant species richness regulates soil respiration through changes in productivity.

Science.gov (United States)

Dias, André Tavares Corrêa; van Ruijven, Jasper; Berendse, Frank

2010-07-01

Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of diversity on soil respiration. We hypothesized that plant diversity could affect soil respiration in two ways. On the one hand, more diverse plant communities have been shown to promote plant productivity, which could increase soil respiration. On the other hand, the nutrient concentration in the biomass produced has been shown to decrease with diversity, which could counteract the production-induced increase in soil respiration. Our results clearly show that soil respiration increased with species richness. Detailed analysis revealed that this effect was not due to differences in species composition. In general, soil respiration in mixtures was higher than would be expected from the monocultures. Path analysis revealed that species richness predominantly regulates soil respiration through changes in productivity. No evidence supporting the hypothesized negative effect of lower N concentration on soil respiration was found. We conclude that shifts in productivity are the main mechanism by which changes in plant diversity may affect soil respiration.

Effects of plant cover on soil N mineralization during the growing season in a sandy soil

Science.gov (United States)

Yao, Y.; Shao, M.; Wei, X.; Fu, X.

2017-12-01

Soil nitrogen (N) mineralization and its availability plays a vital role in regulating ecosystem productivity and C cycling, particularly in semiarid and desertified ecosystems. To determine the effect of plant cover on N turnover in a sandy soil ecosystem, we measured soil N mineralization and inorganic N pools in soil solution during growing season in a sandy soil covered with various plant species (Artemisia desertorum, Salix psammophila, and Caragana korshinskii). A bare sandy soil without any plant was selected as control. Inorganic N pools and N mineralization rates decreased overtime during the growing season, and were not affected by soil depth in bare land soils, but were significantly higher at the 0-10 cm layer than those at the 10-20 cm soil layer under any plant species. Soil inorganic N pool was dominated by ammonium, and N mineralization was dominated by nitrification regardless of soil depth and plant cover. Soils under C. korshinskii have significant higher inorganic N pools and N mineralization rate than soils under bare land and A. desertorum and S. psammophila, and the effects of plant cover were greater at the 0-10 cm soil layer than at the 10-20 cm layer. The effects of C. korshinskii on soil inorganic N pools and mineralization rate varied with the stage of growing season, with greater effects on N pools in the middle growing season, and greater effects on mineralization rate at the last half of the growing season. The results from this study indicate that introduction of C. korshinskii has the potential to increase soil N turnover and availability in sandy soils, and thus to decrease N limitation. Caragana korshinskii is therefore recommend for the remediation of the desertified land.

Global Change Effects on Plant-Soil Interactions

DEFF Research Database (Denmark)

Dam, Marie

of this dissertation has been to determine how soil food web structure and function is affected when the quantity and quality of plant input is altered under global change. By studying the abundance and composition of soil organisms, particularly those in the rhizosphere, closely associated with living plants, we...... (Paper III). Furthermore, by way of meta-analysis, the role of organisms in global change effects on ecosystem function is modelled (Paper IV). Among CO2, warming and summer drought, CO2 is the factor most consistently impacting soil organisms. CO2 increases abundance of microorganisms and nematodes...... suggest that not only the global change effects on established ecosystems, but also the global change effects on plant community composition as well as land use management may determine the composition and function of soil food webs in the future....

Transuranic behavior in soils and plants

International Nuclear Information System (INIS)

Wildung, R.E.; Garland, T.R.; Cataldo, D.A.; Rogers, J.E.; McFadden, K.M.; Jenne, E.A.; Schreckhise, R.G.

1981-01-01

The principal objective of this study is to gather information about soil, plant, and foliar interaction factors that influence the availability of transuranics to agricultural plants and animals. This paper discusses plant processes which influence transport across the plant root membrane and foliar surfaces, and the form and sites of deposition of transuranic elements in mature plants

Distribution of 14C in soil and rice plants following application of 14C - parathion to soil

International Nuclear Information System (INIS)

Andrea, M.M. de; Ruegg, E.F.

1983-01-01

Amount of residues of 14 C-parathion in soil rice plants after application of the insecticide to soil were determined in four systems studied during five weeks: pots of soil with and without plants and open or enclosed by a transparent cover. Measurements of amounts volatilized and 14 CO 2 evolution from the pesticide were made in closed system without plants. The bound residues in soil and plants were also determined. Results indicated that parathion half life in a Gley Humic soil was about two weeks. Very little radiocarbon was taken up by rice plants; of this, more was found in shoots of plants enclosed, probably by collection of the volatilized material by plants. About 6% and 4% of the 14 C-parathion were found as volatilized material and 14 CO 2 , respectively after five weeks. Bound residues varied very little and reached a maximum of 22% in soil and in plants amounted to less than 2% at the final of the experiment. (Author) [pt

Phytoremediation of radiocesium in different soils using cultivated plants

International Nuclear Information System (INIS)

Suzuki, Yasukazu; Saito, Takashi; Tsukada, Hirofumi

2012-01-01

A huge amount of radionuclides were released into the environment after the Fukushima Daiichi nuclear power plant accident. Radiocesium, which is one of the more prevalent radionuclides, was deposited in the soil. It is well known that radiocesium is adsorbed into the soil and binds strongly to clay. As a result, it is difficult to reduce the contamination level in the soil. We examine the possibility of decontamination by means of phytoremediation. Four species of plants (sunflower, sorghum, amaranth, and buckwheat) were sown in light-colored Andosol and gray lowland soil. When the plants matured, they were harvested and separated into their different parts, i.e., flower, leaf, stem, and root. The removal percentage of 137 Cs for the aboveground parts, which is defined as the ratio of the total content of 137 Cs in the aboveground biomass of plants to that in the cultivated soil of 0-15 cm depth, was 0.013-0.93% for the light-colored Andosol and 0.0072-0.038% for the gray lowland soil. The plants exhibiting the highest value cultivated in the light-colored Andosol and gray lowland soil were amaranth (0.093%) and sunflower (0.038%), respectively. This indicates that it is difficult to remove radiocesium from contaminated soil by means of phytoremediation. (author)

Analysis of Driven Pile Capacity within Pre-Bored Soil : Research Project Capsule

Science.gov (United States)

2017-10-01

Pre-boring is a method used to facilitate large displacement pile driving in hard/dense soils (see Figure 1). By pre-boring a pilot hole, the end bearing and side friction within the pre-bored zone are reduced, thus aiding pile driving installation. ...

Heavy Metal Polluted Soils: Effect on Plants and Bioremediation Methods

Directory of Open Access Journals (Sweden)

G. U. Chibuike

2014-01-01

Full Text Available Soils polluted with heavy metals have become common across the globe due to increase in geologic and anthropogenic activities. Plants growing on these soils show a reduction in growth, performance, and yield. Bioremediation is an effective method of treating heavy metal polluted soils. It is a widely accepted method that is mostly carried out in situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Microorganisms and plants employ different mechanisms for the bioremediation of polluted soils. Using plants for the treatment of polluted soils is a more common approach in the bioremediation of heavy metal polluted soils. Combining both microorganisms and plants is an approach to bioremediation that ensures a more efficient clean-up of heavy metal polluted soils. However, success of this approach largely depends on the species of organisms involved in the process.

A new approach for soil-plant transfer calculations

International Nuclear Information System (INIS)

Dorp, F. van; Eleveld, R.; Frissel, M.J.

1979-01-01

Models to calculate radiation doses to man caused by normal or accidental release of radionuclides from nuclear industries often include the transfer of these nuclides from soil to plant. This soil-plant transfer is mostly described with a black box approach by using concentration factors. This approach has several disadvantages, the most important being the lack of physical meaning of a concentration factor. We propose to describe the soil-plant transfer of radionuclides as a function of plant and soil parameters all having a physical meaning. The separate parameters are open to experimental determination but a realistic estimation of the parameters is also possible, or the use of a combination of both. Depending on the purpose of the calculation, realistic or conservative values of the parameters can be used and the degree of conservatism can be indicated. (author)

Plant nutrition and soil fertility manual

National Research Council Canada - National Science Library

Jones, J. Benton

2012-01-01

.... With over 70 percent new material, the second edition of the Plant Nutrition and Soil Fertility Manual discusses the principles determining how plants grow and the elements essential for successful...

Comparative effects of irradiation, fumigation, and storage on the free amino acids and sugar contents of green, black and oolong teas

International Nuclear Information System (INIS)

Kausar, Tusneem; Akram, Kashif; Kwon, Joong-Ho

2013-01-01

Food irradiation or chemical fumigation can be used to ensure the hygienic quality of teas. The comparative effects of gamma irradiation (5 and 10 kGy) and fumigation (MeBr and PH 3 ) were investigated on the amino acids and sugar contents of Camellia sinensis (green, black and oolong teas) during storage (15±12 °C). The major amino acids found in teas were theanine and glutamic acid. Irradiation increased amino acids such as, leucine, alanine, and glutamic acid, and decreased the histidine. PH 3 fumigation resulted in a decrease of tyrosine content; however, the effect of MeBr fumigation was negligible. Storage showed no significant effect on the amino acid content of the irradiated and fumigated teas. Sucrose, glucose, and fructose contents significantly increased upon gamma irradiation (p≤0.05). However, fumigation and subsequent storage did not affect the sugar contents. Irradiation could be a preferred alternative choice to address food safety problems as fumigation is restricted in many countries. - Highlights: ► Teas were investigated for the changes during storage on irradiation and fumigation. ► The effect on amino acid contents was more prominent on irradiation than fumigation. ► The sucrose, glucose, and fructose contents increased on gamma irradiation. ► Fumigation and storage did not affect the sugar contents in the teas. ► Irradiation could be an effective alternative for fumigants

Effect of application timing and method on efficacy and phytotoxicity of 1,3-D, chloropicrin and metam-sodium combinations in squash plasticulture.

Science.gov (United States)

Desaeger, Johan A; Seebold, Kenneth W; Csinos, Alex S

2008-03-01

Metam-sodium, 1,3-dichloropropene (1,3-D) and chloropicrin are widely used soil fumigants. Combined application of metam-sodium and 1,3-D + chloropicrin is intended to improve efficacy and broaden spectrum of control, but little is known about the effect on crop safety. This study aimed to evaluate the effects of application timing of fumigant combinations on soilborne pest and disease control (nematodes, soil fungi and weeds) and growth of squash. Two separate tests with chisel-injected and drip-applied fumigant combinations and plant-back times ranging from 1 to 4 weeks were conducted in Tifton, GA, USA, in spring and fall 2002. Fumigant combinations using 1,3-D, chloropicrin and metam-sodium were as effective as methyl bromide in controlling Meloidogyne incognita (Kofoid & White) Chitwood, Pythium irregulare Buis., Rhizoctonia solani Kühn and Cyperus esculentus L. Chisel-applied combinations were more effective in terms of root-knot nematode control than drip-applied combinations. Root-knot nematode reduced squash yields by up to 60%. Phytotoxicity problems and lower yields were observed during spring, especially following 1,3-D + chloropicrin and when plant-back periods were shorter. The main problem with fumigant alternatives to methyl bromide may not be reduced efficacy but, in particular for 1,3-D products, loss of flexibility in terms of longer plant-back periods. (c) 2008 Society of Chemical Industry.

Soil-Plant-Microbe Interactions in Stressed Agriculture Management: A Review

Institute of Scientific and Technical Information of China (English)

Shobhit Raj VIMAL; Jay Shankar SINGH; Naveen Kumar ARORA; Surendra SINGH

2017-01-01

The expected rise in temperature and decreased precipitation owing to climate change and unabated anthropogenic activities add complexity and uncertainty to agro-industry.The impact of soil nutrient imbalance,mismanaged use of chemicals,high temperature,flood or drought,soil salinity,and heavy metal pollutions,with regard to food security,is increasingly being explored worldwide.This review describes the role of soil-plant-microbe interactions along with organic manure in solving stressed agriculture problems.Beneficial microbes associated with plants are known to stimulate plant growth and enhance plant resistance to biotic (diseases) and abiotic (salinity,drought,pollutions,etc.) stresses.The plant growth-promoting rhizobacteria (PGPR) and mycorrhizae,a key component of soil microbiota,could play vital roles in the maintenance of plant fitness and soil health under stressed environments.The application of organic manure as a soil conditioner to stressed soils along with suitable microbial strains could further enhance the plant-microbe associations and increase the crop yield.A combination of plant,stress-tolerant microbe,and organic amendment represents the tripartite association to offer a favourable environment to the proliferation of beneficial rhizosphere microbes that in turn enhance the plant growth performance in disturbed agro-ecosystem.Agriculture land use patterns with the proper exploitation of plant-microbe associations,with compatible beneficial microbial agents,could be one of the most effective strategies in the management of the concerned agriculture lands owing to climate change resilience.However,the association of such microbes with plants for stressed agriculture management still needs to be explored in greater depth.

Phytoremediation of radiocesium in different soils using cultivated plants

International Nuclear Information System (INIS)

Suzuki, Yasukazu; Saito, Takashi; Tsukada, Hirofumi

2013-01-01

A huge amount of radionuclides were released into the environment after the Fukushima Daiichi nuclear power plant accident. Radiocesium, which is one of the more prevalent radionuclides, was deposited in the soil. It is well known that radiocesium is adsorbed into the soil and binds strongly to clay. As a result, it is difficult to reduce the contamination level in the soil. We examine the possibility of decontamination by means of phytoremediation. Four species of plants (sunflower, sorghum, amaranth, and buckwheat) were sown in light-colored Andosol and gray lowland soil. When the plants matured, they were harvested and separated into their different parts, i.e., flower, leaf, stem, and root. The removal percentage of "1"3"7Cs for the aboveground parts, which is defined as the ratio of the total content of "1"3"7Cs in the aboveground biomass of plants to that in the cultivated soil of 0-15 cm depth, was 0.013- 0.93% for the light-colored Andosol and 0.0072-0.038% for the gray lowland soil. The plants exhibiting the highest value cultivated in the light-colored Andosol and gray lowland soil were amaranth (0.093%) and sunflower (0.038%), respectively. This indicates that it is difficult to remove radiocesium from contaminated soil by means of phytoremediation. (author)

An experimental study on mass loading of soil particles on plant surfaces

International Nuclear Information System (INIS)

Li, J. G.; Gerzabek, M. H.; Mueck, K.

1994-01-01

Radionuclide contaminated soil adhered to plant surfaces can contribute to human ingestion dose. To determine this contribution, a method of 46 Sc neutron activation analysis was established and tested, by which a detection limit of 0.05 mg soil per g dry plant biomass can be obtained. In the field and greenhouse experiment the mass loading of soil on ryegrass (Lolium perenne L.) and broadbean (Vicia faba L.) was investigated and the contribution from rainsplash and wind erosion were evaluated separately. Soil retained on plant surfaces in field conditions in Seibersdorf/Austria was 5.77 ± 1.44 mg soil per g dry plant for ryegrass and 9.51 ± 0.73 mg soil per g dry plant for broadbean. Estimates of contribution from rainsplash and wind erosion to soil contamination of plants during the experimental period are 68 % and 32 % for broadbean 47 % and 53 % for ryegrass respectively. Mass loading results from field studies indicate that soil adhesion on plant surfaces can contribute up to 23 % of plant 137 Cs contamination, the transfer factors modified by mass loading decline differently, depending on 137 Cs concentration of the soil and the soil mass adhered to plant surfaces. (author)

Interannual variability of plant phenology in tussock tundra: modelling interactions of plant productivity, plant phenology, snowmelt and soil thaw

NARCIS (Netherlands)

Wijk, van M.T.; Williams, M.; Laundre, J.A.; Shaver, G.R.

2003-01-01

We present a linked model of plant productivity, plant phenology, snowmelt and soil thaw in order to estimate interannual variability of arctic plant phenology and its effects on plant productivity. The model is tested using 8 years of soil temperature data, and three years of bud break data of

Arbuscular-mycorrhizal networks inhibit Eucalyptus tetrodonta seedlings in rain forest soil microcosms.

Directory of Open Access Journals (Sweden)

David P Janos

Full Text Available Eucalyptus tetrodonta, a co-dominant tree species of tropical, northern Australian savannas, does not invade adjacent monsoon rain forest unless the forest is burnt intensely. Such facilitation by fire of seedling establishment is known as the "ashbed effect." Because the ashbed effect might involve disruption of common mycorrhizal networks, we hypothesized that in the absence of fire, intact rain forest arbuscular mycorrhizal (AM networks inhibit E. tetrodonta seedlings. Although arbuscular mycorrhizas predominate in the rain forest, common tree species of the northern Australian savannas (including adult E. tetrodonta host ectomycorrhizas. To test our hypothesis, we grew E. tetrodonta and Ceiba pentandra (an AM-responsive species used to confirm treatments separately in microcosms of ambient or methyl-bromide fumigated rain forest soil with or without severing potential mycorrhizal fungus connections to an AM nurse plant, Litsea glutinosa. As expected, C. pentandra formed mycorrhizas in all treatments but had the most root colonization and grew fastest in ambient soil. E. tetrodonta seedlings also formed AM in all treatments, but severing hyphae in fumigated soil produced the least colonization and the best growth. Three of ten E. tetrodonta seedlings in ambient soil with intact network hyphae died. Because foliar chlorosis was symptomatic of iron deficiency, after 130 days we began to fertilize half the E. tetrodonta seedlings in ambient soil with an iron solution. Iron fertilization completely remedied chlorosis and stimulated leaf growth. Our microcosm results suggest that in intact rain forest, common AM networks mediate belowground competition and AM fungi may exacerbate iron deficiency, thereby enhancing resistance to E. tetrodonta invasion. Common AM networks-previously unrecognized as contributors to the ashbed effect-probably help to maintain the rain forest-savanna boundary.

134Cs uptake by four plant species and Cs-K relations in the soil-plant system as affected by Ca(OH)2 application to an acid soil

International Nuclear Information System (INIS)

Massas, I.; Skarlou, V.; Haidouti, C.; Giannakopoulou, F.

2010-01-01

Three rates of Ca(OH) 2 were applied to an acid soil and the 134 Cs uptake by radish, cucumber, soybean and sunflower plants was studied. The 134 Cs concentration in all plant species was reduced from 1.6-fold in the sunflower seeds to 6-fold in the soybean vegetative parts at the higher Ca(OH) 2 rate. Potassium (K) concentration in plants was also reduced, but less effectively. The significantly decreased 134 Cs-K soil to plant distribution factors (D.F.) clearly suggest a stronger effect of soil liming on 134 Cs than on K plant uptake. This observation was discussed in terms of ionic interactions in the soil matrix and within the plants. The results also indicated that the increased Ca 2+ concentration in the exchange phase and in the soil solution along with the improved root activity, due to the soil liming, enhanced the immobilization of 134 Cs in the soil matrix and consequently lowered the 134 Cs availability for plant uptake.

Screening of plants for phytoremediation of oil-contaminated soil.

Science.gov (United States)

Ikeura, Hiromi; Kawasaki, Yu; Kaimi, Etsuko; Nishiwaki, Junko; Noborio, Kosuke; Tamaki, Masahiko

2016-01-01

Several species of ornamental flowering plants were evaluated regarding their phytoremediation ability for the cleanup of oil-contaminated soil in Japanese environmental conditions. Thirty-three species of plants were grown in oil-contaminated soil, and Mimosa, Zinnia, Gazania, and cypress vine were selected for further assessment on the basis of their favorable initial growth. No significant difference was observed in the above-ground and under-ground dry matter weight of Gazania 180 days after sowing between contaminated and non-contaminated plots. However, the other 3 species of plants died by the 180th day, indicating that Gazania has an especially strong tolerance for oil-contaminated soil. The total petroleum hydrocarbon concentration of the soils in which the 4 species of plants were grown decreased by 45-49% by the 180th day. Compared to an irrigated plot, the dehydrogenase activity of the contaminated soil also increased significantly, indicating a phytoremediation effect by the 4 tested plants. Mimosa, Zinnia, and cypress vine all died by the 180th day after seeding, but the roots themselves became a source of nutrients for the soil microorganisms, which led to a phytoremediation effect by increase in the oil degradation activity. It has been indicated that Gazania is most appropriate for phytoremediation of oil-contaminated soil.

Caesium Radionuclide Uptake from Wet Soil to Kangkung Plant (Ipomoea sp)

International Nuclear Information System (INIS)

Putu Sukmabuana; Poppy Intan Tjahaja

2009-01-01

Caesium radionuclide transfer from soil to kangkung plant (Ipomoea sp) generally consumed by people had been examined to obtain transfer factor value for internal radiation dose assessment via soil-plant-human pathway. The kangkung plants were cultivated on watered soil medium containing 134 Cs with concentration of about 80 Bq/g, and the 134 Cs uptake by plants, i.e root, stem, and leaves, were measured using gamma spectrometer. The 134 Cs plant uptake was expressed as transfer factor, i.e. ratio of plant 134 Cs concentration to 134 Cs concentration on soil medium. From this research it was obtained transfer factor value of 134 C from soil to plant is 0.07, and the transfer factor for root, stem, and leaves are 0.34 ; 0.05 ; 0,03 respectively, after 45 days cultivation. The transfer factor values are less than one, indicate that kangkung plant do not accumulate Cs radionuclide from soil. (author)

Linking plants, fungi and soil mechanics

Science.gov (United States)

Yildiz, Anil; Graf, Frank

2017-04-01

Plants provide important functions in respect soil strength and are increasingly considered for slope stabilisation within eco-engineering methods, particularly to prevent superficial soil failure. The protective functions include hydrological regulation through interception and evapo-transpiration as well as mechanical stabilisation through root reinforcement and, to a certain extent, chemical stabilisation through sticky metabolites. The ever-growing application of plants in slope stabilisation demanded more precise information of the vegetation effects and, concomitant, led the models for quantifying the reinforcement shoot up like mushrooms. However, so far, the framework and interrelationships for both the role of plants and the quantification concepts have not been thoroughly analysed and comprehensively considered, respectively, often resulting in unsatisfactory results. Although it seems obvious and is implicitly presupposed that the plant specific functions related to slope stability require growth and development, this is anything but given, particularly under the often hostile conditions dominating on bare and steep slopes. There, the superficial soil layer is often characterised by a lack of fines and missing medium-sized and fine pores due to an unstable soil matrix, predominantly formed by coarse grains. Low water retention capacity and substantial leaching of nutrients are the adverse consequences. Given this general set-up, sustainable plant growth and, particularly, root development is virtually unachievable. At exactly this point mycorrhizal fungi, the symbiotic partners of almost all plants used in eco-engineering, come into play. Though, they are probably well-known within the eco-engineering community, mycorrhizal fungi lead a humble existence. This is in spite of the fact that they supply their hosts with water and nutrients, improving the plant's ability to master otherwise unbridgeable environmental conditions. However, in order to support

UNDERSTANDING PLANT-SOIL RELATIONSHIPS USING CONTROLLED ENVIRONMENT FACILITIES

Science.gov (United States)

Although soil is a component of terrestrial ecosystems, it is comprised of a complex web of interacting organisms, and therefore, can be considered itself as an ecosystem. Soil microflora and fauna derive energy from plants and plant residues and serve important functions in mai...

Soil-plant transfer models for metals to improve soil screening value guidelines valid for São Paulo, Brazil.

NARCIS (Netherlands)

Dos Santos-Araujo, Sabrina N; Swartjes, Frank A; Versluijs, Kees W; Moreno, Fabio Netto; Alleoni, Luís R F

2017-01-01

In Brazil, there is a lack of combined soil-plant data attempting to explain the influence of specific climate, soil conditions, and crop management on heavy metal uptake and accumulation by plants. As a consequence, soil-plant relationships to be used in risk assessments or for derivation of soil

Review of effect of soil on radionuclide uptake by plants

International Nuclear Information System (INIS)

Sheppard, S.C.; Evenden, W.G.

1987-03-01

This review was undertaken to improve the understanding of, and to compile the available data concerning, the transfer of uranium (U), thorium (Th) and lead (Pb) from soils to plants. The emphasis of the review was on the absorption of these elements from the soil by plant roots, and the mechanisms underlying this process were outlined. The behaviour of U, Th and Pb in soils and plants was discussed with illustration by data from the literature. An extensive compilation of plant/soil concentration ratios (CR) was completed and the most relevant data for Canadian nuclear facilities were selected. Very few data were found for edible plants and these did not represent the range of soil types found near Canadian nuclear facilities. Recommendations of the most fruitful research directions were made. 69 refs

Spatial heterogeneity of plant-soil feedback affects root interactions and interspecific competition.

Science.gov (United States)

Hendriks, Marloes; Ravenek, Janneke M; Smit-Tiekstra, Annemiek E; van der Paauw, Jan Willem; de Caluwe, Hannie; van der Putten, Wim H; de Kroon, Hans; Mommer, Liesje

2015-08-01

Plant-soil feedback is receiving increasing interest as a factor influencing plant competition and species coexistence in grasslands. However, we do not know how spatial distribution of plant-soil feedback affects plant below-ground interactions. We investigated the way in which spatial heterogeneity of soil biota affects competitive interactions in grassland plant species. We performed a pairwise competition experiment combined with heterogeneous distribution of soil biota using four grassland plant species and their soil biota. Patches were applied as quadrants of 'own' and 'foreign' soils from all plant species in all pairwise combinations. To evaluate interspecific root responses, species-specific root biomass was quantified using real-time PCR. All plant species suffered negative soil feedback, but strength was species-specific, reflected by a decrease in root growth in own compared with foreign soil. Reduction in root growth in own patches by the superior plant competitor provided opportunities for inferior competitors to increase root biomass in these patches. These patterns did not cascade into above-ground effects during our experiment. We show that root distributions can be determined by spatial heterogeneity of soil biota, affecting plant below-ground competitive interactions. Thus, spatial heterogeneity of soil biota may contribute to plant species coexistence in species-rich grasslands. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Radiochlorine concentration ratios for agricultural plants in various soil conditions

International Nuclear Information System (INIS)

Kashparov, V.; Colle, C.; Levchuk, S.; Yoschenko, V.; Zvarich, S.

2007-01-01

Long-term field experiments have been carried out in the Chernobyl exclusion zone in order to determine the parameters governing radiochlorine ( 36 Cl) transfer to plants from four types of soil, namely, Podzoluvisol, Greyzem, Phaeozem and Chernozem. Radiochlorine concentration ratios (CR = concentration of 36 Cl in the fresh plant material divided by its concentration in the dried soil in the upper 20 cm layer) were obtained in green peas (2.6 ± 0.4), onions (1.5 ± 0.5), potatoes (8 ± 1), clover (90 ± 26) and ryegrass (158 ± 88) hay, oat seeds (36 ± 23) and straw (305 ± 159), wheat seeds (35 ± 10) and straw (222 ± 82). These values correlate with the stable chlorine values for the same plants. It was shown that 36 Cl plant/soil CR in radish roots (CR = 9.7 ± 1.4) does not depend on the stable chlorine content in the soil (up to 150 mg kg -1 ), soil type and thus, that stable chlorine CR values (9.4 ± 1.2) can also be used for 36 Cl. Injection of additional quantities of stable chlorine into the soil (100 mg kg -1 of dry soil) with fertilizer does not change the soil-to-plant transfer of 36 Cl. The results from a batch experiment showed that chlorine is retained in the investigated soils only by live biota and transfers quickly (in just a few hours) into the soil solution from dry vegetation even without decomposition of dead plants and is integrated in the migration processes in soil

Radiochlorine concentration ratios for agricultural plants in various soil conditions

Energy Technology Data Exchange (ETDEWEB)

Kashparov, V. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Strasse 7, Chabany, Kiev Region 08162 (Ukraine); Colle, C. [Institute for Radioprotection and Nuclear Safety (IRSN/DEI/SECRE), Cadarache bat 159, BP 3, 13115 Saint Paul-Lez-Durance (France)]. E-mail: claude.colle@irsn.fr; Levchuk, S. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Strasse 7, Chabany, Kiev Region 08162 (Ukraine); Yoschenko, V. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Strasse 7, Chabany, Kiev Region 08162 (Ukraine); Zvarich, S. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Strasse 7, Chabany, Kiev Region 08162 (Ukraine)

2007-06-15

Long-term field experiments have been carried out in the Chernobyl exclusion zone in order to determine the parameters governing radiochlorine ({sup 36}Cl) transfer to plants from four types of soil, namely, Podzoluvisol, Greyzem, Phaeozem and Chernozem. Radiochlorine concentration ratios (CR = concentration of {sup 36}Cl in the fresh plant material divided by its concentration in the dried soil in the upper 20 cm layer) were obtained in green peas (2.6 {+-} 0.4), onions (1.5 {+-} 0.5), potatoes (8 {+-} 1), clover (90 {+-} 26) and ryegrass (158 {+-} 88) hay, oat seeds (36 {+-} 23) and straw (305 {+-} 159), wheat seeds (35 {+-} 10) and straw (222 {+-} 82). These values correlate with the stable chlorine values for the same plants. It was shown that {sup 36}Cl plant/soil CR in radish roots (CR = 9.7 {+-} 1.4) does not depend on the stable chlorine content in the soil (up to 150 mg kg{sup -1}), soil type and thus, that stable chlorine CR values (9.4 {+-} 1.2) can also be used for {sup 36}Cl. Injection of additional quantities of stable chlorine into the soil (100 mg kg{sup -1} of dry soil) with fertilizer does not change the soil-to-plant transfer of {sup 36}Cl. The results from a batch experiment showed that chlorine is retained in the investigated soils only by live biota and transfers quickly (in just a few hours) into the soil solution from dry vegetation even without decomposition of dead plants and is integrated in the migration processes in soil.

Interspecific competition of early successional plant species in ex-arable fields as influenced by plant-soil feedback

OpenAIRE

Jing, Jingying; Bezemer, T. Martijn; Van der Putten, Wim H.

2015-01-01

Plant–soil feedback can affect plants that belong to the same (intraspecific feedback) or different species (interspecific feedback). However, little is known about how intra- and interspecific plant–soil feedbacks influence interspecific plant competition. Here, we used plants and soil from early-stage ex-arable fields to examine how intra- and interspecific plant–soil feedbacks affect the performance of 10 conditioning species and the focal species, Jacobaea vulgaris. Plants were grown alon...

Effect of soil type on radionuclides in plants

International Nuclear Information System (INIS)

1988-12-01

The research was undertaken to provide plant/soil concentration ratio (CR) data for uranium (U), thorium (Th) and lead (Pb) using crops and soils typical of Canada. A clay, a silt, a sand and an organic soil were used and spinach, potatoes, corn, blueberries, wild rice, barley and radish were grown. CR values decreased among the soils in the order sand > silt = clay > organic. CR values were lower in potato flesh than in potato peels, and usually lower in grains than in the associated stems. the geometric mean CR values for U, Th and Pb on a dry plant/dry soil basis were 0.013, 0.0022, and 0.0050, respectively

Nuclear pre-mRNA processing in plants

Energy Technology Data Exchange (ETDEWEB)

Reddy, A.S.N. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Biology and Program in Molecular Plant Biology; Golovkin, M. (eds.) [Thomas Jefferson Univ., Philadelphia, PA (United States). Dept. of Microbiology

2008-07-01

This volume of CTMI, entitled Nuclear premRNA Processing in Plants, with 16 chapters from leading scientists in this area, summarizes recent advances in nuclear pre-mRNA processing and its role in plant growth and development. It provides researchers in the field, as well as those in related areas, with an up-to-date and comprehensive, yet concise, overview of the current status and future potential of this research in understanding plant biology. The first four chapters focus on spliceosome composition, genome-wide alternative splicing, and splice site requirements for U1 and U12 introns using computational and empirical approaches. Analysis of sequenced plant genomes has revealed that 80% of all protein-coding nuclear genes contain one or more introns. The lack of an in vitro plant splicing system has made it difficult to identify general and plant-specific components of splicing machinery in plants. The next three chapters focus on serine/arginine-rich (SR) proteins, a family of highly conserved proteins, which are known to play key roles in constitutive and regulated splicing of pre-mRNA and other aspects of RNA metabolism in metazoans. These proteins engage both in RNA binding and protein.protein interactions and function as splicing regulators at multiple stages of spliceosome assembly. This family of proteins has expanded considerably in plants with several plant-specific SR proteins. Several serendipitous discoveries made using forward genetics are indicating that RNA metabolism (alternative splicing, alternative polyadenylation, mRNA transport) plays an important role in many aspects of plant growth and development and in plant responses to biotic and abiotic stresses. The next seven chapters focus on these aspects of RNA metabolism. The plant hormone abscisic acid (ABA) regulates a number of physiological processes during plant growth and development. The next chapter or A.B. Rose discusses the ways introns affect gene expression both positively and

Nuclear pre-mRNA processing in plants

International Nuclear Information System (INIS)

Reddy, A.S.N.; Golovkin, M.

2008-01-01

This volume of CTMI, entitled Nuclear premRNA Processing in Plants, with 16 chapters from leading scientists in this area, summarizes recent advances in nuclear pre-mRNA processing and its role in plant growth and development. It provides researchers in the field, as well as those in related areas, with an up-to-date and comprehensive, yet concise, overview of the current status and future potential of this research in understanding plant biology. The first four chapters focus on spliceosome composition, genome-wide alternative splicing, and splice site requirements for U1 and U12 introns using computational and empirical approaches. Analysis of sequenced plant genomes has revealed that 80% of all protein-coding nuclear genes contain one or more introns. The lack of an in vitro plant splicing system has made it difficult to identify general and plant-specific components of splicing machinery in plants. The next three chapters focus on serine/arginine-rich (SR) proteins, a family of highly conserved proteins, which are known to play key roles in constitutive and regulated splicing of pre-mRNA and other aspects of RNA metabolism in metazoans. These proteins engage both in RNA binding and protein.protein interactions and function as splicing regulators at multiple stages of spliceosome assembly. This family of proteins has expanded considerably in plants with several plant-specific SR proteins. Several serendipitous discoveries made using forward genetics are indicating that RNA metabolism (alternative splicing, alternative polyadenylation, mRNA transport) plays an important role in many aspects of plant growth and development and in plant responses to biotic and abiotic stresses. The next seven chapters focus on these aspects of RNA metabolism. The plant hormone abscisic acid (ABA) regulates a number of physiological processes during plant growth and development. The next chapter or A.B. Rose discusses the ways introns affect gene expression both positively and

Interspecific competition of early successional plant species in ex-arable fields as influenced by plant-soil feedback

NARCIS (Netherlands)

Jing, Jingying; Bezemer, T. Martijn; Van der Putten, Wim H.

2015-01-01

Plant–soil feedback can affect plants that belong to the same (intraspecific feedback) or different species (interspecific feedback). However, little is known about how intra- and interspecific plant–soil feedbacks influence interspecific plant competition. Here, we used plants and soil from

Effects of Soil Quality Enhancement on Pollinator-Plant Interactions

Directory of Open Access Journals (Sweden)

Yasmin J. Cardoza

2012-01-01

Full Text Available Both biotic and abiotic factors can affect soil quality, which can significantly impact plant growth, productivity, and resistance to pests. However, the effects of soil quality on the interactions of plants with beneficial arthropods, such as pollinators, have not been extensively examined. We studied the effects of vermicompost (earthworm compost, VC soil amendment on behavioral and physiological responses of pollinators to flowers and floral resources, using cucumbers, Cucumis sativus, as our model system. Results from experiments conducted over three field seasons demonstrated that, in at least two out of three years, VC amendment significantly increased visit length, while reducing the time to first discovery. Bumblebee (Bombus impatiens workers that fed on flowers from VC-amended plants had significantly larger and more active ovaries, a measure of nutritional quality. Pollen fractions of flowers from VC-grown plants had higher protein compared to those of plants grown in chemically fertilized potting soil. Nectar sugar content also tended to be higher in flowers from VC-grown plants, but differences were not statistically significant. In conclusion, soil quality enhancement, as achieved with VC amendment in this study, can significantly affect plant-pollinator interactions and directly influences pollinator nutrition and overall performance.

Decomposition of Straw in Soil after Stepwise Repeated Additions

DEFF Research Database (Denmark)

Sørensen, Lasse Holst

1979-01-01

after the first repeated addition of labelled straw the soils were subjected to a number of “stress” treatments: addition of unlabelled glucose, air-drying, oven-drying, grinding and fumigation with vapour of chloroform, respectively. The CO2 that developed during the first 10 days after the treatments......, grinding the most. The effect of each treatment declined with an increasing number of successive additions of straw. The ratio between CO2 evolved after grinding and fumigation, respectively, revealed that grinding also exposed non-biomass material to accelerated decomposition. The effects of the stress...

Predicting molybdenum toxicity to higher plants: Influence of soil properties

International Nuclear Information System (INIS)

McGrath, S.P.; Mico, C.; Curdy, R.; Zhao, F.J.

2010-01-01

The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED 50 ) of Mo in different soils, explaining > 65% of the variance in ED 50 for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. - Amorphous iron oxides or organic carbon were found to be the best predictors of the toxicity threshold values of Mo to higher plants on different soils.

Plant uptake of pentachlorophenol from sludge-amended soils

International Nuclear Information System (INIS)

Bellin, C.A.; O'Connor, G.A.

1990-01-01

A greenhouse study was conducted to determine the effects of sludge on plant uptake of 14 C-pentachlorophenol (PCP). Plants included tall fescue (Festuca arundinacea Schreb.), lettuce (Latuca sativa L.), carrot (Daucus carota L.), and chile pepper (Capsicum annum L.). Minimal intact PCP was detected in the fescue and lettuce by gas chromatography/mass spectrometry (GC/MS) analysis. No intact PCP was detected in the carrot tissue extracts. Chile pepper was not analyzed for intact PCP because methylene chloride extracts contained minimal 14 C. The GC/MS analysis of soil extracts at harvest suggests a half-life of PCP of about 10 d independent of sludge rate or PCP loading rate. Rapid degradation of PCP in the soil apparently limited PCP availability to the plant. Bioconcentration factors (dry plant wt./initial soil PCP concentration) based on intact PCP were < 0.01 for all crops, suggesting little PCP uptake. Thus, food-chain crop PCP uptake in these alkaline soils should not limit land application of sludge

Soil-plant transfer models for metals to improve soil screening value guidelines valid for São Paulo, Brazil.

Science.gov (United States)

Dos Santos-Araujo, Sabrina N; Swartjes, Frank A; Versluijs, Kees W; Moreno, Fabio Netto; Alleoni, Luís R F

2017-11-07

In Brazil, there is a lack of combined soil-plant data attempting to explain the influence of specific climate, soil conditions, and crop management on heavy metal uptake and accumulation by plants. As a consequence, soil-plant relationships to be used in risk assessments or for derivation of soil screening values are not available. Our objective in this study was to develop empirical soil-plant models for Cd, Cu, Pb, Ni, and Zn, in order to derive appropriate soil screening values representative of humid tropical regions such as the state of São Paulo (SP), Brazil. Soil and plant samples from 25 vegetable species in the production areas of SP were collected. The concentrations of metals found in these soil samples were relatively low. Therefore, data from temperate regions were included in our study. The soil-plant relations derived had a good performance for SP conditions for 8 out of 10 combinations of metal and vegetable species. The bioconcentration factor (BCF) values for Cd, Cu, Ni, Pb, and Zn in lettuce and for Cd, Cu, Pb, and Zn in carrot were determined under three exposure scenarios at pH 5 and 6. The application of soil-plant models and the BCFs proposed in this study can be an important tool to derive national soil quality criteria. However, this methodological approach includes data assessed under different climatic conditions and soil types and need to be carefully considered.

An experimental study on mass loading of soil particles on plant surfaces

International Nuclear Information System (INIS)

Li, J.; Gerzabek, M.H.; Mueck, K.

1994-03-01

Radionuclide contaminated soil adhered to plant surfaces can contribute to human ingestion dose. To determine this contribution, a method of 46 Sc neutron activation analysis was established and tested, by which a detection limit of 0.05 mg soil per g dry plant biomass can be obtained. In the field and greenhouse experiment the mass loading of soil on ryegrass (Lolium perenne L.) and broad bean (Vicia faba L.) was investigated and the contribution from rainsplash and wind erosion were evaluated separately. Soil retained on plant surfaces in field conditions in Seibersdorf/Austria was 5.77 ± 1.44 mg soil per g dry plant for ryegrass and 9.51 ± 0.73 mg soil per g dry plant for broad bean. Estimates of contribution from rainsplash and wind erosion to soil contamination of plant during the experimental period are 68 % and 32 % for broadbean, 47 % and 53 % for ryegrass, respectively. Mass loading results from field studies indicate that soil adhesion on plant surfaces can contribute up to 23 % of plant 137 Cs contamination, the transfer factors modified by mass loading decline differently, depending on 137 Cs concentration of the soil and the soil mass adhered to plant surfaces. (authors)

Radium - 226 levels in some sudanese plants and soils

International Nuclear Information System (INIS)

Sam, A.K.

1993-01-01

The natural levels of 226 Ra in plant and soil samples have been studied. The field study was mainly conducted in western Sudan (Darfur and Kurdofan) where areas of high natural background radiation have been identified and Khartoum area was taken as a control to (i) assess in natural setting the soil-to-plant concentration ratios (concentration in dry sample / concentration in dry soil) of the naturally occurring radionuclide 226 Ra, (ii) establish base-line data on Radium activity concentration levels in environmental materials and (iii) explore the area of high natural radiation background in western Sudan.Low level gamma spectrometry, employing high purity germanium detector (HPGe) of relative efficiency 12%, has been used for the determination of 226 Ra activity concentrations in plant and soil samples. The mean Radium activity concentration found in soil ranged from 14.41 Bq/Kg to 79.08 Bq/Kg, the values correspond to the reported normal background levels of 226 Ra in soils worldwide. Radium activity concentrations found in Sudanese plants were significantly higher compared to those related to plants from normal background regions and significantly lower than those reported for plants from high background regions in other countries. The mean soil/plant concentration ratios (CRs) found in this study were 0.12, 0.15, 0.17 and 0.08 for whole plants, fruits and leafy vegetables, root vegetables and grains, respectively. These ranges of CR values are comparable with overall range of CR where environmental conditions are normal. The estimated daily intakes by individuals consuming foods of local origin were 1.00, 10.4 and 7.91 Bq/Day of radium Khour Abu Habil, Arkuri and Dumpir, respectively. Since the dietary habits were different, as it was noticed, these results have been much lower in comparison with those obtained from some European countries and United States. (author), 44 refs., 18 tabs., 13 figs

Fate of polycyclic aromatic hydrocarbons in plant-soil systems: Plant responses to a chemical stress in the root zone

Energy Technology Data Exchange (ETDEWEB)

Hoylman, Anne M. [Univ. of Tennessee, Knoxville, TN (United States)

1994-01-01

Under laboratory conditions selected to maximize root uptake, plant tissue distribution of PAH-derived ¹⁴C was largely limited to root tissue of Malilotus alba. These results suggest that plant uptake of PAHs from contaminated soil via roots, and translocation to aboveground plant tissues (stems and leaves), is a limited mechanism for transport into terrestrial food chains. However, these data also indicate that root surface sorption of PAHs may be important for plants grown in soils containing elevated concentration PAHs. Root surface sorption of PAHs may be an important route of exposure for plants in soils containing elevated concentrations of PAHS. Consequently, the root-soil interface may be the site of plant-microbial interactions in response to a chemical stress. In this study, evidence of a shift in carbon allocation to the root zone of plants exposed to phenanthrene and corresponding increases in soil respiration and heterotrophic plate counts provide evidence of a plant-microbial response to a chemical stress. The results of this study establish the importance of the root-soil interface for plants growing in PAH contaminated soil and indicate the existence of plant-microbial interactions in response to a chemical stress. These results may provide new avenues of inquiry for studies of plant toxicology, plant-microbial interactions in the rhizosphere, and environmental fates of soil contaminants. In addition, the utilization of plants to enhance the biodegradation of soil contaminants may require evaluation of plant physiological changes and plant shifts in resource allocation.

Plant-soil interactions promote co-occurrence of three nonnative woody shrubs.

Science.gov (United States)

Kuebbing, Sara E; Classen, Aimée T; Call, Jaime J; Henning, Jeremiah A; Simberloff, Daniel

2015-08-01

Ecosystems containing multiple nonnative plant species are common, but mechanisms promoting their co-occurrence are understudied. Plant-soil interactions contribute to the dominance of singleton species in nonnative ranges because many nonnatives experience stronger positive feedbacks relative to co-occurring natives. Plant-soil interactions could impede other nonnatives if an individual nonnative benefits from its soil community to a greater extent than its neighboring nonnatives, as is seen with natives. However, plant-soil interactions could promote nonnative co-occurrence if a nonnative accumulates beneficial soil mutualists that also assist other nonnatives. Here, we use greenhouse and field experiments to ask whether plant-soil interactions (1) promote the codominance of two common nonnative shrubs (Ligustrum sinense and Lonicera maackii) and (2) facilitate the invasion of a less-common nonnative shrub (Rhamnus davurica) in deciduous forests of the southeastern United States. In the greenhouse, we found that two of the nonnatives, L. maackii and R. davurica, performed better in soils conditioned by nonnative shrubs compared to uninvaded forest soils, which. suggests that positive feedbacks among co-occurring nonnative shrubs can promote continued invasion of a site. In both greenhouse and field experiments, we found consistent signals that the codominance of the nonnatives L. sinense and L. maackii may be at least partially explained by the increased growth of L. sinense in L. maackii soils. Overall, significant effects of plant-soil interactions on shrub performance indicate that plant-soil interactions can potentially structure the co-occurrence patterns of these nonnatives.

Interlaboratory Comparetive Studies of Soil/Plant Analysis Methods ...

African Journals Online (AJOL)

The information on analytical techniques that are used for soil and plant analyses in different agricultural laboratories of Kenya was gathered and compiled in table forms. Performance of six laboratories was compaired for different elements and parameters of soil and plant samples. Chemical analysis of identical samples ...

Effects of soil depth and plant-soil interaction on microbial community in temperate grasslands of northern China.

Science.gov (United States)

Yao, Xiaodong; Zhang, Naili; Zeng, Hui; Wang, Wei

2018-07-15

Although the patterns and drivers of soil microbial community composition are well studied, little is known about the effects of plant-soil interactions and soil depth on soil microbial distribution at a regional scale. We examined 195 soil samples from 13 sites along a climatic transect in the temperate grasslands of northern China to measure the composition of and factors influencing soil microbial communities within a 1-m soil profile. Soil microbial community composition was measured using phospholipid fatty acids (PLFA) analysis. Fungi predominated in topsoil (0-10 cm) and bacteria and actinomycetes in deep soils (40-100 cm), independent of steppe types. This variation was explained by contemporary environmental factors (including above- and below-ground plant biomass, soil physicochemical and climatic factors) >58% in the 0-40 cm of soil depth, but soils. Interestingly, when we considered the interactive effects between plant traits (above ground biomass and root biomass) and soil factors (pH, clay content, and soil total carbon, nitrogen, phosphorous), we observed a significant interaction effect occurring at depths of 10-20 cm soil layer, due to different internal and external factors of the plant-soil system along the soil profile. These results improve understanding of the drivers of soil microbial community composition at regional scales. Copyright © 2018 Elsevier B.V. All rights reserved.

Reduction of Cadmium Uptake of Rice Plants Using Soil Amendments in High Cadmium Contaminated Soil: A Pot Experiment

Directory of Open Access Journals (Sweden)

Dian Siswanto

2013-05-01

Full Text Available The aims of this study were to investigate the effect of agricultural residues on reducing cadmium uptake in rice plants. The rice plants growing on no cadmium/free cadmium soils (N, Cd soils (Cds, and Cd soils each amended with 1% w/w of coir pith (CP, coir pith modified with sodium hydroxide (CPm and corncob (CC under high cadmium contaminated soil with an average 145 mg Cd kg-1 soil were investigated. The results showed that the cumulative transpiration of rice grown in various treatments under high cadmium contaminated soil followed the order: Cds > CPm ≥ CP ≥ CC. These transpirations directly influenced cadmium accumulation in shoots and husks of rice plants. The CC and CP seemed to work to reduce the cadmium uptake by rice plants indicated by accumulated cadmium in the husk that were 2.47 and 7.38 mg Cd kg-1 dry weight, respectively. Overall, transpiration tended to drive cadmium accumulation in plants for rice grown in high cadmium contaminated soil. The more that plants uptake cadmium, the lower cadmium that remains in the soil.

Plant effects on soil denitrification - a review of potential mechanisms

Science.gov (United States)

Malique, Francois; Butterbach-Bahl, Klaus; Dannenmann, Michael

2017-04-01

Denitrification is a microbial process occurring in soils, both producing and consuming the potent greenhouse gas nitrous oxide (NO), competing for nitrate with plants and hydrological leaching pathways, removing nutrients and reactive nitrogen from the biosphere, and closing the global nitrogen cycle. Despite its obvious importance, denitrification remained among the least well quantified biogeochemical processes in soils. This is due to enormous methodological difficulties involved in the direct quantification of soil microbial denitrification rates (mainly with regard to the terminal product N2) and the denitrification nitrogen gas product ratios (NO:N2O:N2), Plants may affect denitrification through a myriad of mechanisms such as e.g., competition for nitrate and water, through oxygen consumption, by regulating litter quality and changing soil pH, and via the exudation of labile carbon or secondary plant compounds involved in shaping the rhizospheric microbial community. However, plant effects on denitrification so far hardly were quantified so that the actual extent of plant control on denitrification is largely unknown. Here, we summarize the current knowledge on mechanisms how plants can affect denitrification rates and N gas product ratios in soils at temporal scales from hours to days and years. We review earlier research to quantify plant effects on denitrification as well as critically discuss the limited methods currently available to quantify plant-soil-denitrifier interactions. Finally, we provide pointers to use plants as tools to manage denitrification, e.g. to improve N use efficiency in agricultural ecosystems and to minimize soil nitrous oxide emissions.

Divergent composition but similar function of soil food webs of individual plants: plant species and community effects

NARCIS (Netherlands)

Bezemer, T.M.; Fountain, T.; Barea, J.M.; Christensen, S.; Dekker, S.C.; Duyts, H.; Hal, van R.; Harvey, J.A.; Hedlund, K.; Maraun, M.; Mikola, J.; Mladenov, A.G.; Robin, C.; Ruiter, de P.C.; Scheu, H.; Setälä, S.; šmilauer, P.; Putten, van der W.H.

2010-01-01

Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and

Divergent composition but similar function of soil food webs beneath individual plants: plant species and community effects

NARCIS (Netherlands)

Bezemer, T.M.; Fountain, M.T.; Barea, J.M.; Christensen, S.; Dekker, S.C.; Duyts, H.; van Hal, R.; Harvey, J.A.; Hedlund, K.; Maraun, M.; Mikola, J.; Mladenov, A.G.; Robin, C.; de Ruiter, P.C.; Scheu, S.; Setälä, H.; Milauer, P.; Van der Putten, W.H.

2010-01-01

Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and

Methyl Bromide Commodity Fumigation Buffer Zone Lookup Tables

Science.gov (United States)

Product labels for methyl bromide used in commodity and structural fumigation include requirements for buffer zones around treated areas. The information on this page will allow you to find the appropriate buffer zone for your planned application.

Influence of copper high-tension lines on plants and soils

Energy Technology Data Exchange (ETDEWEB)

Kraal, H.; Ernst, W.

1976-09-01

The copper contents of plants and soils were determined in relation to the distance from copper high-tension lines. In the vicinity of the cables clayey and fenny soils had demonstrably higher copper contents, due to corrosion of the cables, than regions 20 m and more outside the high-tension lines. On these soils, however, copper accumulation in the plants was low in comparison with those from a sandy soil, although this soil itself showed no copper increase in relation to the cables. The contaminated plants may present a risk of poisoning for sheep within a 20 m distance on both sides of the cables. No changes in plant species composition and in the copper tolerance of Agrostis tenuis were observed.

Predicting molybdenum toxicity to higher plants: Influence of soil properties

Energy Technology Data Exchange (ETDEWEB)

McGrath, S.P., E-mail: steve.mcgrath@bbsrc.ac.u [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Mico, C. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Curdy, R. [Laboratory for Environmental Biotechnology (LBE), Swiss Federal Institute of Technology Lausanne (EPFL) Station 6 CH, 1015 Lausanne (Switzerland); Zhao, F.J. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom)

2010-10-15

The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED{sub 50}) of Mo in different soils, explaining > 65% of the variance in ED{sub 50} for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. - Amorphous iron oxides or organic carbon were found to be the best predictors of the toxicity threshold values of Mo to higher plants on different soils.

Relationship of sulfur content of soils and plants

Energy Technology Data Exchange (ETDEWEB)

Hengl, F; Reckendorfer, P

1928-01-01

Crops were fertilized with fertilizers which contained chloride and sulfate in order to examine how the sulfur content of a plant may be affected by that of the soil. At the time of flowering the respective chlorine or sulfate content of the plants was considerably above that of the controls; differences were less, however, when the plants were fully mature. Sulfate, in particular, was little different. In field observations, little correlation was noted between sulfate content of plants and soils. Natural variations in the sulfur content of plants were greater than the increases attributable to smoke air pollution. 2 tables.

A soil-based model to predict radionuclide transfer in a soil-plant system

International Nuclear Information System (INIS)

Roig, M.; Vidal, M.; Tent, J.; Rauret, G.; Roca, M.C.; Vallejo, V.R.

1998-01-01

The aim of this work was to check if the main soil parameters predefined as ruling soil-plant transfer were sufficient to predict a relative scale of radionuclide mobility in mineral soils. Two agricultural soils, two radionuclides ( 85 Sr and 134 Cs), and two crops (lettuce and pea) were used in these experiments following radioactive aerosol deposition simulating the conditions of a site some distance far away from the center of a nuclear accident, for which condensed deposition would be the more significant contribution. The available fraction of these radionuclides was estimated in these soils from experiments in which various reagents were tested and several experimental conditions were compared. As a general conclusion, the soil parameters seemed to be sufficient for prediction purposes, although the model should be improved through the consideration of physiological aspects, especially those depending of the plant selectivity according to the composition of the soil solution

Greater soil carbon accumulation in deeper soils in native- than in exotic-dominated grassland plantings in the southern Plains

Science.gov (United States)

Wilsey, B. J.; Xu, X.; Polley, H. W.; Hofmockel, K. S.

2017-12-01

Global change includes invasion by non-native plant species, and invasion may affect carbon cycling and storage. We tested predictions in central Texas in an experiment that compares mixtures of all exotic or all native species under two summer irrigation treatments (128 or 0 mm) that varies the amount of summer drought stress. At the end of the eighth growing season after establishment, soils were sampled in 10 cm increments to 100 cm depth to determine if soil C differed among treatments, and if treatments differentially affected soil C in deeper soils. Soil C content was significantly (5%) higher under native plantings than under exotic species plantings (P plantings increased with depth, and native plantings had higher soil C in deeper soil layers than in surface layers (native-exotic x depth, P plantings had decreasing soil C with depth. Soil C:N ratio and δ13C/12C were also significantly affected by native-exotic status, with soils in exotic plots having a significantly greater C4 contribution than native soils. Soil C was unaffected by summer irrigation treatments. Our results suggest that a significant amount of carbon could be sequestered by replacing exotic plant species with native species in the southern Plains, and that more work should be conducted at deeper soil depths. If we had restricted our analyses to surface soil layers (e.g. top 30 cm), we would have failed to detect depth differences between natives and exotics.

Soil-to-plant concentration factors for radiological assessments

International Nuclear Information System (INIS)

Ng, Y.C.; Thompson, S.E.; Colsher, C.S.

1982-09-01

This report presents the results of a literature review to derive soil-to-plant concentration factors to predict the concentration of a radionuclide in plants from that in soil. The concentration factor, B/sub v/ is defined as the ratio of the concentration of a nuclide in the edible plant part to that in dry soil. CR (the concentration ratio) is similarly defined to denote the concentration factor for dry feed consumed by livestock. B/sub v/ and CR values are used to assess the dose from radionuclides deposited onto soil and transferred into crop plants via roots. Approaches for deriving B/sub v/ and CR values are described, and values for food and feed are tabulated for individual elements. The sources of uncertainty are described, and the factors that contribute to the inherent variability of the B/sub v/ and CR values are discussed. Summary tables of elemental B/sub v/ and CR values and statistical parameters that characterize their distributions provide a basis for a systematic updating of many of the B/sub v/ values in Regulatory Guide 1.109. They also provide a basis for selecting B/sub v/ and CR values for other applications that involve the use of equilibrium models to predict the concentration of radionuclides in plants from that in soil

Plant tolerance to diesel minimizes its impact on soil microbial characteristics during rhizoremediation of diesel-contaminated soils

International Nuclear Information System (INIS)

Barrutia, O.; Garbisu, C.; Epelde, L.; Sampedro, M.C.; Goicolea, M.A.; Becerril, J.M.

2011-01-01

Soil contamination due to petroleum-derived products is an important environmental problem. We assessed the impacts of diesel oil on plants (Trifolium repens and Lolium perenne) and soil microbial community characteristics within the context of the rhizoremediation of contaminated soils. For this purpose, a diesel fuel spill on a grassland soil was simulated under pot conditions at a dose of 12,000 mg diesel kg -1 DW soil. Thirty days after diesel addition, T. repens (white clover) and L. perenne (perennial ryegrass) were sown in the pots and grown under greenhouse conditions (temperature 25/18 o C day/night, relative humidity 60/80% day/night and a photosynthetic photon flux density of 400 μmol photon m -2 s -1 ) for 5 months. A parallel set of unplanted pots was also included. Concentrations of n-alkanes in soil were determined as an indicator of diesel degradation. Seedling germination, plant growth, maximal photochemical efficiency of photosystem II (F v /F m ), pigment composition and lipophylic antioxidant content were determined to assess the impacts of diesel on the studied plants. Soil microbial community characteristics, such as enzyme and community-level physiological profiles, were also determined and used to calculate the soil quality index (SQI). The presence of plants had a stimulatory effect on soil microbial activity. L. perenne was far more tolerant to diesel contamination than T. repens. Diesel contamination affected soil microbial characteristics, although its impact was less pronounced in the rhizosphere of L. perenne. Rhizoremediation with T. repens and L. perenne resulted in a similar reduction of total n-alkanes concentration. However, values of the soil microbial parameters and the SQI showed that the more tolerant species (L. perenne) was able to better maintain its rhizosphere characteristics when growing in diesel-contaminated soil, suggesting a better soil health. We concluded that plant tolerance is of crucial importance for the

Vanadium bioavailability and toxicity to soil microorganisms and plants.

Science.gov (United States)

Larsson, Maja A; Baken, Stijn; Gustafsson, Jon Petter; Hadialhejazi, Golshid; Smolders, Erik

2013-10-01

Vanadium, V, is a redox-sensitive metal that in solution, under aerobic conditions, prevails as the oxyanion vanadate(V). There is little known regarding vanadium toxicity to soil biota, and the present study was set up to determine the toxicity of added vanadate to soil organisms and to investigate the relationship between toxicity and vanadium sorption in soils. Five soils with contrasting properties were spiked with 7 different doses (3.2-3200 mg V kg(-1)) of dissolved vanadate, and toxicity was measured with 2 microbial and 3 plant assays. The median effective concentration (EC50) thresholds of the microbial assays ranged from 28 mg added V kg(-1) to 690 mg added V kg(-1), and the EC50s in the plant assays ranged from 18 mg added V kg(-1) to 510 mg added V kg(-1). The lower thresholds were in the concentration range of the background vanadium in the untreated control soils (15-58 mg V kg(-1)). The vanadium toxicity to plants decreased with a stronger soil vanadium sorption strength. The EC50 values for plants expressed on a soil solution basis ranged from 0.8 mg V L(-1) to 15 mg V L(-1) and were less variable among soils than corresponding values based on total vanadium in soil. It is concluded that sorption decreases the toxicity of added vanadate and that soil solution vanadium is a more robust measure to determine critical vanadium concentrations across soils. © 2013 SETAC.

Absorption of atmospheric NO2 by plants and soils, (1)

International Nuclear Information System (INIS)

Matsumaru, Tsuneo; Shiratori, Koji; Yoneyama, Tadakatsu; Totsuka, Tsumugu.

1979-01-01

Tomato, sunflower and corn plants were grown in culture solution containing three different concentrations of 15 N-labelled KNO 3 (260 ppm N, 105 ppm N, and 26 ppm N) as a nitrogen nutrient, and fumigated with 0.3 ppm NO 2 for 2 weeks during their vegetative stages. The amount of NO 2 nitrogen absorbed into the plants was estimated by ''difference method'' and '' 15 N method.'' '' 15 N method'' was found to give more probable values than ''difference method.'' According to '' 15 N method,'' the nitrogen derived from NO 2 was about 16% (tomato), 22% (sunflower), and 14% (corn) of the increased amount of total nitrogen in the whole plants in the 105 ppm N plot, and these percentages increased in the 26 ppm N plot. Difference in nitrogen concentration of the culture solution resulted in big change in the dry-weight increase of the tomato and sunflower plants, but the absorption rate of NO 2 nitrogen based on the dry weight changed slightly. The absorption rate of NO 2 nitrogen was around 0.8 mg (gDW) -1 day -1 in tomato and sunflower plants, and 0.3 mg (gDW) -1 day -1 in corn plant. Leaves were found to be an active sink of NO 2 and the nitrogen of NO 2 seemed to be rapidly transformed into compounds of high molecules in the leaf cells. (author)

Fumigation success for California facility.

Science.gov (United States)

Hacker, Robert

2010-02-01

As Robert Hacker, at the time director of facilities management at the St John's Regional Medical Center in Oxnard, California, explains, the hospital, one of the area's largest, recently successfully utilised a new technology to eliminate mould, selecting a cost and time-saving fumigation process in place of the traditional "rip and tear" method. Although hospital managers knew the technology had been used extremely effectively in other US buildings, this was reportedly among the first ever healthcare applications.

Accumulation of Pb, Cd and Zn from contaminated soil to various plants and evaluation of soil remediation with indicator plant (Plantago lanceolata L.)

Energy Technology Data Exchange (ETDEWEB)

Zupan, M.; Lobnik, F.; Kadunc, V. [Ljubljana Univ. (Slovenia). Agronomy Dept., Center for Soil and Environmental Science; Hudnik, V. [National Institute of Chemistry Hajdrihova 19, Ljubljana (Slovenia)

1997-12-31

The accumulation of cadmium, lead, and zinc by different major cultivated plants from soils contaminated with heavy metals, is presented. The vegetables, crops, and the indicator plant narrow leaf plantain (Plantago lanceolata L.) were used in a field experiment including 3 areas with different levels of pollution. The highest concentrations of heavy metals were observed in edible green parts of vegetables (endive, spinach, lettuce) and roots (carrot, red beet, radish). The heavy metal content in leguminous plants (pods and seeds) was very low compared to high soil concentrations. Wheat and maize showed lower concentrations in grains and kernels than in green parts. Lime and vermiculite were used for reduction of Cd availability to plants in polluted soil. The Cd concentration decreased in the narrow leaf plantain in the presence of both lime and vermiculite in acid soil. In the higher-pH soil the Cd availability to spinach was greatly reduced in the presence of vermiculite

Using a plant hormone and a thioligand to improve phytoremediation of Hg-contaminated soil from a petrochemical plant.

Science.gov (United States)

Cassina, L; Tassi, E; Pedron, F; Petruzzelli, G; Ambrosini, P; Barbafieri, M

2012-09-15

Mercury-contaminated soils from a petrochemical plant in southern Italy were investigated to assess the phytoextraction efficiency of crop plants treated with the phytohormone, cytokinine (CK foliar treatment), and with the thioligand, ammonium thiosulfate (TS, soil application). Plant biomass, evapotranspiration, Hg uptake and distribution in plant tissues following treatment were compared. Results indicate the effectiveness of CK in increasing plant biomass and the evapotranspiration rate while TS treatment promoted soil Hg solubility and availability. The simultaneous addition of CK and TS treatments increased Hg uptake and translocation in both tested plants with up to 248 and 232% in Brassica juncea (Indian mustard) and Helianthus annuus (sunflower) respectively. B. juncea was more effective in Hg uptake, whereas H. annuus gave better response regarding plant biomass production. The effectiveness of the treatments was confirmed by the calculation of Hg phytoextraction and evaluation of labile-Hg residue in the soil after plant growth. In one growing cycle the plants subject to simultaneous CK and TS treatment significantly reduced labile-Hg pools that were characterized by the soil sequential extraction, but did not significantly affect the pseudototal metal content in the soil. Results support the use of plant growth regulators in the assisted phytoextraction process for Hg-contaminated soils. Copyright © 2012 Elsevier B.V. All rights reserved.

Soil Penetration by Earthworms and Plant Roots--Mechanical Energetics of Bioturbation of Compacted Soils.

Directory of Open Access Journals (Sweden)

Siul Ruiz

Full Text Available We quantify mechanical processes common to soil penetration by earthworms and growing plant roots, including the energetic requirements for soil plastic displacement. The basic mechanical model considers cavity expansion into a plastic wet soil involving wedging by root tips or earthworms via cone-like penetration followed by cavity expansion due to pressurized earthworm hydroskeleton or root radial growth. The mechanical stresses and resulting soil strains determine the mechanical energy required for bioturbation under different soil hydro-mechanical conditions for a realistic range of root/earthworm geometries. Modeling results suggest that higher soil water content and reduced clay content reduce the strain energy required for soil penetration. The critical earthworm or root pressure increases with increased diameter of root or earthworm, however, results are insensitive to the cone apex (shape of the tip. The invested mechanical energy per unit length increase with increasing earthworm and plant root diameters, whereas mechanical energy per unit of displaced soil volume decreases with larger diameters. The study provides a quantitative framework for estimating energy requirements for soil penetration work done by earthworms and plant roots, and delineates intrinsic and external mechanical limits for bioturbation processes. Estimated energy requirements for earthworm biopore networks are linked to consumption of soil organic matter and suggest that earthworm populations are likely to consume a significant fraction of ecosystem net primary production to sustain their subterranean activities.

Soil-plant transfer of Cs-137 and Sr-90 in digestate amended agricultural soils- a lysimeter scale experiment

Science.gov (United States)

Mehmood, Khalid; Berns, Anne E.; Pütz, Thomas; Burauel, Peter; Vereecken, Harry; Zoriy, Myroslav; Flucht, Reinhold; Opitz, Thorsten; Hofmann, Diana

2014-05-01

Radiocesium and radiostrontium are among the most problematic soil contaminants following nuclear fallout due to their long half-lives and high fission yields. Their chemical resemblance to potassium, ammonium and calcium facilitates their plant uptake and thus enhances their chance to reach humans through the food-chain dramatically. The plant uptake of both radionuclides is affected by the type of soil, the amount of organic matter and the concentration of competitive ions. In the present lysimeter scale experiment, soil-plant transfer of Cs-137 and Sr-90 was investigated in an agricultural silty soil amended with digestate, a residue from a biogas plant. The liquid fraction of the digestate, liquor, was used to have higher nutrient competition. Digestate application was done in accordance with the field practice with an application rate of 34 Mg/ha and mixing it in top 5 cm soil, yielding a final concentration of 38 g digestate/Kg soil. The top 5 cm soil of the non-amended reference soil was also submitted to the same mixing procedure to account for the physical disturbance of the top soil layer. Six months after the amendment of the soil, the soil contamination was done with water-soluble chloride salts of both radionuclides, resulting in a contamination density of 66 MBq/m2 for Cs-137 and 18 MBq/m2 for Sr-90 in separate experiments. Our results show that digestate application led to a detectable difference in soil-plant transfer of the investigated radionuclides, effect was more pronounced for Cs-137. A clear difference was observed in plant uptake of different plants. Pest plants displayed higher uptake of both radionuclides compared to wheat. Furthermore, lower activity values were recorded in ears compared to stems for both radionuclides.

Plant uptake of 134Cs in relation to soil properties and time

International Nuclear Information System (INIS)

Massas, I.; Skarlou, V.; Haidouti, C.

2002-01-01

134 Cs uptake by sunflower and soybean plants grown on seven different soils and its relation to soil properties were studied in a greenhouse pot experiment. Soil in each pot was contaminated by dripping the 134 Cs in layers, and sunflower and soybean plants were grown for three and two successive periods, respectively. 134 Cs plant uptake was expressed as the transfer factor (TF) (Bq kg -1 plant/Bq kg -1 soil) and as the daily plant uptake (flux) (Bq pot -1 day -1 ) taking into account biomass production and growth time. For the studied soils and for both plants, no consistent trend of TFs with time was observed. The use of fluxes, in general, provided less variable results than TFs and stronger functional relationships. A negative power functional relationship between exchangeable potassium plus ammonium cations expressed as a percentage of cation exchange capacity of each soil and 134 Cs fluxes was found for the sunflower plants. A similar but weaker relationship was observed for soybean plants. The significant correlation between sunflower and soybean TFs and fluxes, as well as the almost identical highest/lowest 134 Cs flux ratios, in the studied soils, indicated a similar effect of soil characteristics on 134 Cs uptake by both plants. In all the studied soils, sunflower 134 Cs TFs and fluxes were significantly higher than the respective soybean values, while no significant difference was observed in potassium content and daily potassium plant uptake (flux) of the two plants

The effect of plant water storage on water fluxes within the coupled soil-plant system.

Science.gov (United States)

Huang, Cheng-Wei; Domec, Jean-Christophe; Ward, Eric J; Duman, Tomer; Manoli, Gabriele; Parolari, Anthony J; Katul, Gabriel G

2017-02-01

In addition to buffering plants from water stress during severe droughts, plant water storage (PWS) alters many features of the spatio-temporal dynamics of water movement in the soil-plant system. How PWS impacts water dynamics and drought resilience is explored using a multi-layer porous media model. The model numerically resolves soil-plant hydrodynamics by coupling them to leaf-level gas exchange and soil-root interfacial layers. Novel features of the model are the considerations of a coordinated relationship between stomatal aperture variation and whole-system hydraulics and of the effects of PWS and nocturnal transpiration (Fe,night) on hydraulic redistribution (HR) in the soil. The model results suggest that daytime PWS usage and Fe,night generate a residual water potential gradient (Δψp,night) along the plant vascular system overnight. This Δψp,night represents a non-negligible competing sink strength that diminishes the significance of HR. Considering the co-occurrence of PWS usage and HR during a single extended dry-down, a wide range of plant attributes and environmental/soil conditions selected to enhance or suppress plant drought resilience is discussed. When compared with HR, model calculations suggest that increased root water influx into plant conducting-tissues overnight maintains a more favorable water status at the leaf, thereby delaying the onset of drought stress. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Ecosystem-scale plant hydraulic strategies inferred from remotely-sensed soil moisture

Science.gov (United States)

Bassiouni, M.; Good, S. P.; Higgins, C. W.

2017-12-01

Characterizing plant hydraulic strategies at the ecosystem scale is important to improve estimates of evapotranspiration and to understand ecosystem productivity and resilience. However, quantifying plant hydraulic traits beyond the species level is a challenge. The probability density function of soil moisture observations provides key information about the soil moisture states at which evapotranspiration is reduced by water stress. Here, an inverse Bayesian approach is applied to a standard bucket model of soil column hydrology forced with stochastic precipitation inputs. Through this approach, we are able to determine the soil moisture thresholds at which stomata are open or closed that are most consistent with observed soil moisture probability density functions. This research utilizes remotely-sensed soil moisture data to explore global patterns of ecosystem-scale plant hydraulic strategies. Results are complementary to literature values of measured hydraulic traits of various species in different climates and previous estimates of ecosystem-scale plant isohydricity. The presented approach provides a novel relation between plant physiological behavior and soil-water dynamics.

Efficacy and residue analysis of nitric oxide fumigation of strawberries for control of Drosophila suzukii

Science.gov (United States)

Nitric oxide (NO) has been demonstrated as an effective fumigant against various insect pests on postharvest products under ultralow oxygen (ULO) conditions. NO showed efficacy against all life stages of insect pests with varied fumigation time and temperature, and had feasible cost-effectiveness to...

Soil to plant transfer of radionuclides: predicting the fate of multiple radioisotopes in plants

International Nuclear Information System (INIS)

Willey, Neil J.

2014-01-01

Predicting soil-to-plant transfer of radionuclides is restricted by the range of species for which concentration ratios (CRs) have been measured. Here the radioecological utility of meta-analyses of phylogenetic effects on alkali earth metals will be explored for applications such as ‘gap-filling’ of CRs, the identification of sentinel biomonitor plants and the selection of taxa for phytoremediation of radionuclide contaminated soils. REML modelling of extensive CR/concentration datasets shows that the concentrations in plants of Ca, Mg and Sr are significantly influenced by phylogeny. Phylogenetic effects of these elements are shown here to be similar. Ratios of Ca/Mg and Ca/Sr are known to be quite stable in plants so, assuming that Sr/Ra ratios are stable, phylogenetic effects and estimated mean CRs are used to predict Ra CRs for groups of plants with few measured data. Overall, there are well quantified plant variables that could contribute significantly to improving predictions of the fate radioisotopes in the soil-plant system

Abscisic acid-dependent changes in transpiration rate with SO/sub 2/ fumigation and the effects of sulfite and pH on stomatal aperture

Energy Technology Data Exchange (ETDEWEB)

Kondo, N.; Maruta, I.; Sugahara, K.

1980-01-01

Transpiration rate of rice plants which contained extremely large amounts of abscisic acid (ABA) decreased rapidly with 2.0 ppm SO/sub 2/ fumigation, reached 20% of the initial level after 5 min exposure, then recovered slightly and thereafter remained constant. SO/sub 2/ fumigation of alday and tobacco (Nicotiana tabacum L. Samsun) which have a lower ABA content showed a 50% decrease in transpiration rate. Similarly, rates for wheat and tobacco (N. tabacum L. Samsun NN) which contained even smaller amounts of ABA than alday and tobacco (Samsun) decreased by 35 and 45%, respectively, 30 min after the beginning of the fumigation. In the cases of broad bean and tobacco (N. glutinosa L.) with low ABA contents, the rates slightly increased immediately after the start of the fumigation and began to decrease gradually 20 and 40 min later, respectively. The transpiration rates of corn and sorghum, in spite of their extremely low ABA contents, decreased significantly with SO/sub 2/ fumigation and reached 65 and 50% of the initial levels after 20 and 40 min exposure, respectively. Foliar application of 0.04 N HCl to peanut leaves remarkably depressed the transpiration rate, while the application of 0.04 M Na/sub 2/SO/sub 3/ decreased the rate only to the same level as water treatment. Foliar application of either HCl or Na/sub 2/SO/sub 3/ to radish leaves exerted no change in the transpiration rate. When 3 X 10/sup -4/ M ABA was applied to radish leaves prior to HCl and Na/sub 2/SO/sub 3/ treatment, the transpiration rate of radish was decreased by HCl application, but not by Na/sub 2/SO/sub 3/.

Soil-plant transfer factors of Co-60 for alfalfa lettuce and spinach

International Nuclear Information System (INIS)

Dumitru, Radu Octavian

1997-01-01

The transfer of Co-60 from soil into plants is a less studied problem. Soil-plant transfer factors for Co-60 known from literature vary by about four orders of magnitude for each kind of plants. We have calculated the average values and have determined the field of variability of the known transfer factors. These indicated us that alfalfa, lettuce and spinach have in this order the greatest absorption capacity of Co-60 from soil. We have determined the physical, chemical and mineralogical properties of the utilized soil. This is a brown reddish forest type soil. The plants have been cultivated in pots by plantlet method of Neubauer and Schneider. The results of our measurements of soil-to-plant transfer factors of 60-Co are the followings: 0.0612 ± 0.0047 for alfalfa, 0.0960 ± 0.0072 for lettuce and 0.1446 ± 0.0107 for spinach. These values prove the strong dependence of the type of soil and plant of the soil-plant transfer factors for Co-60. (author)

Heavy metal toxicity in rice and soybean plants cultivated in contaminated soil

Directory of Open Access Journals (Sweden)

Maria Lígia de Souza Silva

2014-04-01

Full Text Available Heavy metals can accumulate in soil and cause phytotoxicity in plants with some specific symptoms. The present study evaluated the specific symptoms on rice and soybeans plants caused by excess of heavy metals in soil. Rice and soybean were grown in pots containing soil with different levels of heavy metals. A completely randomized design was used, with four replications, using two crop species and seven sample soils with different contamination levels. Rice and soybean exhibited different responses to the high concentrations of heavy metals in the soil. Rice plants accumulated higher Cu, Mn, Pb and Zn concentrations and were more sensitive to high concentrations of these elements in the soil, absorbing them more easily compared to the soybean plants. However, high available Zn concentrations in the soil caused phytotoxicity symptoms in rice and soybean, mainly chlorosis and inhibited plant growth. Further, high Zn concentrations in the soil reduced the Fe concentration in the shoots of soybean and rice plants to levels considered deficient.

Influência da adubação e da fumigação do solo, na incidência de nematôides em tubérculos de batatinha Influence of fertilizers and soil fumigation on the nematode incidence of potato tubers

Directory of Open Access Journals (Sweden)

O. J. Boock

1959-01-01

Full Text Available Dentre as causas que podem levar ao fracasso a cultura da batatinha (Solanum tuberosum L. no Brasil, sobressaem as devidas aos nematóides causadores de galhas ou pipoca Meloidogyne incognita (Kofoide & White, 1919 Chitwood, 1949. Os tubérculos, quando atacados, tornam-se impróprios ao plantio e ao consumo apodrecendo rapidamente. Em vista dêsse fato vêm sendo realizadas, no Instituto Agronômico de Campinas, experiências visando ao combate àquela praga. Os resultados obtidos ultimamente, quando se procurou constatar a influência sôbre a redução da infestação exercida pelas adubações e pelas fumigações do solo com dibrometo de etileno, forneceram os seguintes esclarecimentos: a adubação não exerceu nenhuma influência sôbre o aumento ou diminuição das infestações dos tubérculos pelos nematóides; o dibrometo de etileno mostrou-se eficiente na redução da infestação, na dose de 276 litros por hectare, não devendo, todavia, ser aplicado no terreno no ato do plantio da batatinha mas sim com antecedência de oito ou mais dias; o melhor espaçamento entre aplicações foi o de 20x20 cm; a produção de tubérculos aumentou satisfatoriamente com a fumigação, principalmente quando o nematocida foi aplicado duas vezes no mesmo terreno, isto é, antes de cada uma das culturas ("da sêca" e "das águas".The most important losses caused by root nematodes to the potato crop in the State of Silo Paulo and other parts of Brazil are due to the species Meloidogyne incognita (Kofoide & White, 1919 Chitwood, 1949 and Pralylenchus steineri Lordello, Zamith & Boock, 1954. The former is quite widespread and measures aiming at its control were studied under field conditions. The present paper reports the results on the influence of fertilizer and soil fumigation with ethilene dibromide at 10%, cither separately or combined, on the nematode infestation of the potato yield. The results of the tests showed that the fertilizer application

Study of radioactive sr and Cs in soil and soil /plant system at Inshas region

International Nuclear Information System (INIS)

Eissa, H.S.M.

2008-01-01

The radioactive fallout is considered one of the most major environmental problems that threats public health. The work presented in this thesis is carried out to investigate the level of radioactivity in different environmental samples of soils and vegetations collected from different locations around the NRC at Inshas area and the area nearby (about 30 km radius). Six different locations: Inshas, Shebeen, Abu-Zaabal, Al-Oboor in addition to two sites in the nuclear research center (old reactor and protection department sites) were chosen for the collection of the soil and plant samples. Most typical egyptian soils (sandy, sandyloam, clayey)from three different places (Al-Oboor, Abu-Zaabal, and Shebeen El-Kanatter) were selected for the experiments carried out under laboratory conditions. The plants investigated were grass, old trees and wheat. Cs 137 and Sr 90 were chosen to represent the most important long-lived radionuclides considering the human health, since these nuclides can enter human body via food chain and increase the radiation burden for many years. The following points are considered in this work: 1- Natural radionuclides concentration in different environmental samples of soil and plant especially (grasses and leaves of old trees) were determined using high resolution gamma-spectroscopic system (hyper-pure germanium detector). 2-Two groups of elements have been determined directly in two plant samples from each location (one grass, and the other old trees) together with their corresponding soils.3- Transfer factors (often used to describe the uptake of the radioisotope from soil to plant)of the log-lived radionuclides 137 Cs and 90 from soil to the wheat plant have been studied by radiotracer experiments .4- The sorption behavior of Cs and Sr radionuclides by the different soil types was investigated kinetically using batch techniques.

Response of plant species to coal-mine soil materials

Energy Technology Data Exchange (ETDEWEB)

Day, A.D.; Tucker, T.C.; Thames, J.L.

1983-03-01

The two-year Black Mesa Coal Mine Research Study on the area near Kayenta, Arizona investigating the growth and establishment of seven plant species in unmined soil and coal-mined soils found that plant species grew better in unmined soil and that irrigation is essential during seedling establishment for the effective stabilization of coal-mined soils in a semi-arid environment. Differences among the species included variations in germination, response to irrigation, seedling establishment, and stem growth. 12 references, 2 figures, 2 tables.

Iron Availability in Tropical Soils and Iron Uptake by Plants

Directory of Open Access Journals (Sweden)

Guilherme Furlan Mielki

Full Text Available ABSTRACT Given the increase in crop yields and the expansion of agriculture in low fertility soils, deficiency of micronutrients, such as iron, in plants grown in tropical soils has been observed. The aim of this study was to evaluate Fe availability and Fe uptake by corn (Zea mays L. plants in 13 different soils, at two depths. Iron was extracted by Mehlich-1, Mehlich-3, and CaCl2 (Fe-CC and was fractionated in forms related to low (Feo and high (Fed crystallinity pedogenic oxyhydroxides, and organic matter (Fep using ammonium oxalate, dithionite-citrate, and sodium pyrophosphate, respectively. In order to relate Fe availability to soil properties and plant growth, an experiment was carried out in a semi-hydroponic system in which part of the roots developed in a nutrient solution (without Fe and part in the soil (the only source of Fe. Forty-five days after seeding, we quantified shoot dry matter and leaf Fe concentration and content. Fed levels were high, from 5 to 132 g kg-1, and Feo and Fe-CC levels were low, indicating the predominance of Fe as crystalline oxyhydroxides and a low content of Fe readily available to plants. The extraction solutions showed significant correlations with various soil properties, many common to both, indicating that they act similarly. The correlation between the Mehlich-1 and Mehlich-3 extraction solutions was highly significant. However, these two extraction methods were inefficient in predicting Fe availability to plants. There was a positive correlation between dry matter and Fe levels in plant shoots, even within the ranges considered adequate in the soil and in the plant. Dry matter production and leaf Fe concentration and content were positively correlated with Fep concentration, indicating that the Fe fraction related to soil organic matter most contributes to Fe availability to plants.

Dependence of soil-to-plant transfer factors of elements on their concentrations in soil

International Nuclear Information System (INIS)

Tsukada, Hirofumi; Watabe, Teruhisa.

1996-01-01

Transfer factors (TFs) of 31 stable elements from soil to plant were determined by neutron activation analysis. Soil and plant samples were collected from 112 farm fields in Aomori prefecture, Japan. The elements described are those that could be detected by this method, which include essential elements for plant growth and nonessential elements. Several of these elements were divided into two groups, each having different TF characteristics. In the first group of elements there was an inverse correlation between the TFs and the soil concentrations of the elements, especially for Cl, K and Ca. The concentrations of these elements in plants were independent of their soil concentrations. However, in the second group, especially Sc and Co, the TFs were independent of the soil concentrations of the elements. The fluctuation of TFs observed in this study was smaller than that previously reported. This may be attributed to the relatively narrow geographic area of the present study. In addition, the TFs for the stable elements in this study were generally one to three orders of magnitude lower than those compiled for radioactive isotopes in previous publications. (author)

Do plant-based amendments improve soil physiochemical and microbiological properties and plant growth in dryland ecosystems?

Science.gov (United States)

Kneller, Tayla; Harris, Richard; Muñoz-Rojas, Miriam

2017-04-01

Background Land intensive practices including mining have contributed to the degradation of landscapes globally. Current challenges in post-mine restoration revolve around the use of substrates poor in organic materials (e.g. overburden and waste rock) and lack of original topsoil which may result in poor seedling recruitment and in later stages in soil nutrient deficiency, metal toxicity, decreased microbial activity and high salinity (Bateman et al., 2016; Muñoz-Rojas et al., 2016). Despite continuous efforts and advances we have not proportionally advanced our capability to successfully restore these landscapes following mining. Recent attempts to improve plant establishment in arid zone restoration programs have included the application of plant based amendments to soil profiles. This approach usually aims to accelerate soil reconstruction via improvement of soil aggregate stability and increase of soil organic carbon, and water holding capacity. Whilst a significant amount of recent research has focused on the application of such amendments, studies on the potential application of plant based materials to recover soil functionality and re-establish plant communities in post-mined landscapes in arid regions are limited. Here we will discuss our work investigating the application of a plant based amendment on soil substrates commonly used in post mining restoration in the Pilbara region, Western Australia. Methodology The study was conducted in a glasshouse facility where environmental conditions were continuously monitored. Using two growth materials (topsoil and waste rock) and a plant based amendment (dry biomass of the most common grass in the Pilbara, Triodia wiseana) five different treatments were tested. Treatments consisted of control soil treatments (topsoil, waste and a mixture of the former soil types (mixture)) and two amended soil treatments (waste amended and mixture amended). Additionally, three different vegetation communities were studies

Heavy metal concentrations in plants and different harvestable parts: A soil-plant equilibrium model

International Nuclear Information System (INIS)

Guala, Sebastian D.; Vega, Flora A.; Covelo, Emma F.

2010-01-01

A mathematical interaction model, validated by experimental results, was developed to modeling the metal uptake by plants and induced growth decrease, by knowing metal in soils. The model relates the dynamics of the uptake of metals from soil to plants. Also, two types of relationships are tested: total and available metal content. The model successfully fitted the experimental data and made it possible to predict the threshold values of total mortality with a satisfactory approach. Data are taken from soils treated with Cd and Ni for ryegrass (Lolium perenne, L.) and oats (Avena sativa L.), respectively. Concentrations are measured in the aboveground biomass of plants. In the latter case, the concentration of metals in different parts of the plants (tillering, shooting and earing) is also modeled. At low concentrations, the effects of metals are moderate, and the dynamics appear to be linear. However, increasing concentrations show nonlinear behaviors. - The model proposed in this study makes possible to characterize the nonlinear behavior of the soil-plant interaction with metal pollution.

Heavy metal concentrations in plants and different harvestable parts: A soil-plant equilibrium model

Energy Technology Data Exchange (ETDEWEB)

Guala, Sebastian D. [Instituto de Ciencias, Universidad Nacional de General Sarmiento, Gutierrez 1150, Los Polvorines, Buenos Aires (Argentina); Vega, Flora A. [Departamento de Bioloxia Vexetal e Ciencia do Solo, Facultade de Bioloxia, Universidade de Vigo, Lagoas, Marcosende, 36310 Vigo, Pontevedra (Spain); Covelo, Emma F., E-mail: emmaf@uvigo.e [Departamento de Bioloxia Vexetal e Ciencia do Solo, Facultade de Bioloxia, Universidade de Vigo, Lagoas, Marcosende, 36310 Vigo, Pontevedra (Spain)

2010-08-15

A mathematical interaction model, validated by experimental results, was developed to modeling the metal uptake by plants and induced growth decrease, by knowing metal in soils. The model relates the dynamics of the uptake of metals from soil to plants. Also, two types of relationships are tested: total and available metal content. The model successfully fitted the experimental data and made it possible to predict the threshold values of total mortality with a satisfactory approach. Data are taken from soils treated with Cd and Ni for ryegrass (Lolium perenne, L.) and oats (Avena sativa L.), respectively. Concentrations are measured in the aboveground biomass of plants. In the latter case, the concentration of metals in different parts of the plants (tillering, shooting and earing) is also modeled. At low concentrations, the effects of metals are moderate, and the dynamics appear to be linear. However, increasing concentrations show nonlinear behaviors. - The model proposed in this study makes possible to characterize the nonlinear behavior of the soil-plant interaction with metal pollution.

Analytical solution describing pesticide volatilization from soil affected by a change in surface condition.

Science.gov (United States)

Yates, S R

2009-01-01

An analytical solution describing the fate and transport of pesticides applied to soils has been developed. Two pesticide application methods can be simulated: point-source applications, such as idealized shank or a hot-gas injection method, and a more realistic shank-source application method that includes a vertical pesticide distribution in the soil domain due to a soil fracture caused by a shank. The solutions allow determination of the volatilization rate and other information that could be important for understanding fumigant movement and in the development of regulatory permitting conditions. The solutions can be used to characterize differences in emissions relative to changes in the soil degradation rate, surface barrier conditions, application depth, and soil packing. In some cases, simple algebraic expressions are provided that can be used to obtain the total emissions and total soil degradation. The solutions provide a consistent methodology for determining the total emissions and can be used with other information, such as field and laboratory experimental data, to support the development of fumigant regulations. The uses of the models are illustrated by several examples.

Characterization of pyroclastic deposits and pre-eruptive soils following the 2008 eruption of Kasatochi Island Volcano, Alaska

Science.gov (United States)

Wang, B.; Michaelson, G.; Ping, C.-L.; Plumlee, G.; Hageman, P.

2010-01-01

The 78 August 2008 eruption of Kasatochi Island volcano blanketed the island in newly generated pyroclastic deposits and deposited ash into the ocean and onto nearby islands. Concentrations of water soluble Fe, Cu, and Zn determined from a 1:20 deionized water leachate of the ash were sufficient to provide short-term fertilization of the surface ocean. The 2008 pyroclastic deposits were thicker in concavities at bases of steeper slopes and thinner on steep slopes and ridge crests. By summer 2009, secondary erosion had exposed the pre-eruption soils along gulley walls and in gully bottoms on the southern and eastern slopes, respectively. Topographic and microtopographic position altered the depositional patterns of the pyroclastic flows and resulted in pre-eruption soils being buried by as little as 1 m of ash. The different erosion patterns gave rise to three surfaces on which future ecosystems will likely develop: largely pre-eruptive soils; fresh pyroclastic deposits influenced by shallowly buried, pre-eruptive soil; and thick (>1 m) pyroclastic deposits. As expected, the chemical composition differed between the pyroclastic deposits and the pre-eruptive soils. Pre-eruptive soils hold stocks of C and N important for establishing biota that are lacking in the fresh pyroclastic deposits. The pyroclastic deposits are a source for P and K but have negligible nutrient holding capacity, making these elements vulnerable to leaching loss. Consequently, the pre-eruption soils may also represent an important long-term P and K source. ?? 2010 Regents of the University of Colorado.

Soil - plant experimental radionuclide transfer factors

International Nuclear Information System (INIS)

Dobrin, R.I.; Dulama, C.N.; Toma, Al.

2006-01-01

Some experimental research was performed in our institute to assess site specific soil-plant transfer factors. A full characterization of an experimental site was done both from pedo-chemical and radiological point of view. Afterwards, a certain number of culture plants were grown on this site and the evolution of their radionuclide burden was then recorded. Using some soil amendments one performed a parallel experiment and the radionuclide root uptake was evaluated and recorded. Hence, transfer parameters were calculated and some conclusions were drawn concerning the influence of site specific conditions on the root uptake of radionuclides. (authors)

Importance of soil-water relation in assessment endpoint in bioremediated soils: Plant growth and soil physical properties

International Nuclear Information System (INIS)

Li, X.; Sawatsky, N.

1995-01-01

Much effort has been focused on defining the end-point of bioremediated soils by chemical analysis (Alberta Tier 1 or CCME Guideline for Contaminated Soils) or toxicity tests. However, these tests do not completely assess the soil quality, or the capability of soil to support plant growth after bioremediation. This study compared barley (Hordeum vulgare) growth on: (i) non-contaminated, agricultural topsoil, (2) oil-contaminated soil (4% total extractable hydrocarbons, or TEH), and (3) oil-contaminated soil treated by bioremediation (< 2% TEH). Soil physical properties including water retention, water uptake, and water repellence were measured. The results indicated that the growth of barley was significantly reduced by oil-contamination of agricultural topsoil. Furthermore, bioremediation did not improve the barley yield. The lack of effects from bioremediation was attributed to development of water repellence in hydrocarbon contaminated soils. There seemed to be a critical water content around 18% to 20% in contaminated soils. Above this value the water uptake by contaminated soil was near that of the agricultural topsoil. For lower water contents, there was a strong divergence in sorptivity between contaminated and agricultural topsoil. For these soils, water availability was likely the single most important parameter controlling plant growth. This parameter should be considered in assessing endpoint of bioremediation for hydrocarbon contaminated soils

Observing plants dealing with soil water stress: Daily soil moisture fluctuations derived from polymer tensiometers

Science.gov (United States)

van der Ploeg, Martine; de Rooij, Gerrit

2014-05-01

Periods of soil water deficit often occur within a plant's life cycle, even in temperate deciduous and rain forests (Wilson et al. 2001, Grace 1999). Various experiments have shown that roots are able to sense the distribution of water in the soil, and produce signals that trigger changes in leaf expansion rate and stomatal conductance (Blackman and Davies 1985, Gollan et al. 1986, Gowing et al. 1990 Davies and Zhang 1991, Mansfield and De Silva 1994, Sadras and Milroy 1996). Partitioning of water and air in the soil, solute distribution in soil water, water flow through the soil, and water availability for plants can be determined according to the distribution of the soil water potential (e.g. Schröder et al. 2013, Kool et al. 2014). Understanding plant water uptake under dry conditions has been compromised by hydrological instrumentation with low accuracy in dry soils due to signal attenuation, or a compromised measurement range (Whalley et al. 2013). Development of polymer tensiometers makes it possible to study the soil water potential over a range meaningful for studying plant responses to water stress (Bakker et al. 2007, Van der Ploeg et al. 2008, 2010). Polymer tensiometer data obtained from a lysimeter experiment (Van der Ploeg et al. 2008) were used to analyse day-night fluctuations of soil moisture in the vicinity of maize roots. To do so, three polymer tensiometers placed in the middle of the lysimeter from a control, dry and very dry treatment (one lysimeter per treatment) were used to calculate water content changes over 12 hours. These 12 hours corresponded with the operation of the growing light. Soil water potential measurements in the hour before the growing light was turned on or off were averaged. The averaged value was used as input for the van Genuchten (1980) model. Parameters for the model were obtained from laboratory determination of water retention, with a separate model parameterization for each lysimeter setup. Results show daily

Cadmium and zinc in plants and soil solutions from contaminated soils

DEFF Research Database (Denmark)

Lorenz, S.E.; Hamon, R.E.; Holm, P.E.

1997-01-01

In an experiment using ten heavy metal-contaminated soils from six European countries, soil solution was sampled by water displacement before and after the growth of radish. Concentrations of Cd, Zn and other elements in solution (K, Ca, Mg, Mn) generally decreased during plant growth, probably...

Selenium Cycling Across Soil-Plant-Atmosphere Interfaces: A Critical Review

Directory of Open Access Journals (Sweden)

Lenny H.E. Winkel

2015-05-01

Full Text Available Selenium (Se is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels.

Unraveling the Plant-Soil Interactome

Science.gov (United States)

Lipton, M. S.; Hixson, K.; Ahkami, A. H.; HaHandkumbura, P. P.; Hess, N. J.; Fang, Y.; Fortin, D.; Stanfill, B.; Yabusaki, S.; Engbrecht, K. M.; Baker, E.; Renslow, R.; Jansson, C.

2017-12-01

Plant photosynthesis is the primary conduit of carbon fixation from the atmosphere to the terrestrial ecosystem. While more is known about plant physiology and biochemistry, the interplay between genetic and environmental factors that govern partitioning of carbon to above- and below ground plant biomass, to microbes, to the soil, and respired to the atmosphere is not well understood holistically. To address this knowledge gap there is a need to define, study, comprehend, and model the plant ecosystem as an integrated system of integrated biotic and abiotic processes and feedbacks. Local rhizosphere conditions are an important control on plant performance but are in turn affected by plant uptake and rhizodeposition processes. C3 and C4 plants have different CO2 fixation strategies and likely have differential metabolic profiles resulting in different carbon sources exuding to the rhizosphere. In this presentation, we report on an integrated capability to better understand plant-soil interactions, including modeling tools that address the spatiotemporal hydrobiogeochemistry in the rhizosphere. Comparing Brachypodium distachyon, (Brachypodium) as our C3 representative and Setaria viridis (Setaria) as our C4 representative, we designed, highly controlled single-plant experimental ecosystems based these model grasses to enable quantitative prediction of ecosystem traits and responses as a function of plant genotype and environmental variables. A metabolomics survey of 30 Brachypodium genotypes grown under control and drought conditions revealed specific metabolites that correlated with biomass production and drought tolerance. A comparison of Brachypodium and Setaria grown with control and a future predicted elevated CO2 level revealed changes in biomass accumulation and metabolite profiles between the C3 and C4 species in both leaves and roots. Finally, we are building an mechanistic modeling capability that will contribute to a better basis for modeling plant water

Enhancing Elementary Pre-Service Teachers' Plant Processes Conceptions

Science.gov (United States)

Thompson, Stephen L.; Lotter, Christine; Fann, Xumei; Taylor, Laurie

2016-01-01

Researchers examined how an inquiry-based instructional treatment emphasizing interrelated plant processes influenced 210 elementary pre-service teachers' (PTs) conceptions of three plant processes, photosynthesis, cellular respiration, and transpiration, and the interrelated nature of these processes. The instructional treatment required PTs to…

Uptake by Plants of Radiostrontium from Contaminated Soils

DEFF Research Database (Denmark)

Andersen, A. J.

1965-01-01

In a recent report from this department it was shown that the extractability of radiostrontium from contaminated soil samples was effectively reduced by heat treatment and by the addition of phosphate to the soil. It was pointed out that, under emergency conditions, heat-treatment of the contamin......In a recent report from this department it was shown that the extractability of radiostrontium from contaminated soil samples was effectively reduced by heat treatment and by the addition of phosphate to the soil. It was pointed out that, under emergency conditions, heat......-treatment of the contaminated soil surface and heavy phosphate application might thus reduce the uptake by plants of radiostrontium more efficiently than liming, which is only effective in soils of low calcium status. In the investigation reviewed here the influence of heat treatment and superphosphate application on the plant...... uptake of radiostrontium was examined in pot experiments. For comparison the effect of applying calcium carbonate to the contaminated soil surface was also determined....

Response of soil aggregate stability to storage time of soil samples

International Nuclear Information System (INIS)

Gerzabek, M.H.; Roessner, H.

1993-04-01

The aim of the present study was to investigate the well known phenomenon of changing aggregate stability values as result of soil sample storage. In order to evaluate the impact of soil microbial activity, the soil sample was split into three subsamples. Two samples were sterilized by means of chloroform fumigation and gamma irradiation, respectively. However, the aggregate stability measurements at three different dates were not correlated with the microbial activity (dehydrogenase activity). The moisture content of the aggregate samples seems to be of higher significance. Samples with lower moisture content (range: 0.4 to 1.9%) exhibited higher aggregate stabilities. Thus, airdried aggregate samples without further treatment don't seem to be suitable for standardized stability measurements. (authors)

Impact of rice-straw biochars amended soil on the biological Si cycle in soil-plant ecosystem

Science.gov (United States)

Li, Zimin; Delvaux, Bruno; Struyf, Eric; Unzué-Belmonte, Dácil; Ronsse, Frederik; Cornelis, Jean-Thomas

2017-04-01

Biochar used as soil amendment can enhance soil fertility and plant growth. It may also contribute to increase the plant mineralomass of silicon (Si). However, very little studies have focused on the plant Si cycling in biochar amended soils. Here, we study the impact of two contrasting biochars derived from rice straws on soil Si availability and plant Si uptake. Rice plants were grown in a hydroponic device using Yoshida nutrient solution, respectively devoid of H4SiO4 (0 ppm Si: Si-) and enriched with it (40 ppm Si: Si+). After 12 weeks, the plants were harvested for further pyrolysis, conducted with holding time of 1h at 500˚ C. The respective rice-biochars are Si-/biochar and Si+/biochar. They exhibit contrasting phytolith contents (0.3 g Si kg-1 vs. 51.3 g Si kg-1), but identical physico-chemical properties. They were applied in two soils differing in weathering stage: a weathered Cambisol (CA) and a highly weathered Nitisol (NI). We then studied the effects of the amended biochar on CaCl2 extractable Si using a 64-days kinetic approach, on the content of soil biogenic Si, and on the uptake of Si by wheat plants grown for 5 weeks. We also quantified Si mineralomass in plants. We compared the effects of biochars to that of wollastonite (Wo)-(CaSiO3), a common Si-fertilizer. Our results show that Si+/biochar significantly increase the content of BSi in both soils. In CA, the cumulative content of CaCl2 extractable Si amounts to 85 mg kg-1 after Si+/biochar amendment, which is below the amount extracted after Wo application (100 mg kg-1). In contrast, in NI, the cumulative content of CaCl2 extractable Si is 198 mg kg-1 in the Si+/biochar amended treatment, which is far above the one measured after Wo application (93 mg kg-1). The Si-/biochar has no effect on the cumulative content of CaCl2 extractable Si in either soil type. Biochars and wollastonite increase the biomass of wheat on both soils. The increase is, however, larger in NI than in CA. In terms of Si

Nutrient leaching when soil is part of plant growth media

Science.gov (United States)

Soils can serve as sorbents for phosphorus (P) within plant growth media, negating the need for artificial sorbents. The purpose of this study was to compare soils with different properties, as part of plant growth media, for their effect on nutrient levels in effluent. Four soils were mixed with sa...

Expression of pathogenesis-related (PR) genes in avocados fumigated with thyme oil vapours and control of anthracnose.

Science.gov (United States)

Bill, Malick; Sivakumar, Dharini; Beukes, Mervyn; Korsten, Lise

2016-03-01

Thyme oil (TO) fumigation (96μll(-1)) to cv. Hass and Ryan avocados significantly reduced anthracnose incidence compared to prochloraz and the untreated control. Also, enhanced activities of β-1,3-glucanase, chitinase were noted in both cultivars. TO fumigation induced the expression of both β-1,3-glucanase and chitinase genes in naturally infected fruit of both cultivars, during storage at 7 or 7.5°C for up to 21d and during subsequent simulated market shelf conditions at 20°C for 5d. However, the impact of TO fumigation on the β-1,3-glucanase gene expression was higher in both cultivars. Higher gene regulation and β-1,3-glucanase, chitinase activities were observed in cv. Ryan compared to Hass. Although TO fumigation significantly reduced anthracnose incidence in both naturally infected cultivars, the inhibitory effect was slightly higher in cv. Ryan than Hass. Thus, postharvest TO fumigation had positive effects on enhancing anthracnose disease resistance during storage and also gave a residual effect during the simulated shelf life. Copyright © 2015 Elsevier Ltd. All rights reserved.

Interrelationships between soil cover and plant cover depending on land use

Directory of Open Access Journals (Sweden)

Tiina Köster

2013-05-01

Full Text Available Interrelationships between soil cover and plant cover of normally developed (or postlithogenic mineral soils are analysed on the basis of four sampling soil groups. The four-link pedo-ecological sequence of analysed soils, rendzinas → brown soils → pseudopodzolic soils → gley-podzols, forms a representative cross section in relation to the normal mineral soils of Estonia. All groups differ substantially from each other in terms of soil properties (calcareousness, acidity, nutrition conditions, profile fabric and humus cover. The primary tasks of the research were (1 to elucidate the main pedo-ecological characteristics of the four soil groups and their suitability for plant cover, (2 to evaluate comparatively soils in terms of productivity, sustainability, biodiversity and environmental protection ability and (3 to analyse possibilities for ecologically sound matching of soil cover with suitable plant cover. On the basis of the same material, the influence of land-use change on humus cover (epipedon fabric, properties of the entire soil cover and soil–plant interrelationship were also analysed. An ecosystem approach enables us to observe particularities caused by specific properties of a soil type (species, variety in biological turnover and in the formation of biodiversity.

Effects of irradiation and fumigation on the antioxidative properties of some spices

International Nuclear Information System (INIS)

Kuruppu, D.P.; Schmidt, K.; Farkas, J.; Langerak, D.I; Duren, M.D.A. van

1985-01-01

The effects of gamma irradiation (5.6 kGy) and ethylene oxide fumigation on the antioxidative activity of marjoram, nutmeg, paprika and black pepper were investigated. Sunflower oil in water emulsion (1:1), dark, at 30 deg C, lard, dark, at 40 deg C, lard, illuminated, at 50 deg C, and lard, dark, at 50 deg C were the substrates utilized for the investigation. Oxidation of the substrates in the presence of 0.2% (by weight) of spices were followed by the determination of peroxide value (PO) and free fatty acide value (FFA). No significant effect of irradiation on the antioxidant activities of spices was revealed. Fumigated marjoram tended to be less antioxidative in lard kept in dark storage at 60 deg C than the non-treated or irradiated spice. Marjoram and nutmeg lost their antioxidant properties in the presence of light. This loss, however, was not influenced by the irradiation or fumigation treatments. (author)

Effects of irradiation and fumigation on the antioxidative properties of some spices

Energy Technology Data Exchange (ETDEWEB)

Kuruppu, D P; Schmidt, K; Farkas, J; Langerak, D I; Duren, M D.A. van

1985-12-01

The effects of gamma irradiation (5.6 kGy) and ethylene oxide fumigation on the antioxidative activity of marjoram, nutmeg, paprika and black pepper were investigated. Sunflower oil in water emulsion (1:1), dark, at 30 deg C, lard, dark, at 40 deg C, lard, illuminated, at 50 deg C, and lard, dark, at 50 deg C were the substrates utilized for the investigation. Oxidation of the substrates in the presence of 0.2% (by weight) of spices were followed by the determination of peroxide value (PO) and free fatty acid value (FFA). No significant effect of irradiation on the antioxidant activities of spices was revealed. Fumigated marjoram tended to be less antioxidative in lard kept in dark storage at 60 deg C than the non-treated or irradiated spice. Marjoram and nutmeg lost their antioxidant properties in the presence of light. This loss, however, was not influenced by the irradiation or fumigation treatments. 13 references, 4 figures, 5 tables.

Fumigant and Repellent Activity of Limonene Enantiomers Against Tribolium confusum du Val.

Science.gov (United States)

Malacrinò, A; Campolo, O; Laudani, F; Palmeri, V

2016-10-01

The use of pesticides, as carried out in the last 50 years, caused several negative environmental and human health consequences, leading to the development of alternative techniques to control pests, such as the use of compounds of plant origin. In this study, we assessed the fumigant and repellent activity of both the enantiomers of limonene, a monoterpene usually found in many plant species, against Tribolium confusum du Val. We tested both molecules at different doses, air temperatures, and in absence and presence of flour. R-(+)-limonene resulted more effective than S-(-)-limonene; indeed, it was able to reach 100% of efficacy at a concentration of 85 mg/L air when tested at different temperatures without flour. Data showed a positive relationship between efficacy and temperature, and a negative effect of the presence of debris on the bioactivity of limonene. Furthermore, repellency trials reported a higher activity of R-(+)-limonene compared to the other enantiomer.

Differential responses of soil bacteria, fungi, archaea and protists to plant species richness and plant functional group identity.

Science.gov (United States)

Dassen, Sigrid; Cortois, Roeland; Martens, Henk; de Hollander, Mattias; Kowalchuk, George A; van der Putten, Wim H; De Deyn, Gerlinde B

2017-08-01

Plants are known to influence belowground microbial community structure along their roots, but the impacts of plant species richness and plant functional group (FG) identity on microbial communities in the bulk soil are still not well understood. Here, we used 454-pyrosequencing to analyse the soil microbial community composition in a long-term biodiversity experiment at Jena, Germany. We examined responses of bacteria, fungi, archaea, and protists to plant species richness (communities varying from 1 to 60 sown species) and plant FG identity (grasses, legumes, small herbs, tall herbs) in bulk soil. We hypothesized that plant species richness and FG identity would alter microbial community composition and have a positive impact on microbial species richness. Plant species richness had a marginal positive effect on the richness of fungi, but we observed no such effect on bacteria, archaea and protists. Plant species richness also did not have a large impact on microbial community composition. Rather, abiotic soil properties partially explained the community composition of bacteria, fungi, arbuscular mycorrhizal fungi (AMF), archaea and protists. Plant FG richness did not impact microbial community composition; however, plant FG identity was more effective. Bacterial richness was highest in legume plots and lowest in small herb plots, and AMF and archaeal community composition in legume plant communities was distinct from that in communities composed of other plant FGs. We conclude that soil microbial community composition in bulk soil is influenced more by changes in plant FG composition and abiotic soil properties, than by changes in plant species richness per se. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

The role of plant-soil feedbacks in driving native-species recovery.

Science.gov (United States)

Yelenik, Stephanie G; Levine, Jonathan M

2011-01-01

The impacts of exotic plants on soil nutrient cycling are often hypothesized to reinforce their dominance, but this mechanism is rarely tested, especially in relation to other ecological factors. In this manuscript we evaluate the influence of biogeochemically mediated plant-soil feedbacks on native shrub recovery in an invaded island ecosystem. The introduction of exotic grasses and grazing to Santa Cruz Island, California, USA, converted native shrublands (dominated by Artemisia californica and Eriogonum arborescens) into exotic-dominated grasslands (dominated by Avena barbata) over a century ago, altering nutrient-cycling regimes. To test the hypothesis that exotic grass impacts on soils alter reestablishment of native plants, we implemented a field-based soil transplant experiment in three years that varied widely in rainfall. Our results showed that growth of Avena and Artemisia seedlings was greater on soils influenced by their heterospecific competitor. Theory suggests that the resulting plant-soil feedback should facilitate the recovery of Artemisia in grasslands, although four years of monitoring showed no such recovery, despite ample seed rain. By contrast, we found that species effects on soils lead to weak to negligible feedbacks for Eriogonum arborescens, yet this shrub readily colonized the grasslands. Thus, plant-soil feedbacks quantified under natural climate and competitive conditions did not match native-plant recovery patterns. We also found that feedbacks changed with climate and competition regimes, and that these latter factors generally had stronger effects on seedling growth than species effects on soils. We conclude that even when plant-soil feedbacks influence the balance between native and exotic species, their influence may be small relative to other ecological processes.

Clinical investigation of CT-guided ozone-blowing and fumigation ...

African Journals Online (AJOL)

Clinical investigation of CT-guided ozone-blowing and fumigation therapy for the chronic ... African Journal of Biotechnology ... In control group, seven patients were completely cured in 45 days after being treated by traditional surgery.

The transport of natural radionuclides from soil to plants

International Nuclear Information System (INIS)

Bikit, I.; Conkic, Lj.; Slivka, J.; Krmar, M.

1995-01-01

The transport and accumulation processes of Ra-226, U-238, Th-232 and K-40 from soil to plants have been studied. Plant samples with consumable parts grown below surface have been bred in natural conditions on soil with enhanced levels of natural radioactivity (barren soil of the uranium mine Gabrovnica-Kalna). An intensive transport of heavy natural radionuclides from soil to the roots was established. The transfer factors for U-238 and Ra-226 have been much bigger than for Th-232. The most intensive uptake was registered for beet root. (author)

{sup 134}Cs uptake by four plant species and Cs-K relations in the soil-plant system as affected by Ca(OH){sub 2} application to an acid soil

Energy Technology Data Exchange (ETDEWEB)

Massas, I., E-mail: massas@aua.g [Soil Science Laboratory, Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, Iera Odos 75, 11855 Athens (Greece); Skarlou, V.; Haidouti, C.; Giannakopoulou, F. [Soil Science Laboratory, Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, Iera Odos 75, 11855 Athens (Greece)

2010-03-15

Three rates of Ca(OH){sub 2} were applied to an acid soil and the {sup 134}Cs uptake by radish, cucumber, soybean and sunflower plants was studied. The {sup 134}Cs concentration in all plant species was reduced from 1.6-fold in the sunflower seeds to 6-fold in the soybean vegetative parts at the higher Ca(OH){sub 2} rate. Potassium (K) concentration in plants was also reduced, but less effectively. The significantly decreased {sup 134}Cs-K soil to plant distribution factors (D.F.) clearly suggest a stronger effect of soil liming on {sup 134}Cs than on K plant uptake. This observation was discussed in terms of ionic interactions in the soil matrix and within the plants. The results also indicated that the increased Ca{sup 2+} concentration in the exchange phase and in the soil solution along with the improved root activity, due to the soil liming, enhanced the immobilization of {sup 134}Cs in the soil matrix and consequently lowered the {sup 134}Cs availability for plant uptake.

Cesium-137 in soils and its soil-to-plant transfer rate

International Nuclear Information System (INIS)

Papastefanou, C.; Manolopoulou, M.; Charalambous, S.

1988-01-01

Measurements of fallout-derived 137 Cs in soils were made in the Valley of Ptolemais, North Greece after the Chernobyl nuclear reactor accident. The 137 Cs concentrations ranged between 290 Bq kg -1 and 7670 Bq kg -1 . It was found that the 137 Cs concentration is inversely proportional to 40 K concentration or potassium content of soils. Cesium-137 transfer coefficients from soil to plants (grass) ranged from 0.02 to 0.2

Recent progress in plant nutrition research: cross-talk between nutrients, plant physiology and soil microorganisms.

Science.gov (United States)

Ohkama-Ohtsu, Naoko; Wasaki, Jun

2010-08-01

Mineral nutrients taken up from the soil become incorporated into a variety of important compounds with structural and physiological roles in plants. We summarize how plant nutrients are linked to many metabolic pathways, plant hormones and other biological processes. We also focus on nutrient uptake, describing plant-microbe interactions, plant exudates, root architecture, transporters and their applications. Plants need to survive in soils with mineral concentrations that vary widely. Describing the relationships between nutrients and biological processes will enable us to understand the molecular basis for signaling, physiological damage and responses to mineral stresses.

Phosphorus cycling in natural and low input soil/plant systems: the role of soil microorganisms

Science.gov (United States)

Tamburini, F.; Bünemann, E. K.; Oberson, A.; Bernasconi, S. M.; Frossard, E.

2011-12-01

Availability of phosphorus (as orthophosphate, Pi) limits biological production in many terrestrial ecosystems. During the first phase of soil development, weathering of minerals and leaching of Pi are the processes controlling Pi concentrations in the soil solution, while in mature soils, Pi is made available by desorption of mineral Pi and mineralization of organic compounds. In agricultural soils additional Pi is supplied by fertilization, either with mineral P and/or organic inputs (animal manure or plant residues). Soil microorganisms (bacteria and fungi) mediate several processes, which are central to the availability of Pi to plants. They play a role in the initial release of Pi from the mineral phase, and through extracellular phosphatase enzymes, they decompose and mineralize organic compounds, releasing Pi. On the other hand, microbial immobilization and internal turnover of Pi can decrease the soil available Pi pool, competing in this way with plants. Using radio- and stable isotopic approaches, we show evidence from different soil/plant systems which points to the central role of the microbial activity. In the presented case studies, P contained in the soil microbial biomass is a larger pool than available Pi. In a soil chronosequence after deglaciation, stable isotopes of oxygen associated to phosphate showed that even in the youngest soils microbial activity highly impacted the isotopic signature of available Pi. These results suggested that microorganisms were rapidly taking up and cycling Pi, using it to sustain their community. Microbial P turnover time was faster in the young (about 20 days) than in older soils (about 120 days), reflecting a different functioning of the microbial community. Microbial community crashes, caused by drying/rewetting and freezing/thawing cycles, were most likely responsible for microbial P release to the available P pool. In grassland fertilization experiments with mineral NK and NPK amendments, microbial P turnover

Fumigant activity of plant essential oils and components from horseradish (Armoracia rusticana), anise (Pimpinella anisum) and garlic (Allium sativum) oils against Lycoriella ingenua (Diptera: Sciaridae).

Science.gov (United States)

Park, Ii-Kwon; Choi, Kwang-Sik; Kim, Do-Hyung; Choi, In-Ho; Kim, Lee-Sun; Bak, Won-Chull; Choi, Joon-Weon; Shin, Sang-Chul

2006-08-01

Plant essential oils from 40 plant species were tested for their insecticidal activities against larvae of Lycoriella ingénue (Dufour) using a fumigation bioassay. Good insecticidal activity against larvae of L. ingenua was achieved with essential oils of Chenopodium ambrosioides L., Eucalyptus globulus Labill, Eucalyptus smithii RT Baker, horseradish, anise and garlic at 10 and 5 microL L(-1) air. Horseradish, anise and garlic oils showed the most potent insecticidal activities among the plant essential oils. At 1.25 microL L(-1), horseradish, anise and garlic oils caused 100, 93.3 and 13.3% mortality, but at 0.625 microL L(-1) air this decreased to 3.3, 0 and 0% respectively. Analysis by gas chromatography-mass spectrometry led to the identification of one major compound from horseradish, and three each from anise and garlic oils. These seven compounds and m-anisaldehyde and o-anisaldehyde, two positional isomers of p-anisaldehyde, were tested individually for their insecticidal activities against larvae of L. ingenua. Allyl isothiocyanate was the most toxic, followed by trans-anethole, diallyl disulfide and p-anisaldehyde with LC(50) values of 0.15, 0.20, 0.87 and 1.47 microL L(-1) respectively.

Straw gasification biochar increases plant available water capacity and plant growth in coarse sandy soil

DEFF Research Database (Denmark)

Hansen, Veronika; Hauggaard-Nielsen, Henrik; Petersen, Carsten Tilbæk

Gasification biochar (GB) contains recalcitrant carbon that can contribute to soil carbon sequestration and soil quality improvement. However, the impact of GB on plant available water capacity (AWC) and plant growth in diverse soil types needs further reserach. A pot experiment with spring barley...... the characteristic low compressibility and high friction giving much better conditions for root penetration increasing yield potentials. Furthermore, risk of drought in dry periods, and nutrient losses in wet periods in coarser soil types is also reduced...

Variability of the soil-to-plant radiocaesium transfer factor for Japanese soils predicted with soil and plant properties.

Science.gov (United States)

Uematsu, Shinichiro; Vandenhove, Hildegarde; Sweeck, Lieve; Van Hees, May; Wannijn, Jean; Smolders, Erik

2016-03-01

Food chain contamination with radiocaesium (RCs) in the aftermath of the Fukushima accident calls for an analysis of the specific factors that control the RCs transfer. Here, soil-to-plant transfer factors (TF) of RCs for grass were predicted from the potassium concentration in soil solution (mK) and the Radiocaesium Interception Potential (RIP) of the soil using existing mechanistic models. The mK and RIP were (a) either measured for 37 topsoils collected from the Fukushima accident affected area or (b) predicted from the soil clay content and the soil exchangeable potassium content using the models that had been calibrated for European soils. An average ammonium concentration was used throughout in the prediction. The measured RIP ranged 14-fold and measured mK varied 37-fold among the soils. The measured RIP was lower than the RIP predicted from the soil clay content likely due to the lower content of weathered micas in the clay fraction of Japanese soils. Also the measured mK was lower than that predicted. As a result, the predicted TFs relying on the measured RIP and mK were, on average, about 22-fold larger than the TFs predicted using the European calibrated models. The geometric mean of the measured TFs for grass in the affected area (N = 82) was in the middle of both. The TFs were poorly related to soil classification classes, likely because soil fertility (mK) was obscuring the effects of the soil classification related to the soil mineralogy (RIP). This study suggests that, on average, Japanese soils are more vulnerable than European soils at equal soil clay and exchangeable K content. The affected regions will be targeted for refined model validation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Diverse effects of arsenic on selected enzyme activities in soil-plant-microbe interactions.

Science.gov (United States)

Lyubun, Yelena V; Pleshakova, Ekaterina V; Mkandawire, Martin; Turkovskaya, Olga V

2013-11-15

Under the influence of pollutants, enzyme activities in plant-microbe-soil systems undergo changes of great importance in predicting soil-plant-microbe interactions, regulation of metal and nutrient uptake, and, ultimately, improvement of soil health and fertility. We evaluated the influence of As on soil enzyme activities and the effectiveness of five field crops for As phytoextraction. The initial As concentration in soil was 50mg As kg(-1) soil; planted clean soil, unplanted polluted soil, and unplanted clean soil served as controls. After 10 weeks, the growth of the plants elevated soil dehydrogenase activity relative to polluted but unplanted control soils by 2.4- and 2.5-fold for sorghum and sunflower (respectively), by 3-fold for ryegrass and sudangrass, and by 5.2-fold for spring rape. Soil peroxidase activity increased by 33% with ryegrass and rape, while soil phosphatase activity was directly correlated with residual As (correlation coefficient R(2)=0.7045). We conclude that soil enzyme activities should be taken into account when selecting plants for phytoremediation. Copyright © 2013 Elsevier B.V. All rights reserved.

Phytostabilization potential of ornamental plants grown in soil contaminated with cadmium.

Science.gov (United States)

Zeng, Peng; Guo, Zhaohui; Cao, Xia; Xiao, Xiyuan; Liu, Yanan; Shi, Lei

2018-03-21

In a greenhouse experiment, five ornamental plants, Osmanthus fragrans (OF), Ligustrum vicaryi L. (LV), Cinnamomum camphora (CC), Loropetalum chinense var. rubrum (LC), and Euonymus japonicas cv. Aureo-mar (EJ), were studied for the ability to phytostabilization for Cd-contaminated soil. The results showed that these five ornamental plants can grow normally when the soil Cd content is less than 24.6 mg·kg -1 . Cd was mainly deposited in the roots of OF, LV, LC and EJ which have grown in Cd-contaminated soils, and the maximum Cd contents reached 15.76, 19.09, 20.59 and 32.91 mg·kg -1 , respectively. For CC, Cd was mainly distributed in the shoots and the maximum Cd content in stems and leaves were 12.5 and 10.71 mg·kg -1 , however, the total amount of Cd in stems and leaves was similar with the other ornamental plants. The enzymatic activities in Cd-contaminated soil were benefited from the five tested ornamental plants remediation. Soil urease and sucrase activities were improved, while dehydrogenase activity was depressed. Meanwhile, the soil microbial community was slightly influenced when soil Cd content is less than 24.6 mg·kg -1 under five ornamental plants remediation. The results further suggested that ornamental plants could be promising candidates for phytostabilization of Cd-contaminated soil.

Biochemical studies on the effect of fluoride on higher plants. II. The effect of fluoride on sucrose-synthesizing enzymes from higher plants

Energy Technology Data Exchange (ETDEWEB)

Yang, S F; Miller, G W

1963-01-01

A study was initiated to characterize the properties of partially purified phosphoglucomutase, uridine diphosphate glucose pyrophosphorylase and uridine diphosphate glucose-fructose transglucosyalse, from various plant sources, with respect to activation by metal ions and inhibition by fluoride. Of the three enzymes studied, only phosphoglucomutase was very sensitive to fluoride. It is likely that the inhibition of sucrose synthesis in fluoride-fumigated plants might be due to the inhibition of phosphoglucomutase, which plays an important role in carbohydrate metabolism. However, at present, there is insufficient evidence to show the inhibition of phosphoglucomutase in vivo by fumigation with hydrogen fluoride.

Using DTPA-extractable soil fraction to assess the bioconcentration factor of plants in phytoremediation of urban soils

Science.gov (United States)

Rodríguez-Bocanegra, Javier; Roca, Núria; Tume, Pedro; Bech, Jaume

2017-04-01

Urban soils may be highly contaminated with potentially toxic metals, as a result of intensive anthropogenic activities. Developing cities are increasing the number of lands where is practiced the urban agriculture. In this way, it is necessary to assess the part of heavy metals that is transferred to plants in order to a) know the potential health risk that represent soils and b) know the relation soil-plant to assess the ability of these plants to remove heavy metals from soil. Nowadays, to assess the bioconcentration factor (BF) of plants in phytoremediation, the pseudototal o total concentration has been used by many authors. Two different urban soils with similar pH and carbonates content but with different pollution degree were phytoremediated with different plant species. Urban soil from one Barcelona district (Spain), the most contaminated soil, showed an extractability of Cu, Pb and Zn of 9.6, 6.7 and 5.8% of the total fraction respectively. The soil from Talcahuano city (Chile), with contents of heavy metals slightly above the background upper limit, present values of 15.5, 13.5 and 12% of the total fraction of studied heavy metals. Furthermore, a peri-urban analysed soil from Azul (Argentina) also showed an elevated extractability with values of 24, 13.5 and 14% of the Cu, Pb and Zn contents respectively. These soils presented more extractability than other disturbed soils, like for example, soils from mine areas. The urban soils present more developed soil with an interaction between solution and solid phase in polluted systems. The most important soil surface functional groups include the basal plane of phyllosilicates and metal hydroxyls at edge sites of clay minerals, iron oxyhydroxides, manganese oxyhydroxides and organic matter. The interaction between solution and solid phase in polluted urban systems tends to form labile associations and pollutants are more readily mobilized because their bonds with soil particles are weaker. Clay and organic

Uptake of radionuclides by plants growing on Brazilian soil: the effect of soil ageing

International Nuclear Information System (INIS)

Wasserman, Maria A.; Rochedo, Elaine R.R.; Ferreira, Ana C.M.; Vidal Perez, Daniel

2008-01-01

The behaviour of radionuclides in soil is governed by several mechanisms that can vary significantly according to the specific reactivity of each element and soil properties. The 137 Cs is one of radionuclides that generally reduces with time its mobility and phytoavailability due to irreversible fixation in high activity clay mineral such as illite, vermiculite and montmorilonite. A long-term experimental essay using Brazilian soils was done in order to determine the effect of ageing of contamination on 137 Cs mobility in soils and transfer to plants. To perform this study, 4 different soils with different properties were contaminated with 137 Cs at different period: The older contamination refers to an urban soil contaminated at the Goiania accident (1987). A similar type of Goiania's soil (Ferralsol rich in Gibbsite) was artificially contaminated with 137 Cs in 1993. A subtropical class of soil (Nitisol) was contaminated in 1996 and two other tropical soils were contaminated in 2000 (Acrisol and Ferralsol rich in Goethite). The time's effect was studied by characterizing the evolution of soil properties and the changes in the distribution of radionuclides between phases till 2006. In addition, the phytoavailability was evaluated by carrying out experiments in lysimeters where radish was sowed at different periods:1996, 2000 and 2004. These results showed that the phytoavailability changed with time only in 2 situations: after changes in some soil properties such as pH or due to Cs fixation in high activity clay mineral when it was present in the soils even as trace mineral. The 137 Cs distribution in soil showed that Fe oxides are the main sink for this element in all type of soil and 14 years after contamination, the 137 Cs was still available for plants in the Ferralsol Gbbiste rich. In the Nitisol, 5 years after contamination, the 137 Cs was not detected as in the slightly acidic phase of sequential extraction neither detectable in radish roots or leaves

Functional diversity of microbial decomposers facilitates plant coexistence in a plant-microbe-soil feedback model.

Science.gov (United States)

Miki, Takeshi; Ushio, Masayuki; Fukui, Shin; Kondoh, Michio

2010-08-10

Theory and empirical evidence suggest that plant-soil feedback (PSF) determines the structure of a plant community and nutrient cycling in terrestrial ecosystems. The plant community alters the nutrient pool size in soil by affecting litter decomposition processes, which in turn shapes the plant community, forming a PSF system. However, the role of microbial decomposers in PSF function is often overlooked, and it remains unclear whether decomposers reinforce or weaken litter-mediated plant control over nutrient cycling. Here, we present a theoretical model incorporating the functional diversity of both plants and microbial decomposers. Two fundamental microbial processes are included that control nutrient mineralization from plant litter: (i) assimilation of mineralized nutrient into the microbial biomass (microbial immobilization), and (ii) release of the microbial nutrients into the inorganic nutrient pool (net mineralization). With this model, we show that microbial diversity may act as a buffer that weakens plant control over the soil nutrient pool, reversing the sign of PSF from positive to negative and facilitating plant coexistence. This is explained by the decoupling of litter decomposability and nutrient pool size arising from a flexible change in the microbial community composition and decomposition processes in response to variations in plant litter decomposability. Our results suggest that the microbial community plays a central role in PSF function and the plant community structure. Furthermore, the results strongly imply that the plant-centered view of nutrient cycling should be changed to a plant-microbe-soil feedback system, by incorporating the community ecology of microbial decomposers and their functional diversity.

Division S-4-soil fertility and plant nutrition

International Nuclear Information System (INIS)

Norman, R.J.; Gilmour, J.T.

1987-01-01

A portion of anhydrous NH 3 fertilizer applied to soil can be rendered nonexchangeable through fixation by clay minerals and soil organic matter. The plant availability of anhydrous NH 3 fixed by these two soil fractions can be important agronomically if such fixation limits plant uptake of the fertilizer N. In this study, three soils with clay and organic C contents ranging from 120 to 310 and 7.8 to 30.1 g kg -1 , respectively, were injected with 15 N-labeled (2 atom % 15 N) liquid anhydrous NH 3 at a rate equivalent to 245 kg N ha -1 . Soluble and exchangeable N were removed by leaching and the soil was cropped to rye grass (Lolium multiflorum Lam.) in pots. Soils were analyzed before and after cropping for clay fixed N and organic matter fixed N. Four cuttings (harvests) were made at 3- to 4-week intervals and roots were collected at the termination of the experiment. Above ground dry matter, total N uptake, and fertilizer-derived fixed N uptake (mg N pot -1 ) increased from the first to the second harvest and declined thereafter. Nitrogen recovered in the roots accounted for <11% of the total N and <7% of the fixed N utilized, and root dry matter accounted for 13 to 14% of the total dry matter produced. The ratio of fertilizer-derived fixed N uptake to total N uptake declined with harvest suggesting that the fixed N became less available to the rye grass with time. Fertilizer-derived fixed N recovered in the rye grass ranged from 19 to 26% of that originally fixed by the soil. The percentages of fertilizer-derived clay fixed N removed from the soils during cropping (35-72%) were much larger than those of the fertilizer-derived organic matter fixed N (<12%) suggesting that a majority of the plant uptake of fixed N originated in the clay fraction. Overall, fertilizer-derived fixed N removal from the soils (21-30%) agreed well with plant uptake data

Remediation aspect of microbial changes of plant rhizosphere in mercury contaminated soil.

Science.gov (United States)

Sas-Nowosielska, Aleksandra; Galimska-Stypa, Regina; Kucharski, Rafał; Zielonka, Urszula; Małkowski, Eugeniusz; Gray, Laymon

2008-02-01

Phytoremediation, an approach that uses plants to remediate contaminated soil through degradation, stabilization or accumulation, may provide an efficient solution to some mercury contamination problems. This paper presents growth chamber experiments that tested the ability of plant species to stabilize mercury in soil. Several indigenous herbaceous species and Salix viminalis were grown in soil collected from a mercury-contaminated site in southern Poland. The uptake and distribution of mercury by these plants were investigated, and the growth and vitality of the plants through a part of one vegetative cycle were assessed. The highest concentrations of mercury were found at the roots, but translocation to the aerial part also occurred. Most of the plant species tested displayed good growth on mercury contaminated soil and sustained a rich microbial population in the rhizosphere. The microbial populations of root-free soil and rhizosphere soil from all species were also examined. An inverse correlation between the number of sulfur amino acid decomposing bacteria and root mercury content was observed. These results indicate the potential for using some species of plants to treat mercury contaminated soil through stabilization rather than extraction. The present investigation proposes a practical cost-effective temporary solution for phytostabilization of soil with moderate mercury contamination as well as the basis for plant selection.

Soil ecotoxicity assessment using cadmium sensitive plants

Energy Technology Data Exchange (ETDEWEB)

An, Youn-Joo

2004-01-01

The crop plants, sorghum and cucumber, can be used as indicator species to assess ecotoxicity of soils contaminated by cadmium. - Four crop plant species (sweet corn, Zea may; wheat, Triticum aestivum; cucumber, Cucumis sativus; and sorghum, Sorghum bicolor) were tested to assess an ecotoxicity in cadmium-amended soils. The measurement endpoints used were seed germination and seedling growth (shoot and root). The presence of cadmium decreased the seedling growth. The medium effective concentration values (EC50) for shoot or root growth were calculated by the Trimmed Spearman-Karber method. Due to the greater accumulation of Cd to the roots, root growth was a more sensitive endpoint than shoot growth. Bioavailability and transport of Cd within plant were related to concentration and species. The ratio of bioaccumulation factor (BAF) in the shoots to the roots indicated high immobilization of Cd in the roots. Seed germination was insensitive to Cd toxicity, and is not recommended for a suitable assay. Among the test plants and test endpoints, root growth of sorghum and cucumber appears to be a good protocol to assess ecotoxicity of soils contaminated by Cd.

Soil ecotoxicity assessment using cadmium sensitive plants

International Nuclear Information System (INIS)

An, Youn-Joo

2004-01-01

The crop plants, sorghum and cucumber, can be used as indicator species to assess ecotoxicity of soils contaminated by cadmium. - Four crop plant species (sweet corn, Zea may; wheat, Triticum aestivum; cucumber, Cucumis sativus; and sorghum, Sorghum bicolor) were tested to assess an ecotoxicity in cadmium-amended soils. The measurement endpoints used were seed germination and seedling growth (shoot and root). The presence of cadmium decreased the seedling growth. The medium effective concentration values (EC50) for shoot or root growth were calculated by the Trimmed Spearman-Karber method. Due to the greater accumulation of Cd to the roots, root growth was a more sensitive endpoint than shoot growth. Bioavailability and transport of Cd within plant were related to concentration and species. The ratio of bioaccumulation factor (BAF) in the shoots to the roots indicated high immobilization of Cd in the roots. Seed germination was insensitive to Cd toxicity, and is not recommended for a suitable assay. Among the test plants and test endpoints, root growth of sorghum and cucumber appears to be a good protocol to assess ecotoxicity of soils contaminated by Cd

Using Plants for the Bioremediation (Phyto-remediation) of Chromium-Contaminated Soils

International Nuclear Information System (INIS)

Abdel-Sabour, M.F.; Al-Salama, Y.J.

2003-01-01

A trial was made to study the use of hyper accumulator plant species to extract Cr out of contaminated soils. Three soils (A,B, and C) were selected in this experiment, Soil A: Polluted soil from El-Gabal El-Asfer farm. (subjected to sewage effluent irrigation for more than 75 years). Soil B: Polluted soil from Bahtem area (subjected to sewage effluent irrigation for more than 30 years). Soil C: Polluted soil from Mostorud area (irrigated with contaminated water for more than 30 years due to direct discharge of industrial wastewater to irrigation water canals). Four Kg of each air-dried surface soil sample (0-20 cm) were packed in plastic containers in three replicates. Four plant species tested in this study namely, Sorghum (Sorghum Vulgar L.), Clover (Trifolium Pretense L.), Panikum (Panicum antidotal) and Canola (Brassica Napous.); were grown on each tested soil in a complete randomized block experimental design. Plant shoots were harvested every 60 days (three cuts) for sorghum, clover and panikum. In case of canola plants, the shoots were harvested after 60 days (vegetative stage) and 85 days(fruiting stage). The roots of all species were collected after the final cut. Initial and final soil samples were taken for Cr analyses using neutron activation analyses technique (NAA)

Post-fire interactions between soil water repellency, soil fertility and plant growth in soil collected from a burned piñon-juniper woodland

Science.gov (United States)

Fernelius, Kaitlynn J.; Madsen, Matthew D.; Hopkins, Bryan G.; Bansal, Sheel; Anderson, Val J.; Eggett, Dennis L.; Roundy, Bruce A.

2017-01-01

Woody plant encroachment can increase nutrient resources in the plant-mound zone. After a fire, this zone is often found to be water repellent. This study aimed to understand the effects of post-fire water repellency on soil water and inorganic nitrogen and their effects on plant growth of the introduced annual Bromus tectorum and native bunchgrass Pseudoroegneria spicata. Plots centered on burned Juniperus osteosperma trees were either left untreated or treated with surfactant to ameliorate water repellency. After two years, we excavated soil from the untreated and treated plots and placed it in zerotension lysimeter pots. In the greenhouse, half of the pots received an additional surfactant treatment. Pots were seeded separately with B. tectorum or P. spicata. Untreated soils had high runoff, decreased soilwater content, and elevated NO3eN in comparison to surfactant treated soils. The two plant species typically responded similar to the treatments. Above-ground biomass and microbial activity (estimated through soil CO2 gas emissions) was 16.8-fold and 9.5-fold higher in the surfactant-treated soils than repellent soils, respectably. This study demonstrates that water repellency can influence site recovery by decreasing soil water content, promoting inorganic N retention, and impairing plant growth and microbial activity.

Use of the neutron activation technique: soil-plant transfer factor

International Nuclear Information System (INIS)

Silva, Wellington Ferrari da; Menezes, Maria Ângela de B.C.; Marques, Douglas José

2017-01-01

Recent studies have demonstrated the importance of the soil-plant transfer factor in the absorption and translocation of chemical elements, thus, it is possible to evaluate a better decision-making in the consecutive plantations. To determine these values, the content of a chemical element present in the plant or part of it with the total content present in the same soil where it is grown is considered. The objective of this study was to determine the concentrations of the chemical elements present in soil, leaf and grains corn, by neutron activation analysis and to compare the different soil-plant transfer factors. The samples were collected in a property located in the region of Biquinhas, MG, and irradiated in the TRIGA MARK I IPR-R1 CDTN / CNEN nuclear reactor. Thus, the concentrations of Br, Ce Fe, K, La, Na, Rb, Zn were determined. The soil-plant transfer factors for the elements found were varied, indicating a greater potassium absorption capacity (K). (author)

Use of the neutron activation technique: soil-plant transfer factor

Energy Technology Data Exchange (ETDEWEB)

Silva, Wellington Ferrari da, E-mail: wferrari250@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pós-Graduação em Ciências e Técnicas Nucleares; Menezes, Maria Ângela de B.C., E-mail: menezes@cdtn.br [Centro Desenvolvimento da Tecnologia Nuclear (SERTA/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Serviço de Técnicas Analíticas. Laboratório de Ativação Neutrônica; Marques, Douglas José, E-mail: douglasjmarques81@yahoo.com.br [Universidade José do Rosário Vellano, Alfenas, MG (Brazil). Setor de Olericultura e Experimentação em Agricultura Orgânica

2017-07-01

Recent studies have demonstrated the importance of the soil-plant transfer factor in the absorption and translocation of chemical elements, thus, it is possible to evaluate a better decision-making in the consecutive plantations. To determine these values, the content of a chemical element present in the plant or part of it with the total content present in the same soil where it is grown is considered. The objective of this study was to determine the concentrations of the chemical elements present in soil, leaf and grains corn, by neutron activation analysis and to compare the different soil-plant transfer factors. The samples were collected in a property located in the region of Biquinhas, MG, and irradiated in the TRIGA MARK I IPR-R1 CDTN / CNEN nuclear reactor. Thus, the concentrations of Br, Ce Fe, K, La, Na, Rb, Zn were determined. The soil-plant transfer factors for the elements found were varied, indicating a greater potassium absorption capacity (K). (author)

Soil to plant transfer values of 137 Cs in soils of tropical agro-ecological systems

International Nuclear Information System (INIS)

Wasserman, Maria Angelica; Ferreira, Ana Cristina Melo; Conti, Claudio Carvalho; Rochedo, Elaine Rua Rodriguez; Bartoly, Flavia; Viana, Aline Gonzalez; Moura, Glaucio Pereira; Poquet, Isabel; Perez, Daniel Vidal

2002-01-01

Recent radioecological studies have showed that some ecosystems present more suitable conditions for soil to plant transfer of some radionuclides, while others present lower transfer when compared with average values. Due to the difficulty to generate, experimentally, soil to plant transfer factors enough to cover the totality of existing soil and vegetation types, an alternative way has been the use of soil to reference plant transfer factor determined in various ecosystems. Trough the use of conversion factors, the reference transfer factor can be converted in values of transfer factor specific for a specific type of crop. These values can be used regionally to improve dose calculation and models for radiological risk assessments. This work presents experimental data for 137 Cs for reference crops grown up in Oxisol, Ultisol and Alfisol. These results allow the assessment of sensibility of main Brazilian soils regarding a radiological contamination with 137 Cs and provide regional parameters values. The results obtained in soils of tropical climate validate the international methodology aiming to derive generic transfer factor values for 137 Cs in reference crops based on a few soil properties such as fertility, pH and organic matter content. (author)

Defoliation and Soil Compaction Jointly Drive Large-Herbivore Grazing Effects on Plants and Soil Arthropods on Clay Soil

NARCIS (Netherlands)

van Klink, R.; Schrama, M.; Nolte, S.; Bakker, J. P.; WallisDeVries, M. F.; Berg, M. P.

In addition to the well-studied impacts of defecation and defoliation, large herbivores also affect plant and arthropod communities through trampling, and the associated soil compaction. Soil compaction can be expected to be particularly important on wet, fine-textured soils. Therefore, we

Defoliation and Soil Compaction Jointly Drive Large-Herbivore Grazing Effects on Plants and Soil Arthropods on Clay Soil

NARCIS (Netherlands)

van Klink, R.; Schrama, M.; Nolte, S.; Bakker, Jan P.; WallisDeVries, M.F.; Berg, M.P.

2015-01-01

In addition to the well-studied impacts of defecation and defoliation, large herbivores also affect plant and arthropod communities through trampling, and the associated soil compaction. Soil compaction can be expected to be particularly important on wet, fine-textured soils. Therefore, we

Morphologic observations on respiratory tracts of chickens after hatchery infectious bronchitis vaccination and formaldehyde fumigation.

Science.gov (United States)

Di Matteo, A M; Soñez, M C; Plano, C M; von Lawzewitsch, I

2000-01-01

The histologic changes in the respiratory tracts of chickens were evaluated after hatchery fumigation with 40% formaldehyde vapors and vaccination against infectious bronchitis virus with live attenuated vaccine (Massachusetts serotype). One-day-old chickens were housed in four isolation units in controlled environmental conditions, fed and watered ad libitum, and separated into four groups: 1) fumigated and vaccinated birds (FV group); 2) nonfumigated and vaccinated birds (NFV group); 3) fumigated and nonvaccinated birds (FNV group); and 4) control group (C group). All birds were tested to be free from Mycoplasma gallisepticum and Mycoplasma synoviae. After necropsy on the first, eighth, and twenty-sixth days after birth, samples from tracheal upper portion and lungs were conventionally processed for light, scanning, and transmission electron microscopy. Tissue response was monitored by microscopic examination of trachea and lung. On the first day of observation, fumigated and vaccinated birds (FV group) showed extensively damaged tracheal epithelium with exfoliated areas and some active glands with electrodense granules, and in the lung, the primary bronchi epithelium had disorganized cilia and abundant lymphocytes, with emphysematous areas in tertiary bronchus. On day 8 after vaccination, cubical and cylindrical tracheal cell proliferation was observed, and on day 26, ciliated columnar epithelium was almost regenerated with heterophil corion infiltration, and hyaline cartilage nodules appeared in parabronchi. The nonfumigated and vaccinated birds (NFV) revealed less injury on the epithelial surface and a more rapid response to epithelial regeneration than the in only fumigated animals (FNV). The control group did not show remarkable morphologic changes. Postvaccinal and fumigation effects on the upper respiratory tract were temporary, whereas in lungs, increased emphysema, cartilage nodules in the interchange zone, and general lymphocyte infiltration had caused

Behavior of iodine in the atmosphere-soil-plant system

International Nuclear Information System (INIS)

Muramatsu, Yasuyuki; Yoshida, Satoshi; Uchida, Shigeo

1996-01-01

Levels and behavior of radioactive and stable iodine in the environment have been studied to obtain parameter values for the assessment of 129 I released from nuclear facilities. The deposition velocity (V D ) of gaseous iodine from the atmosphere to rice grains (rough rice) was 0.00048 cm 3 g -1 s -1 for CH 3 I and 0.15 cm 3 g -1 s -1 for I 2 . The ratio of the iodine distribution in a grain exposed to CH 3 I was as follows, rough rice : brown rice (hulled rice) : polished rice = 1.0 : 0.49 : 0.38. The distribution ratio in polished rice for CH 3 I was about 20 times higher than that for I 2 . The soil-solution distribution coefficient (K d ) for both I - and IO 3 - varied very widely, i.e. -1 . High values were found in soils having high concentrations of total organic carbon, active-Al and active-Fe (Al and Fe extracted by a mixture of oxalic acid and ammonium oxalate). Andosol, one of the most typical Japanese soils derived from deposits of volcanic ash, showed specifically high K d values. The soil-to-plant transfer factors (or concentration ratio) in the edible parts of crops were in the range 0.0002-0.016. The transfer factors for tomato, sweet potato, carrot, soybeans and rice were significantly lower than their leaf values. The value for rice (polished) was 0.002. Iodine was found to be evaporated from the soil-plant system as CH 3 I. The emission of CH 3 I from rice plants grown on flooded soil was much higher than that from oat plants grown on unflooded soil. The 129 I levels in environmental samples collected in and around Tokai-mura, where a spent nuclear fuel reprocessing plant is located, have been determined by neutron activation analysis. The concentrations of 129 I in surface soils ranged from -1 . The 129 I concentrations in forest soil tended to be higher than those in field soils. Most of the 129 I was retained in the first 10 cm of the surface soil collected from forests in Tokai-mura. (author)

Persistence of endosulfan and its metabolites in tomato plants and soil

International Nuclear Information System (INIS)

Carazo, E.; Barquero, M.; Valverde, B.

1999-01-01

Tests were conducted to study the persistence of 14 C-labelled α and β -endosulfan in tomato plants and soil under the greenhouse conditions when applied at the rate and number of applications used by tomato growers in Costa Rica. Two applications, at 30 and 55 days after planting were made. Plant and soil samples were extracted 37, 49, 71 and 125 days after planting and analyzed by LSC, TLC and GC-ECD. At 37 days after planting the compounds identified were α-endosulfan, β-endosulfan and endosulfan sulphate with a combined concentration of 3.6 mg/kg in plant and 0.6 mg/kg in the soil. At 49 days after planting the same three compounds were found at the combined concentration of 1.51 mg/kg in the plant and at 0.34 mg/kg in the soil. After 71 days low levels of α-endosulfan, β-endosulfan, endosulfan sulphate and endosulfan lactone were found in plants and soil. Similarly, at 125 days low levels of these compounds as well as low levels of two other metabolites, endosulfan alcohol and endosulfan ether were detected. Under the conditions of the experiment endosulfan residues do not seem to be significant or persistant. (author)

Effects of gasification biochar on plant-available water capacity and plant growth in two contrasting soil types

DEFF Research Database (Denmark)

Hansen, Veronika; Hauggaard-Nielsen, Henrik; Petersen, Carsten Tilbæk

2016-01-01

Abstract Gasification biochar (GB) contains recalcitrant carbon that can contribute to soil carbon sequestration and soil quality improvement. However, the impact of GB on plant-available water capacity (AWC) and plant growth in diverse soil types still needs to be explored. A pot experiment......, the reduced water regime significantly affected plant growth and water consumption, whereas the effect was less pronounced in the coarse sand. Irrespective of the soil type, both GBs increased AWC by 17–42%, with the highest absolute effect in the coarse sand. The addition of SGB to coarse sand led...

Alleviating soil acidity through plant organic compounds

Directory of Open Access Journals (Sweden)

Anderson R. Meda

2001-06-01

Full Text Available A laboratory experiment was conducted to evaluate the effects of water soluble plant extracts on soil acidity. The plant materials were: black oat, oil seed radish, white and blue lupin, gray and dwarf mucuna, Crotalaria spectabilis and C. breviflora, millet, pigeon pea, star grass, mato grosso grass, coffee leaves, sugar cane leaves, rice straw, and wheat straw. Plant extracts were added on soil surface in a PVC soil column at a rate of 1.0 ml min-1. Both soil and drainage water were analyzed for pH, Ca, Al, and K. Plant extracts applied on the soil surface increased soil pH, exchangeable Ca ex and Kex and decreased Al ex. Oil seed radish, black oat, and blue lupin were the best and millet the worst materials to alleviate soil acidity. Oil seed radish markedly increased Al in the drainage water. Chemical changes were associated with the concentrations of basic cations in the plant extract: the higher the concentration the greater the effects in alleviating soil acidity.Foram conduzidos experimentos de laboratórios para avaliar os efeitos de extratos de plantas solúveis em água na acidez do solo. Os materiais de plantas foram: aveia preta, nabo, tremoço branco e azul, mucuna cinza e anã, Crotalaria spectabilis e C. breviflora, milheto, guandu, grama estrela, grama mato grosso, folhas de café, folhas de cana-de-açúcar, palhada de arroz e palhada de trigo. Foi utilizado o seguinte procedimento para o extrato da planta solúvel em água: pesar 3g de material de planta, adicionar 150 ml de água, agitar por 8h e filtrar. Os extratos de plantas foram adicionados na superfície do solo em uma coluna de PVC (1 ml min-1. Após, adicionou-se água deionizada em quantidade equivalente a três volumes de poros. Os extratos de plantas aumentaram o pH, Ca e K trocável e diminuíram Al. Nabo, aveia preta e tremoço azul foram os melhores e milheto o pior material para amenizar a acidez do solo. Nabo aumentou Al na água de drenagem. As altera

Heavy Metal Polluted Soils: Effect on Plants and Bioremediation Methods

OpenAIRE

Chibuike, G. U.; Obiora, S. C.

2014-01-01

Soils polluted with heavy metals have become common across the globe due to increase in geologic and anthropogenic activities. Plants growing on these soils show a reduction in growth, performance, and yield. Bioremediation is an effective method of treating heavy metal polluted soils. It is a widely accepted method that is mostly carried out in situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Microorganisms and plants employ different mechanisms for...

Rhizosphere bacterial carbon turnover is higher in nucleic acids than membrane lipids: implications for understanding soil carbon cycling

Directory of Open Access Journals (Sweden)

Ashish A. Malik

2015-04-01

Full Text Available Using a pulse-chase 13CO2 plant labeling experiment we compared the flow of plant carbon into macromolecular fractions of root-associated soil microorganisms. Time dependent 13C dilution patterns in microbial cellular fractions were used to calculate their turnover time. The turnover times of microbial biomolecules were found to vary: microbial RNA (19 h and DNA (30 h turned over fastest followed by chloroform fumigation extraction-derived soluble cell lysis products (14 d, while phospholipid fatty acids (PLFAs had the slowest turnover (42 d. PLFA/NLFA 13C analyses suggest that both mutualistic arbuscular mycorrhizal and saprophytic fungi are dominant in initial plant carbon uptake. In contrast, high initial 13C enrichment in RNA hints at bacterial importance in initial C uptake due to the dominance of bacterial derived RNA in total extracts of soil RNA. To explain this discrepancy, we observed low renewal rate of bacterial lipids, which may therefore bias lipid fatty acid based interpretations of the role of bacteria in soil microbial food webs. Based on our findings, we question current assumptions regarding plant-microbe carbon flux and suggest that the rhizosphere bacterial contribution to plant assimilate uptake could be higher. This highlights the need for more detailed quantitative investigations with nucleic acid biomarkers to further validate these findings.

Influence of Sulfur Fumigation on the Chemical Constituents and Antioxidant Activity of Buds of Lonicera japonica

Directory of Open Access Journals (Sweden)

Ai-Li Guo

2014-10-01

Full Text Available Lonicera japonica flos is widely used as a pharmaceutical resource and a commonly-employed ingredient in healthy food, soft beverages and cosmetics in China. Sometimes, sulfur fumigation is used during post-harvest handling. In this study, a comprehensive comparison of the chemical profile between sun-dried and sulfur-fumigated samples was conducted by HPLC fingerprints and simultaneous quantification of nine constituents, including secologanic acid, along with another eight usually-analyzed markers. Secologanic acid was destroyed, and its sulfonates were generated, whereas caffeoylquinic acids were protected from being oxidized. The residual sulfur dioxide in sulfur-fumigated samples was significantly higher than that in sun-dried samples, which might increase the potential incidence of toxicity to humans. Meanwhile, compared with sun-dried samples, sulfur-fumigated samples have significantly stronger antioxidant activity, which could be attributed to the joint effect of protected phenolic acids and flavonoids, as well as newly-generated iridoid sulfonates.

Effects of Nitrogen Fixing Pre-Crops and Fertilizers on Physical and Chemical Properties Down the Soil Profile

Science.gov (United States)

Hobley, E.; Honermeier, B.; Don, A.; Gocke, M. I.; Amelung, W.; Kogel-Knabner, I.

2016-12-01

We investigated the effects of pre-crops with and without biological nitrogen fixation capacity (fava beans, clover mulch, fodder maize) and fertilization (no fertilizer, NPK fertilizer, PK fertilizer) on soil physico-chemical properties (bulk density, electrical conductivity, soil organic carbon (SOC) concentration and stocks, N concentration and stocks) and their depth distribution (down to 1 m) at a long-term field experiment set up in 1982 in Gießen, Germany. Fertilization had significant but small impacts on the soil chemical environment, most particularly the salt content of the soil, with PK fertilization increasing electrical conductivity throughout the soil profile. Similarly, fertilization resulted in a small reduction of soil pH throughout the entire soil profile. The soil was physically and chemically affected by the type of pre-crop. Plots with fava beans and maize had lower bulk densities in the subsoil than those with clover. Pre-crop type also significantly affected the depth distribution of both N and SOC. Specifically, clover pre-cropping led to an enrichment of N at the surface compared with fava beans and maize. SOC enrichment at the surface was also observed under clover, with the effect most pronounced under PK fertilization. Combined with the bulk density effects, this shift in N distribution resulted in significantly higher N stocks under clover than under fava beans. However, the total stocks of SOC were not affected by pre-crop or fertilizer regime. Our results indicate that humans influence C and N cycling and distribution in soils through the selection of pre-crops and that the influence of crop type is greater than that of fertilization regimes. Pre-cropping with clover, which is used as a mulch, leads to N enrichment in the topsoil, reducing the need for N fertilizer for the subsequent cereal crop. In contrast, the use of fava beans as a pre-crop does not lead to N enrichment. We believe this is due to the greater rooting depth of

Transfer of 226Ra to plants from two types of soil

International Nuclear Information System (INIS)

Rosiak, L.; Pietrzak-Flis, Z.

1998-01-01

The transfer of 226 Ra to plants used as food (carrot, parsley, wheat) and as fodder (grass, maize) was studied. The plants were grown on two types of soil: sandy soil (l) and sandy loam soil (II) in an open field (exposure to dry and wet deposition, resuspension and soil adhesion) and in polyethylene tent with an underground irrigation system (isolation from wet deposition and from water splash on soil). The plants were grown simultaneously on the open and sheltered fields. The average concentrations of total 226 Ra and of exchangeable 226 Ra were 8.48 ± 0.50 Bq/kg dw was 0.62 ± 0.07 Bq/kg dw , respectively, in Soil I and 12.2 ± 0.56 Bq/kg dw and 0.66 ± 0.05 Bq/kg dw , respectively, in Soil II. 226 Ra was determined in the above-ground parts of the plants after washing in distilled water, in the rinse obtained from washing, in the insoluble residue separated from the rinse, and in the roots. The data obtained allowed us to determine the incorporated radionuclide in the plants and on their surface. Statistical analysis of the data indicates that there is no difference in the incorporated 226 Ra for plants grown on the open field and in the tent. This indicates that Ra enter the plants mainly through the root system, while the pathway via leaves and stems is negligible

Martian Soil Plant Growth Experiment: The Effects of Adding Nitrogen, Bacteria, and Fungi to Enhance Plant Growth

Science.gov (United States)

Kliman, D. M.; Cooper, J. B.; Anderson, R. C.

2000-01-01

Plant growth is enhanced by the presence of symbiotic soil microbes. In order to better understand how plants might prosper on Mars, we set up an experiment to test whether symbiotic microbes function to enhance plant growth in a Martian soil simulant.

Bioremediation of industrially contaminated soil using compost and plant technology.

Science.gov (United States)

Taiwo, A M; Gbadebo, A M; Oyedepo, J A; Ojekunle, Z O; Alo, O M; Oyeniran, A A; Onalaja, O J; Ogunjimi, D; Taiwo, O T

2016-03-05

Compost technology can be utilized for bioremediation of contaminated soil using the active microorganisms present in the matrix of contaminants. This study examined bioremediation of industrially polluted soil using the compost and plant technology. Soil samples were collected at the vicinity of three industrial locations in Ogun State and a goldmine site in Iperindo, Osun State in March, 2014. The compost used was made from cow dung, water hyacinth and sawdust for a period of twelve weeks. The matured compost was mixed with contaminated soil samples in a five-ratio pot experimental design. The compost and contaminated soil samples were analyzed using the standard procedures for pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), phosphorus, exchangeable cations (Na, K, Ca and Mg) and heavy metals (Fe, Mn, Cu, Zn and Cr). Kenaf (Hibiscus cannabinus) seeds were also planted for co-remediation of metals. The growth parameters of Kenaf plants were observed weekly for a period of one month. Results showed that during the one-month remediation experiment, treatments with 'compost-only' removed 49 ± 8% Mn, 32 ± 7% Fe, 29 ± 11% Zn, 27 ± 6% Cu and 11 ± 5% Cr from the contaminated soil. On the other hand, treatments with 'compost+plant' remediated 71 ± 8% Mn, 63 ± 3% Fe, 59 ± 11% Zn, 40 ± 6% Cu and 5 ± 4% Cr. Enrichment factor (EF) of metals in the compost was low while that of Cu (EF=7.3) and Zn (EF=8.6) were high in the contaminated soils. Bioaccumulation factor (BF) revealed low metal uptake by Kenaf plant. The growth parameters of Kenaf plant showed steady increments from week 1 to week 4 of planting. Copyright © 2015 Elsevier B.V. All rights reserved.

Soil-to-plant halogens transfer studies

Energy Technology Data Exchange (ETDEWEB)

Kashparov, V. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine); Colle, C. [Institute for Radioprotection and Nuclear Safety (IRSN/DEI/SECRE), Cadarache bat 159, BP 3, 13115 Saint Paul-lez-Durance (France)]. E-mail: claude.colle@irsn.fr; Zvarich, S. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine); Yoschenko, V. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine); Levchuk, S. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine); Lundin, S. [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Str.7, Chabany, Kiev Region 08162 (Ukraine)

2005-07-01

Long-term controlled experiments under natural conditions in the field have been carried out in the Chernobyl Exclusion zone in order to determine the parameters governing radioiodine transfer to plants from four types of soils (podzoluvisol, greyzem and typical and meadow chernozem) homogeneously contaminated in the 20-cm upper layer with an addition of {sup 125}I. An absence of {sup 125}I depletion in arable soil layers due to volatilization was noted up to one year after contamination. During one year, depletion due to the vertical migration of radioiodine from the arable layer of each of the soils did not exceed 4% of the total {sup 125}I content. Radioiodine concentration ratios (CR) were obtained in radish roots, lettuce leaves, bean pods, and wheat grain and straw. The highest CR values were observed in podzoluvisol: 0.01-0.03 for radish roots and lettuce leaves, 0.003-0.004 for bean pods and 0.001 for wheat grains. In the other three soils, these values were one order of magnitude lower. The parameters relating to changes in radioiodine bioavailability were determined, based on the contamination dynamics of plants in field conditions.

Variation of the rare earth element concentrations in the soil, soil extract and in individual plants from the same site

International Nuclear Information System (INIS)

Wyttenbach, A.; Tobler, L.; Furrer, V.; Schleppi, P.

1998-01-01

Samples of various types (spruce needles, blackberry leaves, soils, and soil extracts) have each been taken at 6 places from the same site. In addition, 4 whirls each from 2 spruce trees were sampled. Rare earth elements (REEs) were determined in these samples by neutron activation analysis with a chemical group separation. Variations between places were found to be small with soils and soil extracts, but large with plants. Variations between whirls were small. Plants neither reflected the soil nor the soil extract. Both plant species were dissimilar, but the logarithm of their ratio was a linear function of the atomic number of the REE. A negative Ce anomaly (with respect to soil) was found in both plant species. (author)

Soil-plant relation in Cuban sugar cane by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Diaz Riso, O.; Griffith Martinez, J.

1996-01-01

This paper shows the result of soil-plant relation in samples from Cuban sugar canes of different soil types and cane varieties, using the INAA from thermal reactor. The behaviour of minor and trace elements in sugar cane leaves is uniform and independent of sugar cane variety or type of soil. The soil-plant relation shows four principal groups of micro elements, according to their absorption by the plant

The USEPA environmental response team TAGA at work at the Hart building fumigation

Energy Technology Data Exchange (ETDEWEB)

Mickunas, D.B.; Turpin, R. [United States Environmental Protection Agency, Edison, NJ (United States). Environmental Response Team; Blaze, S.; Wood, J. [Lockheed Martin Inc., Edison, NJ (United States). Response Engineering and Analytical Contract

2004-07-01

This paper describes the fumigation activities conducted at the Hart Senate Office building in Washington, DC in October 2001 following the delivery of a letter containing anthrax. Anthrax spores were dispersed in areas within the office. The United States States Environmental Protection Agency Environmental Response Team (USEPA/ERT) was responsible for the decontamination activities. Chlorine dioxide was chosen as the anthrax sporicide after a detailed technical review and consultation with scientific experts. ERT provided continuous, near real-time ambient air monitoring during the fumigation process. The monitoring was conducted to ensure that the nearby residences were not impacted by the chlorine dioxide fumigant. The monitoring plan required the use of a Trace Atmospheric Gas Analyzer (TAGA), a triple quadrupole mass spectrometer mounted in a mobile laboratory. The monitoring activities of ERT's mobile laboratory were outlined in this paper along with the logistical and technical aspects of the air monitoring. More than 130 hours of TAGA monitoring was performed and 2.3 million data points were collected. No chlorine or chlorine dioxide concentrations were observed above the action limits during any fumigation event. The building was cleared by the health and regulatory agencies and re-opened in January 2002. It was concluded that TAGA is an excellent technology to monitor these compounds because is is extremely sensitive and selective. 2 tabs., 5 figs.

78 FR 36507 - Notice of Availability of a Treatment Evaluation Document; Methyl Bromide Fumigation of Blueberries

Science.gov (United States)

2013-06-18

... treatment schedule for blueberries at a temperature of 60[emsp14][deg]F at a dosage rate of 2 lbs gas/1,000...] Notice of Availability of a Treatment Evaluation Document; Methyl Bromide Fumigation of Blueberries... and Quarantine Treatment Manual an additional treatment schedule for methyl bromide fumigation of...

Soil stabilization linked to plant diversity and environmental context in coastal wetlands.

Science.gov (United States)

Ford, Hilary; Garbutt, Angus; Ladd, Cai; Malarkey, Jonathan; Skov, Martin W

2016-03-01

Plants play a pivotal role in soil stabilization, with above-ground vegetation and roots combining to physically protect soil against erosion. It is possible that diverse plant communities boost root biomass, with knock-on positive effects for soil stability, but these relationships are yet to be disentangled. We hypothesize that soil erosion rates fall with increased plant species richness, and test explicitly how closely root biomass is associated with plant diversity. We tested this hypothesis in salt marsh grasslands, dynamic ecosystems with a key role in flood protection. Using step-wise regression, the influences of biotic (e.g. plant diversity) and abiotic variables on root biomass and soil stability were determined for salt marshes with two contrasting soil types: erosion-resistant clay (Essex, southeast UK) and erosion-prone sand (Morecambe Bay, northwest UK). A total of 132 (30-cm depth) cores of natural marsh were extracted and exposed to lateral erosion by water in a re-circulating flume. Soil erosion rates fell with increased plant species richness ( R 2  = 0.55), when richness was modelled as a single explanatory variable, but was more important in erosion-prone ( R 2  = 0.44) than erosion-resistant ( R 2  = 0.18) regions. As plant species richness increased from two to nine species·m -2 , the coefficient of variation in soil erosion rate decreased significantly ( R 2  = 0.92). Plant species richness was a significant predictor of root biomass ( R 2  = 0.22). Step-wise regression showed that five key variables accounted for 80% of variation in soil erosion rate across regions. Clay-silt fraction and soil carbon stock were linked to lower rates, contributing 24% and 31%, respectively, to variation in erosion rate. In regional analysis, abiotic factors declined in importance, with root biomass explaining 25% of variation. Plant diversity explained 12% of variation in the erosion-prone sandy region. Our study indicates that soil stabilization

The effect of partial soil sterilization on plant parasitic nematodes and plant growth

NARCIS (Netherlands)

Eissa, M.F.M.

1971-01-01

Research was carried out on the possible yield increase of crops in The Netherlands by the use of PSS (partial soil sterilization) on the soil, on the basis of published as well as unpublished data and by experimentation with different disinfectants, soils and plants.

Following review of the

Sewage sludge fertiliser use: implications for soil and plant copper evolution in forest and agronomic soils.

Science.gov (United States)

Ferreiro-Domínguez, Nuria; Rigueiro-Rodríguez, Antonio; Mosquera-Losada, M Rosa

2012-05-01

Fertilisation with sewage sludge may lead to crop toxicity and environmental degradation. This study aims to evaluate the effects of two types of soils (forest and agronomic), two types of vegetation (unsown (coming from soil seed bank) and sown), and two types of fertilisation (sludge fertilisation and mineral fertilisation, with a no fertiliser control) in afforested and treeless swards and in sown and unsown forestlands on the total and available Cu concentration in soil, the leaching of this element and the Cu levels in plant. The experimental design was completely randomised with nine treatments and three replicates. Fertilisation with sewage sludge increased the concentration of Cu in soil and plant, but the soil values never exceeded the maximum set by Spanish regulations. Sewage sludge inputs increased both the total and Mehlich 3 Cu concentrations in agronomic soils and the Cu levels in plant developed in agronomic and forest soils, with this effect pronounced in the unsown swards of forest soils. Therefore, the use of high quality sewage sludge as fertiliser may improve the global productivity of forest, agronomic and silvopastoral systems without creating environmental hazards. Copyright © 2012 Elsevier B.V. All rights reserved.

Soil microbial species loss affects plant biomass and survival of an introduced bacterial strain, but not inducible plant defences.

Science.gov (United States)

Kurm, Viola; van der Putten, Wim H; Pineda, Ana; Hol, W H Gera

2018-02-12

Plant growth-promoting rhizobacteria (PGPR) strains can influence plant-insect interactions. However, little is known about the effect of changes in the soil bacterial community in general and especially the loss of rare soil microbes on these interactions. Here, the influence of rare soil microbe reduction on induced systemic resistance (ISR) in a wild ecotype of Arabidopsis thaliana against the aphid Myzus persicae was investigated. To create a gradient of microbial abundances, soil was inoculated with a serial dilution of a microbial community and responses of Arabidopsis plants that originated from the same site as the soil microbes were tested. Plant biomass, transcription of genes involved in plant defences, and insect performance were measured. In addition, the effects of the PGPR strain Pseudomonas fluorescens SS101 on plant and insect performance were tested under the influence of the various soil dilution treatments. Plant biomass showed a hump-shaped relationship with soil microbial community dilution, independent of aphid or Pseudomonas treatments. Both aphid infestation and inoculation with Pseudomonas reduced plant biomass, and led to downregulation of PR1 (salicylic acid-responsive gene) and CYP79B3 (involved in synthesis of glucosinolates). Aphid performance and gene transcription were unaffected by soil dilution. Neither the loss of rare microbial species, as caused by soil dilution, nor Pseudomonas affect the resistance of A. thaliana against M. persicae. However, both Pseudomonas survival and plant biomass respond to rare species loss. Thus, loss of rare soil microbial species can have a significant impact on both above- and below-ground organisms. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Plant remediation of soil contaminated with 137Cs

International Nuclear Information System (INIS)

Yang Juncheng; Zhang Jianfeng; Zhu Yongyi; Chen Jingjie; Mei Yong; Jiang Huimin

2005-01-01

A pot experiment was conducted to evaluate the bio-remediation of soils contaminated with 137 Cs. The selected plants are Cucurbita moschata Duchesne, Brassica chinensis L, Chloris virgata, Beta oulgaris L. Hongye, Beta oulgaris L. Dongshengye and Beta oulgaris L. The soils samples were taken from the paddy field, 2 km from the Dayawan nuclear power plant and Qinshan nuclear power plant, respectively, and cinnamon soil from the cultivated land in Beijing. The results show that all the employed species of plant have a higher accumulation to 137 Cs with the increased grade of the radioactivity of 137 Cs. A good correlation exist with the coefficient (r 2 ) of 0.9989. When the contaminated radioactivity of 137 Cs is in the same level the uptake of Cucurbita moschata Duchesne, Brassica chinensis L. and Chloris virgata increased with the decrease of pH value ranged 5.22-7.69. The ability of bioremediation in the orders were Chloris virgata, Brassica chinensis L., Beta oulgaris L. Hongye, Cucurbita moschata Duchesne, Beta oulgaris L. and Beta oulgaris L. Dongshengye, according to the comprehensive evaluation of transfer factor, specific activity of plant in dry weight of biomass and total absorption of 137 Cs by the individual plant in the same area. (authors)

A more holistic understanding of soil organic matter pools of alpine and pre-alpine grassland soils in a changing climate

Science.gov (United States)

Garcia Franco, Noelia; Wiesmeier, Martin; Kiese, Ralf; Dannenmann, Michael; Wolf, Benjamin; Brandhuber, Robert; Beck, Robert; Kögel-Knabner, Ingrid

2016-04-01

In southern Germany, the alpine and pre-alpine grassland systems (> 1 Mio ha) provide an important economic value via fodder used for milk and meat production and grassland soils support environmental key functions (C and N storage, water retention, erosion control and biodiversity hot spot). In addition, these grassland soils constitute important regions for tourism and recreation. However, the different land use and management practices in this area introduce changes which are likely to accelerate due to climate change. The newly launched SUPSALPS project within the BonaRes Initiative of the German Ministry for Education and Research is focused on the development and evaluation of innovative grassland management strategies under climate change with an emphasis on soil functions, which are on the one hand environmental sustainable and on the other hand economically viable. Several field experiments of the project will be initialized in order to evaluate grassland soil functioning for a range of current and climate adapted management practices. A multi-factorial design combines ongoing and new plant-soil meso-/macrocosm and field studies at a multitude of existing long-term research sites along an elevation gradient in Bavaria. One of the specific objectives of the project is to improve our knowledge on the sensitivity of specific soil organic matter (SOM) fractions to climate change. Moreover, the project aims to determine the processes and mechanisms involved in the build-up and stabilization of C and N pools under different management practices. In order to derive sensitive SOM pools, a promising physical fractionation method was developed that enables the separation of five different SOM fractions by density, ultrasonication and sieving separation: fine particulate organic matter (fPOM), occluded particulate organic matter (oPOM>20μm and oPOM 20 μm; medium + fine silt and clay, management changes.

Effect of tillage and fumigation on Pasteuria penetrans

Science.gov (United States)

The endospore-forming bacterium Pasteuria penetrans (Pp) is a parasite of Meloidogyne spp. In this study, the effect of tillage and the fumigant 1,3-dichloropropene (1,3-D) on numbers of Pp and suppression of M. incognita (Mi) was evaluated from 2011-2013. A split-plot experiment was established i...

Base-line data on everglades soil-plant systems: elemental composition, biomass, and soil depth

International Nuclear Information System (INIS)

Volk, B.G.; Schemnitz, S.D.; Gamble, J.F.; Sartain, J.B.

1975-01-01

Plants and soils from plots in the Everglades Wildlife Management Area, Conservation Area 3, were examined. Chemical composition (N, P, K, Ca, Mg, Na, Cu, Fe, Mn, Zn, Co, Sr, Pb, Ni, Cr, Al, and Si) of most plant and soil digests was determined. Cladium jamaicense was the predominant plant species contributing to biomass in all plots except the wet prairie, where Rhynchospora sp. and Panicum hemitomon were most common. The biomass of dead C. jamaicense was greater than that of the living plants in unburned saw-grass plots. The burned saw grass, muck burn, and wet prairie were characterized by a large number of plant species per square meter but smaller average biomass production than the unburned saw-grass locations. Levels of Cu, Mn, Ca, Mg, K, and N in C. jamaicense differed significantly across locations. Highly significant differences in elemental composition existed between plant species. Concentrations of several elements (particularly Zn, Ca, Mg, P, and N) were low in live C. jamaicense compared with other plant species. Cesium-137 levels ranged from 670 to 3100 pCi/kg in sandy and in organic soils, respectively. Polygonum had a 137 Cs level of 11,600 pCi/kg. Dead C. jamaicense indicated a rapid leaching loss of 137 Cs from dead tissue

Plant species effects on soil nutrients and chemistry in arid ecological zones.

Science.gov (United States)

Johnson, Brittany G; Verburg, Paul S J; Arnone, John A

2016-09-01

The presence of vegetation strongly influences ecosystem function by controlling the distribution and transformation of nutrients across the landscape. The magnitude of vegetation effects on soil chemistry is largely dependent on the plant species and the background soil chemical properties of the site, but has not been well quantified along vegetation transects in the Great Basin. We studied the effects of plant canopy cover on soil chemistry within five different ecological zones, subalpine, montane, pinyon-juniper, sage/Mojave transition, and desert shrub, in the Great Basin of Nevada all with similar underlying geology. Although plant species differed in their effects on soil chemistry, the desert shrubs Sarcobatus vermiculatus, Atriplex spp., Coleogyne ramosissima, and Larrea tridentata typically exerted the most influence on soil chemistry, especially amounts of K(+) and total nitrogen, beneath their canopies. However, the extent to which vegetation affected soil nutrient status in any given location was not only highly dependent on the species present, and presumably the nutrient requirements and cycling patterns of the plant species, but also on the background soil characteristics (e.g., parent material, weathering rates, leaching) where plant species occurred. The results of this study indicate that the presence or absence of a plant species, especially desert shrubs, could significantly alter soil chemistry and subsequently ecosystem biogeochemistry and function.

Peat soil composition as indicator of plants growth environment

Science.gov (United States)

Noormets, M.; Tonutare, T.; Kauer, K.; Szajdak, L.; Kolli, R.

2009-04-01

Exhausted milled peat areas have been left behind as a result of decades-lasting intensive peat production in Estonia and Europe. According to different data there in Estonia is 10 000 - 15 000 ha of exhausted milled peat areas that should be vegetated. Restoration using Sphagnum species is most advantageous, as it creates ecological conditions closest to the natural succession towards a natural bog area. It is also thought that the large scale translocation of vegetation from intact bogs, as used in some Canadian restoration trials, is not applicable in most of European sites due to limited availability of suitable donor areas. Another possibility to reduce the CO2 emission in these areas is their use for cultivation of species that requires minimum agrotechnical measures exploitation. It is found by experiments that it is possible to establish on Vaccinium species for revegetation of exhausted milled peat areas. Several physiological activity of the plant is regulated by the number of phytohormones. These substances in low quantities move within the plant from a site of production to a site of action. Phytohormone, indole-3-acetic acid (IAA) is formed in soils from tryptophane by enzymatic conversion. This compound seems to play an important function in nature as result to its influence in regulation of plant growth and development. A principal feature of IAA is its ability to affect growth, development and health of plants. This compound activates root morphology and metabolic changes in the host plant. The physiological impact of this substance is involved in cell elongation, apical dominance, root initiation, parthenocarpy, abscission, callus formation and the respiration. The investigation areas are located in the county of Tartu (58˚ 22' N, 26˚ 43' E), in the southern part of Estonia. The soil of the experimental fields belongs according to the WRB soil classification, to the soils subgroups of Fibri-Dystric Histosols. The investigation areas were

Modelling 137Cs uptake in plants from undisturbed soil monoliths

International Nuclear Information System (INIS)

Waegeneers, Nadia; Smolders, Erik; Merckx, Roel

2005-01-01

A model predicting 137 Cs uptake in plants was applied on data from artificially contaminated lysimeters. The lysimeter data involve three different crops (beans, ryegrass and lettuce) grown on five different soils between 3 and 5 years after contamination and where soil solution composition was monitored. The mechanistic model predicts plant uptake of 137 Cs from soil solution composition. Predicted K concentrations in the rhizosphere were up to 50-fold below that in the bulk soil solution whereas corresponding 137 Cs concentration gradients were always less pronounced. Predictions of crop 137 Cs content based on rhizosphere soil solution compositions were generally closer to observations than those based on bulk soil solution composition. The model explained 17% (beans) to 91% (lettuce) of the variation in 137 Cs activity concentrations in the plants. The model failed to predict the 137 Cs activity concentration in ryegrass where uptake of the 5-year-old 137 Cs from 3 soils was about 40-fold larger than predicted. The model generally underpredicted crop 137 Cs concentrations at soil solution K concentration below about 1.0 mM. It is concluded that 137 Cs uptake can be predicted from the soil solution composition at adequate K nutrition but that significant uncertainties remain when soil solution K is below 1 mM

Analysis of Soil Parameters in Almadenejos. Behavior of Mercury in Soil-Plant System

International Nuclear Information System (INIS)

Fernandez, R.; Sierra, M. J.; Villadoniga, M.; Millan, R.

2010-01-01

This scientific-technical report is the result of the stay of Rocio Fernandez Flores practices in the Research Unit soil degradation of the Department of Environment CIEMAT. The aim of this study is to determine the behaviour of mercury in soil of Almadenejos (Almaden, Ciudad Real, Espana) by using a six-step sequential extraction procedure and evaluate the transfer of this pollutant to Marrubium vulgare L., predominant in the area and studied for years due to its ability to accumulate large amounts of mercury without visual symptoms of toxicity. Furthermore, the results will be useful in order to determine if this plant specie could be used as phyto extractor in the recovery mercury contaminated soils. The results show that total mercury concentrations in soil ranged from 709 mg kg-1 to 22,616 mg kg-1. Regarding mercury distribution among different soil fractions, this heavy metal is mainly found in the fraction assigned in the fi nal insoluble residues, the oxidizable fraction and in the crystalline Fe-Mn oxydroxides, on the other hand, barely 1% or lower is readily available to plants However, Marrubium vulgare is able to accumulate high amount of mercury (3.5 - 373.5 mg kg-1). Regarding the mercury distribution inside the plant, mercury concentration in the root was higher than in the aerial part. Within the aerial part the maximum mercury concentration was generally found in leaves. According to the obtained results, Marrubium vulgare L. could be considered as a (hyper)accumulator plant. (Author) 57 refs.

Effects of plant-soil feedback on tree seedling growth under arid conditions

NARCIS (Netherlands)

Meijer, S.S.; Holmgren, M.; Putten, van der W.H.

2011-01-01

Aims: Plants are able to influence their growing environment by changing biotic and abiotic soil conditions. These soil conditions in turn can influence plant growth conditions, which is called plant–soil feedback. Plant–soil feedback is known to be operative in a wide variety of ecosystems ranging

Assessing soil and plant parameters affecting uranium availability and plant uptake

International Nuclear Information System (INIS)

Vandenhove, H.

2009-01-01

In the assessment of the potential impact of contaminants in soils and the requirement for the implementation of corrective actions, it is important to determine the contaminant's mobility and bioavailability and to identify the processes and parameters ruling it. Mobility and bioavailability of contaminants are among others affected by the physicochemical characteristics of the environment itself and plant properties. This is also the case for uranium (U), reported to be the most frequent radionuclide contaminant in ground and surface water and soils. The actual failure of the available transfer factor (TF) data and their broad relation to soil type to be an appropriate measure for food chain transfer in assessment models, calls for a more mechanistic understanding of the individual processes affecting bioavailability. The objectives of this study were (1) to test if Diffusive Gradient in Thin film (DGT) measured concentrations adequately assess U bioavailability and (2) to evaluate if differences in U uptake by plants can be explained by variation in root-mediated changes in selected soil properties and assess the role of organic acids in this process

CATT as a non-chemical pest and nematode control method in strawberry mohter planting stock

NARCIS (Netherlands)

Kruistum, van G.; Hoek, J.; Verschoor, J.A.

2014-01-01

Until 2008 methyl bromide (MeBr) was used in The Netherlands for fumigation of strawberry runners, intended as mother planting stock, to make them free of contamination by strawberry tarsonemid mites (Phytonemus pallidus). As an alternative of MeBr fumigation a 48 h CATT method was developed and

Plants increase laccase activity in soil with long-term elevated CO2 legacy

DEFF Research Database (Denmark)

Partavian, Asrin; Mikkelsen, Teis Nørgaard; Vestergård, Mette

2015-01-01

[CO2] stimulate laccase activity. We incubated soil exposed to seven years of elevated or ambient field [CO2] in ambient or elevated [CO2] chambers for six months either with or without plants (Deschampsia flexuosa). Elevated chamber [CO2] increased D. flexuosa production and belowground respiration....... Interestingly, plants also grew larger in soil with an elevated [CO2] legacy. Plants stimulated soil microbial biomass, belowground respiration and laccase activity, and the plant-induced laccase stimulation was particularly apparent in soil exposed to long-term elevated [CO2] in the field, whereas laccase......Actively growing plants can stimulate mineralization of recalcitrant soil organic matter (SOM), and increased atmospheric [CO2] can further enhance such plant-mediated SOM degradation. Laccases are central for recalcitrant SOM decomposition, and we therefore hypothesized that plants and elevated...

Fertilizer balance in the soil-plant system

International Nuclear Information System (INIS)

Reichardt, K.; Libardi, P.L.; Victoria, R.L.; Ruschel, A.P.; Nascimento Filho, V.F. do; Saito, S.M.T.

A report is presented on a beans culture project developed to study in detail processes on: (1)Nitrogen - fixation, mineralization, denetrification and absorption by the plant (effect of plant variety; selection of the efficient rhizobia; bacteria specificity for the plant; inocculation longevity; persistence and competition with bacteria found naturally in the soil, etc.) (2)Phosphorus and Potassium interactions with nitrogen absorption, residual effects of natural phosphates. The transformations suffered by nitrogen and the ways it follows after its application to the soil were also studied aiming at a rational handling of the fertilizer. The use of fertilizers by the plants was studied through stable and radioactive isotopes, information being sought on absorption efficiency, phosphorus - and potassium interactions with nitrogen absorption, and effects of natural phosphates. Three types of experiments were carried out: I-Nitrogen fixation experiments II-Nitrogen-and Potassium fertility experiments III-Laboratory experiments [pt

Soil to plant transfer factor of radiocesium by pot experiment

International Nuclear Information System (INIS)

Jalil, A.; Rahman, M.M.; Koddus, A.; Chand, M.M.; Zaman, M.A.; Ahmad, G.U.

2002-01-01

This paper deals with the soil to plant transfer factor (TF) of radiocesium (Cs 137 ) considered to be an important parameter while calculating radiological doses due to the potential release of radionuclides into the environment. In the present work, TF values were measured for the main foodstuffs in Bangladesh such as leafy vegetables (Lalshak, Palangshak), Ladyfinger, Radish, Potato, Potato Plant, Paddy, Paddy plant, Grass, Ginger, Ginger plant, Turmeric, and Turmeric plant by pot experiments grown in the AERE soil. Soil characteristics have also been investigated to assist the measured values of the corresponding radionuclide. TF values of the leafy parts and products of the corresponding plants were found in the range of 2.02x10 -1 to 1.8x10 -2 , which are reasonably comparable with the value found in the literature. It has been observed that the TF values in the leafy part of the plants are higher than the products. (author)

Soil and plant response to used potassium silicate drilling fluid application.

Science.gov (United States)

Yao, Linjun; Anne Naeth, M

2015-10-01

Use of drilling waste generated from the oil and gas industry for land reclamation has potential to be a practical and economical means to improve soil fertility and to decrease landfills. A four month greenhouse experiment with common barley (Hordeum vulgare L.) on three different textured soils was conducted to determine soil and plant response to incorporated or sprayed potassium silicate drilling fluid (PSDF). Two PSDF types (used once, used twice) were applied at six rates (10, 20, 30, 40, 60, 120m(3)ha(-1)) as twelve PSDF amendments plus a control (non PSDF). Effects of PSDF amendment on plant properties were significant, and varied through physiological growth stages. Barley emergence and below ground biomass were greater with used once than used twice PSDF at the same application rate in clay loam soil. Used twice PSDF at highest rates significantly increased barley above ground biomass relative to the control in loam and sand soil. All PSDF treatments significantly increased available potassium relative to the control in all three soils. Soil electrical conductivity and sodium adsorption ratio increased with PSDF addition, but not to levels detrimental to barley. Soil quality rated fair to poor with PSDF amendments in clay loam, and reduced plant performance at the highest rate, suggesting a threshold beyond which conditions are compromised with PSDF utilization. PSDF application method did not significantly affect plant and soil responses. This initial greenhouse research demonstrates that PSDF has potential as a soil amendment for reclamation, with consideration of soil properties and plant species tolerances to determine PSDF types and rates to be used. Copyright © 2015 Elsevier Inc. All rights reserved.

Study of soil-plant transfer of 226Ra under greenhouse conditions

International Nuclear Information System (INIS)

Soudek, Petr; Petrova, Sarka; Benesova, Dagmar; Kotyza, Jan; Vagner, Martin; Vankova, Radomira; Vanek, Tomas

2010-01-01

A soil-plant transfer study was performed using soil from a former uranium ore processing factory in South Bohemia. We present the results from greenhouse experiments which include estimates of the time required for phytoremediation. The accumulation of 226 Ra by different plant species from a mixture of garden soil and contaminated substrate was extremely variable, ranging from 0.03 to 2.20 Bq 226 Ra/g DW. We found differences in accumulation of 226 Ra between plants from the same genus and between cultivars of the same plant species. The results of 226 Ra accumulation showed a linear relation between concentration of 226 Ra in plants and concentration of 226 Ra in soil mixtures. On the basis of these results we estimated the time required for phytoremediation, but this appears to be too long for practical purposes.

High plant uptake of radiocesium from organic soils due to Cs mobility and low soil K content

International Nuclear Information System (INIS)

Sanchez, A.L.; Wright, S.M.; Naylor, C.; Kennedy, V.H.; Dodd, B.A.; Singleton, D.L.; Barnett, C.L.; Stevens, P.A.

1999-01-01

Post-Chernobyl experience has demonstrated that persistently high plant transfer of 137 Cs occurs from organic soils in upland and seminatural ecosystems. The soil properties influencing this transfer have been known for some time but have not been quantified. A pot experiment was conducted using 23 soils collected from selected areas of Great Britain, which were spiked with 134 Cs, and Agrostis capillaris grown for 19--45 days. The plant-to-soil 134 Cs concentration ratio (CR) varied from 0.06 to 44; log CR positively correlated to soil organic matter content (R 2 = 0.84), and CR values were highest for soils with low distribution coefficients (K d ) of 134 Cs. Soils with high organic matter contents and high concentrations of NH 4 + in solution showed high 134 Cs mobility (low K d ). The plant-to-soil solution 134 Cs ratio decreased sharply with increasing soil solution K + . A two parameter linear model, used to predict log CR from soil solution K + and K d , explained 94% of the variability in CR values. In conclusion, the high transfer of 134 Cs in organic soils is related to both the high 134 Cs mobility (low clay content and high NH 4 + concentrations) and low K availability

Influence of conventional biochar and ageing biochar application to arable soil on soil fertility and plant yield

Science.gov (United States)

Dvořáčková, Helena; Záhora, Jaroslav; Elbl, Jakub; Kynický, Jindřich; Hladký, Jan; Brtnický, Martin