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1.
Purpose
Humic matter (HM) is the leftover from life and at the same time the source for new life. The resulting complex system with many interactions has become a crucial part for the anthropocene and by this for the survival of mankind. Based on the results of the application of advanced analytical tools, the structures, reactions and interactions of HM are discussed.Materials and methods
HM was investigated from different water samples (ground water, bog lake, waste water effluent). Fulvic acids (FA) and humic acids (HA) were isolated from a bog lake and from waste water effluent according to the XAD-method described by the International Humic Substances Society. Parameters like dissolved organic carbon (DOC), spectral absorption coefficient at λ?=?254 nm (SAK), AOX (on activated carbon absorbable organically bound halogen) and THM (trihalomethanes) were determined according to ISO standard methods. For additional characterization, size exclusion chromatography coupled with online DOC detection and solid-state NMR were applied. The degradation of HM was studied by heterogeneous photocatalysis with titanium dioxide. Membrane separation, done as ultra- and nanofiltration, was used to characterize different size fractions of HM.Results and discussion
The water solubility and hence the omnipresence of HM in aquatic systems opens the door for obtaining well-defined samples for experiments with meaningful results. Information on transport properties and reactivity, derived from the molecular size of HM, was obtained by using membrane filtration at different pore sizes. Photocatalytic degradation of HM was investigated by irradiation of suspensions with TiO2 as catalyst. Small organic acids (e.g. formic acid) were formed before total mineralisation occurred.Conclusions
It can be concluded that the properties of HM are well derivable from their molecular data. The resulting character of HM with respect of the human environment seems to be obviously ambivalent and asks for a sound understanding and proper management to support life in a sustainable way.2.
M. Itävaara M. Vikman Maunuksela Liisa A. Vuorinen 《Compost science & utilization》2013,21(3):174-183
Increased recycling of organic wastes has raised concern about the quality of compost end products. In addition to the limit values for heavy metals and impurities including weeds and pathogens, the quality criteria for compost products should also include criteria for maturity. There is a tremendous number of maturity assays, developed earlier by several authors, and recommended to be used to evaluate maturity of composts. Because no such single test alone reliably demonstrates the complex properties occurring during maturization of compost, we developed a fast and easy-to-use two-phase test scheme for the assessment of maturity. In the first phase the degradation phase e.g. stability of compost samples is evaluated by using a carbon dioxide evolution test and/or determination of the NO3-N/NH4-N ratio by simple test strips. In the second phase, the toxicity of the compost is evaluated by a plant growth test, germination tests and/or the Flash bioluminescence test. Eleven plants composting sewage sludge, source-separated biowaste, manure or a combination of these raw materials were sampled after 1-3 weeks of composting and when the compost was considered “ready for use”. Chemical and physical analyses were considered useful as additional information when evaluating maturity especially when the results were not conclusively clear. This fast and easy-to-use test scheme was designed especially for the composting plant operators and official laboratories responsible for evaluating compost quality. 相似文献
3.
Susceptible Trifolium plants often exhibit symptoms of iron (Fe)‐deficiency chlorosis when grown on high pH, calcareous soils. A greenhouse method was developed to screen seedlings for Fe‐deficiency chlorosis. ‘Yuchi’ arrowleaf (T. vesiculosum Savi.) and ‘Dixie’ crimson (I. incarnatum L.) clover seedlings were grown in “Super Cell”; Cone‐tainers in six calcareous Texas soils differing in Fe and selected other chemical characteristics. At the fourth trifoliolate leaf stage, chlorosis was induced by saturating the soil for a minimum of 2 weeks. The soils differed in their capacity to induce chlorosis in both clovers. Yuchi was more susceptible than Dixie, showing a higher percentage of chlorosis in five of the six soils. The results indicate that this screening method would be a useful tool for studying Fe‐deficiency chlorosis in Trifolium spp. 相似文献
4.
B. Jickling 《Water, air, and soil pollution》2000,123(1-4):467-476
Sustainability has become a focal topic and important goal for many people concerned about environmental issues. It is, therefore, important for educators, and others, to talk about sustainability with their students and colleagues—about its meaning, curricular application, and practice. However, I do not think this is sufficient. In this paper I will examine limitations of the language of sustainability and implications for environmental thinking. Before launching into a critique, I do acknowledge the importance of "sustainability" and the usefulness of this concept. Many ecological processes are not sustained—not kept going continuously. Species are going extinct at an alarming rate and whole ecosystems are at risk. So, sustainability is important. However, we must also pay attention to what sustainability is not. And, we should consider why these limitations matter. For example, "education for sustainability" has gained rapid acceptance, yet little critical attention has been given to the term. Just as many environmental educators have expressed reservations about "education for sustainable development," I believe there are serious problems associated with allowing our work to be subsumed by the term "education for sustainability." In this presentation I will explore reasons for educators, and others, to be concerned about relying on the language and goals of sustainability. These areas of concern, or limitations, are discussed in terms of determinism, exclusivity, and conceptualization. Some suggestions are provided to help refocus our direction. 相似文献
5.
Reinbacher Lara Bacher Sven Praprotnik Eva Grabenweger Giselher 《Journal of Soils and Sediments》2021,21(6):2357-2368
Journal of Soils and Sediments - The successful implementation of a plant protection product depends on its effectiveness against a target species and its safety for the environment. Risk... 相似文献
6.
Masood Akhtar Fayyaz‐ul ‐Hassan Mukhtar Ahmed Rifat Hayat Claudio O. Stckle 《Land Degradation \u0026amp; Development》2016,27(3):630-640
Rainwater harvesting in small dams has good potential to provide supplementary agricultural irrigation during critical crop growth stages. Field experiments were conducted to evaluate cropping patterns: fallow–wheat (FW), mash–wheat (MaW), sorghum–wheat (SW), maize (grain)–wheat (MW), maize (grain)–gram (MG) and mung–canola (MuC); under two conditions: irrigated (Command area of Pira Fatehial small dam) and rainfed (Un‐command area) on sandy loam soil during three years (2009 to 2011). Treatments were arranged in a randomized complete block design, three factor factorial (cropping patterns, irrigated/non‐irrigated conditions and years) using four replications. The highest grain yield of wheat (5.6 Mg ha−1) was obtained from the MaW cropping pattern as compared to those from MW, FW and SW cropping patterns. Summer crops (sorghum fodder, maize grain and mash) performed excellent under irrigated conditions. Water use efficiency of wheat (14.3 kg ha−1mm−1) following mash under both the conditions exhibited higher values than when compared with those from SW, FW and MW cropping patterns. However, nutrient use efficiency in SW cropping pattern surpassed the others. Performance of all crops remained better under the irrigated condition during both all seasons and years, as rainfall deficiency was compensated by supplementary irrigations. Hence, this study concluded that farmers having water resources for supplemental irrigation should adopt the MW cropping pattern, based on grain yield, efficient utilization of available supplemental water and better utilization of nutrients. Similarly, based on improved nutrient utilization and monitory outputs, the MaW sequence should be followed in rain‐fed areas for better resource management. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
Anita Jeyam Rachel S. McCrea Thomas Bregnballe Morten Frederiksen Roger Pradel 《Journal of Agricultural, Biological & Environmental Statistics》2018,23(1):1-19
The Cormack–Jolly–Seber (CJS) model assumes that all marked animals have equal recapture probabilities at each sampling occasion, but heterogeneity in capture often occurs and should be taken into account to avoid biases in parameter estimates. Although diagnostic tests are generally used to detect trap-dependence or transience and assess the overall fit of the model, heterogeneity in capture is not routinely tested for. In order to detect and identify this phenomenon in a CJS framework, we propose a test of positive association between previous and future encounters using Goodman–Kruskal’s gamma. This test is based solely on the raw capture histories and makes no assumption on model structure. The development of the test is motivated by a dataset of Sandwich terns (Thalasseus sandvicensis), and we use the test to formally show that they exhibit heterogeneity in capture. We use simulation to assess the performance of the test in the detection of heterogeneity in capture, compared to existing and corrected diagnostic goodness-of-fit tests, Leslie’s test of equal catchability and Carothers’ extension of the Leslie test. The test of positive association is easy to use and produces good results, demonstrating high power to detect heterogeneity in capture. We recommend using this new test prior to model fitting as the outcome will guide the model-building process and help draw more accurate biological conclusions. Supplementary materials accompanying this paper appear online. 相似文献
8.
Evaluation for Applied Materials of Eco-technology 总被引：1，自引：1，他引：1
The eco-materials （include natural and artificial material） applied in the eco-technology in internal currently,usually lack of evaluation for applicative conditions. Hence,this study carryon the whole research and identifications to draft the eco- materials of eco-technology. The evaluation models of applied materials for eco-technology were proposed. The quantitative score were obtained by expert＇s person evaluation. Three models were proposed to quantify the effects of applied materials on the ecological environment. The statistical procedures were adopted to compare the performance of these materials for eco- technology. The results indicated that the comparison of applied materials can be treated by quantitative analysis. For the further analysis,more evaluated data from expert＇s experience need to be collected then the bias of person subject can be reduced. In addition to reach the benefits in the respects of ecosystem, society, economy and function, also practice the comprehensive effects in eco-technology. 相似文献
9.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):2737-2743
Abstract A method was devised in which plant roots can be easily and uniformly radiolabelled with 14C for use in soil decomposition studies. The roots were labelled from an exogenous sugar solution for a total period of 48 hours after which root decomposition studies could be performed. The method offers distinct advantages over the existing constant 14C‐CO2 atmosphere labelling method. 相似文献
10.
《Communications in Soil Science and Plant Analysis》2012,43(3-4):177-190
Abstract This study describes an economical and simple apparatus and methodology for preparing plant material for δ13C analysis by the combustion of material in sealed Pyrex tubes at 550°C. The largest difference in δ13C for samples combusted at 550°C in Pyrex tubes compared with those combusted at 800°C in the more expensive Vycor tubes was 0.65 δ units. Pyrex combustion tubes are approximately 7% of the cost of Vycor tubes and are easier to handle. Excellent reproducibility was observed with an average standard deviation for samples combusted at 550°C and 800°C of 0.12 and 0.13 units of δ13C, respectively. During the cryogenic distillation of CO2 from the other gasses generated during the combustion, equilibration and evacuation times were varied between 10 s and 120 s. Sample size was varied between 0.4 mg and 2.2 mg. Variations in evacuation time, equilibrium time, and sample size did not significantly affect the value for δ13C. The total duration for the cryogenic distillation of one sample was approximately 5 min. In inter‐laboratory comparisons, the values for δ13C of various plant samples were found not to be significantly different. 相似文献
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R.A. Poluektov S.M. Fintushal I.V. Oparina D.V. Shatskikh V.V. Terleev E.T. Zakharova 《Archives of Agronomy and Soil Science》2013,59(6):609-635
A system for simulation of crop dynamics is described. It includes a dynamic crop model for several cultures and a model shell. The model permits to simulate crop dynamics on the second level of plant productivity. The model shell serves for organization and implementation of series of computer experiments in dialogue regime. As it is known, soil and climatic conditions in the majority of Russia's regions differ from that in West Europe in a principal way. It especially concerns the continental Russia regions where deep droughts regularly occur, or Northwest regions, which are subjected to excess of water. So a special attention in model development was paid on account of the influence of water stress on plant production process. 相似文献
13.
《Communications in Soil Science and Plant Analysis》2012,43(13-14):1665-1681
Abstract Significant losses of nitrogen (N) can occur via volatilization of ammonia (NH3) when non‐incorporated broadcast applications of urea or urea‐containing fertilizers are made. This study was conducted to determine the efficacy of urea nitricphosphate (UNP) as an N and phosphorus (P) source for cool‐season grasses and to evaluate NH3 volatilization potential of UNP as compared to urea under laboratory conditions. A three‐year field study compared UNP to ammonium nitrate (AN) and urea at 56 and 112 kg N/ha for tall fescue (Festuca arundinacea Schreb.) and smooth brome (Bromus inermis Leyss.). Brome yields were significantly higher from UNP as compared to urea for one of the three years. No such differences occurred with fescue. Nitrogen uptake was significantly higher from UNP as compared to urea for one year each for brome and fescue. Phosphorus uptake by brome was significantly higher from UNP as compared to urea for two years. Laboratory incubation studies showed significantly lower NH3 volatilization from UNP than from urea after seven days, but no significant differences after 14 days. The delay in NH3 volatilization was due to the diffusion and subsequent hydrolysis of urea immediately below the soil zone initially influenced by the UNP. The reduction in NH3 volatilization at the early time could partially be attributed to an inhibition of urea hydrolysis and significantly lower soil pH values for UNP as compared to urea in the upper 30 mm of soil cores. The general conclusion from the field and laboratory work was that UNP is a suitable N source for cool‐season grasses, with the primary potential benefit being delayed NH3 volatilization as compared to urea. 相似文献
14.
Soil： An Extreme Habitat for Microorganisms？ 总被引：4，自引：0，他引：4
The question is asked whether soils can be regarded as extreme environments with respect to microorganisms. Afterdefining some extreme environments in a general sense, special properties of extreme environments are compared to soilhabitats, with special emphasis laid on time frame and localities. In relation to water availability, nutrients and otherproperties, such places as aggregates can show properties of extreme habitats. These features, which can act at differentlevels of the system from the community level down to the cellular level, are summarized as stress factors. The latter,where many switches are located leading to different strategies of survival, is described as the most important one. Thisraises the question of how organisms have adapted to such conditions. The soil system demands a broad spectrum ofadaptations and/or adjustments for a highly variable environment. The soil microorganisms‘ adaptation can thus be seenas the highest kind of flexibility and is more useful than any other special adaptation. 相似文献
15.
《Communications in Soil Science and Plant Analysis》2012,43(17-18):2181-2188
Abstract Phosphorus (P) and potassium (K) requirements of snap bean (Phaseolus vulgaris L.) in North Florida are not well defined in the literature. Response of a bush type snap bean to P and K was determined in a 2‐year test at NFREC, Quincy. The resulting data were used in site specific soil‐test interpretations. Residual soil‐P levels were 7, 11, 29, and 66 mg/kg the first yr and 7, 12, 21, and 42 mg/kg the second yr, no fertilizer K was added either yr. Residual soil‐K was 26, 60, and 73 mg/kg the first yr. Fertilizer K was added the second yr at 0,95, and 190 kg/ha. Soil samples were collected from each plot near the beginning of each growing season for determination of soil‐test P and K levels. Soil type was Norfolk loamy fine sand (fine loamy, siliceous, thermic, Typic Kandiudult). Maximum nutrient levels required for snap bean were: soil‐test P 30 mg/kg and soil‐test K 80 mg/kg. Soil‐test interpretations for P were: low <15 mg/kg, medium 15 to 30 mg/kg, and high >30 mg/kg. Potassium soil‐test interpretations were low <40 mg/kg, medium 40 to 80 mg/kg, and high >80 mg/kg. 相似文献
16.
Arup Kumar MANDAL 《土壤圈》2023,33(1):231-235
<正>Dear Editor,Soil sodicity is the primary limiting factor in sustainable crop production in arid and semiarid regions, where the water scarcity, low rainfall, and poor-quality (salty) groundwater are common occurrence (Datta et al., 2019; Hosain,2019; Minhas et al., 2019; Kumar and Sharma, 2020).Globally, five categories of salt-affected soils have been identified, based on the nature and composition of salts(Szabolcs and Várallyay, 1971; Kovda, 1973; Szabolcs,1989). These soils are sali... 相似文献
17.
Hughes R 《Public health nutrition》2007,10(4):324-325
18.
《Communications in Soil Science and Plant Analysis》2012,43(4):383-406
Abstract Soil pot culture experiment was conducted on 22 soils of Balewal‐Phaguwala‐Narike (BPN) and 24 soils of Isri‐Langrian‐Narike (ILN) associations using rice (PR 106) as test crop at 0 and 7.5 ppm Zn levels. Chelating extractants 0.005M DTPA, 0.01M EDTA‐(NH4)2CO3 and 0.05M EDTA, extracted more soil Zn than double‐acid and were significantly correlated with each other as well as with soil pH and clay in BPN and only with clay in ILN soil association. Soil CaCO3 governed the double‐acid extractable Zn in these soils. Dry matter yield and Zn uptake by rice significantly increased with 7.5 ppm Zn application. The response was higher in ILN than BPN soil association, The DTPA method gave the highest correlation with Bray's yield and Zn uptake (r =0.72 and 0.55) followed by 0.05M EDTA (r ‐ 0.75 and 0.61) or EDTA‐(NH4)2CO3 (r =0.70 and 0.61). The predictability of rice yield improved from 18–27 to 27–35, 32–43, 34–44 and 51–55 percent as a result of stepwise inclusion of pH, CaCO3, organic carbon (OC) and clay respectively in the regression equation alongwith Zn extracted by chelating agents. The critical levels of DTPA, EDTA‐(NH4)2CO3 and EDTA extractable Zn significantly differed in the two associations and were 0.69, 0.82 and 1.24 ppm in BPN and O.BC, 1.09 and 1.42 ppm in ILN soil association. Soil properties further affected the critical levels. This for DTPA available Zn was 0.80 and 1.03 ppm in soil containing less and greater than 2% CaCO3, 1.03 and 0.80 ppm in soils containing less and greater than 0.25% OC. These values for EDTA‐(NH4)2CO3 available Zn were 1.09 and 0.91 ppm Zn in soils containing less and greater than 15% clay suggesting that critical levels of Zn for each category of soil properties should be considered while making recommendations of Zn fertilization of crops., 相似文献
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Methods for estimating Pg content in P type humic acid and for calculating Δlog K of its Pb fraction
Osamu Sato 《Soil Science and Plant Nutrition》2013,59(4):343-351
Based on the assumption that P type humic acid is composed of green fraction (Pg) and brown fraction (Pb),. methods for estimating Pg content and calculatlng Δlog K of Pb by analyzing the absorption curve of P type humic acid were presented. A green fraction of P type humic acid obtained from an alpine meadow soil by gel filtration was used as the Pg standard (λmax 450, 575, and 615 nm, E 1% 290, 126, and 168). Alkaline solutions of standard Pg obeyed the Beer-Lambert law within the concentration range of 1.6 to 31 ppm. To verify the methods, Pg content in the mixed solutions of Pg and A, B, or Rp type humic acid was estimated. It was found that the recovery of Pg would be 95±14 (2S) per cent with a probability of 0.99. Also, the calculation of Δlog K of humic acid in the mixed solutions gave satisfactory results. It was distinctly shown that the shape of absorption spectra of P type humic acid did not only depend on Pg content, but also on Δlog K of Pb. 相似文献