Sample records for mg kg-1 soil

  1. Rapacuronium 2.0 or 2.5 mg kg(-1) for rapid-sequence induction : comparison with succinylcholine 1.0 mg kg(-1)

    Blobner, M; Mirakhur, RK; Wierda, JMKH; Wright, PMC; Olkkola, KT; Debaene, B; Pendeville, P; Engbaek, J; Rietbergen, H; Sparr, HJ


    The purpose of this nine-centre study in 602 patients was to show that the frequency of acceptable intubating conditions after rapacuronium 2.0 or 2.5 mg kg(-1) is not more than 10% lower than the frequency after succinylcholine 1.0 mg kg(-1) during rapid-sequence induction of anaesthesia with fenta

  2. Sugammadex 4.0 mg kg-1 reversal of deep rocuronium-induced neuromuscular blockade

    Yu, Buwei; Wang, Xiangrui; Hansen, Søren Helbo


    Objective: Maintenance of deep Neuro Muscular Blockade (NMB) until the end of surgery may be beneficial in some surgical procedures. The selective relaxant binding agent sugammadex rapidly reverses deep levels of rocuronium-induced NMB. The purpose of this study was to evaluate the efficacy...... and safety of sugammadex 4.0 mg kg-1 for reversal of deep rocuronium-induced NMB in Chinese and Caucasian patients. Methods: This was an open-label, multicenter, prospective Phase III efficacy study in adult American Society of Anesthesiologists Class 1-3 patients scheduled for surgery under general...... anesthesia and requiring deep NMB. All patients received intravenous propofol and opioids for induction and maintenance of anesthesia, and a single intubation dose of rocuronium 0.6 mg/kg, with maintenance doses of 0.1-0.2 mg/kg as required. Sugammadex 4.0 mg/kg was administered after the last dose...

  3. Efficacy, safety and pharmacokinetics of sugammadex 4 mg kg-1 for reversal of deep neuromuscular blockade in patients with severe renal impairment.

    Panhuizen, I F; Gold, S J A; Buerkle, C; Snoeck, M M J; Harper, N J N; Kaspers, M J G H; van den Heuvel, M W; Hollmann, M W


    This study evaluated efficacy and safety of sugammadex 4 mg kg(-1) for deep neuromuscular blockade (NMB) reversal in patients with severe renal impairment (creatinine clearance [CLCR] Sugammadex 4 mg kg(-1) was administered at 1-2 post-tetanic counts for reversal of rocuronium NMB. Primary efficacy variable was time from sugammadex to recovery to train-of-four (T4/T1) ratio 0.9. Equivalence between groups was demonstrated if two-sided 95% CI for difference in recovery times was within -1 to +1 min interval. Pharmacokinetics of rocuronium and overall safety were assessed. The intent-to-treat group comprised 67 patients (renal n=35; control n=32). Median (95% CI) time from sugammadex to recovery to T4/T1 ratio 0.9 was 3.1 (2.4-4.6) and 1.9 (1.6-2.8) min for renal patients vs controls. Estimated median (95% CI) difference between groups was 1.3 (0.6-2.4) min; thus equivalence bounds were not met. One control patient experienced acceleromyography-determined NMB recurrence, possibly as a result of premature sugammadex (4 mg kg(-1)) administration, with no clinical evidence of NMB recurrence observed. Rocuronium, encapsulated by Sugammadex, was detectable in plasma at day 7 in 6 patients. Bioanalytical data for sugammadex were collected but could not be used for pharmacokinetics. Sugammadex 4 mg kg(-1) provided rapid reversal of deep rocuronium-induced NMB in renal and control patients. However, considering the prolonged sugammadex-rocuronium complex exposure in patients with severe renal impairment, current safety experience is insufficient to support recommended use of sugammadex in this population. NCT00702715. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email:

  4. Postoperative impairment of motor function at train-of-four ratio ≥0.9 cannot be improved by sugammadex (1 mg kg-1).

    Baumüller, E; Schaller, S J; Chiquito Lama, Y; Frick, C G; Bauhofer, T; Eikermann, M; Fink, H; Blobner, M


    A train-of-four ratio (TOFR) ≥0.9 measured by quantitative neuromuscular monitoring is accepted as an indication of sufficient neuromuscular recovery for extubation, even though many postsynaptic acetylcholine receptors may still be inhibited. We investigated whether antagonism with sugammadex after spontaneous recovery to TOFR≥0.9 further improves muscle function or subjective well-being. Following recovery to TOFR≥0.9 and emergence from anaesthesia, 300 patients randomly received either sugammadex 1.0 mg kg(-1) or placebo. Fine motor function (Purdue Pegboard Test) and maximal voluntary grip strength were measured before and after surgery (before and after test drug administration). At discharge from the postanaesthesia care unit, well-being was assessed with numerical analogue scales and the Quality-of-Recovery Score 40 (QoR-40). Patients' fine motor function [6 (sd 4) vs 15 (3) pegs (30 s)(-1), Psugammadex or placebo, motor function was significantly improved in both groups but did not reach the preoperative level. There was no difference between groups at any time. Global well-being was unaffected (QoR-40: placebo, 174 vs 185; sugammadex, 175 vs 186, P>0.05). Antagonizing rocuronium at TOF≥0.9 with sugammadex 1.0 mg kg(-) (1) did not improve patients' motor function or well-being when compared with placebo. Our data support the view that TOFR≥0.9 measured by electromyography signifies sufficient recovery of neuromuscular function. The trial is registered at (NCT01101139). © The Author 2014. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email:

  5. Children and parental anxiolysis in paediatric ambulatory surgery: a randomized controlled study comparing 0.3 mg kg-1 midazolam to tablet computer based interactive distraction.

    Marechal, C; Berthiller, J; Tosetti, S; Cogniat, B; Desombres, H; Bouvet, L; Kassai, B; Chassard, D; de Queiroz Siqueira, M


    The operating theatre, anaesthesia induction and separation from parents create fear and anxiety in children. Anxiety leads to adverse behavioral changes appearing and sometimes persisting during the postoperative period. Our aim was to compare the effects of midazolam (0.3 mg kg(-)(1): MDZ) for premedication with age-appropriate tablet game apps (TAB) on children anxiety during and after ambulatory surgery. A randomized controlled trial was conducted from May 16th, 2013 to March 25th, 2014 at the Children Hospital of Lyon. The primary outcome of this study was the change in m-YPAS score at the time of anaesthetic mask induction. Anxiety was also assessed in the waiting surgical area, at the time of separation with parents and when back in the ambulatory surgery ward. One hundred and eighteen patients aged four-11 yr were recruited, 60 in the TAB Group and 58 in the MDZ Group. Main endpoint was missing for three patients from the MDZ Group. At the time of mask induction, there was no significant difference between MDZ and TAB Group for the m-YPAS score (40.5 (18.6) vs 41.8 (20.7), P = 0.99). There was no significant correlation between m-YPAS score and its evolution over the four period of time between subjects. We were not able to show whether TAB is superior to MDZ to blunt anxiety in children undergoing ambulatory surgery. TAB is a non-pharmacological tool which has the capacity in reducing perioperative stress without any sedative effect in this population. NCT 02192710. © The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email:

  6. [Effects of exogenous iron on lead accumulation in Typha latifolia from a lead-contaminated soil].

    Zhong, Shun-Qing; Xu, Jian-Ming


    A pot experiment was conducted to study the effects of adding 100 and 500 mg x kg(-1) of exogenous iron (Fe) on the lead (Pb) accumulation in Typha latifolia growing on a soil with 0, 100, 500 and 1000 mg x kg(-1) of Pb, respectively. In treatment 500 mg Fe x kg(-1), the Pb concen tration in T. latifolia shoots and roots was higher, compared with that in treatment 100 mg Fe x kg(-1). When the soil Pb concentration was 1000 mg x kg(-1), the Pb concentration in T. lati folia shoots and roots in treatment 500 mg Fe x kg(-1) increased by 33.7% and 50.5%, respectively, compared with that in treatment 100 mg Fe x kg(-1). The exchangeable Pb concentration in rhizosphere soil was 77.0% -114.6% higher in treatment 500 mg Fe x kg(-1) than in treatment 100 mg Fe x kg(-1). When the soil Pb concentration was 0, 100 and 1000 mg x kg(-1), the root dry mass in treatment 500 mg Fe x kg(-1) had a significant decrease, compared with that in treatment 100 mg Fe x kg(-1). It was suggested that adding appropriate amount of Fe to Pb-contaminated wetland soil could increase the availability of soil Pb and improve the Pb accumulation in plants.

  7. Effect of heavy metals on pH buffering capacity and solubility of Ca, Mg, K, and P in non-spiked and heavy metal-spiked soils.

    Najafi, Sarvenaz; Jalali, Mohsen


    In many parts of the world, soil acidification and heavy metal contamination has become a serious concern due to the adverse effects on chemical properties of soil and crop yield. The aim of this study was to investigate the effect of pH (in the range of 1 to 3 units above and below the native pH of soils) on calcium (Ca), magnesium (Mg), potassium (K), and phosphorus (P) solubility in non-spiked and heavy metal-spiked soil samples. Spiked samples were prepared by cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn) as chloride salts and incubating soils for 40 days. The pH buffering capacity (pHBC) of each sample was determined by plotting the amount of H(+) or OH(-) added (mmol kg(-1)) versus the related pH value. The pHBC of soils ranged from 47.1 to 1302.5 mmol kg(-1) for non-spiked samples and from 45.0 to 1187.4 mmol kg(-1) for spiked soil samples. The pHBC values were higher in soil 2 (non-spiked and spiked) which had higher calcium carbonate content. The results indicated the presence of heavy metals in soils generally decreased the solution pH and pHBC values in spiked samples. In general, solubility of Ca, Mg, and K decreased with increasing equilibrium pH of non-spiked and spiked soil samples. In the case of P, increasing the pH to about 7, decreased the solubility in all soils but further increase of pH from 7, enhanced P solubility. The solubility trends and values for Ca, Mg, and K did not differed significantly in non-spiked and spiked samples. But in the case of P, a reduction in solubility was observed in heavy metal-spiked soils. The information obtained in this study can be useful to make better estimation of the effects of soil pollutants on anion and cation solubility from agricultural and environmental viewpoints.

  8. Heavy Metals (Mg, Mn, Ni and Sn contamination in Soil Samples of Ahvaz II Industrial Estate of Iran in 2013

    Soheil l Sobhanardakani


    Full Text Available Background & Aims of the Study: Due to the rapid industrial development in Khuzestan province of Iran during recent years, this study was performed to analyze the variation of metals concentrations (Mg, Mn, Ni, and Sn in soil samples of Ahvaz II Industrial estate during the spring season of 2013. Materials & Methods: In this experimental study, 27 topsoil samples were collected from nine stations. The intensity of the soil contamination was evaluated, using a contamination factor (Cf and geo-accumulation index (I-geo. Results:  The mean soil concentrations (in mg kg-1 (dry weight were in ranged within 870-1144 (Mg, 188-300 (Mn, 93-199 (Ni and 9-15 (Sn. The data indicated that the I-geo value for all metals falls in class ‘1’. Also the Cf value for Mg and Mn falls in class ‘0’, the Cf value for Sn falls in class ‘1’ and the Cf value for Ni falls in the classes of ‘1’ and ‘2’. The result of the Pearson correlation showed that there were significant positive associations between all metals. Conclusions: According to the results which were achieved by a cluster analysis, there were significant positive associations among all metals based on Pearson correlation coefficient, especially between Ni and Sn; also both of them with Mn. Because the Ni originates from oil sources it can be resulted that Mn and Sn originate from oil sources, too. Therefore, industrial activities and exploitation of oil reservoirs are the main cause of pollution in that area. Also, it can be concluded that, with increasing the distance from the source of pollution, the accumulation of contaminants in the soil samples decreased.

  9. Vanadium bioavailability and toxicity to soil microorganisms and plants.

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


    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.

  10. Effect of exchangeable Mg on saturated hydraulic conductivity, disaggregation and clay dispersion of disturbed soils

    Zhang, X. C.; Norton, L. D.


    Different opinions exist regarding the specific effect of Mg on soil physical and chemical properties. We hypothesized that Mg 2+, compared with Ca 2+, reduces saturated hydraulic conductivity ( Ks) via promoting clay swelling, disaggregation, and clay dispersion. Two soils (mixed, mesic Typic Hapludalfs) in packed soil columns were leached with either Ca- or Mg-containing solutions at the successive concentrations of 250, 10, 2, 0.5, and 0 mM. Critical flocculation concentration (CFC) in either Ca or Mg systems was determined with flocculation series tests. Aggregate stability and mean weight diameter (MWD) were assessed by wet-sieving. The CFCs were higher in Mg than in Ca for both soils, indicating that Mg is more dispersive than Ca. The MWDs measured using 1-2 mm aggregates of both soils were significantly larger for Ca-soils than for Mg-soils ( P=0.05). The Ksr (normalized with initial Ks) started to decline at higher concentrations for Mg than for Ca, and the reduction was much greater in Mg than in Ca above 0.5 mM. The Ksr and percent transmittance (inversely related to turbidity) of leachate at a given eluted pore volume following 'steady state' were higher in Ca than in Mg for both soils ( P=0.1), indicating lower permeability and more clay dispersion with the Mg treatment. Swelling and disaggregation, which reduced large pores, appeared to be the dominant process causing the rapid initial decline of Ksr. Clay dispersion and subsequent pore plugging became progressively important when electrolyte concentration was reduced to below CFCs.

  11. Single doses of ivermectin 400 micrograms/kg-1: the most effective dosage in bancroftian filariasis.

    Moulia-Pelat, J P; Glaziou, P; Nguyen, L N; Cartel, J L


    Forty-three Wuchereria bancrofti carriers were given four successive semi-annual single doses of ivermectin 100 (IVER 100). The geometric mean microfilaremia (mf) recurrence percentage as compared to the pre-initial treatment mf level was 35%, 21%, 17% and 17% at 6, 12, 18 and 24 months, respectively. However, the recurrence of mf 6 months after the fourth treatment remained high in several individuals: 15 have been considered as 'bad responders' and 28 as 'good responders' individuals. At month 24 (M 24), they were randomly allocated into 2 groups. A first group was treated with a fifty and a sixth dose of IVER 100, at M24 and M30, respectively; the second one was treated, at the same time, with single doses of IVER 400 (IVER 400). At M 36, the mf recurrence percentage (mf M36/mf M0) was significantly higher in patients treated with IVER 100 than IVER 400 (11% vs 1%, p < 10(-4). From the group IVER 100, 6 out of the 8 'bad responders' remained 'bad responders' whereas there were none of the 7 in the group IVER 400. Moreover, there were only 2 more patients in the group IVER 100 showing sustained complete zero mf, whereas they were 13 in the group IVER 400. Single doses of IVER 400 were effective on 'bad responders'; IVER 400 must be recommended for semi-annual mass treatment in bancroftian filariasis.

  12. Effects of the combination of decitabine and homoharringtonine in SKM-1 and Kg-1a cells.

    Geng, Suxia; Yao, Han; Weng, Jianyu; Tong, Jiaqi; Huang, Xin; Wu, Ping; Deng, Chengxin; Li, Minming; Lu, Zesheng; Du, Xin


    The methylation inhibitor decitabine (DAC) has great therapeutic value for myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). However, DAC monotherapy is associated with relatively low rates of overall response and complete remission. Previous studies have shown promising results for combination treatment regimens including DAC. Homoharringtonine (HHT), an alkaloid from Chinese natural plants and Cephalotaxus, has demonstrated potential for leukemia treatment. Our studies have suggested that the combination of DAC and HHT has synergistic effects for inhibiting the viability of SKM-1 and Kg-1a cells. This combination leads to enhanced inhibition of colony formation and apoptosis induction compared with DAC alone in SKM-1 but not Kg-1a cells. Only high-dose DAC and HHT significantly up-regulate caspase-3 and caspase-9 and inhibit BCL-XL in the SKM-1 cell line. The combined effects of DAC plus HHT on apoptosis may not only depend on regulation of the apoptosis-related genes we examined but others as well. HHT had no demethylation effects, and HHT in combination with DAC had no enhanced effects on hypomethylation and DNMT1, DNMT3A and DNMT3B mRNA expression in SKM-1 cells. Overall, these results suggest that DAC used in combination with HHT may have clinical potential for MDS treatment.

  13. 白藜芦醇增强TRAIL对人髓系白血病KG-1a细胞的细胞毒作用%Resveratrol enhances cytotoxicity of TRAIL to human promyloblastic leukemia KG-1a cells

    胡亮杉; 孙茂本; 曾雅丽; 李玉华; 邓兰; 郭坤元


    目的:观察白藜芦醇作用前后TRAIL对人髓系白血病KG-1a细胞的细胞毒作用的变化.方法:流式细胞仪检测KG-1a细胞表面CD34 和CD38的表达,二甲氧唑黄(XTT)细胞增殖及细胞毒性检测试剂盒检测白藜芦醇作用前后TRAIL对KG-1a细胞增殖的影响,AnnexinV-FITC/PI染色流式细胞仪检测细胞凋亡变化.流式细胞仪检测白藜芦醇作用前后KG-1a细胞表面TRAIL死亡受体表达变化.结果:人髓系白血病KG-1a细胞 CD34+CD38-占(58.67±2.87)%,10~1 000 ng/ml 的TRAIL对KG-1a细胞增殖无明显影响,但对白藜芦醇作用后的KG-1a细胞的增殖有明显抑制作用,白藜芦醇能促进TRAIL诱导KG-1a细胞凋亡,并能上调KG-1a细胞表面TRAIL死亡受体DR5的表达.结论:白藜芦醇能增强TRAIL对人髓系白血病KG-1a细胞的细胞毒作用,其机制可能与白藜芦醇上调KG-1a细胞表面TRAIL死亡受体DR5的表达有关.%Objective :To explore the cytotoxicity of TRAIL to human acute promyeloblastic leukemia KG-1a cells treated with resvera trol .Methods :The expression of CD34 and CD38 on the Surface of KG-1 cells was detected by flow cytometry ;The effects of various concentration TRAIL on proliferation of KG-1a cells treated with or without resveratrol were analyzed by XTT cell proliferation and cytotoxicity assay kit ;The changes of apoptosis in KG-1a cells treated with or without resveratrol induced by TRAIL were detected by flow cytometry through the staining of AnnexinV-FITC /PI ;The effects of resveratrol on the expression of DR4/5 on the surface of KG-1a cells were detected by flow cytometry .Results :The CD34+ CD38- percent age of KG-1a cells was (58 .67±2 .87 )% ;10-1 000 ng/ml of TRAIL had no effects on the proliferation of KG-1a cells ,while could inhibit the proliferation of KG-1a cells treated with resveratrol ;Moreover ,resveratrol could enhance the apoptosis of KG-1a cells induced by TRAIL and up-regulate the expression of TIRAIL death receptors DR5

  14. Fluorine content in soils of Northern Pomoravlje

    Jakovljević Miodrag D.


    Full Text Available Soil sampling was carried out in the Velika Morava river valley, covering the area from Velika Plana to the mouth of Morava to the Danube. The composite soil samples, representing alluvial soils (22 samples, cambisols (14 and smonitzas (4, were taken from plough layers, based on a regular square grid with intervals set at 5x5 km, covering total area of 100,000 ha. The total and available fluorine contents were determined in the soils samples. The highest average amount of total fluorine was found for alluvial soils (391 mg kg-1, then for smonitzas (348 mg kg-1 and the lowest one for cambisols (285 mg kg-1. These amounts are within normal fluorine content for soils (150-400 mg kg-1, although the maximum found levels were even about 500 mg kg-1. The available fluorine content was very low (< 1 mg kg-1, being mostly less than 0.2 % from its total amount, so it could be concluded that there was no danger from fluorine accumulation in the plants. Statistically significant correlation coefficient between total and available fluorine contents was not obtained. The total and available fluorine contents have mostly been in the correlation (with positive sign with soil pH and the content of mechanical fraction silt+clay. Significant correlation coefficients between total fluorine content and the content of some heavy metals (Cr, Ni, Co, Cu, As were also found, which indicated their mutual geochemical origin.

  15. Influence of Exogenous Lanthanum on Fertility Parameters of Red Soil and Paddy Soil

    谢祖彬; 朱建国; 褚海燕; 曾青; 张雅丽; 曹志洪


    The effects of exogenous La on the fertility parameters such as cation exchange capacity (CEC), exchangeable basic cations, and exchangeable acidity in red soil and paddy soil were studied with soil column simulation. The results show that with increasing amount of the added La, the proportion of exchangeable La in soils increases and there is more exchangeable La in red soil than in paddy soil. When the concentration of La is more than 600 mg*kg-1, the proportion of exchangeable La almost remains constant. When the concentration of La is less than 1200 mg*kg-1, there is no significant effect on CEC in red soil. But when the concentration of La is more than 1200 mg*kg-1, it has significant effect on CEC in paddy soil. The application of La resulted in increasing exchangeable aluminum, Ca and Mg in soil solution, and decreasing exchangeable Ca and Mg retained in soils. But when the concentration of La is less than 150 mg*kg-1, it has no significant influence on CEC, exchangeable Ca and Mg, and exchangeable acidity in red soil and paddy soil.

  16. Soil solution interactions may limit Pb remediation using P amendments in an urban soil

    Lead (Pb) contaminated soils are a potential exposure hazard to the public. Amending soils with phosphorus (P) may reduce Pb soil hazards. Soil from Cleveland, OH containing 726 ± 14 mg Pb kg-1 was amended in a laboratory study with bone meal and triple super phospha...

  17. Industrial contamination of soil related to some active and closed mine facilities in the Republic of Macedonia

    Tasev Goran K.


    Full Text Available Several industrial pollution sources at the territory of the Republic of Macedonia, were studied, one Pb-Zn mine with mill, one copper mine with mill and copper leaching facility, as well as one former Pb-Zn smelting facility near the city of Veles and one Fe-Ni smelting facility near the city of Kavadarci. The concentrations of heavy metals at Veles hot-spot were in the range: 20÷1823 mg kg- 1Pb, 29÷2395 mg kg-1Zn, 28÷65 mgkg-1Cd, 27÷82 mg kg-1 Cu, 39÷164 mg kg-1Ni, 508÷938 mgkg-1Mn and 1.6÷3.8% Fe, all of them being above Dutch standard optimal values. The vicinity of the Feni plant displayed concentrations of heavy metals as follows: 16÷31 mg kg-1 Pb, 117÷286 mgkg-1 Zn, 13÷24 mg kg-1Co, 42÷119 mg kg-1 Cu, 158÷292 mg kg-1Ni, 119÷236 mg kg-1 Cr and 2.24÷3.79% Fe. Airborne dust measurements around the Zletovo mine displayed multiplexed above standard values, with an exception of nickel, there enrichment factors ranged from mediate ones such were those for copper of 20.8, cadmium of 28.7, arsenic of 32.5 up to high ones for zinc with 341.7 and lead 925. Soil samples around the Zletovo mine displayed: 19.3-76.9 g kg-1 Fe, 643-28000 mg kg-1 Mn, 42.3-529.66 mg kg-1 Pb and 138-3240 mg kg-1 Zn. Finally around the Bucim copper mine the results displayed the following findings: 13.1÷225 mg kg-1 As, 0.67÷17.9 mg kg-1 Cd, 30.1÷171 mg kg-1 Cr, 17.8÷1734 mg kg-1 Cu, 9.8÷69.4 mg kg-1 Ni, 46÷3456 mg kg-1 Pb, 88÷3438 mg kg-1 Zn, 169÷998 mg kg-1 Mn, 0.73÷5.02% Fe.

  18. Effect of Phosphate Addition on Cadmium Precipitation and Adsorption in Contaminated Arable Soil with a Low Concentration of Cadmium.

    Kim, Sung Un; Owens, Vance N; Kim, Yong Gyun; Lee, Sang Mong; Park, Hyean Cheal; Kim, Keun Ki; Son, Hong Joo; Hong, Chang Oh


    The objectives of this study were to determine (1) the phosphorus (P) level required to induce cadmium (Cd) precipitation in a contaminated arable soil with low concentrations of Cd and (2) the primary mechanism of Cd immobilization at different P levels. Phosphorus was added at levels of 0 800, 1600, and 16,000 mg P kg(-1) to a soil containing 5.57 mg Cd kg(-1). The concentration of 1 M NH4OAc extractable Cd decreased significantly with P levels up to 1600 mg kg(-1) due to an increase in soil pH and negative charge of soil (psoil containing low levels of this heavy metal.

  19. Dechlorination of DDT, DDD and DDE in soil (slurry) phase using magnesium/palladium system.

    Gautam, Sumit Kumar; Suresh, Sumathi


    Mg0/Pd4+ was able to dechlorinate >99% of extractable DDT (initial concentration of 10 mg DDT kg(-1) of soil) and >90% of extractable DDT (initial concentration of 50 mg DDT kg(-1) of soil) in soil slurry. Mg0/Pd4+ was also found to be effective in dechlorinating of 50 mg kg(-1) DDD and DDE, in soil aged for varying time periods. GC-MS analyses revealed the formation of 1,1-diphenylethane as an end product from DDT, DDE and DDD. To the best of our knowledge this is the first report describing the application Mg0/Pd4+ system for remediation of DDT, DDD and DDE contaminated soil. We conclude that reductive dechlorination reaction catalyzed by Mg0/Pd4+ may be a promising system to remediate soil contaminated with DDT and its dechlorinated products such as DDD and DDE.

  20. [Effects of hydroxyapatite on growth and quality of potato (Solanum tuberosum L.) in Cd polluted soil].

    Song, Yong; He, Tan; Liu, Ming-Yue; Zeng, Min; Liao, Bo-Han


    A pot experiment was conducted in a glasshouse to study effects of hydroxyapatite amending Cd polluted soil on growth and quality of potato (Solanum tuberosum L.). In the experiment, 3 levels of Cd pollution (0, 5, and 10 mg x kg(-1)) and 6 levels of hydroxyapatite application (0, 4, 8, 10, 16, and 30 g x kg(-1)) in soil were prepared to plant 2 potato varieties (Zhongshusanhao and Daxiyang in Chinese system). The results showed that Cd pollution in soil resulted in decrease in yield per plant of potato; for example, in the soils with 5 and 10 mg x kg(-1) of Cd, the yield per plant decreased 24%-31% and 41%-45%, respectively. Applying hydroxyapatite to Cd pollution could greatly increase yield per plant of potato. Compared to the soil without hydroxyapatite, 10 or 30 g x kg(-1) hydroxyapatite added to the soil with 5 or 10 mg x kg(-1) of Cd increased 17%-9% or 45%-58% in yield per plant. Due to hydroxyapatite amending Cd polluted soil, chlorophyll contents in leaves and superoxide dismutase (SOD) activities in tubers enhanced and malondialdehyde (MDA) contents in tubers declined apparently. Meanwhile, quality of potato tubers was obviously improved, such as increase in vitamin C contents, starch contents, and protein contents in potato tubers. With hydroxyapatite applying from 0 to 30 g x kg(-1), Cd contents in potato tubers deceased from 0.87-0.95 mg x kg(-1) to 0.13-0.21 mg x kg(-1) by 78%-85% in the soils with 5 mg x kg(-1) of Cd, and from 1.86-1.93 mg x kg(-1) to 0.52-0.65 mg x kg(-1) by 66%-72% in the soils with 10 mg x kg(-1) of Cd. The experiment indicated that the mechanism of hydroxyapatite alleviating soil Cd toxicity main included rising soil pH values, reducing effective Cd contents in soil, and Ca from hydroxyapatite blocking soil Cd moving to potato. However, ability of hydroxyapatite alleviating soil Cd toxicity was limited, and excessive hydroxyapatite to soil exhibited stress effects on growth and quality of potato. In the Cd polluted soils with

  1. status of pesticides and degradation products in soil after clean-up ...


    DDE 30200 mg kg-1 dw and 2,4'-DDE 3000 mg kg-1 dw. ... compounds was very slow and that no significant degradation had occurred to the DDT residues in soil .... D. E. F. G. H. I. J. K. CREW Offices. Former storage area. N. Figure 2:.

  2. Effects of rice straw on the speciation of cadmium (Cd) and copper (Cu) in soils

    Cui, Y.S.; Du, X.; Weng, L.P.; Zhu, Y.G.


    Four soils were collected from different sites of China in Lechang (LC, Guangdong province), Changsha (CS, Hunan province), Jiaxing UX, Zhejiang province) and Hangzhou (HZ, Zhejiang province), and were spiked with Cu (50 mg kg(-1)) and Cd (5 mg kg(-1)). The effects of rice straw addition (6%) on the

  3. Microwave Acid Extraction to Analyze K and Mg Reserves in the Clay Fraction of Soils

    Araína Hulmann Batista

    Full Text Available ABSTRACT: Extraction of K and Mg with boiling 1 mol L-1 HNO3 in an open system for predicting K and Mg uptake by plants is a method of low reproducibility. The aim of this study was to compare the extraction capacity of different acid methods relative to hydrofluoric acid extraction for K and Mg. A further objective was to develop a chemical extraction method using a closed system (microwave for nonexchangeable and structural forms of these nutrients in order to replace the traditional method of extraction with boiling HNO3 on a hot plate (open system. The EPA 3051A method can be used to estimate the total content of K in the clay fraction of soils developed from carbonate and phyllite/mica schist rocks. In the clay fraction of soils developed from basalt, recoveries of K by the EPA 3051A (pseudo-total method were higher than for the EPA 3052 (total hydrofluoric extraction method. The relative abundance of K and Mg for soils in carbonate rocks, phyllite/mica schist, granite/gneiss, and basalt determined by aqua regia digestion is unreliable. The method using 1 mol L-1 HNO3 in an closed system (microwave showed potential for replacing the classical method of extraction of nonexchangeable forms of K (boiling 1 mol L-1 HNO3 in an open system - hot plate and reduced the loss of Si by volatilization.

  4. [Assessment of Soil Fluorine Pollution in Jinhua Fluorite Ore Areas].

    Ye, Qun-feng; Zhou, Xiao-ling


    The contents of. soil total fluorine (TF) and water-soluble fluorine (WF) were measured in fluorite ore areas located in Jinhua City. The single factor index, geoaccumulation index and health risk assessment were used to evaluate fluorine pollution in soil in four fluorite ore areas and one non-ore area, respectively. The results showed that the TF contents in soils were 28. 36-56 052. 39 with an arithmetic mean value of 8 325.90, a geometric mean of 1 555. 94, and a median of 812. 98 The variation coefficient of TF was 172. 07% . The soil WF contents ranged from 0. 83 to 74. 63 with an arithmetic mean value of 16. 94, a geometric mean of 10. 59, and a median of 10. 17 The variation coefficient of WF was 100. 10%. The soil TF and WF contents were far higher than the national average level of the local fluorine epidemic occurrence area. The fluoride pollution in soil was significantly affected by human factors. Soil fluorine pollution in Yangjia, Lengshuikeng and Huajie fluorite ore areas was the most serious, followed by Daren fluorite ore area, and in non-ore area there was almost no fluorine pollution. Oral ingestion of soils was the main exposure route. Sensitivity analysis of model parameters showed that children's weight exerted the largest influence over hazard quotient. Furthermore, a significant positive correlation was found among the three kinds of evaluation methods.

  5. Distribution and mobility of mercury in soils of a gold mining region, Cuyuni river basin, Venezuela.

    Santos-Francés, F; García-Sánchez, A; Alonso-Rojo, P; Contreras, F; Adams, M


    An extensive and remote gold mining region located in the East of Venezuela has been studied with the aim of assessing the distribution and mobility of mercury in soil and the level of Hg pollution at artisanal gold mining sites. To do so, soils and pond sediments were sampled at sites not subject to anthropological influence, as well as in areas affected by gold mining activities. Total Hg in regionally distributed soils ranged between 0.02 mg kg(-1) and 0.40 mg kg(-1), with a median value of 0.11 mg kg(-1), which is slightly higher than soil Hg worldwide, possibly indicating long-term atmospheric input or more recent local atmospheric input, in addition to minor lithogenic sources. A reference Hg concentration of 0.33 mg kg(-1) is proposed for the detection of mining affected soils in this region. Critical total Hg concentrations were found in the surrounding soils of pollutant sources, such as milling-amalgamation sites, where soil Hg contents ranged from 0.16 mg kg(-1) to 542 mg kg(-1) with an average of 26.89 mg kg(-1), which also showed high levels of elemental Hg, but quite low soluble+exchangeable Hg fraction (0.02-4.90 mg kg(-1)), suggesting low Hg soil mobility and bioavailability, as confirmed by soil column leaching tests. The vertical distribution of Hg through the soil profiles, as well as variations in soil Hg contents with distance from the pollution source, and Hg in pond mining sediments were also analysed.

  6. TGF-β1对白血病KG-1细胞株Gli1表达的影响%Effect of TGF-β1 on Gli1 expression in KG-1 cell line

    李哲; 潘静


    Objective To prove that there was cross talk between Hh signaling pathway and TGF-β signaling pathway in KG-1 cells line. Methods (1) KG-1 cells were treated with 0. 1 ng/mL,l ng/mL,and 10 ng/mL TGF-β1 for 6 h,12 h,and 24 h respectively. Cells were collected after stimulation. Total mRNA was extracted. Glil expression was detected by real-time PCR. (2) KG-1 cells were treated with 5 ng/mL TGFβ1 and 5 ng/mL TGF-β1 +5 μmol SIS3 respectively for 24h. Cells were collected after stimulation. Total mRNA was extracted. Glil expression was detected. Results (1) When 1- 10 ng/mL TGF-β1 acted on the KG-1 cells respectively for 6 h, 12 h and 24 h, significant reduction of Glil mRNA in response to TGF-β1 was observed in KG-1 cells, emerging at 12 h and lasting at least 24 h,lower than that of the control group. (2) When 5 ng/mL TGF-β1 and 5 ng/mL TGF-β1 +5 μmol SIS3 acted on the KG-1 cells respectively for 24 h respectively,Glil expression of mRNA of control group was higher than that of TGF-β1 group, while much lower than that of TGF-β1 +SIS3 group. Conclusion TGF-β1significantly decreased Glil expression in KG-1 cells. Glil induction in KG-1 cells by TGF-β1 was a Smad3-dependent manner. This effect was independent from the Ptch/Smo axis.%目的 证明在白血病KG-1细胞株中存在TGF-β信号通路对Gli的调控作用.方法 (1)用0.1、1、10 ng/mL TGF-β1分别作用于KG-1细胞,时间分别为6、12、24 h.处理结束后收集细胞,提取mRNA,检测Gli1的表达.(2)5 ng/mL TGF-β1、5 ng/mL TGF-β1联合5 μmol SIS3分别作用于KG-1细胞24 h.处理结束后收集细胞,提取mRNA,检测Gli1的表达.结果 (1)1~10 ng/mL TGF-β1分别作用于KG-1细胞6、12、24 h,从12 h起并至少持续至24 h,其Gli1的mRNA表达较对照组明显减少;(2)5 ng/mL TGF-β1、5ng/mL TGF-β1联合5 μmol SIS3分别作用于KG-1细胞24 h,其Gli1的mRNA表达与对照组比较:5 ng/mL TGF-β1组较对照组降低,而5 ng/mL TGF-β1联合5 μmol SIS3组较

  7. Identification of As accumulation plant species growing on highly contaminated soils.

    Gisbert, Carmina; Almela, Concepción; Vélez, Dinoraz; López-Moya, J Rafael; de Haro, Antonio; Serrano, Ramón; Montoro, Rosa; Navarro-Aviñó, Juan


    Soils from the alluvial flats of the Turia River, Valencia, Spain, which were highly contaminated by decades of industrial activity, were surveyed for native plant species that could be candidates useful in phytoremediation. Concentrations of heavy metals and arsenic (As) in soils reached 25,000 mg Kg(-1) Pb, 12,000 mg Kg(-1) Zn, 70 mg Kg(-1) Cd, and 13500 mg Kg(-1) As. The predominant vegetation was collected and species identified. Soil samples and the corresponding plant shoots were analyzed to determine the amount of As accumulated by the various plant species. Several were able to tolerate more than 1000 mg Kg(-1) As in the soil. Bassia scoparia (Chenopodiaceae) survive in soil with 8375 mg Kg(-1) As. Arsenic accumulation in shoots of the various plant species investigated ranged from 0.1 to 107 mg Kg(-1) dw. Bassia scoparia (Chenopodiaceae), Inula viscosa (Asteraceae), Solanum nigrum (Solanaceae), and Hirschfeldia incana (Brassicaceae) had the highest values for As accumulation.

  8. Arsenic Contamination of Water-Soil-Crop System in an Industrial Area of Bangladesh

    M. Ahmed


    Full Text Available The arsenic (As concentrations of irrigation water, soils and vegetables were investigated in an agricultural section of Gazipur industrial area in Bangladesh, where industrial wastewater is mixed with irrigation water. The results showed that the mean As concentration of the irrigation water (0.16-0.62 mg L-1 exceeded the permissible limit for agricultural purposes recommended by the Food and Agriculture Organization (0.10 mg L-1. The mean As concentration of soils (6.48-9.75 mg kg-1 did not exceed the tolerable limit for agricultural soils recommended by the FAO (20.0 mg kg-1. While, the As concentration of the respective vegetables in average varied from 0.63 to 1.07 mg kg-1 dry weight, and the highest As concentration in average was observed in taro root (1.26-2.31 mg kg-1, followed by helencha leaf (1.85-2.02 mg kg-1. The average As concentration of root vegetables (1.84 mg kg-1 exceeded the permissible limit of 1.0 mg kg-1 suggested by the Food and Agriculture Organization, while that of leafy (0.77 mg kg-1 and fruit vegetables (0.14 mg kg-1 did not exceed the limit. Soils irrigated with As containing water that holds much amount of As showed a positive correlation with the vegetable As concentration. A decrease in the As concentration from soil to vegetable was found in root, leafy and fruit vegetables. However, the vegetables were not safe for human consumption. Some countermeasures are, therefore, necessary to reduce the vegetable As concentration.INTERNATIONAL JOURNAL OF ENVIRONMENT Volume-6, Issue-1, Dec-Feb 2016/17, page: 76-86

  9. Determining breakthrough of the soil fumigant chloropicrin from 120 mg XAD-4 sorbent tubes

    Ashworth, D. J.; Zheng, W.; Yates, S. R.

    The emission to the atmosphere of soil fumigants such as chloropicrin represents a potentially important human exposure pathway. Commonly, determining the air concentration of fumigants is carried out by pumping air through sorbent tubes which chemically retain the fumigant. In order to obtain an accurate measurement, it is essential that the fumigant does not break through the sorbent tubes, since this would result in an underestimation. Using a simple apparatus, we tested the potential for chloropicrin breakthrough from 120 mg XAD-4 sorbent tubes. The effects of chloropicrin loading (0.33 and 3.3 mg) and air flow rate (50 and 1000 mL min -1) on the transport of chloropicrin through six XAD-4 tubes (connected in series) were examined over time periods ranging from 1 to 360 min. The higher flow rate led to rapid and high breakthrough of the chloropicrin, especially at the longer time periods. At 360 min, all six tubes together retained only 46-54% (depending on initial loading) of the added chloropicrin. At the lower flow rate, essentially all of the added chloropicrin was always retained on the first two tubes. The effect of flow rate was greater than that of initial chloropicrin loading and sampling time. It is concluded that when 120 mg XAD-4 tubes are used in soil fumigant emission studies, it should be at low flow rates only and always with at least one back-up tube.

  10. Magnetic gold nanoparticles: synthesis, characterization and its application in the delivery of FITC into KG-1 cells.

    Hao, Yuzhi; Song, Steven; Yang, Xiaoyan; Xing, James; Chen, Jie


    In this article, we report a new method-a sonication method to disperse iron oxide nanoparticles into smaller nanoparticles and make gold ions absorb onto the surface or trapped in the micropores of the iron oxide nanoparticles using sonication action. By using quick reduction of ascorbic acid and post-HCI solution treatment, gold covered magnetic nanoparticles (mGNPs) with spherical morphology and uniform size were synthesized in a water solution. The size of the mGNPs was found to be 20-30 nm. Some ideal mGNPs possessed a core-shell structure. The mGNPs were non-cytotoxic and mGNP-fluorescein isothiocyanate (FITC) can enter KG-1 cells when driven by an external magnetic force, which was confirmed by confocal imaging. The confocal image also showed the FITC inside the KG-1 cells was near the nucleus. The fluorescein isothiocyanate (FITC) delivery efficiency is about 100% according to the flow cytometry results.

  11. Gross N transformation rates after application of household compost or domestic sewage sludge to agricultural soil

    Ambus, P.; Kure, L.K.; Jensen, E.S.


    Gross N mineralization and immobilization was examined in soil amended with compost and sewage sludge on seven occasions during a year using N-15 pool dilution and enrichment techniques. Gross N mineralization was initially stimulated with both wastes and accelerated through the first 112 days...... of incubation, peaking at 5 mg with compost compared with 4 mg in control and sludge-treated soil. The magnitudes of mineralization rates exceeded those of immobilization by on average 6.3 ( compost) and 11.4 ( sludge) times, leading to a persistent net N mineralization cumulating...... up to 160 mg soil(compost) and 54 mg soil (sludge) over the season from May to November. The numerical model FLUAZ comprehensively predicted rates of gross mineralization and immobilization. Sludge exhibited an early season N-release, whereas compost released only 10% of the N...

  12. [Fluorine speciation and its distribution characteristics in selected agricultural soils of North China Plain].

    Yi, Chun-Yao; Wang, Bing-Guo; Jin, Meng-Gui


    The objectives of this study were to study fluorine speciation and its distribution characteristics in the cultivated soils of wheat-corn fields at the typical areas, the North China Plain. The fluorine contents in cultivated soils and profile soils were measured by consecutive extraction. The results showed that the soil total fluorine (T-F) content at typical areas in the North China Plain ranged from 338.31 mg x kg(-1) to 781.67 mg x kg(-1), with a mean of 430.46 mg x kg(-1). The soil fluorine speciation with the highest content was Residual-Fluorine (Res-F), with a mean of 402.73 mg x kg(-1). The average content of Water soluble Fluorine (Ws-F) was 14.39 mg x kg(-1). The result indicated that the cultivated soil in the study area was at a relatively high fluoride pollution level, which may be harmful to human health and the ecological environment. The contents of Organic Fluorine (Or-F) and Fe/Mn Oxide-Fluorine (Fe/ Mn-F) were also quite high, with a mean of 8.90 mg x kg(-1) and 4.10 mg x kg(-1), respectively. The exchangeable fluorine (Ex-F) only had a very small amount of 0.33 mg x kg(-1). Soil Ws-F was positively correlated with soil pH and CEC, while it was negatively correlated with the percentage of soil clay. The content of soil Fe/Mn-F was positively correlated with soil pH, CEC and the sand grain content percentage, while it was negatively correlated with the clay grain content percentage. The soil pH value had the most significant influence on the water soluble fluorine (Ws-F) and Fe/Mn Oxide-Fluorine (Fe/Mn-F), and the soil CEC had the most significant influence on the soil total fluorine (T-F) and residual-Fluorine (Res-F) by stepwise regression analysis. In the soil profiles, the T-F content appeared as peaks and valleys representing the change of the soil lithology in the vadose zone. The Ws-F in the soil profiles mainly changed in the depth of 0-100 cm near the surface soil and was little influenced by the soil lithology. But it was strongly

  13. Zinc transformations in neutral soil and zinc efficiency in maize fertilization.

    Alvarez, Jose M; Gonzalez, Demetrio


    The effect of six Zn sources (Zn-phenolate, Zn-EDDHA, Zn-EDTA, Zn-lignosulfonate, Zn-polyflavonoid, and Zn-glucoheptonate) was studied by applying different Zn levels to a representative Calcic Haploxeralf neutral soil (the predominant clay is montmorillonite) in incubation and greenhouse experiments. Zinc soil behavior was evaluated by sequential DTPA and Mehlich-3 extraction procedures. In the incubation experiment, the highest percentage recovery values of Zn applied to soil occurred in the water-soluble plus exchangeable fraction (29%) in fertilization with 20 mg of Zn kg(-1) of Zn-EDTA fertilizer. In the greenhouse experiment with maize (Zea mays L.), a comparison of different Zn carriers showed that the application of six fertilizers did not significantly increase the plant dry matter yield among fertilizer treatments. The highest yield occurred when 20 mg of Zn kg(-1) was applied as Zn-EDDHA fertilizer (79.4 g per pot). The relative effectiveness of the Zn sources in increasing Zn concentration in plants was in the following order: Zn-EDTA (20 mg kg(-1)) > Zn-EDDHA (20 mg kg(-1)) approximately Zn-EDTA (10 mg kg(-1)) > Zn-EDDHA (10 mg kg(-1)) approximately Zn-phenolate (both rates) approximately Zn-polyflavonoid (both rates) approximately Zn-lignosulfonate (both rates) approximately Zn-glucoheptonate (both rates) > untreated Zn. The highest amounts of Zn taken up by the plants occurred when Zn was applied as Zn-EDTA fertilizer (20 mg kg(-1), 7.44 mg of Zn per pot; 10 mg kg(-1) Zn rate, 3.93 mg of Zn per pot) and when Zn was applied as Zn-EDDHA fertilizer (20 mg kg(-1) Zn rate, 4.66 mg Zn per pot). After the maize crop was harvested, sufficient quantities of available Zn remained in the soil (DTPA- or Mehlich-3-extractable Zn) for another harvest.

  14. Geomorphic controls on mercury accumulation in soils from a historically mined watershed, Central California Coast Range, USA

    Holloway, J.M.; Goldhaber, M.B.; Morrison, J.M.


    Historic Hg mining in the Cache Creek watershed in the Central California Coast Range has contributed to the downstream transport of Hg to the San Francisco Bay-Delta. Different aspects of Hg mobilization in soils, including pedogenesis, fluvial redistribution of sediment, volatilization and eolian transport were considered. The greatest soil concentrations (>30 mg Hg kg-1) in Cache Creek are associated with mineralized serpentinite, the host rock for Hg deposits. Upland soils with non-mineralized serpentine and sedimentary parent material also had elevated concentrations (0.9-3.7 mg Hg kg-1) relative to the average concentration in the region and throughout the conterminous United States (0.06 mg kg-1). Erosion of soil and destabilized rock and mobilization of tailings and calcines into surrounding streams have contributed to Hg-rich alluvial soil forming in wetlands and floodplains. The concentration of Hg in floodplain sediment shows sediment dispersion from low-order catchments (5.6-9.6 mg Hg kg-1 in Sulphur Creek; 0.5-61 mg Hg kg-1 in Davis Creek) to Cache Creek (0.1-0.4 mg Hg kg-1). These sediments, deposited onto the floodplain during high-flow storm events, yield elevated Hg concentrations (0.2-55 mg Hg kg-1) in alluvial soils in upland watersheds. Alluvial soils within the Cache Creek watershed accumulate Hg from upstream mining areas, with concentrations between 0.06 and 0.22 mg Hg kg-1 measured in soils ~90 km downstream from Hg mining areas. Alluvial soils have accumulated Hg released through historic mining activities, remobilizing this Hg to streams as the soils erode.

  15. Influence of activated charcoal amendment to contaminated soil on dieldrin and nutrient uptake by cucumbers.

    Hilber, Isabel; Wyss, Gabriela S; Mäder, Paul; Bucheli, Thomas D; Meier, Isabel; Vogt, Lea; Schulin, Rainer


    Activated charcoal (AC) amendments have been suggested as a promising, cost-effective method to immobilize organic contaminants in soil. We performed pot experiments over two years with cucumber (Cucumis sativus L.) grown in agricultural soil with 0.07 mg kg(-1) of weathered dieldrin and 0, 200, 400, and 800 mg AC per kg soil. Dieldrin fresh weight concentrations in cucumber fruits were significantly reduced from 0.012 to an average of 0.004 mg kg(-1), and total uptake from 2 to 1 microg in the 800 mg kg(-1) AC treatment compared to the untreated soil. The treatment effects differed considerably between the two years, due to different meteorological conditions. AC soil treatments did neither affect the availability of nutrients to the cucumber plants nor their yield (total fruit wet weight per pot). Thus, some important prerequisites for the successful application of AC amendments to immobilize organic pollutants in agricultural soils can be considered fulfilled.


    H. Sahraoui


    Full Text Available Anthropogenic activities such as mining have increased the prevalence and occurrence of trace elements soil contamination. Abandoned mine tailings cause the contamination of adjacent agricultural soils. In Lakhouat mining area (West-Northern Tunisia, the dispersion of particles containing Pb, Zn and Cd results in the contamination of the surrounding agricultural soils. These soils presented high concentrations of Pb (1272 mg kg-1, Zn (5543 mg kg-1 and Cd (25 mg kg-1. Furthermore, the tailing sample and soil sample close the dam tailing presented higher concentrations of Pb, Zn and Cd and conferred more limitation factors for revegetation than adjacent soils of mining area. The main limiting factors of mine soils are their low effective depth, low organic matter content and low phosphorus content and an imbalance between potassium and manganese exchangeable cations. These mine soils are strongly affected by high Pb, Zn and Cd levels which hinder revegetation.

  17. Chemical soil properties in the river basin of Vacacaí-Mirim

    Pedro Daniel da Cunha Kemerich


    Full Text Available The levels of metals in soils have increased gradually with the modernization of agriculture which has occurred in recent years. The human action performed by man in nature is the main cause of this phenomenon. On this basis, the present study’s aim is to evaluate changes in soil chemical properties due to different uses and occupations in the river basin of Vacacaí-Mirim. The technique used for analysis was EDXRF, where the values were spacialized with the aid of the software Surfer 10. Values for Barium ranged from the detection limit (DL to 7,608.27 mg/kg -1 with an average of 1,286.71± 2,295.18 mg/kg-1, the concentration of Phosphorus ranged from DL to 2,327.02 mg/kg -1 with an average of 676.45±700.05 mg/kg-1, Manganese anged from DL to 5,533.51 mg/kg -1 with an average of 1,057.34 ±1,380.81 mg/kg-1, the values for Silicon ranged 229,114.70 to 832,568.70 mg/kg-1 with a mean of 696,134.25±144,950.56 mg/kg -1, Zinc concentration ranged from DL to 429.98 mg/kg-1 with an average of 145.725±123.78 mg/kg-1. Based on these results, it is possible to identify that the concentrations of the metals studied and the land use are closely linked, since concentrations are higher in areas that have agricultural uses, which require larger amounts of chemicals. Thus, it can be observed that the soils under the uses of rice, soybeans and pasture had greater influence on the concentration of the element barium, phosphorus, however, had most influence by the land use in pasture and soybeans.

  18. Fluorine distribution in soil in the vicinity of an accidental spillage of hydrofluoric acid in Korea.

    An, Jinsung; Lee, Hyun A; Lee, Junseok; Yoon, Hye-On


    This study assessed the status of fluorine (F) in soil in the vicinity of a spillage of anhydrous hydrofluoric acid in Korea. Gaseous hydrogen fluoride dispersed was suspected to have contaminated the surrounding soil environment. Total and water soluble F concentrations in soil within a 1 km radius of the spillage were determined. Total F concentrations (mean=222±70.1 mg kg(-1)) were lower than the Korean limit value (i.e., 400 mg kg(-1)) and several reported measurements of background F concentrations in soils except for a single outlying case. Soluble F concentrations ranged from 0.111 to 6.40 mg kg(-1) (mean=2.20±1.80 mg kg(-1)). A negative correlation between the soluble F concentration of soil and distance from the spillage was observed. This indicates that the soluble F concentration has a crucial role in fractionating the F concentration arising from a 'non natural input' i.e., the spillage. The F content of rice samples seemed to be significantly influenced by the soluble F concentrations of soils. Rice samples collected from the control and affected areas contained 41 mg kg(-1) and 578 mg kg(-1) of total F, respectively.

  19. Rimsulfuron in soil: Effects on microbiological properties under varying soil conditions

    Ljiljana Radivojević; Ljiljana Šantrić; Jelena Gajić Umiljendić,


    The effects of rimsulfuron a sulfonylurea herbicide on the growth and activity of soil microorganisms under laboratory conditions was investigated in two soils. The application rates were: 0.2, 2.0 and 20.0 mg a.i kg-1 soil. The lowest concentration tested was the label rate (0.2 mg a.i kg-1), and the other two were ten and hundred times higher. No adverse effects on microbiological processes were observed for the label rate. Decrease in microbial biomass c...

  20. Activity and functional diversity of microbial communities in long-term hydrocarbon and heavy metal contaminated soils

    Markowicz Anna


    Full Text Available The impacts of long-term polycyclic aromatic hydrocarbons (PAHs and heavy metal pollution on soil microbial communities functioning were studied in soils taken from an old coke plant. The concentrations of PAHs in the tested soils ranged from 171 to 2137 mg kg-1. From the group of tested heavy metals, concentrations of lead were found to be the highest, ranging from 57 to 3478 mg kg-1, while zinc concentrations varied from 247 to 704 mg kg-1 and nickel from 10 to 666 mg kg-1. High dehydrogenase, acid and alkaline phosphatase activities were observed in the most contaminated soil. This may indicate bacterial adaptation to long-term heavy metal and hydrocarbon contamination. However, the Community Level Physiological Profiles (CLPPs analysis showed that the microbial functional diversity was reduced and influenced to a higher extent by some metals (Pb, Ni, moisture and conductivity than by PAHs.

  1. [Toxicity and accumulation of copper and nickel in wheat plants cropped on alkaline and acidic field soils].

    Huang, Jin-Sun; Wei, Dong-Pu; Guo, Xue-Yan; Ma, Yi-Bing


    Field experiments were conducted to study the toxicity of added copper (Cu) and nickel (Ni) in soils to wheat and metal accumulation in wheat plants. The results showed that the yields of wheat straw and grain were decreased with the increasing concentration of Cu and Ni added to soils. The added Cu concentrations yielding 10% inhibition of wheat yield (EC10) were 499.6 mg x kg(-1) for alkaline soils (Dezhou, pH 8.90), and 55.7 mg x kg(-1) for acidic soils (Qiyang, pH 5.31). The toxicity of Cu or Ni in acidic soils were significantly higher than that in alkaline soils. With increasing addition of Cu or Ni, the contents of Cu in wheat grains initially increased and then keep at constant level, while the accumulation of Ni in grains linearly increased. The contents of Cu and Ni in Qiyang wheat grains were 6.07-9.26 mg x kg(-1) and 0.53-31.78 mg x kg(-1), and those of in Dezhou were 5.24-10. 52 mg x kg(-1) and 0.16-25.33 mg x kg(-1). In both field experimental sites, the contents of Cu in wheat grains meet the national standard for food safety. These findings showed that Cu is more relevant to ecological risk assessments than to food safety assessments for wheat grown in soils that have been contaminated with Cu.

  2. [Relationship between tumorous stem mustard yield and soil fertility in Fuling, Southwest China].

    Zhao, Huan; Qin, Song; Wang, Zheng-Yin; Li, Hui-He; Lü, Hui-Feng


    By combining field investigation and indoor chemical analysis, the relationship between tumorous stem mustard yield and soil fertility factors was investigated in the main planting areas of tumorous stem mustard in Fuling, Southwest China. The results showed that available Ca, Mg, Fe, Mn, Cu and Zn in the soil were rich (3034, 260, 11.2, 26.1, 1.15 and 1.50 mg x kg(-1), respectively), available P was moderate (19.3 mg x kg(-1)), and organic matter, available N, available K and available S were deficient (9.05 g x kg(-1), 89.2 mg x kg(-1), 106 mg x kg(-1) and 27.0 mg x kg(-1), respectively). The yield of tumorous stem mustard was significantly positively correlated with soil pH and available Ca, whilst significantly (P soil fertility factors on the yield of tumorous stem mustard was available Mn > available Cu > pH > available Fe > available K > available Ca > available Mg > available S > available N > available Zn > organic matter > available P. The linear equation (Y = 31636 + 3.63X(6)) of soil available Ca and the yield, was established by stepwise regression analysis.

  3. Size of Microbial Biomass in Soils of China



    The microbial biomass C,N and P of soils all over China were determined in this study to study their affecting factors.The results,about 100-417 mg C kg-1 soil,18-51 mg Nkg-1 soil and 4.4-27.3mg P kg-1 soil,showed the biomass C,N and P in linear relationship with the soil total organic C,toal N and soil organic P.The ratios of C:Nand C:P,ranging from 5.6 to 9.6 and from 11.2 to 48.4 respectively,were affected by soil pH.texture,crop rotation,macroclimate etc.The ratio of C:N in soil biomass increases gradually from the north to the south in China.

  4. Effect of cadmium alone and in combination with butachlor on soil enzymes.

    Wang, Jinhua; Lu, Yitong; Ding, Hui; Shen, Guoqing


    The ecological toxicity of cadmium (Cd, 10 mg kg(-1 )of dry weight soil) and butachlor (10, 50 and100 mg kg(-1 )of dry weight soil) in both their single and combined effects on soil urease and phosphatase was studied after 1, 3, 7, 14, 21 and 28 days exposure under controlled conditions in paddy and phaeozem soils. The results showed that Cd reduced the activities of urease and phosphatase at early incubation time (1-7 days), while the reduction almost disappeared at the end of the incubation. The effect of Cd on phosphatase was more pronounced than that on urease. The activities of urease and phosphatase were reduced by butachlor, while urease activity was significantly (P butachlor were 10 and 50 mg kg(-1) at the end of the incubation. When Cd (10 mg kg(-1)) was combined with butachlor (50 and 100 mg kg(-1)), the activities of urease and phosphatase became lower than without combination at early incubation time, which indicated that the toxicity of Cd significantly increased (P butachlor (10 mg kg(-1)), the activities of urease and phosphatase became higher than those without combination at the end of the incubation, which indicated that the toxicity of Cd decreased. It was indicated that the combined effects depended largely on the incubation time and the concentration ratio of Cd and butachlor. In addition, it was showed that the combined effects of butachlor and Cd appeared different in paddy from phaeozem, which may be related to the different properties of these soils.

  5. Heavy metal content in soils under different wastewater irrigation patterns in Chihuahua, Mexico.

    Maldonado, V M; Arias, H O Rubio; Quintana, R; Saucedo, R A; Gutierrez, M; Ortega, J A; Nevarez, G V


    An area near the city of Chihuahua has been traditionally irrigated with wastewater to grow forage crops. It has been hypothesized that metal levels could be found in these soils high enough to cause potential health problems to the population. The objective of this study was to determine heavy metal concentrations in different soils due to irrigation practices. Four soil types were evaluated; a soil with a past and present history of wastewater irrigation (S1), a soil with a history of wastewater irrigation until 2003 (S2), a soil with no irrigation history (S3), and a soil similar to S1 and adjacent to the river where the wastewater is transported (S11). Three soil depths were evaluated; 0-15, 15-30 and 30-50 cm. Consequently, a total of 150 soil samples were analyzed evaluating pH, EC, OM and the following elements; Na, K, Cd, Pb, Ni, Cr, Cu and Fe. The pH (P=0.000) and EC (P=0.000) were different for each soil type but no differences were noted for soil depth and the interaction. Maximum pH levels were noted in S3 with a value of 8.74 while maximum EC was observed in S1 with a value of 0.850 dSm-1. The OM level was different for soil type (P=0.000), soil depth (P=0.005) and the interaction (P=0.014). S1 and S11 obtained maximum levels of OM while minimum levels were noted in S3. Maximum OM levels were observed at the 0-15 cm depth followed by the 15-30 cm depth and finally at the 30-50 cm depth. The highest concentration of metals was as follows: K in S1 (359.3 mg kg-1); Cd in S1 (4.48 mg kg-1); Pb in S11 (155.83 mg kg-1); Ni in S1 (10.74 mg kg-1); Cu in S1 (51.36 mg kg-1); B in S3 (41.5 mg kg-1); Fe in S3 (20,313.0 mg kg-1), Cr in S3 (44.26 mg kg-1) and Na in S3 (203.0 mg kg-1). The conclusion is that some metals are present in the soils due to anthropogenic activities but others are present in natural forms.

  6. Evaluación de la toxicidad de cobre en suelos a través de biomarcadores de estrés oxidativo en eisenia foetida Assessment of copper toxicity in soils using biomarkers of oxidative stress in eisenia foetida

    Hernán Gaete; María Eliana Hidalgo; Alexander Neaman; Gonzalo Ávila


    Copper toxicity in soil was evaluated using biomarkers of oxidative stress (catalase enzyme activity, superoxide dismutase and lipid peroxidation) in the earthworm Eisenia foetida. Agricultural topsoils from mining areas of the Aconcagua river basin were collected. Total copper concentrations were in the range of 94-959 mg kg-1, while the exchangeable copper concentrations were in the range of 46-2225 µg kg-1. Earthworms exposed to soil with exchangeable copper concentrations above 32 µg kg-1...

  7. How historical copper contamination affects soil structure and mobilization and transport of colloids

    Paradelo, Marcos; Møldrup, Per; Holmstrup, Martin

    of copper concentration on the movement of an inert tracer, tritium, and the mobilization and transport of colloid particles in undisturbed soil cores (10 cm diameter and 8 cm height). The cores were sampled along a copper gradient of 21 to 3837 mg Cu kg-1 soil on an abandoned arable soil polluted by copper...

  8. Three-year performance of in-situ mass stabilised contaminated site soils using MgO-bearing binders.

    Wang, Fei; Jin, Fei; Shen, Zhengtao; Al-Tabbaa, Abir


    This paper provides physical and chemical performances of mass stabilised organic and inorganic contaminated site soils using a new group of MgO-bearing binders over 3 years and evaluated the time-dependent performance during the 3 years. This study took place at a contaminated site in Castleford, UK in 2011, where MgO, ground granulated blastfurnace slag (GGBS) and Portland cement (PC) were mixed with the contaminated soils in a dry form using the ALLU mass mixing equipment. Soil cores were retrieved 40-day, 1-year and 3-year after the treatment. The core quality, strength, and the leaching properties were determined via physical observation, unconfined compressive strength (UCS) and batch leaching tests. After 3-year treatment, the UCS values of ALLU mixes were in the range of 50-250kPa; the leachate concentrations of Cd, Pb, Cu and Zn (except Ni) in all mixes were lower than their drinking water standards; and the leachability of total organics was in the range of 10-105mg/L. No apparent degradation of the mass stabilised materials after 3 years' exposure to the field conditions was found. MgO-GGBS blends were found able to provide higher strength and less leachability of contaminants compared to PC and MgO-only mixes in mass stabilised soils.

  9. Effective Treatment of Trichloroethylene-Contaminated Soil by Hydrogen Peroxide in Soil Slurries

    CAI Xin-De; DU Wen-Ting; WU Jia-Yi; LI Rong-Fei; GUO Yang; YANG Zi-Jiang


    Trichloroethylene (TCE),as one of the most common chlorinated organic compounds in soils and aquifers at many industrial sites,is carcinogenic and often recalcitrant in environment.TCE degradation in artificially contaminated soil samples was conducted using Fenton-like processes,i.e.,by addition of excess hydrogen peroxide (H2O2).H2O2 could directly oxidize TCE without addition of ferrous iron in contaminated soil.Under the optimal condition (H2O2 concentration of 300 mg kg-1,pH at 5.0,and reaction time of 30 miu),the removal efficiency of TCE in the soil was up to 92.3%.When the initial TCE concentration increased from 30 to 480 mg kg-1 in soil,the TCE removal rates varied from 89.2% to 86.6%; while the residual TCE in soil ranged from 2.28 to 47.57 mg kg-1.Results from successive oxidations showed that the TCE removal rate with the TCE concentration of 180 mg kg-1 increased slightly from 91.6% to 96.2% as the number of successive oxidation cycle increased from one to four.Therefore,increasing the frequency of H2O2 oxidation was perhaps a feasible way to increase TCE removal rate for TCE-contaminated soil.

  10. Effect of long-term zinc pollution on soil microbial community resistance to repeated contamination.

    Klimek, Beata


    The aim of the study was to compare the effects of stress (contamination trials) on the microorganisms in zinc-polluted soil (5,018 mg Zn kg(-1) soil dry weight) and unpolluted soil (141 mg Zn kg(-1) soil dw), measured as soil respiration rate. In the laboratory, soils were subjected to copper contamination (0, 500, 1,500 and 4,500 mg kg(-1) soil dw), and then a bactericide (oxytetracycline) combined with a fungicide (captan) along with glucose (10 mg g(-1) soil dw each) were added. There was a highly significant effect of soil type, copper treatment and oxytetracycline/captan treatment. The initial respiration rate of chronically zinc-polluted soil was higher than that of unpolluted soil, but in the copper treatment it showed a greater decline. Microorganisms in copper-treated soil were more susceptible to oxytetracycline/captan contamination. After the successive soil contamination trials the decline of soil respiration was greater in zinc-polluted soil than in unpolluted soil.

  11. Hyperaccumulation of metals by Thlaspi caerulescens as affected by root development and Cd-Zn/Ca-Mg interactions.

    Saison, Carine; Schwartz, Christophe; Morel, Jean-Louis


    The aim of this work was to study, in a rhizobox experiment, the phytoextraction of metals by the hyperaccumulator plant Thlaspi caerulescens in relation to the heterogeneity of metal pollution. Six treatments were designed with soils containing various levels of metals. Homogeneous soils and inclusions of soils in other soil matrices were prepared in order to vary metal concentration and localization. Growth parameters of the plant (rosette diameter and shoot biomass) and localization of roots and shoot uptake of Zn, Cd, Ca, and Mg were determined after 10 weeks of growth. The plants grown on the polluted industrial soils provided a larger biomass and had lower mortality rates than those grown on the agricultural soil. Moreover, these plants accumulated more Zn and Cd (up to 17,516 and 375 mg kg(-1) DM, respectively) than plants grown on the agricultural soil (up to 7300 mg Zn kg(-1) and 83 mg Cd kg(-1) DM). The roots preferentially explored metal-contaminated areas. The exploration of polluted soil inclusions by the roots was associated with a higher extraction of metals. Zinc and Cd in the shoots of Thlaspi caerulescens were negatively correlated with Ca and Mg concentrations; however, the soil supply for these two elements was identical. This suggests that there is competition for the uptake of these elements and that Zn is preferentially accumulated.

  12. Analysis on Cu and Zn Concentrations in Agricultural Soils of Ili District, Xinjiang Autonomous Region, China

    YANG Jing-na


    Full Text Available The aim of this work is mainly to investigate the contents of copper(Cuand zinc(Znin agricultural soils to provide basic infor-mation for the establishment of green and organic production base in Ili District, Xinjiang Autonomous Region. 600 topsoil samples of the a-gricultural land were collected from eight counties of Ili District, and the contents of Cu and Zn were determined by AAS after microwave di-gestion. The statistics analysis showed that the mean contents of Cu and Zn in the agricultural soils of Ili District were 28.68 mg·kg-1 and 83.17 mg·kg-1, respectively. The concentrations of Cu in the agricultural soils of Ili District ranged from 11.07 mg·kg-1 to 59.90 mg·kg-1, 85% of which ranged from 20 mg·kg-1 to 40 mg·kg-1; and the concentrations of Zn in the agricultural soils of Ili District ranged from 39.58 mg·kg-1 to 160.40 mg·kg-1, 90%of which ranged from 60 mg·kg-1 to 110 mg·kg-1. Furthermore, compared the Cu and Zn contents of the tested soils among the eight counties, Cu contents in Tekes County were higher than other counties, while Zn contents showed little difference. The con-tents of Cu and Zn in the tested soils were all below the threshold values that were established in the national environmental quality standard for soils(secondary standards, GB 15618-1995, but about 7% and 21% were higher than the Cu and Zn background values of soil in Ili District, respectively. Furthermore, the concentrations of Cu and Zn in soils of Ili District accord with the environmental requirements for or-ganic and green production base regulated by national standard of organic products(GB/T 19630-2011and industrial standard of green food(NY/T 391-2013.

  13. An Abandoned Copper Mining Site in Cyprus and Assessment of Metal Concentrations in Plants and Soil.

    Baycu, G; Tolunay, D; Ozden, H; Csatari, I; Karadag, S; Agba, T; Rognes, S E


    Mining is an important source of metal pollution in the environment and abandoned mines are extremely restricted habitats for plants. Some plant species growing on metalliferous soils around mine tailings and spoil-heaps are metal-tolerant and accumulate high concentrations of metals. In this investigation, we aimed to perform a research in the CMC-abandoned copper mining area in Lefke-North Cyprus to assess the recent metal pollution in soil and plant systems. We collected 16 soil samples and 25 plant species from 8 localities around the vicinity of tailing ponds. Some concentrations of metals in soil samples varied from 185 to 1023 mg kg(-1) Cu, 15.2 to 59.2 mg kg(-1) Ni, 2.3 to 73.6 mg kg(-1) Cd and metals for plants ranged from 0.135 to 283 mg kg(-1) Cu, 0.26 to 31.2 mg kg(-1) Ni, 0.143 to 277 mg kg(-1) Cd. Atriplex semibaccata, Acacia cyanophylla, Erodium spp., Inula viscosa, Juncus sp., Oxalis pes-caprea, Pistacia lentiscus, Senecio vulgaris and Tragopogon sinuatus accumulated higher concentrations. BCF for Atriplex semibaccata was found very high, for this reason this plant can tentatively be considered as a hyperaccumulator of Cu and Cd, but it needs further investigation for its potential in phytoremediation.

  14. Influence of plant growth on degradation of linear alkylbenzene sulfonate in sludge-amended soil.

    Mortensen, G K; Egsgaard, H; Ambus, P; Jensen, E S; Grøn, C


    Widespread application of sewage sludge to agricultural soils in Denmark has led to concern about the possible accumulation and effects of linear alkylbenzene sulfonate (LAS) in the soil ecosystem. Therefore, we have studied the uptake and degradation of LAS in greenhouse pot experiments. Sewage sludge was incorporated into a sandy soil to give a range from very low to very high applications (0.4 to 90 Mg dry wt. ha(-1)). In addition, LAS was added as water solutions. The soil was transferred to pots and sown with barley (Hordeum vulgare L. cv. Apex), rape (Brassica napus L. cv. Hyola 401), or carrot (Daucus carota L.). Also, plant-free controls were established. For all additions there was no plant uptake above the detection limit at 0.5 mg LAS kg(-1) d.w, but plant growth stimulated the degradation. With a growth period of 30 d, LAS concentrations in soil from pots with rape had dropped from 27 to 1.4 mg kg(-1) dry wt., but in plant-free pots the concentration decreased only to 2.4 mg kg(-1) dry wt. When LAS was added as a spike, the final concentration in soil from planted pots was 0.7 mg kg(-1) dry wt., but in pots without plants the final concentration was much higher (2.5 mg kg(-1) dry wt.). During degradation, the relative fraction of homologues C10, C11, and C12 decreased, while C13 increased.

  15. Soluble organic nitrogen in forest soils of northeast China

    SONG Li-chen; HAO Jing-mei; CUI Xiao-yang


    Soluble organic nitrogen (SON) is recognized as a sensitive indicator of soil nitrogen status. The present work was conducted in the temperate forests of northeast China where soils are typically characterized by high organic matter and high organic nitrogen content, and soil sampling was made in early spring just after the freeze-thaw period. The water extracted SON pools in the organic layer of forest soils were measured within the range from 156.0 mg·kg-1 to 292.6 mg·kg-1, a similar magnitude of salt solution extracted SON pools reported in literatures. However, the water soluble SON pools in 0-15 cm mineral soils in present study were much higher (3-10 times) than any other reports, ranging from 58.6 mg·kg-1 to 125.2 mg·kg-1. Water soluble SON varied markedly among the soils under different forests and at different sites. The SON in water extracts were positively and significantly correlated to soil organic matter and total nitrogen contents, but negatively correlated to microbial biomass nitrogen (MBN). The reasons of the abnormally large SON pools and the negative correlations between SON and MBN in the 0-15cm mineral soils in this study were specially discussed.

  16. [Soil soluble organic matter, microbial biomass, and enzyme activities in forest plantations in degraded red soil region of Jiangxi Province, China].

    Jiang, Yu-mei; Chen, Cheng-long; Xu, Zhi-hong; Liu, Yuan-qiu; Ouyang, Jing; Wang, Fang


    Taking the adjacent 18-year-old pure Pinus massoniana pure forest (I), P. massoniana, Liquidamber fomosana, and Schima superba mixed forest (II), S. superba pure forest (III), L. fomosana (IV) pure forest, and natural restoration fallow land (CK) in Taihe County of Jiangxi Province as test sites, a comparative study was made on their soil soluble organic carbon (SOC) and nitrogen (SON), soil microbial biomass C (MBC) and N (MBN), and soil urease and asparaginase activities. In 0-10 cm soil layer, the pool sizes of SOC, SON, MBC, and MBN at test sites ranged in 354-1007 mg x kg(-1), 24-73 mg x kg(-1), 203-488 mg x kg(-1), and 24-65 mg x kg(-1), and the soil urease and asparaginase activities were 95-133 mg x kg(-1) x d(-1) and 58-113 mg x kg(-1) x d(-1), respectively. There were significant differences in the pool sizes of SOC, SON, MBC, and MBN and the asparaginase activity among the test sites, but no significant difference was observed in the urease activity. The pool sizes of SOC and SON were in the order of IV > CK > III > I > II, those of MBC and MBN were in the order of CK > IV > III > I > II, and asparaginase activity followed the order of IV > CK > III > II > I. With the increase of soil depth, the pool sizes of SOC, SON, MBC, and MBN and the activities of soil asparaginase and urease decreased. In 0-20 cm soil layer, the SOC, SON, MBC, MBN, total C, and total N were highly correlated with each other, soil asparaginase activity was highly correlated with SOC, SON, TSN, total C, total N, MBC, and MBN, and soil urease activity was highly correlated with SON, TSN, total C, MBC and MBN.

  17. Dynamics and Relationships of Ca,Mg,Fe in Litter,Soil Fauna and Soil in Pinus koraiensis-Broadleaf Mixed Forest

    SONG Bo; YIN Xiuqin; ZHANG Yu; DONG Weihua


    The Liangshui Natural Reserve in Heilongjiang Province of China was selected as the study area.The authors collected the samples of forest litter (Tilia amurensis,Fraxinus mandshurica,Pinus koraiensis,Acer mono,Betula costata,and mixed litter),soil in humus horizon (0-5cm) and soil horizon (5-20cm),and soil macrofauna (Oligochaeta,Geophiloporpha and Juliformia) from 2001 to 2002.The role of soil macrofauna in the material cycle was analyzed through comparing the macro-element contents among various parts of the subsystems and using enrichment index (EI).The results indicate that dynamic changes of various litters are very complicated.The contents of Fe in each kind of litter increase firstly,and then decrease in the study period.The changes of macro-element contents are greater in the broad-leaf litter than in the coniferous litter,and the mixed litter is in the middle level,but the differences among them are not significant.The contents of Mg and Fe in humus are higher than those in soil,but the contents of Ca in soil are higher than that in humus.The dynamic changes of macro-element contents in soil and soil fauna are not consistent with those in litter.The diplopod presented obvious enrichment of Ca and Mg (EI>1),but it does not significantly enrich Fe.Earthworm has a stronger enrichment ability of Fe than diplopod and scolopendra,but EI<1.Soil fauna can make great influences on the material cycle of the subsystems.

  18. Long-Term Effects of Legacy Copper Contamination on Microbial Activity and Soil Physical Properties

    Arthur, Emmanuel; Møldrup, Per; Holmstrup, Martin

    , Denmark. Soil samples obtained from the fallow field were used to determine total microbial activity using fluorescein diacetate and dehydrogenase assays. The physical properties measured included water-dispersible clay, bulk density, air permeability and air-filled porosity. Significant differences......-filled porosity and air permeability occurred for Cu concentrations >900 mg kg-1. There was significant negative correlation between microbial activity and the susceptibility of clay dispersion by water. These results suggest that a threshold level for Cu exists (~500 mg kg-1 for this soil type) beyond which...... in microbial activity (for both assays) were observed at Cu concentrations >500 mg kg-1. Although, unfavorable changes in all physical properties were obvious for Cu concentrations >500 mg kg-1, significant increases in bulk density and water dispersible-clay, together with decreases in total porosity, air...

  19. Efeitos do manganês sobre a soja cultivada em solo de Cerrado do Triângulo Mineiro Effects of manganese on soybean growth in a cerrado soil of Triângulo Mineiro, MG, Brazil



    Full Text Available A deficiência de Mn em soja [Glycine max (L. Merrill] e em outras culturas pode ser devida aos seus baixos teores no solo, ou à indisponibilidade do elemento induzida pela aplicação de calcário. O objetivo deste trabalho foi verificar a composição mineral da soja em relação à disponibilidade de Mn no solo. Em casa de vegetação foi conduzido um experimento utilizando um solo coletado no município de Patrocínio, MG, onde o café mostra sintomas de deficiência desse elemento. As doses de Mn foram: 0, 10, 50 e 100 mg kg-1 e um tratamento adicional com aplicação foliar de 0,6% de Mn e duas doses de calcário, ou seja: 0 e 2,7 t ha-1. Os teores de Mn na planta aumentaram com a dose de Mn no solo, e diminuíram com a aplicação de calcário. O menor teor de Mn encontrado nas folhas foi de 84 mg kg-1 na dose 0 de Mn com calcário. O Mn provocou um aumento na produção de matéria seca e de vagens, em relação a ambas as doses de calcário. A calagem não induziu o aparecimento de sintomas de deficiência de Mn. A aplicação foliar de Mn foi eficiente em aumentar e manter a produção.Manganese deficiency in soybean [Glycine max (L. Merrill and in other crops could be due to its low levels in the soil, or to its unavailability induced by liming. The objective of this research was to verify the soybean mineral composition in relation to Mn availability. An experiment was carried out in a greenhouse, using soil from Patrocínio, MG, Brazil, where the cultivated coffee shows symptoms of Mn deficiency. Mn was applied at the rates of zero, 10, 50 and 100 mg kg-1 with an additional treatment of 0.6% of foliar applied Mn and two rates of lime, namely: zero and 2.7 t ha-1. Mn concentration in the plant tissue was increased with the rate of lime application; liming, however, caused a Mn reduction. It must be pointed out that the lowest Mn level in the leaves was 84 mg kg-1, at the zero rate of Mn with lime. Mn ratio caused an increase both in

  20. Combinational effects of sulfomethoxazole and copper on soil microbial community and function.

    Liu, Aiju; Cao, Huansheng; Yang, Yan; Ma, Xiaoxuan; Liu, Xiao


    Sulfonamides and Cu are largely used feed additives in poultry farm. Subsequently, they are spread onto agricultural soils together with contaminated manure used as fertilizer. Both sulfonamides and Cu affect the soil microbial community. However, an interactive effect of sulfonamides and Cu on soil microorganisms is not well understood. Therefore, a short-time microcosm experiment was conducted to investigate the interaction of veterinary antibiotic sulfomethoxazole (SMX) and Cu on soil microbial structure composition and functions. To this end, selected concentrations of SMX (0, 5, and 50 mg kg(-1)) and Cu (0, 300, and 500 mg kg(-1)) were combined, respectively. Clear dose-dependent effects of SMX on microbial biomass and basal respiration were determined, and these effects were amplified in the presence of additional Cu. For activities of soil enzymes including β-glucosidase, urease, and protease, clear reducing effects were determined in soil samples containing 5 or 50 mg kg(-1) of SMX, and the interaction of SMX and Cu was significant, particularly in soil samples containing 50 mg kg(-1) SMX or 500 mg kg(-1) Cu. SMX amendments, particularly in combination with Cu, significantly reduced amounts of the total, bacterial, and fungal phospholipid fatty acids (PLFAs) in soil. Moreover, the derived ratio of bacteria to fungi decreased significantly with incremental SMX and Cu, and principal component analysis of the PLFAs showed that soil microbial composition was significantly affected by SMX interacted with Cu at 500 mg kg(-1). All of these results indicated that the interaction of SMX and Cu was synergistic to amplify the negative effect of SMX on soil microbial biomass, structural composition, and even the enzymatic function.

  1. Phytoextraction potential of sunflower and white mustard plants in zinc-contaminated soil

    Marta Zalewska


    Full Text Available Phytoextraction relies on plants with a high capacity to absorb heavy metals and remove them from the soil. The objective of this study was to analyze the potential of sunflower (Helianthus annuus L. and white mustard (Sinapis alba L. for phytoextraction of Zn-contaminated soil. Research was based on a strict pot experiment conducted in a greenhouse. Seven treatments were established with increasing Zn concentrations: 0, 25, 50, 100, 200, 400, and 600 mg Zn kg-1 air-dry soil. The first tested plant was fodder sunflower. In the following year, white mustard was sown in the same pots. Plants were harvested at the end of the flowering stage. The toxic effect of Zn on sunflower yields occurred at the contamination level of 200 mg Zn kg-1 soil. In the second year of the experiment, a significant decrease in mustard biomass took place in response to 400 mg Zn kg-1 soil. The contamination level of 600 mg Zn kg-1 soil resulted in complete plant death. Plant growth was not inhibited even at high tissue Zn concentrations of 515 mg Zn kg-1 sunflower DM and 422 mg Zn kg-1 mustard DM. The 2-yr cropping system did not contribute to a significant decrease in soil Zn content. Despite high concentrations of Zn in sunflower and mustard plants, total Zn uptake accounted for only 1% to 8% of the Zn rate introduced into the soil. However, in the long run, the growing of crops could reduce Zn contamination levels in the soil. The relatively high tolerance of sunflower and white mustard for Zn contamination and rapid growth of these species are possible alternatives for phytoextraction and phytostabilization of Zn-contaminated soil.

  2. Geochemical pattern of soils in Bobovdol valley, Bulgaria. Assessment of Cd and Co contents

    Ivona Nikova


    Full Text Available The chemical composition of soils spread in the Bobov dol valley was studied in order to reveal the natural and anthropogenic patterns of Cd and Co spatial distribution. A sampling procedure based on the irregular grid of points and validated analytical methods were used in the field and laboratory studies. It is found that Cd content varies from 0.21 to 0.90 mg kg-1 in studied soils and the average value of 0.55 mg kg-1 coincides with concentration demarcating soil pollution (0.5 mg kg-1. Co content ranges from 2.22 to 15.76 mg kg-1 and in 70 % of sampled points exceeds the natural background content of 7.8 mg kg-1 found in local rocks. Still, Cd enrichment of studied soils is more significant than Co’s with coefficient of Clarke concentration of 3.67. Hence, the secondary deposition of studied elements as a result of the Bobov dol Thermal power plant air emissions is verified by results obtained. The spatial distribution of Cd and Co is featured with an altitudinal gradient in deposition and a trend of quantitative depletion in the South of Plant. Soil organic matter and pH have no influence on the content and spatial distribution of studied elements. Elements iron affinity governs their geochemical linkage in soils although cobalt occurs allied with aluminum and titanium.

  3. Is soil dressing a way once and for all in remediation of arsenic contaminated soils? A case study of arsenic re-accumulation in soils remediated by soil dressing in Hunan Province, China.

    Su, Shiming; Bai, Lingyu; Wei, Caibing; Gao, Xiang; Zhang, Tuo; Wang, Yanan; Li, Lianfang; Wang, Jinjin; Wu, Cuixia; Zeng, Xibai


    The investigation of arsenic (As) re-accumulation in an area previously remediated by soil dressing will help in sustainable controlling the risks of As to local ecosystems and should influence management decisions about remediation strategies. In this study, As content in an area remediated by soil dressing and the possible As accumulation risk in agricultural products were investigated. The results indicated that after 7 years of agricultural activities, the average As content (24.6 mg kg(-1)) in surface soil of the investigated area increased by 83.6% compared with that (13.4 mg kg(-1)) in clean soil. Of the surface soil samples (n = 88), 21.6% had As levels that exceeded the limits of the Environmental Quality Standard for Soils of China (GB 15618-1995) and 98.9% of the surface soil samples with As contents exceeding that in clean soil was observed. Soil dressing might be not a remediation method once and for all in some contaminated areas, even though no significant difference in available As content was found between clean (0.18 mg kg(-1)) and surface (0.22 mg kg(-1)) soils. The foreign As in surface soil of the investigated area mainly specifically sorbed with soil colloid or associated with hydrous oxides of Fe and Al, or existed in residual fraction. The upward movement of contaminated soil from the deeper layers and the atmospheric deposition of slag particles might be responsible for the re-accumulation of As in the investigated area. Decreases in soil pH in the investigated soils and the fact that no plant samples had As levels exceeding the limits of the National Food Safety Standards for Contaminants of China (GB 2762-2012) were also observed.

  4. [Effects of colistin sulfate residue on soil microbial community structure].

    Ma, Yi; Peng, Jin-Ju; Chen, Jin-Jun; Fan, Ting-Li; Sun, Yong-Xue


    By using fumigation extraction and phospholipid fatty acid (PLFA) methods, the change of characteristics of soil microbial community structure caused by residue of colistin sulfate (CS) was studied. The results showed that the CS (w(cs) > or = 5 mg x kg(-1)) had a significant effect on the microbial biomass carbon (MBC) and it was dose-dependent where MBC decreased with the increase of CS concentration in soil. The MBC in soil decreased by 52. 1% when the CS concentration reached 50 mg x kg(-1). The total PLFA of soil in each CS treatment was significantly decreased during the sampling period compared with the control group and showed a dose-dependent relationship. The soil microbial community structure and diversity in the low CS group (w(cs) = 0.5 mg x kg(-1)) were not significantly different from the control group on 7th and 49th day. However, they were significantly different on 21st and 35th day especially in the high CS group (w(cs) = 50 mg x kg(-1)). It was concluded that CS could change the structure of soil microorganisms and varied with time which might be caused by the chemical conversion and degradation of CS in soil.

  5. [Vertical distribution patterns of nitrogen, phosphorus, and potassium in Chinese pine forest soils developed from different parent materials in Songshan Mountain Nature Reserve, Beijing of China].

    Gou, Li-hui; Sun, Zhao-di; Nie, Li-shui; Luo, Pan-pan; Wu, Ji-Gui; Xu, Wu-de


    Taking the soils developed from two kinds of parent materials (granite and limestone) under Pinus tabulaeformis forest at the same altitude in Songshan Mountain Nature Reserve of Beijing as test objects, this paper studied the vertical distribution patterns of soil total nitrogen, available phosphorus, and available potassium. The soil developed from granite had the total nitrogen, available phosphorus, and available potassium contents being 1.61-2. 35 g kg-1, 5. 84-10.74 mg kg- 1, and 39.33-93.66 mg kg-1, while that developed from limestone had the total nitrogen, available phosphorus, and available potassium contents being 1. 69 -2. 36 g kg-1, 4.45-8.57 mg . kg-1, and 60.66-124.00 mg kg-1, respectively. The total nitrogen, available phosphorus, and available potassium contents in the two soils were the highest in 0-10 cm layer, decreased with increasing depth, and had significant differences between different layers, showing that the soil total nitrogen, available phosphorus, and available potassium had a strong tendency to accumulate in surface layer. Such a tendency was more obvious for the soil developed from limestone. The paired t-test for the two soils indicated that the total nitrogen content in different layers had no significant difference, whereas the available phosphorus content in 0-10 cm layer and the available potassium content in 10-20 cm layer differed significantly.

  6. Slurry bioreactor modeling using a dissimilatory arsenate-reducing bacterium for remediation of arsenic-contaminated soil.

    Soda, Satoshi; Kanzaki, Masaya; Yamamuara, Shigeki; Kashiwa, Masami; Fujita, Masanori; Ike, Michihiko


    A slurry bioreactor using a dissimilatory arsenate (As(V))-reducing bacterium is proposed for remediation of arsenic-contaminated soils. Bacterial As(V) reduction can cause arsenic extraction from the solid to the liquid phase because arsenite, As(III), is much less adsorptive than As(V). A mathematical model was developed incorporating the reversible sorption process of arsenic as well as bacterial growth and decay via As(V) reduction. A linear isotherm equation expressed the sorption process. The model included Haldane kinetics with high As(V) concentrations and cell inactivation by toxicity due to As(III). Extraction experiments used synthetic contaminated soils (forest soil, Soil SF, 1100 mg kg(-1); paddy soil, Soil SP, 1100 mg kg(-1)) and actual contaminated soils (Soil AH 2200 mg kg(-1) and Soil AL, 220 mg kg(-1)) at 5% w/v slurry concentration. Simulation results matched the observed changes of arsenic concentrations in the liquid phase. The respective extraction efficiencies of arsenic were 63%, 41%, 20%, and 55% for SF, SP, AH, and AL soils. Sensitivity analyses showed that the rate-limiting step was the desorption rate of As(V) from the solid to the liquid phase, rather than the As(V)-reducing rate. The proposed model provides a useful framework for understanding and predicting the extraction of arsenic from soil.

  7. Contrasting Effects of Farmyard Manure (FYM) and Compost for Remediation of Metal Contaminated Soil.

    Sabir, Muhammad; Ali, Amanat; Zia-Ur-rehman, Muhammad; Hakeem, Khalid Rehman


    We investigated effect of farm yard manure (FYM) and compost applied to metal contaminated soil at rate of 1% (FYM-1, compost-1), 2% (FYM-2, compost-2), and 3% (FYM-3, compost-3). FYM significantly (P compost increased root dry weight compared to control. Amendments significantly increased nickel (Ni) in shoots and roots of maize except compost applied at 1%. FYM-3 and -1 caused maximum Ni in shoots (11.42 mg kg(-1)) and roots (80.92 mg kg(-1)), respectively while compost-2 caused maximum Ni (14.08 mg kg(-1)) and (163.87 mg kg(-1)) in shoots and roots, respectively. Plants grown in pots amended with FYM-2 and compost-1 contained minimum Cu (30.12 and 30.11 mg kg(-1)) in shoots, respectively. FYM-2 and compost-2 caused minimum zinc (Zn) (59.08 and 66.0 mg kg(-1)) in maize shoots, respectively. FYM-2 caused minimum Mn in maize shoots while compost increased Mn in shoots and roots compared to control. FYM and compost increased the ammonium bicarbonate diethylene triamine penta acetic acid (AB-DTPA) extractable Ni and Mn in the soil and decreased Cu and Zn. Lower remediation factors for all metals with compost indicated that compost was effective to stabilize the metals in soil compared to FYM.

  8. [Using atomic fluorescence spectrometry to study the spatial distribution of As and Hg in orchard soils].

    Zhao, Xi-Mei; Lü, Chun-Yan; Liu, Qing; Zhu, Xi-Cun


    Aqua regia digestion, double channels-atomic fluorescence spectrometry method was used to determine the concentrations of As and Hg in orchard soils of Qixia City - the main apple production area of Shandong province. Validate The detection limitation, accuracy and precision of the method were validated, the spatial distribution was analyzed, and the characteristics of As and Hg pollution in Qixia orchard soils were assessed. The results showed that the range of As concentration in Qixia soils is between 2.79 and 20.93 mg x kg(-1), the average concentration is 10.59 mg x kg(-1), the range of Hg concentration in Qixia soil is between 0.01 and 0.79 mg x kg(-1), the average concentration is 0.12 mg x kg(-1). The variation of As concentration in soils is small, whereas that of Hg concentration is large. Frequency distribution graphics of As and Hg showed that the concentration of As in soils is according with the normal distribution approximately and the concentrations are mostly between 7 and 15 mg x kg(-1), the concentration of Hg in soil isn't according with the normal distribution and the concentrations are mostly between 0.03 and 0.21 mg x kg(-1). The correlations between the concentrations of As or Hg in soils and the nutrient are not significant and there is no significant correlation even between As and Hg. Based on the environmental technical terms for green food production area, the As concentration in orchard soil of Qixia City is at clean level, but there are 4.76% of sample points with Hg pollution index exceeding 1, and this should be attracted the attention of the administrators.

  9. Three-year performance of in-situ solidified/stabilised soil using novel MgO-bearing binders.

    Jin, Fei; Wang, Fei; Al-Tabbaa, Abir


    A new group of MgO-bearing binders has been developed recently which showed improved sustainability and technical performance compared to Portland cement (PC). However, the application of these MgO-bearing binders in the Solidification/Stabilisation (S/S) techniques is very limited. This study investigates the three-year performance of a highly contaminated soil treated by in-situ S/S using MgO-bearing binders and PC. The core quality, strength, permeability and the leaching properties of the S/S materials were evaluated. The effects of binder composition, addition of inorgano-organo-clay (IOC) and the grout content on the properties of the 3-y S/S materials are discussed. It is found that although MgO alone provided negligible strength to the soil, it is superior in immobilising both inorganic and organic contaminants. Replacing MgO by ground granulated blast-furnace slag (GGBS) significantly enhanced the strength while also performed well in immobilising the contaminants. The improved pH buffering capacity was attributed to the low solubilities of brucite and hydrotalcite-like phases formed in the MgO-bearing binders, and was also the reason for the improved performance in stabilising contaminants. The addition of IOC slightly decreased the strength and the permeability of the S/S materials but inconsistent effect on the contaminant immobilisation was found depending on the binder composition. This study showed no degradation of the S/S materials after 3 y exposure to field conditions and has proved the applicability and the advantages of MgO-bearing binders over PC in S/S.

  10. Changes in Soil C and N Contents and Mineralization Across a Cultivation Chronosequence of Paddy Fields in Subtropical China

    LI Zhong-Pei; ZHANG Tao-Lin; HAN Feng-Xiang; P. FELIX-HENNINGSEN


    Dynamics of soil organic matter in a cultivation chronosequence of paddy fields were studied in subtropical China.Mineralization of soil organic matter was determined by measuring CO2 evolution from soil during 20 days of laboratory incubation. In the first 30 years of cultivation, soil organic C and N contents increased rapidly. After 30 years, 0-10 cm soil contained 19.6 g kg-1 organic C and 1.62 g kg-1 total N, with the corresponding values of 18.1 g kg-1 and 1.50 g kg-1 for 10-20 cm, and then remained stable even after 80 years of rice cultivation. During 20 days incubation the mineralization rates of organic C and N in surface soil (0-10 cm) ranged from 2.2% to 3.3% and from 2.8% to 6.7%,respectively, of organic C and total N contents. Biologically active C size generally increased with increasing soil organic C and N contents. Soil dissolved organic C decreased after cultivation of wasteland to 10 years paddy field and then increased. Soil microbial biomass C increased with number of years under cultivation, while soil microbial biomass N increased during the first 30 years of cultivation and then stabilized. After 30 years of cultivation surface soil (0-10 cm)contained 332.8 mg kg-1 of microbial biomass C and 23.85 mg kg-1 of microbial biomass N, which were 111% and 47% higher than those in soil cultivated for 3 years. It was suggested that surface soil with 30 years of rice cultivation in subtropical China would have attained a steady state of organic C content, being about 19 g kg-1.

  11. Economic incentive for applying vetiver grass to remediate lead, copper and zinc contaminated soils.

    Danh, Luu Thai; Truong, Paul; Mammucari, Raffaella; Fostert, Neil


    The application of vetiver grass (Chrysopogon zizaniodes) for phytoremediation of heavy metal contaminated soils can be promoted by economic return through essential oil production. Four levels of lead (0, 500, 2000, and 8000 mg kg(-1) dry soil), copper (0, 100, 400, and 1600 mg kg(-1) dry soil) and zinc (0, 400, 1600, and 6400 mg kg(-1) dry soil) were used to study their effects on vetiver growth, essential oil composition and yield. This study also investigated the effect of nitrogen concentrations on vetiver oil yield. Vetiver accumulated high concentrations of Pb, Cu and Zn in roots (3246, 754 and 2666 mg kg(-1), respectively) and small amounts of contaminants in shoots (327, 55, and 642 mg kg(-1), respectively). Oil content and yield were not affected at low and moderate concentrations of Cu and Zn. Only the application of Pb had a significant detrimental effect on oil composition. Extraction of vetiver essential oils by hydrodistillation produced heavy metal free products. High level of nitrogen reduced oil yields. Results show that phytoremediation of Cu and Zn contaminated soils by vetiver can generate revenue from the commercialization of oil extracts.

  12. Arsenic hyperaccumulation by Pteris vittata from arsenic contaminated soils and the effect of liming and phosphate fertilisation.

    Caille, N; Swanwick, S; Zhao, F J; McGrath, S P


    Pot experiments were carried out to investigate the potential of phytoremediation with the arsenic hyperaccumulator Pteris vittata in a range of soils contaminated with As and other heavy metals, and the influence of phosphate and lime additions on As hyperaccumulation by P. vittata. The fern was grown in 5 soils collected from Cornwall (England) containing 67-4550 mg As kg(-1) and different levels of metals. All soils showed a similar distribution pattern of As in different fractions in a sequential extraction, with more than 60% of the total As being associated with the fraction thought to represent amorphous and poorly-crystalline hydrous oxides of Fe and Al. The concentration of As in the fronds ranged from 84 to 3600 mg kg(-1), with 0.9-3.1% of the total soil As being taken up by P. vittata. In one soil which contained 5500 mg Cu kg(-1) and 1242 mg Zn kg(-1), P. vittata suffered from phytotoxicity and accumulated little As (0.002% of total). In a separate experiment, neither phosphate addition (50mg P kg(-1) soil) nor liming (4.6 g CaCO3 kg(-1) soil) was found to affect the As concentration in the fronds of P. vittata, even though phosphate addition increased the As concentration in the soil pore water. Between 4 and 7% of the total soil As was taken up by P. vittata in 4 cuttings in this experiment. The results indicate that P. vittata can hyperaccumulate As from naturally contaminated soils, but may be suitable for phytoremediation only in the moderately contaminated soils.

  13. Dynamics of nitrogen in a PAHs contaminated soil amended with biosolid or vermicompost in the presence of earthworms.

    Contreras-Ramos, S M; Alvarez-Bernal, D; Dendooven, L


    Nitrogen mineralization in PAHs contaminated soil in presence of Eisenia fetida amended with biosolid or vermicompost was investigated. Sterilized and unsterilized soil was contaminated with PAHs, added with E. fetida and biosolid or vermicompost and incubated aerobically for 70 days, while dynamics of inorganic N were monitored. Addition of E. fetida to sterilized soil increased concentration of NH(4)(+) 100> mg N kg(-1), while concentrations in unsterilized remained 80 mg kg(-1). Addition of PAHs had no significant effect on concentration of NH(4)(+) compared to the unamended soil, except in the soil added with biosolid. Addition of E. fetida to sterilized soil increased concentration of NO(2)(-) 15> mg N kg(-1) while concentrations in unsterilized soil remained 20 mg kg(-1). Addition of PAHs had no significant effect on concentration of NO(2)(-) compared to the unamended soil. Addition of biosolid and vermicompost increased concentration of NO(3)(-), while addition of E. fetida decreased concentration of NO(3)(-) in biosolid amended soil. It was found that NH(4)(+) and NO(2)(-) oxidizers were present in the gut of E. fetida, but their activity was not sufficient enough to inhibit a temporarily increase in concentrations of NH(4)(+) and NO(2)(-). Contamination with PAHs induced immobilization of N in biosolid or vermicompost amended soil, as did feeding of E. fetida on biosolid or vermicompost.

  14. Influence of soil properties and phosphate addition on arsenic uptake from polluted soils by velvetgrass (Holcus lanatus).

    Lewińska, K; Karczewska, A


    Four kinds of soil material were used in a pot experiment with velvetgrass (Holcus lanatus). Two unpolluted soils: sand (S) and loam (L) were spiked with sodium arsenite (As II) and arsenate (As V), to obtain total arsenic (As) concentrations of 500 mg As kg(-1). Two other soils (ZS I, ZS III), containing 3320 and 5350 mg As kg(-1), were collected from Zloty Stok where gold and arsenic ores were mined and processed for several centuries. The effects of phosphate addition on plants growth and As uptake were investigated. Phosphate was applied to soils in the form of NH4H2PO4 at the rate 0.2 g P/kg. Average concentrations of arsenic in the shoots of velvetgrass grown in spiked soils S and L without P amendment were in the range 18-210 mg As kg(-1) d.wt., whereas those in plants grown on ZS I and ZS II soils were considerably lower, and varied in the range 11-52 mg As kg(-1) d.wt. The addition of phosphate caused a significant increase in plant biomass and therefore the total amounts of As taken up by plants, however, the differences in As concentrations in the shoots of velvetgrass amended and non-amended with phosphate were not statistically significant.

  15. [Effects of soil covering on solar greenhouse pepper water use efficiency and soil nitrate N and available phosphorus contents].

    Zhou, Mao-juan; Liang, Yin-li; Chen, Jia-rui; Xiong, Ya-mei; Wei, Ze-xiu


    A greenhouse study on the effects of soil covering on pepper (Capsicum anmuum L.) water use efficiency and soil nitrate and available phosphorus contents showed that straw mulch + plastic film mulch could get the highest pepper yield water use efficiency (33.04 kg . m(-3)) and economic water use efficiency (50.22 yuan . m(-3)), followed by plastic film mulch, with the two parameters being 18.81 kg . m(-3) and 28.57 yuan . m(-3), respectively. Significant differences of nitrate N content in 0-20 cm soil layer were observed among different treatments. The control had the highest nitrate N content (50.33 mg . kg(-1)), followed by straw mulch (31.98 mg . kg(-1)) and straw + plastic film mulch (31.96 mg . kg(-1)), and plastic film mulch and applying water preserving agent. Compared with the control, soil covering could increase the nitrate N use efficiency of pepper, and decrease the accumulation of nitrate N in plough layer. In 0-20 cm soil layer, treatment plastic film mulch had the lowest available phosphorus content (0.72 mg . kg(-3)), and the second (0. 92 mg . kg(-1)) was the treatment straw + plastic film mulch. Treatments straw + plastic film mulch and plastic film mulch could increase pepper fruit yield and fertilizer use efficiency, and decrease fertilizer loss.


    Peter Ondrišík


    Full Text Available We researched the influence of soil cultivation and fertilization on changes of nitrate, ammonium and inorganic nitrogen content in soil during the monitored vegetation periods (2004/2005 – 2005/2006. This experiment was realized on experimental bases of Slovak University of Agriculture in Nitra – Dolná Malanta on the winter/summer wheat (Triticum aestivum, variety Bonita, with red clover as its before-crop. In the field trial we used two types of tillage, B1 – conventional tillage up to the depth of 0,25 m and B2 – disc ploughing up to 0,15 m, with three variants of fertilization, 0 – unfertilized control, PH – fertilization according to its content in soil and PZ – fertilization according to its content in soil + plough down of post harvest residues. Samples of the soil were taken from the two soil depth (0,0- 0,3 m and 0,3-0,6 m and in each vegetation period there were 8 takings of soil samples in four repetitions. During monitored vegetation period this dynamics was changeable. The content of nitrate nitrogen in the soil in autumn was about 40 % higher than content of ammonium nitrate. This tendency changed in spring, when the average content of ammonium nitrogen was higher than the content of nitrate nitrogen on average about 60 %. The cultivation had significant influence on dynamics of inorganic nitrogen. The average content of inorganic nitrogen in conventional tillage up to the depth of 0,25 m was 8,43 and in disc ploughing it was 7,60 The influence of fertilization on changes of inorganic nitrogen was significantly important. Monitored ways of fertilization within the content of nitrates in the soil had the following averages: in unfertilized soil 7,48, in fertilized soil NPK 8,20 and in the soil fertilized with plough down of post harvest residues 8,37 In the first and second variety of soil cultivation we found out a low increase of average concentration of nitrates in the

  17. Valores de referência local e avaliação da contaminação por zinco em solos adjacentes a áreas mineradas no município de Vazante-MG Establishing local reference values and determining contamination of zinc in soils of Vazante-MG

    Meubles Borges Júnior


    Full Text Available A contaminação dos solos por metais pesados é um problema atual que requer abordagem adequada, tendo em vista as necessidades da sociedade moderna. Em áreas de mineração, a avaliação da contaminação de solos constitui ferramenta importante para o gerenciamento de áreas degradadas. Este trabalho foi desenvolvido com o objetivo de estabelecer valores de referência local (VRL para Zn em solos adjacentes a áreas mineradas no município de Vazante-MG, tendo em vista avaliar a contaminação ambiental. Foram coletadas amostras de perfis de solos remanescentes em área mineralizada, a jusante e montante dessa, nas profundidades de 0-2, 2-5, 5-10, 10-20, 20-50, 50-100 e 100-150 cm. Foram determinados os teores totais de Zn, bem como as formas disponíveis (Mehlich-3 e DTPA. Optou-se por determinar o VRL a partir da média ponderada dos teores de Zn nas camadas de 0 - 20 cm dos perfis a montante. De posse desse valor, calcularam-se o fator de contaminação (FC e o índice de geoacumulação (IGeo para cada perfil. O VRL obtido para Zn foi de 1.262 mg kg-1, que é muito alto em relação aos padrões de qualidade, sugerindo monitoramento e restrição ao uso agrícola e residencial dos solos na área. Não obstante, esse valor é inferior aos valores de intervenção (VI´s para as áreas industriais adotados no Estado de São Paulo, EUA e Canadá. Os solos das áreas mineralizadas apresentaram maiores valores para o fator de contaminação, com destaque para o perfil 5 localizado na área mineralizada em exploração (área minerada. De acordo com o IGeo, os perfis de solo a jusante foram classificados como não poluídos a moderadamente poluídos.Soil contamination by heavy metals is a current concern that requires a suitable approach, taking the needs of modern societies into account. In mined areas the evaluation of soil contamination is an important tool for the management of degraded areas. This study was carried out in order to

  18. Effects of Bio-char on Soil Microbes in Herbicide Residual Soils

    WANG Gen-lin


    Full Text Available Effects of biological carbon (bio-char on soil microbial community were studied by pot experiments simulating long residual herbicide residues in soil environment, which clarifed the improvement of biochar and its structural properties on soil microenvironment. The results showed that fungi and actinomycetes had the same effect tendency within 0~0.72 mg·kg-1 in clomazone residue which increased the role of stimulation with crop growth process prolonged, especially in high residue treatment, but strong inhibitory effect on bacteria community was occured early which returned to normal until sugar beet growth to fiftieth day. Soil fungi community decreased with bio-char adding, but had no significant difference with the control. When clomazone residue in soil was below 0.24 mg·kg-1, soil actinomycetes community was higher than control without bio-char, bacteria increased first and then reduced after adding carbon as below 0.12 mg·kg-1. Biochar was ‘deep hole’ structure containing C, O, S and other elements. The results showed that a certain concentration clomazone residue in soil would stimulate soil fungi and actinomycetes to grow. After adding the biochar, the inhibition effect of high herbicides residual on bacterial would be alleviated.

  19. Effects of Acetochlor and Methamidophos on Fungal Communities in Black Soils

    LI Xin-Yu; ZHANG Hui-Wen; ZHOU Qi-Xing; SU Zhen-Cheng; ZHANG Cheng-Gang


    Using plate counting and ergosterol assay, single and joint effects of acetochlor and methamidophos on the dynamics of soil fungal population and total fungal biomass in the black soil zone of Northeast China were investigated. The results demonstrated that acetochlor at high concentration levels (150 and 250 mg kg-1) had an acute and mostly chronic toxicity on both the soil fungal population and total fungal biomass, but at a low concentration (50 mg kg-1) generally had a stimulating effect that was stronger with total fungal biomass than with the soil fungal population. Methamidophos at a high concentration level (250 mg kg-1) alone and almost all of its combinations with various dosages of acetochlor increased the soil fungal population, whereas at most sampling dates with 250 mg methamidophos kg-1 soil, total fungal biomass increased, but in combination with acetochlor it was decreased in the early period of incubation and then increased 28 days after incubation. Thus, through measuring the number of colony forming unit of the soil fungal population along with the total fungal biomass, a better understanding on effects of agrochemicals on soil fungi could be made.

  20. Salinomycin overcomes ABC transporter-mediated multidrug and apoptosis resistance in human leukemia stem cell-like KG-1a cells

    Fuchs, Dominik [Research Group Molecular Neuro-Oncology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany); Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg (Germany); Daniel, Volker; Sadeghi, Mahmoud; Opelz, Gerhard [Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg (Germany); Naujokat, Cord, E-mail: [Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg (Germany)


    Leukemia stem cells are known to exhibit multidrug resistance by expression of ATP-binding cassette (ABC) transporters which constitute transmembrane proteins capable of exporting a wide variety of chemotherapeutic drugs from the cytosol. We show here that human promyeloblastic leukemia KG-1a cells exposed to the histone deacetylase inhibitor phenylbutyrate resemble many characteristics of leukemia stem cells, including expression of functional ABC transporters such as P-glycoprotein, BCRP and MRP8. Consequently, KG-1a cells display resistance to the induction of apoptosis by various chemotherapeutic drugs. Resistance to apoptosis induction by chemotherapeutic drugs can be reversed by cyclosporine A, which effectively inhibits the activity of P-glycoprotein and BCRP, thus demonstrating ABC transporter-mediated drug resistance in KG-1a cells. However, KG-1a are highly sensitive to apoptosis induction by salinomycin, a polyether ionophore antibiotic that has recently been shown to kill human breast cancer stem cell-like cells and to induce apoptosis in human cancer cells displaying multiple mechanisms of drug and apoptosis resistance. Whereas KG-1a cells can be adapted to proliferate in the presence of apoptosis-inducing concentrations of bortezomib and doxorubicin, salinomycin does not permit long-term adaptation of the cells to apoptosis-inducing concentrations. Thus, salinomycin should be regarded as a novel and effective agent for the elimination of leukemia stem cells and other tumor cells exhibiting ABC transporter-mediated multidrug resistance.

  1. The identification of 'hotspots' of heavy metal pollution in soil-rice systems at a regional scale in eastern China.

    Li, Wanlu; Xu, Binbin; Song, Qiujin; Liu, Xingmei; Xu, Jianming; Brookes, Philip C


    Chinese agricultural soils and crops are suffering from increasing damage from heavy metals, which are introduced from various pollution sources including agriculture, traffic, mining and especially the flourishing private metal recycling industry. In this study, 219 pairs of rice grain and corresponding soil samples were collected from Wenling in Zhejiang Province to identify the spatial relationship and pollution hotspots of Cd, Cu, Ni and Zn in the soil-rice system. The mean soil concentrations of heavy metals were 0.316 mg kg(-1) for Cd, 47.3 mg kg(-1) for Cu, 31.7 mg kg(-1) for Ni and 131 mg kg(-1) for Zn, and the metal concentrations in rice grain were 0.132 mg kg(-1) for Cd, 2.46 mg kg(-1) for Cu, 0.223 mg kg(-1) for Ni and 17.4 mg kg(-1) for Zn. The coefficient of variability (CV) of soil Cd, Cu and rice Cd were 147%, 146% and 180%, respectively, indicating an extensive variability. While the CVs of other metals ranged from 23.4% to 84.3% with a moderate variability. Kriging interpolation procedure and the Local Moran's I index detected the locations of pollution hotspots of these four metals. Cd and Cu had a very similar spatial pattern, with contamination hotspots located simultaneously in the northwestern part of the study area, and there were obvious hotspots for soil Zn in the north area, while in the northeast for soil Ni. The existence of hotspots may be due to industrialization and other anthropogenic activities. An Enrichment Index (EI) was employed to measure the uptake of heavy metals by rice. The results indicated that the accumulation and availability of heavy metals in the soil-rice system may be influenced by both soil heavy metal concentrations and soil physico-chemical properties. Cross-correlograms quantitatively illustrated that EIs were significantly correlated with soil properties. Soil pH and organic matter were the most important factors controlling the uptake of heavy metals by rice. As results, positive measures should be taken into

  2. Phytoremediation potential of wild plants growing on soil contaminated with heavy metals.

    Čudić, Vladica; Stojiljković, Dragoslava; Jovović, Aleksandar


    Phytoremediation is an emerging technology that employs higher plants to cleanup contaminated environments, including metal-polluted soils. Because it produces a biomass rich in extracted toxic metals, further treatment of this biomass is necessary. The aim of our study was to assess the five-year potential of the following native wild plants to produce biomass and remove heavy metals from a polluted site: poplar (Populus ssp.), ailanthus (Ailanthus glandulosa L.), false acacia (Robinia pseudoacacia L.), ragweed (Artemisia artemisiifolia L.), and mullein (Verbascum thapsus L). Average soil contamination with Pb, Cd, Zn, Cu, Ni, Cr, and As in the root zone was 22,948.6 mg kg-1, 865.4 mg kg-1, 85,301.7 mg kg-1, 3,193.3 mg kg-1, 50.7 mg kg-1, 41.7 mg kg-1,and 617.9 mg kg-1, respectively. We measured moisture and ash content, concentrations of Pb, Cd, Zn, Cu, Ni, Cr, and As in the above-ground parts of the plants and in ash produced by combustion of the plants, plus gross calorific values. The plants' phytoextraction and phytostabilisation potential was evaluated based on their bioconcentration factor (BCF) and translocation factor (TF). Mullein was identified as a hyperaccumulator for Cd. It also showed a higher gross calorific value (19,735 kJ kg-1) than ragweed (16,469 kJ kg-1).The results of this study suggest that mullein has a great potential for phytoextraction and for biomass generation, and that ragweed could be an effective tool of phytostabilisation.

  3. Conversion of Natural Ecosystems to Cropland Increases the Soil Net Nitrogen mineralization and Nitrification in Tibet

    YANG Li-Lin; ZHANG Fu-Suo; MAO Ren-Zhao; JU Xiao-Tang; Cai Xiao-Bu; LI Ya-Hai


    A comparative study was conducted to determine the NH+4 and NO-3 concentrations in soil profiles and to examine the net itrogen (N) mineralization and nitrification in adjacent forest, grassland, and cropland soils on the Tibetan Plateau. Cropland soil showed significantly higher inorganic N concentrations in soil profiles compared with forest and grassland soils. NO-3-Naccounted for 70%-90% of inorganic N in cropland soil, while NH+4-N was the main form of inorganic N in forest and grassland soils. The average net N mineralization rate at 0-20 cm depth was approximately twice in cropland soil (1.48 mg kg-1 d-1) as high as in forest (0.83 mg kg-1 d-1) or grassland soil (0.72 mg kg-1 d-1). Cropland showed strong net nitrification, with the net rate almost equal to the total net N mineralization. Urea addition stimulated soil respiration, particularly in forest oil. Most urea-N, however, remained as NH+4 in forest and grassland soils, while NO-3 was the main form of inorganic N to increase n cropland soil. Higher rates of net nitrification in cropland soils suggest that land use change on the Tibetan Plateau may lead to high N losses through nitrate leaching.

  4. Evaluation of cadmium in greenhouse soils and agricultural products of Jiroft (Iran) using microwave digestion prior to atomic absorption spectrometry determination.

    Afzali, Daryoush; Fathirad, Fariba; Afzali, Zahra; Majdzadeh-Kermani, Seyed Mohammad Javad


    This study determines total levels of potentially toxic trace element, Cd (II) in Jiroft (Kerman, Iran) greenhouse soil and agricultural products that are grown in these greenhouses (tomatoes and cucumbers), and the comparison with soil outside of greenhouse using microwave digestion prior to flame atomic absorption spectrometry determination. The results show that the cadmium concentration in greenhouse soil is 0.9-1.9 mg kg(-1) and out of greenhouse is 0.4-1.0 mg kg(-1). Also, cadmium concentration range in tomatoes and cucumbers is about 0.07-0.40 mg kg(-1). The obtained results show that the concentration of this metal in greenhouse soil is higher than outside soil samples and is below the safe limit.

  5. Multi-criteria analysis of soil pollution by heavy metals in the vicinity of the Copper Smelting Plant in Bor (Serbia



    Full Text Available This study highlights the consequences on soil pollution of one hund­red years of manufacturing in the Copper Mining and Smelting Complex RTB-Bor (Serbia. Soil sediments were taken via a probe from the surface layer of the soil at twelve different measuring points. The measuring points were all within 20 km of the smelting plant, which included both urban and rural zones. Soil sampling was performed using a soil core sampler in such way that a core of a soil of radius 5 cm and depth of 30 cm was removed. Subsequently, the samples were analyzed for pH and heavy metal concentrations (Cu, Pb, As, Cd, Mn, Ni and Hg using different spectrometric methods. The obtained results for the heavy metal contents in the samples show high values: 2,540 mg kg-1 Cu; 230 mg kg-1 Pb; 6 mg kg-1 Cd; 530 mg kg-1 Ni; 1,300 mg kg-1 Mn; 260 mg kg-1 As and 0.3 mg kg-1 Hg. In this study, critical zones of polluted soil were iden­tified and ranked according to their metal contents by the multi-criteria deci­sion method Preference Organization Method for Enrichment Evaluation/Geo­metrical Analysis for Interactive Assistance – PROMETHEE/GAIA, which is the preferred multivariate method commonly used in chemometric studies. The ranking results clearly showed that the most polluted zones are at locations holding the vital functions of the town. Therefore, due to the high bioavail­abi­lity of heavy metals through com­plex reactions with organic species in the sediments, consequences for human health could drastically emerge if these metals enter the food chain.

  6. [Dynamics of microbial biomass P and its affecting factors in a long-term fertilized black soil].

    Li, Dongpo; Wu, Zhijie; Chen, Lijun; Zhu, Ping; Ren, Jun; Liang, Chenghua; Peng, Chang; Gao, Hongjun


    This paper studied the microbial biomass P in a long-term fertilized black soil. The soil was fertilized by farmyard manure (M2, M4) and chemical fertilizer (NPK), and the dynamics of soil microbial biomass P was monitored during crop growth season. The results showed that the microbial biomass P in different treatments was 8.75-47.68 mg x kg(-1) (M4), 3.02-37.16 mg x kg(-1) (M2), 1.59-10.62 mg x kg(-1) (NPK), and 0.76-6.74 mg x kg(-1) (CK). The microbial biomass P in M4 and M2 was the highest at reproductive growth stage, and that in NPK and CK was the highest at early growth stage. The significant difference of soil microbial biomass P induced by different amounts and types of fertilizer application was not varied with the period and stage of plant growth. In all treatments, no significant correlation was found between the dynamics of soil microbial biomass P and the soil biological, physical and chemical properties in plant growth period. Soil microbial biomass P had a very significant positive correlation with soil biological, physical and chemical properties (expect K), and a significant positive correlation with the N, P and K contents of plants and soil water content.

  7. Impact of a long-term fire retardant (Fire Trol 931) on the leaching of Ca, Mg, and K from a Mediterranean forest loamy soil.

    Michalopoulos, Charalampos; Koufopoulou, Sofia; Tzamtzis, Nikolaos; Pappa, Athina


    The present laboratory study was conducted in pot soil taken from forest. The leaching of calcium (Ca), magnesium (Mg), and potassium (K) (plant macronutrients) due to the application of a nitrogen phosphate-based long-term fire retardant (LTFR) (Fire Trol 931) was investigated. The concentrations of Ca(2+), Mg(2+), and K(+) were measured in the resulting leachates from pots with forest soil and pine tree alone and in combination with fire. Magnesium is a minor component of Fire Trol 931. The leaching of Ca(2+), Mg(2+), and K(+) from treated soils with the retardant pots was significantly greater than that from control pots. The leaching of Mg(2+) was found to be of small percentage of the initially applied Mg quantities. Fire Trol 931 application resulted in the leaching of Ca(2+), Mg(2+), and K(+) from a typical Mediterranean forest soil in pots, following the application of simulated annual precipitation probably due to ammonium (one of the major retardant components) soil deposition that mobilizes base cations from the soil. It seems that LTFR application may result in chemical leaching from the soil to the drainage water.

  8. Soil fertility status and nutrients provided to spring barley (Hordeum distichon L. by pig slurry

    Melisa Gómez-Garrido


    Full Text Available Nutrient recycling using pig slurry is a common agricultural practice to manage the ever-increasing amounts of wastes from the pig industry. This study was conducted in the southeast of Spain to quantify the enrichments in major (N, P, K, Mg and minor (Zn, Fe, Cu, and Mn nutrients in soils amended with D1-170 kg N ha-1 (European Union legislated dose or D2-340 kg N ha-1, and understand the influence of pig slurry on yield and nutrient uptake in two crop seasons of spring barley (Hordeum distichon L. Compared to control, D2 increased NO3--N by 11.4X to 109 mg kg-1, Olsen-P by 6.9X to 423 mg kg-1, exchange K (2.5X to 1.6 cmol+ kg-1, Mg (1.7X to 1.8 cmol+ kg-1, diethylene-triamine pentaacetic acid (DTPA-Zn (94X to 18.2 mg kg-1, and Fe (2X to 11.3 mg kg-1. Available NO3--N, Olsen-P, and DTPA-Zn have the best correlations with crop yield and nutrient uptake. These results indicate that the assessment of soil fertility status at 1-mo after pig slurry addition provides a good indicator for potential yield and uptake of barley. However, it is suggested that leachates should be monitored to effectively manage potential releases of nitrate and phosphate into the environment.

  9. Survival of Pseudomonas fluorescence X16(luxAB)Strain in Soils Accumulated with Mixed Rare Earth Elements

    唐欣昀; 孙亦阳; 温崇庆; 甘旭华; 张自立


    Rare earth elements(REE)are applied as micro-fertilizer in large scale in China and there is growing concern about the environmental effects of REE accumulation in soils. Accumulation of REE was simulated in lab by adding REE to three soils and the survival of Pseudomonas fluorescence X16 strain marked with luxAB gene in soils was detected. Curvilinear regression method was applied to analyze the survival pattern. The stimulation values, EC50 and NOEC values for X16 strain were calculated to compare the toxic intensity of REE in different soils. The stimulation(peak)values in red soil, yellow fluovo-aquic soil and yellow cinnamon soil, are 11.55~18.08,0~2.13, 2.37~4.62 mg·kg-1 , respectively. EC50 values are 13.47~39.12, 6.59~56.18, 372~1034 mg·kg-1, respectively.NOEC values are 5.62 ~21.41, 0.00~4.53, 133.3~327.1 mg·kg-1, respectively. Tangents values of regression equation of the survival of X16 strain in red soil are the maximum ones indicating that REE accumulation in red soil has stronger inhibitory effects than in other two soils. The soil order, reflecting toxic intensity of REE is as follows: red soil>yellow fluovic-aquic soil>yellow cinnamon soil.

  10. Estimating soil zinc concentrations using reflectance spectroscopy

    Sun, Weichao; Zhang, Xia


    Soil contamination by heavy metals has been an increasingly severe threat to nature environment and human health. Efficiently investigation of contamination status is essential to soil protection and remediation. Visible and near-infrared reflectance spectroscopy (VNIRS) has been regarded as an alternative for monitoring soil contamination by heavy metals. Generally, the entire VNIR spectral bands are employed to estimate heavy metal concentration, which lacks interpretability and requires much calculation. In this study, 74 soil samples were collected from Hunan Province, China and their reflectance spectra were used to estimate zinc (Zn) concentration in soil. Organic matter and clay minerals have strong adsorption for Zn in soil. Spectral bands associated with organic matter and clay minerals were used for estimation with genetic algorithm based partial least square regression (GA-PLSR). The entire VNIR spectral bands, the bands associated with organic matter and the bands associated with clay minerals were incorporated as comparisons. Root mean square error of prediction, residual prediction deviation, and coefficient of determination (R2) for the model developed using combined bands of organic matter and clay minerals were 329.65 mg kg-1, 1.96 and 0.73, which is better than 341.88 mg kg-1, 1.89 and 0.71 for the entire VNIR spectral bands, 492.65 mg kg-1, 1.31 and 0.40 for the organic matter, and 430.26 mg kg-1, 1.50 and 0.54 for the clay minerals. Additionally, in consideration of atmospheric water vapor absorption in field spectra measurement, combined bands of organic matter and absorption around 2200 nm were used for estimation and achieved high prediction accuracy with R2 reached 0.640. The results indicate huge potential of soil reflectance spectroscopy in estimating Zn concentrations in soil.

  11. Biodegradation of petroleum compounds in soil by a solid-phase circulating bioreactor with poultry manure amendments.

    Fallgren, Paul H; Jin, Song


    Petroleum compounds account for the vast majority of contaminants in soils. Bioremediation is a widely accepted strategy in degrading these contaminants. This study demonstrates the effectiveness of nitrogenous nutrient (nitrogen) amendments in enhancing biodegradation of petroleum contaminants in soil by using a solid-phase circulating bioreactor (SCB). In a bench-scale SCB, total petroleum hydrocarbon (TPH) concentration (~5000 mg kg(-1)) in soil decreased 92% within 15 days. In a scaled-up SCB system containing approximately 120 kg petroleum-contaminated soil (TPH at approximately 125,000 mg kg(-1)), a degradation rate of 635 mg kg(-1)d(-1) was obtained from the poultry manure-amended treatment during a 200-day period of operation. Treatments with the same amount of nitrogen (as ammonium nitrate) attained a TPH degradation rate of 469 mg kg(-1)d(-1) during the same period. Control SCB unit, which was maintained under the same aerobic conditions but not amended with nitrogen, had a TPH degradation rate of 273 mg kg(-1)d(-1). Results from this study indicate that SCB can achieve significantly higher degradative rates than conventional landfarming (reported rates petroleum contaminants in soils.

  12. Difficultly Extractable Fixed Ammonium in Some Soils of China



    Ninety-three soil samples and 19 sedimentary rock samples collected from 21 provinces of China were analyzed for their contents of fixed ammonium and total N by Kjeldahl-HF method.Results showed that amount of difficultly extractable fixed ammonium(the fixed ammonium that is not determinable by Kjeldahl procedures commonly used for soils) in soils ranged from 0 to 202 mg kg-1,It was generally more than 50 mg kg-1 in soils in Changji and Turpan districts,Xinjiang,accounting for 3.2%-36.8% with an average of 13.9% of the total N.For some Orthents derived from purple shale and purple sandstone in Sichuan and Hunan provinces and Chao soils derived from secondary loess in Henan Province and Ningxia Autonomous Region it was generally around 30 mg kg-1,accounting for 4%-7% of the total soil N,and for most of the rest of soils studied,with the exception of some subsoils,no or trace difficultly extractable fixed ammonium could be detected.It was sugested that the difficultly extractable fixed ammonium was originated from parent rock,and for slightly weathered soils derived from parent materials rich in this form of N the Kjeldahl method might give underestimation of total soil N.

  13. Hydrocarbon contamination increases the liquid water content of frozen Antarctic soils.

    Siciliano, Steven D; Schafer, Alexis N; Forgeron, Michelle A M; Snape, Ian


    We do not yet understand why fuel spills can cause greater damage in polar soils than in temperate soils. The role of water in the freezing environment may partly be responsible for why polar soils are more sensitive to pollution. We hypothesized that hydrocarbons alter the liquid water in frozen soil, and we evaluated this hypothesis by conducting laboratory and field experiments at Casey Station, Antarctica. Liquid water content in frozen soils (theta(liquid)) was estimated by time domain reflectometry in laboratory, field collected soils, and in situ field measurements. Our results demonstrate an increase in liquid water associated with hydrocarbon contamination in frozen soils. The dependence of theta(liquid) on aged fuel and spiked fuel were almost identical,with a slope of 2.6 x 10(-6) mg TPH (total petroleum hydrocarbons) kg(-1) for aged fuel and 3.1 x 10(-6) mg TPH kg(-1) for spiked fuel. In situ measurements found theta(liquid) depends, r2 = 0.75, on fuel for silt loam soils (theta(liquid) = 0.094 + 7.8 x 10(-6) mg TPH kg(-1)) but not on fuel for silt clay loam soils. In our study, theta(liquid) doubled in field soils and quadrupled in laboratory soils contaminated with diesel which may have profound implications on frost heave models in contaminated soils.

  14. Successive chlorothalonil applications inhibit soil nitrification and discrepantly affect abundances of functional genes in soil nitrogen cycling.

    Teng, Ying; Zhang, Manyun; Yang, Guangmei; Wang, Jun; Christie, Peter; Luo, Yongming


    Broad-spectrum fungicide chlorothalonil (CTN) is successively applied into intensive agriculture soil. However, the impacts of successive CTN applications on soil nitrification and related microorganisms remain poorly understood. A microcosm study was conducted to reveal the effects of successive CTN applications on soil nitrification and functional genes involved in soil nitrogen (N) cycling. The CTN at the dosages of 5 mg kg(-1) dry soil (RD) and 25 mg kg(-1) dry soil (5RD) was successively applied into the test soil at 7-day intervals which resulted in the accumulations of CTN residues. After 28 days of incubation, CTN residues in the RD and 5RD treatments were 3.14 and 69.7 mg kg(-1) dry soil respectively. Net nitrification rates in the RD and 5RD treatments were lower than that obtained from the blank control (CK). Real-time PCR analysis revealed that AOA and AOB amoA gene abundances were significantly decreased by CTN applications. Moreover, CTN applications also discrepantly decreased the abundances of functional genes involved in soil denitrification, with the exception of nosZ gene. Principal component analysis further supported the observation that successive CTN applications could result in enhanced ecological toxicity.

  15. [Effects of fertilization on soil CO2 flux in Castanea mollissima stand].

    Zhang, Jiao-Jiao; Li, Yong-Fu; Jiang, Pei-Kun; Zhou, Guo-Mo; Shen, Zhen-Ming; Liu, Juan; Wang, Zhan-Lei


    In June 2011-June 2012, a fertilization experiment was conducted in a typical Castanea mollissima stand in Lin' an of Zhejiang Province, East China to study the effects of inorganic and organic fertilization on the soil CO2 flux and the relationships between the soil CO2 flux and environmental factors. Four treatments were installed, i. e., no fertilization (CK), inorganic fertilization (IF), organic fertilization (OF), half organic plus half inorganic fertilization (OIF). The soil CO2 emission rate was determined by the method of static closed chamber/GC technique, and the soil temperature, soil moisture content, and soil water-soluble organic carbon (WSOC) concentration were determined by routine methods. The soil CO2 emission exhibited a strong seasonal pattern, with the highest rate in July or August and the lowest rate in February. The annual accumulative soil CO2 emission in CK was 27.7 t CO2 x hm(-2) x a(-1), and that in treatments IF, OF, and OIF was 29.5%, 47.0%, and 50.7% higher than the CK, respectively. The soil WSOC concentration in treatment IF (105.1 mg kg(-1)) was significantly higher than that in CK (76.6 mg x kg(-1)), but was obviously lower than that in treatments OF (133.0 mg x kg(-1)) and OIF (121.2 mg x kg(-1)). The temperature sensitivity of respiration (Q10) in treatments CK, IF, OF, and OIF was 1.47, 1.75, 1.49, and 1.57, respectively. The soil CO2 emission rate had significant positive correlations with the soil temperature at the depth of 5 cm and the soil WSOC concentration, but no significant correlation with soil moisture content. The increase of the soil WSOC concentration caused by fertilization was probably one of the reasons for the increase of soil CO2 emission from the C. mollissima stand.

  16. Enrichment and exposure assessment of As, Cr and Pb of the soils in the vicinity of Stawell, Victoria, Australia.

    Noble, Ryan R P; Hough, Robert M; Watkins, Ronald T


    Stawell Gold Mine in NW Victoria, Australia, mines ores that contain large concentrations of As and significant quantities of the metals Pb and Cr. The aim of this research was to understand the dispersion, enrichment and probable exposure of these potentially hazardous elements around the mine site. Fifty-five surface soil samples were collected near the mine (mine show greater concentrations of As, Cr and Pb than those near a regionally determined background. This is attributed to the combination of a natural geochemical halo around mineralization and anthropogenic dispersion due to mining and urbanization. Total As concentrations were between 16 and 946 mg kg(-1) near the mine in a regional background of 1-16 mg kg(-1). Total Cr concentrations were between 18 and 740 mg kg(-1) near the mine in a regional background of 26-143 mg kg(-1). Total Pb concentrations were between 12 and 430 mg kg(-1) near the mine in a regional background of 9-23 mg kg(-1). Dispersion of contaminant elements from the present ore processing is mining practices. The bioavailable As, Cr and Pb, soil ingestion rates and Risk Reference Doses were used to estimate health risks. An average toddler (12 kg) would need to consume at least 1.5 g, and most likely 12 g, of soil per day to show some symptoms of As toxicity. The maximum measured bioavailable As would pose a risk at average ingestion rates of 200 mg per day. Individuals with soil-eating disorders would exceed the safe daily consumption limits for As, and potentially Cr and Pb. Small children are not typically exposed to soil everyday, very few have soil eating disorders, and, therefore, the health risk from the soils around the mine is minimal.

  17. Soil organic carbon distribution in roadside soils of Singapore.

    Ghosh, Subhadip; Scharenbroch, Bryant C; Ow, Lai Fern


    Soil is the largest pool of organic carbon in terrestrial systems and plays a key role in carbon cycle. Global population living in urban areas are increasing substantially; however, the effects of urbanization on soil carbon storage and distribution are largely unknown. Here, we characterized the soil organic carbon (SOC) in roadside soils across the city-state of Singapore. We tested three hypotheses that SOC contents (concentration and density) in Singapore would be positively related to aboveground tree biomass, soil microbial biomass and land-use patterns. Overall mean SOC concentrations and densities (0-100 cm) of Singapore's roadside soils were 29 g kg(-1) (4-106 g kg(-1)) and 11 kg m(-2) (1.1-42.5 kg m(-2)) with median values of 26 g kg(-1) and 10 kg m(-2), respectively. There was significantly higher concentration of organic carbon (10.3 g kg(-1)) in the top 0-30 cm soil depth compared to the deeper (30-50 cm, and 50-100 cm) soil depths. Singapore's roadside soils represent 4% of Singapore's land, but store 2.9 million Mg C (estimated range of 0.3-11 million Mg C). This amount of SOC is equivalent to 25% of annual anthropogenic C emissions in Singapore. Soil organic C contents in Singapore's soils were not related to aboveground vegetation or soil microbial biomass, whereas land-use patterns to best explain variance in SOC in Singapore's roadside soils. We found SOC in Singapore's roadside soils to be inversely related to urbanization. We conclude that high SOC in Singapore roadside soils are probably due to management, such as specifications of high quality top-soil, high use of irrigation and fertilization and also due to an optimal climate promoting rapid growth and biological activity.

  18. Chromium Displacement in Subtropical Soils Fertilized with Hydrolysed Leather: A Laboratory Study.

    Bavaresco, Jovana; Fink, Jessé R; Rodrigues, Maria Lucia K; Gianello, Clesio; Barrón, Vidal; Torrent, José


    Prolonged use of biosolids with high metal content may result in diffuse pollution across large regions, especially if such ions can move freely through the soil profile and reach underground water sources. The objective of this study was to verify whether Cr added to the soil surface in the form of hydrolysed leather or a soluble salt would migrate over significant distances in four subtropical soils differing in physical, chemical and mineralogical properties. Horizontal and vertical mobility were assessed in Petri dishes and small pots, respectively, using low (12 mg kg(-1) soil) and high Cr levels (150 mg kg(-1) soil) added to the soil surface. Irrespective of concentration, soluble Cr salts were found to move more easily in soils with low organic matter and clay content. Contrarily, Cr added as hydrolysed leather exhibited negligible mobility and tended to accumulate in the vicinity of application.

  19. The impact of land use on soil properties in a karst agricultural region of Southwest China: a case study of Xiaojiang watershed, Yunnan%典型岩溶农业区土地利用变化对土壤性质的影响——以云南小江流域为例



    Supported by RS and GIS, the land use change from 1982 to 2003 were analyzed and the impacts of land use changes on pH value, organic matter, total N, total P, total K, available N, available P, and available K in soil of Xiaojiang watershed, a typical karst agricultural region of Yunnan Province, Southwest China were assessed. The following aspects are concluded. (1) The total land use converted during the past 20 years in Xiaojiang watershed covers an area of 610.12 km2, of which 134.29 km2 of forestland was converted into cultivated land, and 210 km2 of unused land was converted into cultivated land. (2) The rapid growth of population and the economic development were the main driving forces of land use change. (3) With the change in land use, the soil properties have been changed significantly. The pH, organic matter, total N, total P, total K, available N, available P and available K in soil in 1982 were 6.3, 38.02 g kg-1, 1.86 g kg-1, 1.63 g kg-1, 10.94 g kg-1, 114.42 g kg-1, 11.65 mg kg-1 and 64.69 mg kg-1g, respectively; and those in 2003 were 6.73, 25.26 g kg-1, 1.41 g kg-1, 0.99 g kg-1, 12.6 g kg-1, 113.43 mg kg-1, 11.11 mg kg-1 and 151.59 mg kg-1, respectively. Pared samples t-test of the tested indices of soil properties indicate that those indices have changed significantly during the last 20 years. But the soil properties changed differently, due to the differences in land use change. (4) Also, with the change in land use and management measures of soil, the modifications in soil properties which developed from carbonate rocks were more sensitive than those in the soil developed from sandstone.

  20. Arsenic in the soils of Zimapán, Mexico.

    Ongley, Lois K; Sherman, Leslie; Armienta, Aurora; Concilio, Amy; Salinas, Carrie Ferguson


    Arsenic concentrations of 73 soil samples collected in the semi-arid Zimapán Valley range from 4 to 14 700 mg As kg(-1). Soil arsenic concentrations decrease with distance from mines and tailings and slag heaps and exceed 400 mg kg(-1) only within 500 m of these arsenic sources. Soil arsenic concentrations correlate positively with Cu, Pb, and Zn concentrations, suggesting a strong association with ore minerals known to exist in the region. Some As was associated with Fe and Mn oxyhydroxides, this association is less for contaminated than for uncontaminated samples. Very little As was found in the mobile water-soluble or exchangeable fractions. The soils are not arsenic contaminated at depths greater than 100 cm below the surface. Although much of the arsenic in the soils is associated with relatively immobile solid phases, this represents a long-term source of arsenic to the environment.

  1. Damping zone in the biological reserve serra dos toledos (Itajubá-MG and its effect on soil quality

    Olivia de Lima; Rogério Melloni


    Full Text Available Areas that comprise "damping zones" are important in minimizing the effects of impacts on the environment as they can affect the conservation unit, and in helping to maintain its natural resources. However, they are not protected and many are handled improperly, compromising the sustainability of the conservation units they should protect. The aim of this study was to evaluate the effect of human disturbance in the damping zone on the soil quality inside the Biological Reserve Serra dos Toledos, Itajubá-MG. For this, there were selected three areas under different activities in the damping zone (pasture, agriculture, and native forest and three areas sided to those, within the Reserve. They were characterized according to various physical, chemical, microbiological, and visual soil quality procedures. Areas that had the worst physical, visual, and microbiological conditions were those located in the damping zone under agriculture and pasture. The microbiological attributes were sensitive to the different areas, due to the direct relation between negative impact of agriculture practiced in the damping zone and the soil quality within the Biological Reserve studied.

  2. Seasonal Dynamics of Soil Labile Organic Carbon and Enzyme Activities in Relation to Vegetation Types in Hangzhou Bay Tidal Flat Wetland.

    Shao, Xuexin; Yang, Wenying; Wu, Ming


    Soil labile organic carbon and soil enzymes play important roles in the carbon cycle of coastal wetlands that have high organic carbon accumulation rates. Soils under three vegetations (Phragmites australis, Spartina alterniflora, and Scirpusm mariqueter) as well as bare mudflat in Hangzhou Bay wetland of China were collected seasonally. Seasonal dynamics and correlations of soil labile organic carbon fractions and soil enzyme activities were analyzed. The results showed that there were significant differences among vegetation types in the contents of soil organic carbon (SOC) and dissolved organic carbon (DOC), excepting for that of microbial biomass carbon (MBC). The P. australis soil was with the highest content of both SOC (7.86 g kg-1) and DOC (306 mg kg-1), while the S. mariqueter soil was with the lowest content of SOC (6.83 g kg-1), and the bare mudflat was with the lowest content of DOC (270 mg kg-1). Soil enzyme activities were significantly different among vegetation types except for urease. The P. australis had the highest annual average activity of alkaline phosphomonoesterase (21.4 mg kg-1 h-1), and the S. alterniflora had the highest annual average activities of β-glycosidase (4.10 mg kg-1 h-1) and invertase (9.81 mg g-1 24h-1); however, the bare mudflat had the lowest activities of alkaline phosphomonoesterase (16.2 mg kg-1 h-1), β-glycosidase (2.87 mg kg-1 h-1), and invertase (8.02 mg g-1 24h-1). Analysis also showed that the soil labile organic carbon fractions and soil enzyme activities had distinct seasonal dynamics. In addition, the soil MBC content was significantly correlated with the activities of urease and β-glucosidase. The DOC content was significantly correlated with the activities of urease, alkaline phosphomonoesterase, and invertase. The results indicated that vegetation type is an important factor influencing the spatial-temporal variation of soil enzyme activities and labile organic carbon in coastal wetlands.

  3. Soil TPH concentration estimation using vegetation indices in an oil polluted area of eastern China.

    Zhu, Linhai; Zhao, Xuechun; Lai, Liming; Wang, Jianjian; Jiang, Lianhe; Ding, Jinzhi; Liu, Nanxi; Yu, Yunjiang; Li, Junsheng; Xiao, Nengwen; Zheng, Yuanrun; Rimmington, Glyn M


    Assessing oil pollution using traditional field-based methods over large areas is difficult and expensive. Remote sensing technologies with good spatial and temporal coverage might provide an alternative for monitoring oil pollution by recording the spectral signals of plants growing in polluted soils. Total petroleum hydrocarbon concentrations of soils and the hyperspectral canopy reflectance were measured in wetlands dominated by reeds (Phragmites australis) around oil wells that have been producing oil for approximately 10 years in the Yellow River Delta, eastern China to evaluate the potential of vegetation indices and red edge parameters to estimate soil oil pollution. The detrimental effect of oil pollution on reed communities was confirmed by the evidence that the aboveground biomass decreased from 1076.5 g m(-2) to 5.3 g m(-2) with increasing total petroleum hydrocarbon concentrations ranging from 9.45 mg kg(-1) to 652 mg kg(-1). The modified chlorophyll absorption ratio index (MCARI) best estimated soil TPH concentration among 20 vegetation indices. The linear model involving MCARI had the highest coefficient of determination (R(2) = 0.73) and accuracy of prediction (RMSE = 104.2 mg kg(-1)). For other vegetation indices and red edge parameters, the R(2) and RMSE values ranged from 0.64 to 0.71 and from 120.2 mg kg(-1) to 106.8 mg kg(-1) respectively. The traditional broadband normalized difference vegetation index (NDVI), one of the broadband multispectral vegetation indices (BMVIs), produced a prediction (R(2) = 0.70 and RMSE = 110.1 mg kg(-1)) similar to that of MCARI. These results corroborated the potential of remote sensing for assessing soil oil pollution in large areas. Traditional BMVIs are still of great value in monitoring soil oil pollution when hyperspectral data are unavailable.

  4. Soil TPH concentration estimation using vegetation indices in an oil polluted area of eastern China.

    Linhai Zhu

    Full Text Available Assessing oil pollution using traditional field-based methods over large areas is difficult and expensive. Remote sensing technologies with good spatial and temporal coverage might provide an alternative for monitoring oil pollution by recording the spectral signals of plants growing in polluted soils. Total petroleum hydrocarbon concentrations of soils and the hyperspectral canopy reflectance were measured in wetlands dominated by reeds (Phragmites australis around oil wells that have been producing oil for approximately 10 years in the Yellow River Delta, eastern China to evaluate the potential of vegetation indices and red edge parameters to estimate soil oil pollution. The detrimental effect of oil pollution on reed communities was confirmed by the evidence that the aboveground biomass decreased from 1076.5 g m(-2 to 5.3 g m(-2 with increasing total petroleum hydrocarbon concentrations ranging from 9.45 mg kg(-1 to 652 mg kg(-1. The modified chlorophyll absorption ratio index (MCARI best estimated soil TPH concentration among 20 vegetation indices. The linear model involving MCARI had the highest coefficient of determination (R(2 = 0.73 and accuracy of prediction (RMSE = 104.2 mg kg(-1. For other vegetation indices and red edge parameters, the R(2 and RMSE values ranged from 0.64 to 0.71 and from 120.2 mg kg(-1 to 106.8 mg kg(-1 respectively. The traditional broadband normalized difference vegetation index (NDVI, one of the broadband multispectral vegetation indices (BMVIs, produced a prediction (R(2 = 0.70 and RMSE = 110.1 mg kg(-1 similar to that of MCARI. These results corroborated the potential of remote sensing for assessing soil oil pollution in large areas. Traditional BMVIs are still of great value in monitoring soil oil pollution when hyperspectral data are unavailable.

  5. Accumulation of oil and grease in soils irrigated with greywater and their potential role in soil water repellency.

    Travis, Micheal J; Weisbrod, Noam; Gross, Amit


    The potential impact of oil and grease (O and G) to soils irrigated with greywater (GW) was investigated. Greywater streams were sampled and analyzed for O and G content, along with corresponding GW-irrigated soils. Untreated kitchen GW averaged 200 mg L(-1) O and G, over an order of magnitude more than other GW streams. GW-irrigated soils showed O and G accumulation of up to 200 mg kg(-l) within the first 20-cm of depth. To determine the potential effects of such O and G accumulation on water movement in soil, capillary rise and water drop penetration time (WDPT) experiments were conducted. The results showed up to 60% decrease in capillary rise when sand containing 250 mg kg(-1) O and G was used. Interestingly, no additional reduction in capillary rise was observed at concentrations above 250 mg kg(-1). WDPT was observed to increase linearly with increased O and G content, up to 1000 mg kg(-1). This work demonstrated that O and G in GW used for irrigation can accumulate in soil and may lead to a significant reduction in the soils ability to transmit water.

  6. [Effects of crop rotation and bio-organic manure on soil microbial characteristics of Chrysanthemum cropping system].

    Xiao, Xin; Zhu, Wei; Du, Chao; Shi, Ya-dong; Wang, Jian-fei


    We conducted a field experiment to evaluate the effects of rotation system and bio-organic manure on soil microbial characteristics of Chrysanthemum cropping system. Taking Chrysanthemum morifolium Ramat and wheat as experimental plants, treatments under Chrysanthemum continuous cropping system (M1), conventional Chrysanthemum-wheat rotation system (M2), and Chrysanthemum-wheat rotation system receiving bio-organic manure application of 200 kg · 667 m(-2) (M3) were designed. Soil chemical properties, soil microbial biomass carbon (MBC) and nitrogen (MBN), and the amounts of different types of soil microorganisms were determined. Results showed that compared with M1, treatments of M2 and M3 significantly increased soil pH, organic matter, available N, P, and K, MBC, MBN, and the amounts of bacteria, fungi and actinomycetes, but decreased the ratio of MBC/MBN, and the relative percentage of fungi in the total amount of microorganisms. Treatment of M3 had the highest contents of soil organic matter, available N, available P, available K, MBC, MBN, and the amounts of bacteria, fungi and actinomycetes, with the values being 15.62 g · kg(-1), 64.75 mg · kg(-1), 83.26 mg · kg(-1), 96.72 mg · kg(-1), 217.40 mg · kg(-1), 38.41 mg · kg(-1), 22.31 x 10(6) cfu · g(-1), 56.36 x 10(3) cfu · g(-1), 15.90 x 10(5) cfu · g(-1), respectively. We concluded that rational crop rotation and bio-organic manure application could weaken soil acidification, improve soil fertility and microbial community structure, increase the efficiency of nutrition supply, and have a positive effect on reducing the obstacles of continuous cropping.

  7. Changes in the chemical composition of an acidic soil treated with marble quarry and marble cutting wastes.

    Tozsin, Gulsen; Oztas, Taskin; Arol, Ali Ihsan; Kalkan, Ekrem


    Soil acidity greatly affects the availability of plant nutrients. The level of soil acidity can be adjusted by treating the soil with certain additives. The objective of this study was to determine the effect of marble quarry waste (MQW) and marble cutting waste (MCW) on the chemical composition and the acidity of a soil. Marble wastes at different rates were applied to an acid soil. Their effectiveness in neutralizing the soil pH was compared with that of agricultural lime. The changes in the chemical composition of the soil were also evaluated with column test at the end of a 75-day incubation period. The results indicated that the MQW and MCW applications significantly increased the soil pH (from 4.71 up to 6.54), the CaCO3 content (from 0.33% up to 0.75%), and the exchangeable Ca (from 14.79 cmol kg(-1) up to 21.18 cmol kg(-1)) and Na (from 0.57 cmol kg(-1) up to 1.07 cmol kg(-1)) contents, but decreased the exchangeable K (from 0.46 cmol kg(-1) down to 0.28 cmol kg(-1)), the plant-available P (from 25.56 mg L(-1) down to 16.62 mg L(-1)), and the extractable Fe (from 259.43 mg L(-1) down to 55.4 mg L(-1)), Cu (from 1.97 mg L(-1) down to 1.42 mg L(-1)), Mn (from 17.89 mg L(-1) down to 4.61 mg L(-1)) and Zn (from 7.88 mg L(-1) down to 1.56 mg L(-1)) contents. In addition, the Cd (from 0.060 mg L(-1) down to 0.046 mg L(-1)), Ni (from 0.337 mg L(-1) down to 0.092 mg L(-1)) and Pb (from 28.00 mg L(-1) down to 20.08 mg L(-1)) concentrations decreased upon the treatment of the soil with marble wastes.

  8. Long-term efficacy of single-dose treatment with 400 of ivermectin in bancroftian filariasis: results at one year.

    Moulia-Pelat, J P; Glaziou, P; Nguyen, L N; Chanteau, S; Martin, P M; Cartel, J L


    In April 1992, a safety trial was performed with a single dose of ivermectin 400 (IVER 400). In 37 bancroftian filariasis carriers, 6 and 12 months after IVER 400 treatment, the microfilaremia recurrences were 3.2% and 13.5%, respectively. As compared to results from other studies with diethylcarbamazine and IVER at different dosages and periodicities, the dosage of IVER 400 seems the most effective; but a yearly intake might not be sufficient.

  9. Zinc Regime in the Sewage Sludge-Soil-Plant System of a City Waste Water Treatment Pond

    Lacatusu Radu


    Full Text Available The sewage sludge from wastewater treatment plant of Iasi, a city with 300,000 inhabitants, for domestic and industrial origin, was stored in a mud pond arranged on an area of 18,920 m2. Chemical analyzes of the sludge showed that, of all the chemical elements determined, only Zn is found at pollutant level (5739 mg∙kg-1, i.e. almost 30 times more than the maximum allowable limit for Zn in soil and 45 times more than the Zn content of the soil on which the mud pond has been set. Over time, the content of Zn in the mud pond, but also from soil to which it has been placed, has become upper the normal content of the surrounding soil up to a depth of 260 cm. On the other hand, the vegetation installed on sewage sludge in the process of mineralization, composed predominantly of Phragmites, Rumex, Chenopodium, and Aster species had accumulated in roots, stems and leaves Zn quantities equivalent to 1463 mg Kg-1, 3988 mg Kg-1, 1463 mg Kg-1, respectively, 1120 mg∙Kg-1. The plants in question represents the natural means of phytoremediation, and sewage sludge as such may constitute a fertilizer material for soils in the area, on which Zn deficiency in maize has been recorded. In addition, the ash resulted from the incineration of plants loaded with zinc may constitute, in its turn, a good material for fertilizing of the soils that are deficient in zinc.

  10. Distribution of potentially toxic elements (PTEs) in tailings, soils, and plants around Gol-E-Gohar iron mine, a case study in Iran.

    Soltani, Naghmeh; Keshavarzi, Behnam; Moore, Farid; Sorooshian, Armin; Ahmadi, Mohamad Reza


    This study investigated the concentration of potentially toxic elements (PTEs) including Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, V, and Zn in 102 soils (in the Near and Far areas of the mine), 7 tailings, and 60 plant samples (shoots and roots of Artemisia sieberi and Zygophylum species) collected at the Gol-E-Gohar iron ore mine in Iran. The elemental concentrations in tailings and soil samples (in Near and Far areas) varied between 7.4 and 35.8 mg kg(-1) for As (with a mean of 25.39 mg kg(-1) for tailings), 7.9 and 261.5 mg kg(-1) (mean 189.83 mg kg(-1) for tailings) for Co, 17.7 and 885.03 mg kg(-1) (mean 472.77 mg kg(-1) for tailings) for Cu, 12,500 and 400,000 mg kg(-1) (mean 120,642.86 mg kg(-1) for tailings) for Fe, and 28.1 and 278.1 mg kg(-1) (mean 150.29 mg kg(-1) for tailings) for Ni. A number of physicochemical parameters and pollution index for soils were determined around the mine. Sequential extractions of tailings and soil samples indicated that Fe, Cr, and Co were the least mobile and that Mn, Zn, Cu, and As were potentially available for plants uptake. Similar to soil, the concentration of Al, As, Co, Cr, Cu, Fe, Mn, Mo, Ni, and Zn in plant samples decreased with the distance from the mining/processing areas. Data on plants showed that metal concentrations in shoots usually exceeded those in roots and varied significantly between the two investigated species (Artemisia sieberi > Zygophylum). All the reported results suggest that the soil and plants near the iron ore mine are contaminated with PTEs and that they can be potentially dispersed in the environment via aerosol transport and deposition.

  11. Accumulation and residue of napropamide in alfalfa (Medicago sativa) and soil involved in toxic response.

    Cui, Li E; Yang, Hong


    Napropamide belongs to the amide herbicide family and widely used to control weeds in farmland. Intensive use of the herbicide has resulted in widespread contamination to ecosystems. The present study demonstrated an analysis on accumulation of the toxic pesticide napropamide in six genotypes of alfalfa (Medicago sativa), along with biological parameters and its residues in soils. Soil was treated with napropamide at 3 mg kg(-1) dry soil and alfalfa plants were cultured for 10 or 30 d, respectively. The maximum value for napropamide accumulation is 0.426 mg kg(-1) in shoots and 2.444 mg kg(-1) in roots. The napropamide-contaminated soil with alfalfa cultivation had much lower napropamide concentrations than the control (soil without alfalfa cultivation). Also, the content of napropamide residue in the rhizosphere was significantly lower than that in the non-rhizosphere soil. M. sativa exposed to 3 mg kg(-1) napropamide showed inhibited growth. Further analysis revealed that plants treated with napropamide accumulated more reactive oxygen species (O(2)(-) and H(2)O(2)) and less amounts of chlorophyll. However, not all cultivars showed oxidative injury, suggesting that the alfalfa cultivars display different tolerance to napropamide. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Phytoremediation for co-contaminated soils of chromium and benzo[a]pyrene using Zea mays L.

    Chigbo, Chibuike; Batty, Lesley


    A greenhouse experiment was carried out to investigate the single effect of benzo[a]pyrene (B[a]P) or chromium (Cr) and the joint effect of Cr-B[a]P on the growth of Zea mays, its uptake and accumulation of Cr, and the dissipation of B[a]P over 60 days. Results showed that single or joint contamination of Cr and B[a]P did not affect the plant growth relative to control treatments. However, the occurrence of B[a]P had an enhancing effect on the accumulation and translocation of Cr. The accumulation of Cr in shoot of plant significantly increased by ≥ 79 % in 50 mg kg(-1) Cr-B[a]P (1, 5, and 10 mg kg(-1)) treatments and by ≥ 86 % in 100 mg kg(-1) Cr-B[a]P (1, 5, and 10 mg kg(-1)) treatments relative to control treatments. The presence of plants did not enhance the dissipation of B[a]P in lower (1and 5 mg kg(-1)) B[a]P contaminated soils; however, over 60 days of planting Z. mays seemed to enhance the dissipation of B[a]P by over 60 % in 10 mg kg(-1) single contaminated soil and by 28 to 41 % in 10 mg kg(-1)B[a]P co-contaminated soil. This suggests that Z. mays might be a useful plant for the remediation of Cr-B[a]P co-contaminated soil.

  13. Heavy metals bioconcentration from soil to vegetables and assessment of health risk caused by their ingestion.

    Garg, V K; Yadav, Poonam; Mor, Suman; Singh, Balvinder; Pulhani, Vandana


    The present study was undertaken to assess the non-carcinogenic human health risk of heavy metals through the ingestion of locally grown and commonly used vegetables viz. Raphanus sativus (root vegetable), Daucus carota (root vegetable), Benincasa hispida (fruit vegetable) and Brassica campestris leaves (leafy vegetable) in a semi-urbanized area of Haryana state, India. Heavy metal quantification of soil and vegetable samples was done using flame atomic absorption spectrophotometer. Lead, cadmium and nickel concentration in vegetable samples varied in range of 0.12-6.54 mg kg(-1), 0.02-0.67 mg kg(-1) and vegetable samples exceeded maximum permissible limit given by World Health Organization/Food and Agriculture Organization and Indian standards. Much higher concentrations of Pb (40-190.5 mg kg(-1)), Cd (0.56-9.85 mg kg(-1)) and Ni (3.21-45.87 mg kg(-1)) were reported in corresponding vegetable fields' soils. Correlation analysis revealed the formation of three primary clusters, i.e. Cu-Cd, Cd-Pb and Ni-Zn in vegetable fields' soils further supported by cluster analysis and principal component analysis. Bioconcentration factor revealed that heavy metals' uptake was more by leafy vegetable than root and fruit vegetables. Hazard index of all the vegetables was less than unity; thus, the ingestion of these vegetables is unlikely to pose health risks to the target population.

  14. Comparison of plant nutrient and environmental soil tests to predict Pb in urban soils.

    Minca, Kristen Kathleen; Basta, Nicholas Thomas


    Most urban soils are not tested for Pb because of the high costs associated with sampling and laboratory analysis of soil contaminants. However, soil testing for plant nutrients is inexpensive and routinely performed for agricultural soils used for food production. The objectives of this study are to determine the ability of 1 M HNO(3), Mehlich 3, and Modified Morgan soil tests to predict total Pb and other contaminants in urban soils. Total Pb was determined from 65 urban vacant residential lots being considered for urban gardens and food production in Cleveland, OH. Extractable Pb was determined using common soil nutrient test methods Mehlich 3 and Modified Morgan extraction, and a 1M HNO(3) extraction. Significant linear regressions between total Pb and Mehlich 3 (r(2)=0.83), 1M HNO(3) (r(2)=0.92), and Modified Morgan (r(2)=0.77) in study soils were found. Most commercial and university soil testing labs use Mehlich 3 which could be implemented as a screening tool for soil Pb, Cu, and Zn. The Mehlich 3 soil test is widely used and is relatively inexpensive (<$15). Our results show that total Pb can be conservatively estimated by the following equation Total Pb (mg kg(-1))=Mehlich 3 Pb (mg kg(-1))×2. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. [Soil fertility characteristics under different land use patterns in depressions between karst hills].

    Liu, Yan; Song, Tong-Qing; Cai, De-Suo; Zeng, Fu-Ping; Peng, Wan-Xia; Du, Hu


    Soil samples were collected from the depressions between karst hills by grid sampling method (5 m x 5 m), soil pH, soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) in surface layer (0-20 cm) under different land use patterns (burning, cutting, cutting plus root removal, enclosure, maize plantation, and pasture plantation) were measured, the main factors of influencing the soil fertility was identified by principal component analysis (PCA), and the relationships between soil nutrients and microorganisms were demonstrated by canonical correlation analysis (CCA). The results showed that the soil was slightly alkaline (pH 7.83-7.98), and the soil fertility differed under the different land use patterns, with 76.78-116.05 g x kg(-1) of SOC, 4.29-6.23 g x kg(-1) of TN, 1.15-1.47 g x kg(-1) of TP, 3.59-6.05 g x kg(-1) of TK, 331.49-505.49 mg x kg(-1) of AN), 3.92-10.91 mg x kg(-1) of AP, and 136.28-198.10 mg x kg(-1) of AK. These soil indexes except pH showed moderate or strong variation. Different land use patterns had various impacts on soil fertility: Soil nutrients such as SOC, TN, TP, and AN were most significantly influenced by land use patterns in the depressions between karst hills; Followed by soil microorganisms, especially soil actinomycetes, and the effect decreased with the increasing gradient of human disturbance from enclosure, burning, cutting, cutting plus root removal, pasture plantation, and maize plantation. CCA elucidated that considerable interactions existed in soil TP with MBP (microbial biomass phosphorus), TK with MBC (microbial biomass carbon), TN with actinomycetes in the burned area, while TN and MBC in the cutting treatment, AP and MBN (microbial biomass nitrogen) in the treatment of cutting plus root removal, pH with MBC and fungus in the enclosure treatment, TN and TK with MBP in the maize plantation, pH with fungi

  16. Vetiver grass is capable of removing TNT from soil in the presence of urea.

    Das, Padmini; Datta, Rupali; Makris, Konstantinos C; Sarkar, Dibyendu


    The high affinity of vetiver grass for 2,4,6 trinitrotoluene (TNT) and the catalytic effectiveness of urea in enhancing plant uptake of TNT in hydroponic media we earlier demonstrated were further illustrated in this soil-pot-experiment. Complete removal of TNT in urea-treated soil was accomplished by vetiver at the low initial soil-TNT concentration (40 mg kg(-1)), masking the effect of urea. Doubling the initial TNT concentration (80 mg kg(-1)) significantly (pvetiver, in the presence of urea. Without vetiver grass, no significant (p=0.475) change in the soil-TNT concentrations was observed over a period of 48 days, suggesting that natural attenuation of soil TNT could not explain the documented TNT disappearance from soil. Copyright 2009 Elsevier Ltd. All rights reserved.

  17. Transfer of cadmium from soil to vegetable in the Pearl River Delta area, South China.

    Zhang, Huihua; Chen, Junjian; Zhu, Li; Yang, Guoyi; Li, Dingqiang


    The purpose of this study was to investigate the regional Cadmium (Cd) concentration levels in soils and in leaf vegetables across the Pearl River Delta (PRD) area; and reveal the transfer characteristics of Cadmium (Cd) from soils to leaf vegetable species on a regional scale. 170 paired vegetables and corresponding surface soil samples in the study area were collected for calculating the transfer factors of Cadmium (Cd) from soils to vegetables. This investigation revealed that in the study area Cd concentration in soils was lower (mean value 0.158 mg kg(-1)) compared with other countries or regions. The Cd-contaminated areas are mainly located in west areas of the Pearl River Delta. Cd concentrations in all vegetables were lower than the national standard of Safe vegetables (0.2 mg kg(-1)). 88% of vegetable samples met the standard of No-Polluted vegetables (0.05 mg kg(-1)). The Cd concentration in vegetables was mainly influenced by the interactions of total Cd concentration in soils, soil pH and vegetable species. The fit lines of soil-to-plant transfer factors and total Cd concentration in soils for various vegetable species were best described by the exponential equation (y = ax(b)), and these fit lines can be divided into two parts, including the sharply decrease part with a large error range, and the slowly decrease part with a low error range, according to the gradual increasing of total Cd concentrations in soils.

  18. Transfer of cadmium from soil to vegetable in the Pearl River Delta area, South China.

    Huihua Zhang

    Full Text Available The purpose of this study was to investigate the regional Cadmium (Cd concentration levels in soils and in leaf vegetables across the Pearl River Delta (PRD area; and reveal the transfer characteristics of Cadmium (Cd from soils to leaf vegetable species on a regional scale. 170 paired vegetables and corresponding surface soil samples in the study area were collected for calculating the transfer factors of Cadmium (Cd from soils to vegetables. This investigation revealed that in the study area Cd concentration in soils was lower (mean value 0.158 mg kg(-1 compared with other countries or regions. The Cd-contaminated areas are mainly located in west areas of the Pearl River Delta. Cd concentrations in all vegetables were lower than the national standard of Safe vegetables (0.2 mg kg(-1. 88% of vegetable samples met the standard of No-Polluted vegetables (0.05 mg kg(-1. The Cd concentration in vegetables was mainly influenced by the interactions of total Cd concentration in soils, soil pH and vegetable species. The fit lines of soil-to-plant transfer factors and total Cd concentration in soils for various vegetable species were best described by the exponential equation (y = ax(b, and these fit lines can be divided into two parts, including the sharply decrease part with a large error range, and the slowly decrease part with a low error range, according to the gradual increasing of total Cd concentrations in soils.

  19. Modeling spatial patterns in soil arsenic to estimate natural baseline concentrations

    Venteris, Erik R.; Basta, Nicolas T.; Bigham, Jerry M.; Rea, Ron


    ABSTRACT Arsenic in soil is an important public health concern. Toxicity guidelines and models based on laboratory studies (i.e., U.S. EPA’s Integrated Risk Information System) should consider natural soil As concentrations to avoid unnecessary remediation burdens on society. We used soil and stream sediment samples from the USGS National Geochemical Survey database to assess the spatial distribution of natural As in a 1.16E+5 km2 area. Samples were collected at 348 soil and 144 stream locations, providing approximately one sample for every 290 km2. Sample sites were selected to minimize the potential influence of anthropogenic inputs. Samples were processed using acid digestion of whole samples (concentrated HCl and ascorbic acid) and concentrations were measured using hydride-generation atomic absorption spectrometry. Soil As ranged from 2.0 to 45.6 mg kg-1. Geostatistical techniques were used to model and map the spatial variability of As. The mean and variance at unsampled locations were estimated using sequential Gaussian simulation. Five areas of elevated concentration (> the median of 10 mg kg-1) were identified and the relationships to geologic parent materials, glacial sedimentation patterns, and soil conditions interpreted. Our results showed As concentrations >10 mg kg-1 were common, and >20 mg kg-1 were not unusual for the central and west central portions of Ohio (USA). In contrast, concentrations <4 mg kg-1 were rare. Measured concentrations typically exceeded the soil As human generic screening levels of 0.39 mg/kg (1); the calculated value that corresponds to a cancer risk level of 1 in 1,000,000 for soil ingestion. Because the As content of Ohio soils is similar to many world soils, the USEPA generic soil screening level of 0.39 mg/kg is of little utility. A more useful and practical approach would be the uses of natural background levels. Regional soil As patterns based on geology and biogeochemistry and not political boundaries should be used

  20. Metal extraction by Alyssum serpyllifolium ssp. lusitanicum on mine-spoil soils from Spain.

    Kidd, P S; Monterroso, C


    The efficiency of Alyssum serpyllifolium ssp. lusitanicum (Brassicaceae) for use in phytoextraction of polymetallic contaminated soils was evaluated. A. serpyllifolium was grown on two mine-spoil soils (MS1 and MS2): MS1 is contaminated with Cr (283 mg kg(-1)) and MS2 is moderately contaminated with Cr (263 mg kg(-1)), Cu (264 mg kg(-1)), Pb (1433 mg kg(-1)) and Zn (377 mg kg(-1)). Soils were limed to about pH 6.0 (MS1/Ca and MS2/Ca) or limed and amended with NPK fertilisers (MS1/NPK and MS2/NPK). Biomass was reduced on MS2/Ca due to Cu phytotoxicity. Fertilisation increased biomass by 10-fold on MS1/NPK, but root growth was reduced by 7-fold compared with MS1/Ca. Plants accumulated Mn, Ni and Zn in shoots, and both metal content and transportation were generally greater in MS2 than in MS1. Zinc bioaccumulation factors (BF, shoot([metal])/soil([metal])) were significantly greater in MS2 than in MS1. However, metal yields were greatest in plants grown on MS1/NPK. Concentrations of EDTA-, NH(4)Cl- and Mehlich 3 (M3)-extractable Mn and Zn were greater after plant growth. Concentrations of M3-extractable Cr, Ni, Pb and Zn were increased at the rhizosphere. Sequential extractions showed changes in the metal distribution among different soil fractions after growth. This could reflect the buffering capacity of these soils or the plants' ability to mobilise metals from less plant-available soil pools. Results suggest that A. serpyllifolium could be suitable for phytoextraction uses in polymetallic-contaminated soils, provided Cu concentrations were not phytotoxic. However, further optimisation of growth and metal extraction are required.

  1. Níveis adequados e tóxicos de zinco na produção de arroz, feijão, milho, soja e trigo em solo de cerrado Adequate and toxic levels of zinc for rice, common bean, corn, soybean and wheat production in cerrado soil

    Nand Kumar Fageria


    Full Text Available Foram conduzidos cinco experimentos em casa de vegetação, para determinação das doses e dos teores adequados e tóxicos de Zn no solo e na planta para as culturas de arroz de terras altas, feijão, milho, soja e trigo. Os tratamentos com Zn foram de 0, 5, 10, 20, 40, 80 e 120 mg de Zn kg-1 de solo. Considerando 90% da produção relativa de matéria seca como parâmetro de determinação das dosagens adequadas de Zn no solo e na planta, recomenda-se para arroz, feijão, milho, soja e trigo aplicação de 10, 1, 3, 2 e 1 mg de Zn kg-1 de solo, respectivamente. Os níveis tóxicos de Zn no solo obtidos com base na redução de 10% na produção foram de 70, 57, 110, 59 e 40 mg Zn kg-1 de solo, respectivamente para arroz, feijão, milho, soja e trigo e conforme a análise do solo pelo extrator Mehlich 1, os níveis adequados de Zn no solo para as citadas culturas foram de 5, 0,7, 2, 0,8 e 0,5 mg Zn kg-1, respectivamente. Pelo extrator DTPA, os níveis adequados de Zn no solo foram de 4 mg kg-1 para o arroz, 1 mg kg-1 para o milho e de 0,3 mg kg-1 para soja, feijão e trigo. A toxidez de zinco no solo com Extrator Mehlich 1 variou de 25 a 94 mg Zn kg-1 e, com extrator DTPA, de 25 a 60 mg Zn kg-1, dependendo da cultura. Os níveis adequados na planta variaram de 18 a 67 mg Zn kg-1 e os tóxicos variaram de 100 a 673 mg Zn kg-1, dependendo da cultura.Five greenhouse experiments were conducted to determine adequate and toxic levels of zinc in upland rice, common bean, corn, soybean, and wheat. The Zn treatments were 0, 5, 10, 20, 40, 80, and 120 mg Zn kg-1 of soil. Relative dry matter yield of 90% was used as a parameter to define the adequate level of Zn applied or the Zn content in the soil and Zn in the plant tissues. Similarly, a 10% reduction in relative dry matter yield was used as a criterion for defining toxic levels in the soil as well as in the plants. An adequate level of applied Zn was 10 mg kg-1 for rice, 1 mg kg-1 for common bean, 3

  2. Soil Phosphorus status in Chinese greenhouse vegetable production system

    Kianpoor Kalkhajeh, Yusef

    Rapid expansion of greenhouse vegetable production (GVP) in China within the last three decades has been accompanied with intensive application of chemical and manure fertilizers, frequent irrigation, and year-round crop rotation. As a consequence, excessive P accumulation and availability have...... to the surrounding below threshold values Overall, very high P contents were measured in 75 representative Chinese GVP top soils (0-20 cm) with total P and Olsen P varying from 260 to 11,200 mg kg-1, and 5 to 740 mg kg-1, respectively. These large variations reflect the significant differences in vegetation history...

  3. Growth and Cadmium Phytoextraction by Swiss Chard, Maize, Rice, Noccaea caerulescens, and Alyssum murale in Ph Adjusted Biosolids Amended Soils.

    Broadhurst, C Leigh; Chaney, Rufus L; Davis, Allen P; Cox, Albert; Kumar, Kuldip; Reeves, Roger D; Green, Carrie E


    Past applications of biosolids to soils at some locations added higher Cd levels than presently permitted. Cadmium phytoextraction would alleviate current land use constraints. Unamended farm soil, and biosolids amended farm and mine soils were obtained from a Fulton Co., IL biosolids management facility. Soils contained 0.16, 22.8, 45.3 mg Cd kg(-1) and 43.1, 482, 812 mg Zn kg(-1) respectively with initial pH 6.0, 6.1, 6.4. In greenhouse studies, Swiss chard (Beta vulgaris var. cicla), a Cd-accumulator maize (inbred B37 Zea mays) and a southern France Cd-hyperaccumulator genotype of Noccaea caerulescens were tested for Cd accumulation and phytoextraction. Soil pH was adjusted from ∼5.5-7.0. Additionally 100 rice (Oryza sativa) genotypes and the Ni-hyperaccumulator Alyssum murale were screened for potential phytoextraction use. Chard suffered phytotoxicity at low pH and accumulated up to 90 mg Cd kg(-1) on the biosolids amended mine soil. The maize inbred accumulated up to 45 mg Cd kg(-1) with only mild phytotoxicity symptoms during early growth at pH>6.0. N. caerulescens did not exhibit phytotoxicity symptoms at any pH, and accumulated up to 235 mg Cd kg(-1) in 3 months. Reharvested N. caerulescens accumulated up to 900 mg Cd kg(-1) after 10 months. Neither Alyssum nor 90% of rice genotypes survived acceptably. Both N. caerulescens and B37 maize show promise for Cd phytoextraction in IL and require field evaluation; both plants could be utilized for nearly continuous Cd removal. Other maize inbreds may offer higher Cd phytoextraction at lower pH, and mono-cross hybrids higher shoot biomass yields. Further, maize grown only for biomass Cd maximum removal could be double-cropped.

  4. Metais pesados, agrotóxicos e combustíveis: efeito na população de colêmbolos no solo Heavy metal, pesticides and fuels: effect in the population of collembola in the soil

    Zaida Inês Antoniolli


    Full Text Available O objetivo deste trabalho foi avaliar o desenvolvimento de colêmbolos no solo com diferentes níveis de metais pesados, combustíveis e agrotóxicos em condição de laboratório. Os tratamentos foram: Cádmio (1, 10 e 100mg kg-1 de solo; Cobre (50, 500 e 5000mg kg-1 de solo; Zinco (100, 1000 e 10000mg kg-1 de solo; fungicida epoxiconazol + piraclostrobina (1 e 2L ha-1; fungicida epoxiconazol (0,75 e 1,5L ha-1; herbicida glifosato (2 e 4L ha-1; óleo lubrificante queimado (5, 50 e 100mL kg-1 solo e óleo diesel (5, 50 e 100mL kg-1 solo e controle. Na dose de 1mg kg-1 de Cd no solo, houve grande aumento na população de colêmbolos e o pH do solo diminuiu à medida que aumentaram as doses de Cd, Zn e Cu no solo. Na presença de combustíveis, os colêmbolos apresentaram incapacidade de reprodução, independente da dose aplicada no solo. O número de colêmbolos apresentou incremento com o aumento da dosagem de glifosato e epoxiconazol. Os metais pesados Cu e Zn têm ação negativa sobre a população de colêmbolos e somente o Cd (1mg kg-1 solo proporciona aumento na população de colêmbolos no solo. A presença de óleo lubrificante queimado e óleo diesel no solo inibem o desenvolvimento dos colêmbolos no solo. Os agrotóxicos glifosato, epoxiconazol e epoxiconazol + piraclostrobina não influenciam negativamente sobre a população de colêmbolos no solo.The aim of this research was to evaluate the collembola development in soils with different levels of heavy metals, fuels and pesticides, in laboratory conditions. Treatments were: Cadmium - 1, 10 and 100mg kg-1 soil; Copper - 50, 500 and 5000mg kg-1 soil; Zinc - 100, 1000 and 10000 mg kg-1 soil; fungicide epoxiconazol + piraclostrobina - 1 and 2L ha-1; fungicide epoxiconazol - 0,75 and 1,5L ha-1; herbicide glyphosate - 2 and 4L ha-1; burned lubricating oil - 5, 50 and 100mL kg-1 soil and diesel oil - 5, 50 and 100mL kg-1 soil and control. In the 1mg kg-1 dose of Cd there was a great

  5. Copper and Zinc Enrichment in Different Size Fractions of Organic Matter from Polluted Soils

    ZHANG Ming-Kui; KE Zi-Xia


    Bioavailability of heavy metals in soil organic matter depends on its components. Characterization of heavy metal distributions in different fractions of soil organic matter is needed for better understanding of the fate of heavy metals. This study investigated the accumulation and partitioning of copper and zinc among different size particulate organic matter (POM) fractions in polluted soils from a former iron ore processing site in western Shaoxing County, Zhejiang Province. Physical fractionations were carried out to separate soil primary particles according to their size and density. Copper and Zn had a heterogeneous distribution among soil particle fractions. Copper and Zn were significantly (p < 0.05) enriched in the POM fractions. > 0.05 mm POM and < 0.05 mm fine soil fractions were mainly responsible for Cu and Zn retention in soils. The POM fraction contained up to 1 322 mg Cu kg-1 and 1 115 mg Zn kg-1 and the fine soil fraction contained up to 422 mg Cu kg-1 and 537 mg Zn kg-1. The total POM fraction was responsible for 15.8%-41.2% and 12.2%-31.7% of the total amount of Cu and Zn, respectively, in the polluted soils. The percentages of Cu and Zn associated with organic matter in < 0.05 mm fine soil fractions for the polluted soils ranged from 14.1% to 24.5%, and 5.4% to 15.8%, respectively. Accumulation of soil organic matter could increase enrichment of Gu (or Zn) in the POM fractions. Also, Cu provided a greater enrichment in the POM fractions than Zn.

  6. Risk assessment of Cd polluted paddy soils in the industrial and township areas in Hunan, Southern China.

    Wang, Meie; Chen, Weiping; Peng, Chi


    Cadmium (Cd) contamination in rice in Youxian, Hunan, China is a major environmental health concern. In order to reveal the Cd contamination in rice and paddy soils and the health risks to the population consuming the local rice grain, field surveys were conducted in eight towns in Youxian, China. The Cd contents of paddy soils averaged 0.228-1.91 mg kg(-1), 90% exceeding the allowable limit of 0.3 mg kg(-1) stipulated by the China Soil Environmental Quality Standards. Low average pH values (for air dried oxidized soils) ranging from 4.98 to 6.02 in paddy soil were also found. More than seventy percent (39 of 53) of the grain samples exceeded the maximum safe concentration of Cd, 0.2 mg kg(-1) on a dry weight basis. Considering the high consumption of local rice (339 g capita(-1) DW d(-1)) and Cd levels measured, dietary ingestion of 78% of the sampled rice grains would have adverse health risks because the intake exposure of Cd was greater than the JECFA recommended exposures, 0.8 µg Cd BW kg(-1) day(-1) or 25 µg Cd BW kg(-1) month(-1).

  7. Cadmium background concentrations to establish reference quality values for soils of São Paulo State, Brazil.

    de Oliveira, Vinicius Henrique; de Abreu, Cleide Aparecida; Coelho, Ricardo Marques; Melo, Leônidas Carrijo Azevedo


    Proper assessment of soil cadmium (Cd) concentrations is essential to establish legislative limits. The present study aimed to assess background Cd concentrations in soils from the state of São Paulo, Brazil, and to correlate such concentrations with several soil attributes. The topsoil samples (n = 191) were assessed for total Cd contents and for other metals using the USEPA 3051A method. The background concentration was determined according to the third quartile (75th). Principal component analysis, Spearman correlation, and multiple regressions between Cd contents and other soil attributes (pH, cation exchange capacity (CEC), clay content, sum of bases, organic matter, and total Fe, Al, Zn, and Pb levels) were performed. The mean Cd concentration of all 191 samples was 0.4 mg kg(-1), and the background concentration was 0.5 mg kg(-1). After the samples were grouped by parent material (rock origin) and soil type, the background Cd content varied, i.e., soils from igneous, metamorphic, and sedimentary rocks harbored 1.5, 0.4, and 0.2 mg kg(-1) of Cd, respectively. The background Cd content in Oxisols (0.8 mg kg(-1)) was higher than in Ultisols (0.3 mg kg(-1)). Multiple regression demonstrated that Fe was primarily attributed to the natural Cd contents in the soils (R (2) = 0.79). Instead of a single Cd background concentration value representing all São Paulo soils, we propose that the concentrations should be specific for at least Oxisols and Ultisols, which are the primary soil types.

  8. White clover nodulation index in heavy metal contaminated soils- a potential bioindicator.

    Manier, Nicolas; Deram, Annabelle; Broos, Kris; Denayer, Franck-Olivier; Van Haluwyn, Chantal


    The morphological effects of heavy metal stress on the nodulation ability of Rhizobium spp. and growth of white clover (Trifolium repens L.) were studied in the laboratory under controlled conditions. Fourteen topsoils were collected from an area with elevated metal concentrations (Cd, Zn, and Pb). White clover was cultivated using a specialized "rhizotron" method to observe the development of root and nodule characteristics. Results show effects of increasing heavy metal concentrations on nodulation development, especially the nodulation index (i.e., the number of nodules per gram of the total fresh biomass). A significant decrease in nodulation index was observed at about 2.64 mg Cd kg(-1), 300 mg Zn kg(-1), and 130 mg Pb kg(-1) in these soils. The sensitivity of the nodulation index in relation to other morphological characteristics is discussed further. It is proposed that the nodulation index of white clover is a suitable bioindicator of increased heavy metal concentrations in soil.

  9. Influencia del uso del suelo en su calidad ambiental en medio semiárido (Murcia SE España Soil environmental quality related to different soil uses in a semiarid zone (Murcia SE Spain

    J. A. Hernández


    Full Text Available La agricultura intensiva y las activida­des mineras se encuentran entre las prin­cipales fuentes de contaminación del sue-lo ocasionando con frecuencia la acumu­lación en el mismo de sales solubles, nu­trientes, metales pesados, etc., con la con­siguiente pérdida de calidad del mismo. Este trabajo plantea conocer la situación de los suelos de un área de Murcia (SE España bajo diferentes usos y parcial­mente afectada por residuos mineros. Los resultados apuntan a que los usos conside­rados, provocan una disminución de cali­dad del suelo. Así, hay una mayor presen­cia de sales solubles (Conductividad Eléc­trica: 3,3-1,9 dS m-1, NO3 (126,5-51,1 mg kg-1 y P asimilable (29,6-2,4 mg kg-1 en los suelos cultivados frente a los no cultivados. Además, gran parte de las muestras presentan niveles de metales pe­sados que superan, ampliamente en oca­siones, los valores de referencia maneja­dos habitualmente: Cd: 10,2 mg kg-1; Cu: 85,2 mg kg-1; Mn: 2307,8 mg kg-1; Pb: 6793,0 mg kg-1; Zn: 4610,0 mg kg-1Intensive agriculture and mining activi­ties are among the soil uses that cause soil contamination because of the accumula­tion of soluble salts, nutrients, heavy met­als, etc. and consequently a loss of soil quality. This study set out to assess the condition of some cultivated and unculti­vated soils in an area of Murcia (SE Spain, known to be partially affected by mine acid materials. The results confirm that the cited activities have lead to a loss of soil quality, limiting their future use. Higher soluble salt (Electrolytic Conduc­tivity: 3,3-1,9 dS m-1, NO3 (126,5-51,1 mg kg-1 and available P (29,6-2,4 mg kg­1 concentrations were measured in the cultivated soils. In addition, many of the soil samples studied presented high levels of heavy metals which exceeded the val­ues usually taken as reference values: Cd: 10,2 mg kg-1; Cu: 85,2 mg kg-1; Mn: 2307,8 mg kg-1; Pb: 6793,0 mg kg-1 and Zn: 4610,0 mg kg-1 .

  10. Assessment of the risk of pollution by sulfur compounds and heavy metals in soils located in the proximity of a disused for 20 years sulfur mine (SE Poland).

    Sołek-Podwika, Katarzyna; Ciarkowska, Krystyna; Kaleta, Dorota


    The study assessed the long-term effects of anthropogenic pressure of the sulfur industry on turf-covered soils located in the vicinity of the sulfur mine Grzybów. The study assumes that 20 years which elapsed since the end of the exploitation of sulfur is a period sufficiently long for the content of sulfur compounds in soils not to exceed the permissible level and that soil of the region can be classified as not contaminated. A part of the study involved identification of changes in the contents Stot. and SSO4(2-) in soils collected in the 1970s and early twenty-first century. It was also traced the relationship between the content of sulfur compounds and selected soil properties and estimated risk of soil environment pollution by heavy metals. Mean contents of trace elements studied amounted to 10.2-10.8 mg kg(-1) for Pb, 14.3-39.4 mg kg(-1) for Zn, 0.2-0.4 mg kg(-1) for Cd, 3.8-32.2 mg kg(-1) for Cr, 2.7-15.1 mg kg(-1) for Cu and 2.9-18.7 mg kg(-1) for Ni. Based on the results of SSO4(2-) content in soils collected at a distance of 1 km from the mine, it was found out that despite the passage of years, the amount of this type of sulfur still is increased and exceeds 0.14 g kg(-1). As the distance from the mine grew lower (from 0.017 to 0.03 g kg(-1)) average content of the sulfur form was observed. In the studied soil material we found generally positive, strong correlation between the Stot. and SSO4(2-) content and analyzed trace elements. The degree of contamination of examined soils with heavy metals was estimated on the basis of the integrated pollution index, which pointed to a moderate and low level of antropogenization of this area. In addition, the relationship between the determined characteristics of soils (Corg. contents, the fraction soils do not occur in mobile forms in the soil solution.

  11. Residues and Analysis of Degradation of Novel Fungicide Picoxystrobin in Cucumber and Soil Under Field Conditions

    SUN Yang


    Full Text Available The analytical method for the residues of picoxystrobin in cucumber vegetable and soil matrices was developed and the dissipation of picoxystrobin under field conditions was studied. The limit of detection(LODof picoxystrobin was 3.5×10 -11 g and the limit of quantifica-tion(LOQwas found to be 0.005 mg·kg -1 in cucumber and soil. At three different spiking levels(0.005, 0.05, 0.25 mg·kg -1, mean recoveries and relative standard deviation(RSDfrom fortified samples in five replicated experiments for each matrix were in the range of 68.61%-122.4% and 1.06%-17.2%, respectively. The results showed that the half-lives of picoxystrobin in cucumber and soil from Tianjin City were 5.71 d and 12.9 d, respectively, the half-lives of picoxystrobin in cucumber and soil from Shandong Province were 2.70 d and 10.3 d, respec-tively, and the half-lives of picoxystrobin in cucumber and soil from Jiangsu Province were 9.76 d and 14.9 d, respectively. The maximum residual concentration of picoxystrobin on the 5th day after the last application was 0.014 mg· kg -1, much lower than the Maximum Residue Limits(MRLsfor picoxystrobin in cucumber according to the standards of EU(0.05 mg·kg-1.

  12. 蝎毒多肽对白血病细胞株KG1a干细胞活性的影响%Study on the effects of PESV on the viability of leukemia stem cells line KG1a

    杨向东; 李红玉; 李德冠; 史哲新; 杨文华; 颜田赅; 闫理想; 王兴丽



  13. Lead and cadmium contamination and exposure risk assessment via consumption of vegetables grown in agricultural soils of five-selected regions of Pakistan.

    Rehman, Zahir Ur; Khan, Sardar; Brusseau, Mark L; Shah, Mohammad Tahir


    Rapid urbanization and industrialization result in serious contamination of soil with toxic metals such as lead (Pb) and cadmium (Cd), which can lead to deleterious health impacts in the exposed population. This study aimed to investigate Pb and Cd contamination in agricultural soils and vegetables in five different agricultural sites in Pakistan. The metal transfer from soil-to-plant, average daily intake of metals, and health risk index (HRI) were also characterized. The Pb concentrations for all soils were below the maximum allowable limits (MAL 350 mg kg(-1)) set by State Environmental Protection Administration of China (SEPA), for soils in China, while Cd concentrations in the soils were exceeded the MAL (61.7-73.7% and 4.39-34.3%) set by SEPA (0.6 mg kg(-)), and European Union, (1.5 mg kg(-1)) respectively. The mean Pb concentration in edible parts of vegetables ranged from 1.8 to 11 mg kg(-1). The Pb concentrations for leafy vegetables were higher than the fruiting and pulpy vegetables. The Pb concentrations exceeded the MAL (0.3 mg kg(-1)) for leafy vegetables and the 0.1 mg kg(-1) MAL for fruity and rooty/tuber vegetables set by FAO/WHO-CODEX. Likewise, all vegetables except Pisum sativum (0.12 mg kg(-1)) contained Cd concentrations that exceeded the MAL set by SEPA. The HRI values for Pb and Cd were vegetable species except Luffa acutangula, Solanum lycopersicum, Benincasa hispada, Momordi charantia, Aesculantus malvaceae, Cucumis sativus, Praecitrullus fistulosus, Brassica oleracea, and Colocasia esculanta for children. Based on these results, consumption of these Pb and Cd contaminated vegetables poses a potential health risk to the local consumers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Some properties of longkong growing soils in Songkhla and Narathiwat province and management

    Malee, N.


    Full Text Available The major problems of longkong (Aglaia dookkoo Griff. production in Thailand are poor quality and low quantity of yield, which may be caused by the imbalance or deficiency of essential nutrients in soils.The objective of this study was to investigate soil properties and land suitability for longkong growth in southern Thailand. Ten private longkong orchards in Songkhla and Narathiwat province were selected asthe experimental sites. The soil samples were taken at 2 depths; 0-15 and 15-30 cm, around the middle of the longkong canopy and outer longkong canopy at the pre-flowering period, then analyzed for some importantchemical and physical properties. Results indicated that longkong soils in the study areas were suitable for longkong plantation. However, some study still had limitation on slope factors especially those located onthe low terrace areas. All of the longkong soils (0-30 cm, inner and outer canopy were the extremely acid to slightly acid soil (soil pH = 3.72-6.16; soil: water = 1: 5, with medium soil organic matter level (6.25-30.28 g kg-1 and very low soil electrical conductivity level (0.041-0.081 dS m-1. The inner canopy soils (0-15 cmwere of medium fertility level (237.80 mg kg-1 of available P and 0.23, 2.33, 0.70 and 0.12 cmolc kg-1 of exchangeable K, Ca, Mg and Na, respectively when compared to the medium to low fertility level (26.77 mgkg-1 of available P and 0.13, 1.46, 0.22, and 0.08 cmolc kg-1 of exchangeable K, Ca, Mg and Na, respectively in the outer canopy soils. However, longkong soils contained a large amount of available P.

  15. Hyperaccumulator oilcake manure as an alternative for chelate-induced phytoremediation of heavy metals contaminated alluvial soils.

    Mani, Dinesh; Kumar, Chitranjan; Patel, Niraj Kumar


    The ability of hyperaccumulator oilcake manure as compared to chelates was investigated by growing Calendula officinalis L for phytoremediation of cadmium and lead contaminated alluvial soil. The combinatorial treatment T6 [2.5 g kg(-1) oilcake manure+5 mmol kg(-1) EDDS] caused maximum cadmium accumulation in root, shoot and flower up to 5.46, 4.74 and 1.37 mg kg(-1) and lead accumulation up to 16.11, 13.44 and 3.17 mg kg(-1), respectively at Naini dump site, Allahabad (S3). The treatment showed maximum remediation efficiency for Cd (RR=0.676%) and Pb (RR=0.202%) at Mumfordganj contaminated site (S2). However, the above parameters were also observed at par with the treatment T5 [2.5 g kg(-1) oilcake manure +2 g kg(-1) humic acid]. Applied EDDS altered chlorophyll-a, chlorophyll-b, and carotene contents of plants while application of oilcake manure enhanced their contents in plant by 3.73-8.65%, 5.81-17.65%, and 7.04-17.19%, respectively. The authors conclude that Calendula officinalis L has potential to be safely grown in moderately Cd and Pb-contaminated soils and application of hyperaccumulator oilcake manure boosts the photosynthetic pigments of the plant, leading to enhanced clean-up of the cadmium and lead-contaminated soils. Hence, the hyperaccumulator oilcake manure should be preferred over chelates for sustainable phytoremediation through soil-plant rhizospheric process.

  16. Water and soil pollution in vineyards of central Thailand.

    Joannon, G; Poss, R; Korpraditskul, R; Brunet, D; Boonsook, P


    Very intensive cultivation systems have been developed in the delta of the Chao Phraya River for about a century. The objective of the study was to determine the fate of the fertilisers and pesticides applied to vineyards grown on raised beds. Water samples were collected from the outlet of a vineyard to determine the discharge of pollutants in the canal. The accumulation of elements in the soil was investigated by analysing soil samples from different fields. Fertilisation was estimated at 670 kg N, 300 kg P, and 560 kg K year(-1) ha(-1). Insecticides and fungicides were applied every four days on average, using up to 23 different molecules. Little N and no P were discharged in the canals in solution and discharge in suspension was minor. Pesticides were detected in 36% of the water samples. The topsoil contained 1600 mg kg(-1) Bray II P, 936 mg kg(-1) exchangeable K, 170 mg kg(-1) total Cu, and 167 mg kg(-1) total Zn. Pesticides were detected in 62% of the fruits after peeling. Overuse of fertilisers did not lead to water pollution, but overuse of pesticides resulted in pollution of the water bodies and of the fruits. Most applied elements accumulated in the soil, resulting in high values of P, K, Cu, and Zn.

  17. Dissipation of polycyclic aromatic hydrocarbons from soil added with manure or vermicompost.

    Alvarez-Bernal, D; García-Díaz, E L; Contreras-Ramos, S M; Dendooven, L


    The dissipation of three PAHs, i.e., 500 mg phenanthrene kg(-1) soil, 350 mg anthracene kg(-1) soil and 150 mg benzo(a)pyrene kg(-1) soil, was investigated in soil from Acolman (México) added with cow manure or vermicompost while production of CO(2) and inorganic N was monitored. At day 0, recovery of added phenanthrene was 95%, anthracene 96% and benzo(a)pyrene 100% in sterilized soil and concentrations did not change significantly in sterilized soil over time. Application of organic material did not affect the concentration of phenanthrene and anthracene, which decreased sharply in the unsterilized soil in the first weeks of the incubation. Less than 3% of the added phenanthrene was detected after 100 days and less than 8.5% of the added anthracene (mean of the two experiments). The decrease in concentration of benzo(a)pyrene (BaP) was not fast as that of phenathrene and anthracene, and 22% was extractable from soil still after 100days. It was concluded that addition of farm yard manure (FYM) and vermicompost only had an effect on the initial dissipation of phenanthrene, anthracene and benzo(a)pyrene in soil of Acolman.

  18. Feasibility of diffuse reflectance infrared Fourier spectroscopy (DRIFTS) to quantify iron-cyanide (Fe-CN) complexes in soil

    Sut-Lohmann, Magdalena; Raab, Thomas


    Contaminated sites create a significant risk to human health, by poisoning drinking water, soil, air and as a consequence food. Continuous release of persistent iron-cyanide (Fe-CN) complexes from various industrial sources poses a high hazard to the environment and indicates the necessity to analyze considerable amount of samples. At the present time quantitative determination of Fe-CN concentration in soil usually requires a time consuming two step process: digestion of the sample (e.g., micro distillation system) and its analytical detection performed, e.g., by automated spectrophotometrical flow injection analysis (FIA). In order to determine the feasibility of diffuse reflectance infrared Fourier spectroscopy (DRIFTS) to quantify the Fe-CN complexes in soil matrix, 42 soil samples were collected (8 to 12.520 mg kg-1CN) indicating single symmetrical CN band in the range 2092 - 2084 cm-1. Partial least squares (PLS) calibration-validation model revealed IR response to CNtot exceeding 1268 mg kg-1 (limit of detection, LOD). Subsequently, leave-one-out cross-validation (LOO-CV) was performed on soil samples containing low CNtot (900 mg kg-1 resulted in LOD equal to 3494 mg kg-1. Our results indicate that spectroscopic data in combination with PLS statistics can efficiently be used to predict Fe-CN concentrations in soil. We conclude that the protocol applied in this study can strongly reduce the time and costs essential for the spatial and vertical screening of the site affected by complexed Fe-CN.

  19. Contamination of soil, medicinal, and fodder plants with lead and cadmium present in mine-affected areas, Northern Pakistan.

    Nawab, Javed; Khan, Sardar; Shah, Mohammad Tahir; Qamar, Zahir; Din, Islamud; Mahmood, Qaisar; Gul, Nayab; Huang, Qing


    This study aimed to investigate the lead (Pb) and cadmium (Cd) concentrations in the soil and plants (medicinal and fodder) grown in chromite mining-affected areas, Northern Pakistan. Soil and plant samples were collected and analyzed for Pb and Cd concentrations using atomic absorption spectrometer. Soil pollution load indices (PLIs) were greater than 2 for both Cd and Pb, indicating high level of contamination in the study area. Furthermore, Cd concentrations in the soil surrounding the mining sites exceeded the maximum allowable limit (MAL) (0.6 mg kg(-1)), while the concentrations of Pb were lower than the MAL (350 mg kg(-1)) set by State Environmental Protection Administration (SEPA) for agriculture soil. The concentrations of Cd and Pb were significantly higher (P soil of the mining-contaminated sites as compared to the reference site, which can be attributed to the dispersion of toxic heavy metals, present in the bed rocks and waste of the mines. The concentrations of Pb and Cd in majority of medicinal and fodder plant species grown in surrounding areas of mines were higher than their MALs set by World Health Organization/Food Agriculture Organization (WHO/FAO) for herbal (10 and 0.3 mg kg(-1), respectively) and edible (0.3 and 0.2 mg kg(-1), respectively) plants. The high concentrations of Cd and Pb may cause contamination of the food chain and health risk.

  20. Metal pollution (Cd, Pb, Zn, and As) in agricultural soils and soybean, Glycine max, in southern China.

    Zhao, Yunyun; Fang, Xiaolong; Mu, Yinghui; Cheng, Yanbo; Ma, Qibin; Nian, Hai; Yang, Cunyi


    Crops produced on metal-polluted agricultural soils may lead to chronic toxicity to humans via the food chain. To assess metal pollution in agricultural soils and soybean in southern China, 30 soybean grain samples and 17 soybean-field soil samples were collected from 17 sites in southern China, and metal concentrations of samples were analyzed by graphite furnace atomic absorption spectrophotometer. The integrated pollution index was used to evaluate if the samples were contaminated by Cd, Pb, Zn and As. Results showed that Cd concentration of 12 samples, Pb concentration of 2 samples, Zn concentration of 2 samples, and As concentrations of 2 samples were above the maximum permissible levels in soils. The integrated pollution index indicated that 11 of 17 soil samples were polluted by metals. Metal concentrations in soybean grain samples ranged from 0.11 to 0.91 mg kg(-1) for Cd; 0.34 to 2.83 mg kg(-1) for Pb; 42 to 88 mg kg(-1) for Zn; and 0.26 to 5.07 mg kg(-1) for As, which means all 30 soybean grain samples were polluted by Pb, Pb/Cd, Cd/Pb/As or Pb/As. Taken together, our study provides evidence that metal pollution is an important concern in agricultural soils and soybeans in southern China.

  1. [Determination of myclobutanil 25% WG degradation dynamics in ginseng root, stem, leaf and soil by HPLC-MS/MS].

    Wang, Yan; Wang, Chun-Wei; Gao, Jie; Cui, Li-Li; Xu, Yun-Cheng


    A high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) method was developed for determining degradation dynamics and final residues of myclobutanil 25% WG in ginseng root, stem, leaf and soil. The samples were extracted with acetonitrile, cleaned-up with primary secondary amine (PSA) solid phase extraction cartridge, separated by Kromasil Eternity-5-C18 (2.1 mm x 150 mm, 5 microm) column with a gradient of acetonitrile and 0.1% formate in water as mobile phases, and analyzed with the multiple reaction monitoring (MRM) in positive ion mode by employing the external standard method. The average recoveries and the relative standard derivations (RSDs) of myclobutanil at the spiked level of 0.01-0.20 mg x kg(-1) were 80.9%-90.7% and 5.54%-9.29%, respectively, and the limit of quantification (LOQ) was 0.005 mg x kg(-1). The method with good reproducible, high precision and low detection limit could meet the requirements of residual analysis on ginseng production. The half-lives of myclobutanil were from 6.25 days to 9.94 days in ginseng root, stem, leaf and soil at spraying dosage of 1 152 g x hm(-2) The final residues were below 0.060 1 mg x kg(-1) in root, below 0.081 7 mg x kg(-1) in stem, 0.006 0-0.102 2 mg x kg(-1) in leaf and below 0.037 6 mg x kg(-1) in soil at spraying dosage range from 576 to 1 152 g x hm(-2). It is recommended that the MRLs of myclobutanil in dried ginseng may be suggested to be 0.10 mg x kg(-1) temporarily, and the preharvest interval was set at 35 days.

  2. Heavy metals bioconcentration from soil to vegetables and appraisal of health risk in Koka and Wonji farms, Ethiopia.

    Eliku, Temesgen; Leta, Seyoum


    Heavy metal accumulation in agricultural crops has grown a major concern globally as a result of a significant health impact on human. The quantification of heavy metals (Cd, Pb, Cr, Zn, Cu, and Ni) in the soil and vegetables at two sites (Koka and Wonji Gefersa) was done using flame atomic absorption spectrophotometer. The mean concentrations of heavy metals in vegetable fields' soil samples obtained from Koka were higher for Pb, Cr, Zn, Cu, and Ni. The overall results of soil samples ranged 0.52-0.93, 13.6-27.3, 10.0-21.8, 44.4-88.5, 11.9-30.3, and 14.7-34.5 mg kg(-1) for Cd, Pb, Cr, Zn, Cu, and Ni, respectively. The concentrations of heavy metals were maximum for Cd (0.41 ± 0.03 mg kg(-1)), Pb (0.54 ± 0.11 mg kg(-1)), Zn (14.4 ± 0.72 mg kg(-1)), Cu (2.84 ± 0.27 mg kg(-1)), and Ni (1.09 ± 0.11 mg kg(-1)) in Cabbage and for Cr (2.63 ± 0.11 mg kg(-1)) in green pepper. The result indicated that Cd has high transfer factor value and Pb was the lowest. The transfer pattern for heavy metals in different vegetables showed a trend in the order: Cd > Zn > Cu > Cr > Ni > Pb. Among different vegetables, cabbage showed the highest value of metal pollution index and bean had the lowest value. Hazard index of all the vegetables was less than unity; thus, the consumption of these vegetables is unlikely to pose health risks to the target population.

  3. Effects of Lanthanum on Microbial Biomass Carbon and Nitrogen in Red Soil

    褚海燕; 朱建国; 谢祖彬; 曹志洪; 李振高; 曾青


    The result of soil culture experiment shows that lanthanum has inhibitory effect on the microbial biomass C and N in red soil, and the inhibition is strengthened with increasing concentration of La. The result of rice pot culture experiment shows that low concentration of La has slight stimulative effect on the microbial biomass C and N in red soil, but its high concentration has inhibitory effect and the inhibition is strengthened with increasing concentration of La. Soil microbial biomass is an important indicator for evaluating rare earths-polluted soil. It is assumed that the critical La concentration is 100 mg*kg-1 at which red soil tends to be polluted.

  4. Resistance of Leukemia KG1 a Cells with Positive N-cadherin in Phase G0Against Killing Activity of VP16%N-cadherin阳性白血病KG1a细胞系在G0期抵抗VP16杀伤的作用

    何侃; 于沛; 邢海燕; 李艳; 田征; 王敏; 唐克晶; 饶青


    抗药性是白血病干细胞的重要特征,为探索N-cadherin阳性的白血病细胞耐受化疗药物VP16杀伤作用的机制,本研究以白血病细胞系KGla为研究模型,利用流式细胞术测定N-cadherin阳性和N-cadherin阴性细胞在G0期比例的差异,利用G-CSF诱导KG1a细胞进入细胞周期,观察G0期细胞比例的变化,并测定诱导后KG1a细胞对VP16的敏感性;再利用EGTA抑制N-cadherin介导的细胞间黏附后,观察KG1a细胞耐药性的变化.结果 显示,N-cadherin阳性的KG1a细胞G0期比例高于N-cadherin阴性的细胞;诱导KG1a细胞进入细胞周期后G0期细胞比例明显下降,KG1a细胞对VP16的敏感性显著升高;利用EGTA处理KG1a细胞24小时抑制N-cadherin的作用后,KG1a细胞在G0期比例降低,KG1a细胞对VP16的药物敏感性显著升高.结论:N-cadherin通过介导白血病细胞之间的黏附作用,使白血病细胞处于G0期的静息状态,从而耐受VP16的杀伤作用.%This study was aimed to investigate the methylation status of WTI gene in leukemia cell lines and its relation with expression of WTI gene. The WTI gene was silenced by DNA methylation or histone deacetylation, and the expression of WTI gene was induced by using HDAC inhibitor and/or demethylation agent of DNA. Some leukemia cell lines (U937, HL-60, K562, KG1) were detected by RT-PCR, MS-PCR, restriction analysis, and DNA sequencing. U937 leukemic cells without WTI mRNA expression were incubated with HDAC inhibitor Trichostatin A (TSA) and/or demethylation agent decitabine. The results showed that the U937 cells did not express WTI gene, but HL-60, K562 and KG1 cells hyghly expressed WTI gene; WTI gene was unmethylated in HL-60 cells, but methylated in K562 and U937 cells. WTI expression could be reactivated by co-incubation with TSA and decitabine, but not was observed by using single drug. It is concluded that WTI promoter is methylated in some leukemia cells, however, the methylation can not affect

  5. Phytoremediation of fuel oil and lead co-contaminated soil by Chromolaena odorata in association with Micrococcus luteus.

    Jampasri, Kongkeat; Pokethitiyook, Prayad; Kruatrachue, Maleeya; Ounjai, Puey; Kumsopa, Acharaporn


    Phytoremediation is widely promoted as a cost-effective technology for treating heavy metal and total petroleum hydrocarbon (TPH) co-contaminated soil. This study investigated the concurrent removal of TPHs and Pb in co-contaminated soil (27,000 mg kg(-1) TPHs, 780 mg kg(-1) Pb) by growing Siam weed (Chromolaena odorata) in a pot experiment for 90 days. There were four treatments: co-contaminated soil; co-contaminated soil with C. odorata only; co-contaminated soil with C. odorata and Micrococcus luteus inoculum; and co-contaminated soil with M. luteus only. C. odorata survived and grew well in the co-contaminated soil. C. odorata with M. luteus showed the highest Pb accumulation (513.7 mg kg(-1)) and uptake (7.7 mg plant(-1)), and the highest reduction percentage of TPHs (52.2%). The higher TPH degradation in vegetated soils indicated the interaction between the rhizosphere microorganisms and plants. The results suggested that C. odorata together with M. luteus and other rhizosphere microorganisms is a promising candidate for the removal of Pb and TPHs in co-contaminated soils.

  6. Ecotoxicity of soils contaminated with industrial and domestic wastewater in western Shenyang, China

    SONG Yufang; ZHOU Qixing; GONG Ping; SUN Tieheng


    Soil samples were collected from 7 sites in the up-, mid- and down-reach along and nearby the wastewater irrigation channel, western Shenyang of China. The concentrations of selected pollutants (mineral oil, PAHs - polycycle aromatic hydrocarbons and Cd) were determined by UV spectrometer, HPLC and AAS (atomic adsorption spectrometer) spectrometer, respectively. Toxicity effects of soils were evaluated by seedling emergence test with root length of wheat as the end-point and by earthworms test with the mortality rate and inhibition rates of body weight as endpoints. Results showed accumulation of pollutants for most soils with concentration of 200.2 ~1600 for mineral oil, 0.33 for Cd and 900.16 2737.91 for PAHs. The inhibition rates of root elongation were from -20% up to 40 %, and mortality rates of earthworms ranged from 0%~40% from the exposure period of two weeks to eight weeks by sampling interval of two weeks, the inhibition rates of earthworm growth were from -19.36% to 34.53%, showing effects of stimulation at 2 weeks to an increasing effects of inhibition at 4, 6 and 8 weeks, respectively. Mortality rates correlated with the loss of body weight of earthworms.This study indicated the potential risk of pollutants of environmental low content in soil by the determination of selected chemicals combined with toxicity indexes.

  7. Study on the Functional Expression of P2X7 Receptor in Human Leukemic Cell Line KG1a%人白血病细胞系KG1a中P2X7受体的表达和功能研究

    张秀军; 孟丽君



  8. Use of Co speciation and soil properties to explain variation in Co toxicity to root growth of barley (Hordeum vulgare L.) in different soils.

    Micó, C; Li, H F; Zhao, F J; McGrath, S P


    The influence of soil properties on the bioavailability and toxicity of Co to barley (Hordeum vulgare L.) root elongation was investigated. Ten soils varying widely in soil properties were amended with seven doses of CoCl2. Soil properties greatly influenced the expression of Co toxicity. The effective concentration of added Co causing 50% inhibition (EC50) ranged from 45 to 863 mg kg(-1), representing almost 20-fold variation among soils. Furthermore, we investigated Co toxicity in relation to Co concentrations and free Co2+ activity in soil solution. The EC50 values showed variation among soils of 17- and 29-fold, based on the Co concentration in soil solution and free Co2+ activity, respectively. Single regressions were carried out between Co toxicity threshold values and selected soil properties. Models obtained showed that soil effective cation exchange capacity (eCEC) and exchangeable calcium were the most consistent single predictors of the EC50 values based on soil added Co.

  9. Impact of Sewage and Industrial Effluent on Soil Plant Health Act on Environment

    T. Subramani


    Full Text Available Effect of continuous irrigation with sewage effluent on soil properties and status of nutrients and pollutant elements in soils and plants in the adjoining areas of Agra and Mathura cities of Uttar Pradesh was ascertained. The physical properties of soils improved due to sewage water irrigation. An appreciable increase in organic carbon, available N, P, K contents was recorded in the sewage water irrigated soils. Electrical conductivity of sewage water irrigated soils was much below the threshold limit of salinity. Application of sewage water resulted in the accumulation of heavy metals in surface soil. The mean contents of total Cd, Cr, Pb in the soils irrigated with sewage water were 2.85, 75.40 and 40.26 mg kg- 1, respectively. The mean values of available Cd, Cr and Pb in soils were 0.21, 0.33 and 1.27 mg kg-1, respectively. The concentration of Cr in lettuce, cabbage and be seem plants grown on sewage water was higher as compared to its tolerance level indicating their accumulation in plants. In general, Cd was relatively higher in lettuce (0.88 mg kg-1. On the other hand, be seemed contained relatively higher amount of Cr and Pb.

  10. Effects of long-term irrigation with untreated municipal wastewater on soil properties and crop quality.

    Aydin, Mehmet Emin; Aydin, Senar; Beduk, Fatma; Tor, Ali; Tekinay, Arzu; Kolb, Marit; Bahadir, Müfit


    Irrigating crops with untreated wastewater leads to elevated concentrations of heavy metals both in soil and cultivated crops. The current study was designed to determine heavy metal (i.e., Pb, Cd, Cr, Cu, Ni, Zn, Hg) accumulation in Konya soils in selected nine sites irrigated with wastewater for over 40 years. Non-irrigated soil samples and soil samples irrigated with well water were taken as control samples. Transport of these pollutants to the wheat samples cultivated in the investigated site was also examined. The obtained results reveal that high alkaline properties and clay structure of Konya soil reduce the mobility of contaminants and cause accumulation in the top layer of soil. Intense effect of wastewater irrigation on soil EC was determined. The highest concentrations of Pb, Cr, Cu, Cd, Zn, Ni, and Hg in wastewater irrigated soil were 5.32, 37.1, 31.5, 11.4, 91.5, 134, and 0.34 mg kg(-1), respectively. Wastewater irrigated soils were strongly polluted by means of Cd (8.23-11.6 mg kg(-1)) and moderately to strongly polluted by means of Ni (47.7-134 mg kg(-1)), exceeding Maximum Admissible Concentrations for Trace Elements in Agricultural Soils and Sewage Sludge Regulation limit values of Turkey. Maximum concentrations found for Pb, Cr, Cu, Cd, Zn, and Ni in wastewater irrigated wheat grain were 8.44, 1.30, 9.10, n.d, 29.31, and 0.94 mg kg(-1), respectively. Besides, Hg was not detected in any samples of wheat grain. Based on the regulation of Turkish Food Codex, Pb contamination in wheat samples grown in the sampling site was evidenced.

  11. Washing of Petroleum and Arsenic Contaminated Soil with Ultrasound and Alkali Phosphate Solution

    Lee, Jung Hwa; Kim, Jae Gon; Cho, Yong-chan; Chon, Chul-Min; Nam, In-Hyun; Keum, Mi Jung


    Soil washing of fine textured soil has been a challenging remedial strategy due to its low remediation efficiency. We adapted ultrasound and dispersion solution to increase the remediation efficiency of the soil washing. The ultrasound and dispersion agent may enhance the dispersion of the aggregate into individual particles and may enhance release of contaminants from the aggregate. We collected the arsenic (As) contaminated silt loam soil from a smelting site, spiked with 1% of diesel and incubated for 6 months. We tested the dispersion rate and the release of diesel with the incubated soil at various pH and concentrations of orthophosphate, pyrophosphate and hexametaphosphate with or without the ultrasound of 28 kHz and 400 W. The As concentrations of coarse (> medium silt) and fine (soil washing was turned out to be pH 11_10 mM Na-hexametaphosphate with the ultrasound. The concentration of total petroleum hydrocarbon of the incubated soil reduced from 3101.3 mg kg-1 to 14.0 mg kg-1 after 10 minute washing at the optimum condition. The fine fraction had much higher As concentration than the coarse fraction: 44.4 mg kg-1 for the fine fraction and 14.4 mg kg-1 for the coarse fraction. The results of this study indicate that the ultrasound and alkali phosphate solution increase the soil washing efficiency and can be a promising technology for the remediation of fine textured contaminated soils. Key Words : Ultrasound, Phosphate solution, Soil washing, Mixed contaminants

  12. Does monensin in chicken manure from poultry farms pose a threat to soil invertebrates?

    Zižek, Suzana; Hrženjak, Rok; Kalcher, Gabrijela Tavčar; Srimpf, Karin; Semrov, Neva; Zidar, Primož


    Monensin is a carboxylic polyether ionophore used in the poultry industry as a coccidiostat. It enters the environment via manure from broiler farms. In spite of its potential presence in the environment, information concerning monensin residues in manure and soil and its toxicity to soil organisms are insufficient. In the present study, two beneficial soil invertebrate species, earthworms (Eisenia andrei) and woodlice (Porcellio scaber), were used to assess the toxicity of monensin. Animals were exposed to a range of monensin concentrations via soil or food. Earthworm reproduction was found to be the most susceptible endpoint (NOEC=3.5 mg kg(-1) dry soil; EC(50)=12.7 mg kg(-1) dry soil), while no adverse effects were recorded in isopods (NOEC⩾849mgkg(-1) dry soil, NOEC⩾357mgkg(-1) dry food). The obtained toxicity data were compared with potential concentrations of monensin in soil. In view of this, manure from broiler chickens treated with monensin at a poultry farm was sampled. According to monensin and nitrogen concentrations in the chicken manure and the degradation time of monensin, the predicted environmental concentration (PEC) was calculated. PEC of monensin is around 0.013 mg kg(-1) soil if manure is used after 3 months of composting and 0.05 mg kg(-1) soil if used without storage. Data for earthworm reproduction was used to estimate the predicted no-effect concentration (PNEC). If fresh chicken manure is applied to terrestrial ecosystems, the risk quotient (PEC/PNEC ratio) is above 1, which indicates that monensin might pose an environmental risk under certain conditions. To prevent this, it is strongly recommended to compost chicken manure for several months before using it as fertiliser. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Effects of fertilization regimes on tea yields, soil fertility, and soil microbial diversity

    Shan-Lian Qiu


    Full Text Available Fertilization is an important agricultural practice for increasing crop yields and influencing soil properties. A field experiment was conducted in the period of 2006-2011 in southeastern China, to investigate the effects of fertilization regimes on tea (Camellia sinensis [L.] Kuntze yields, soil chemical properties, and soil bacterial and fungal communities. The field experiment included six treatments: (1 unfertilized control (CON; (2 chemical fertilizers (NPK; (3 half-chemical fertilizers plus half-organic manure (1/2NPKOM; (4 organic manure fertilizers (OM; (5 half-chemical fertilizers plus half-organic manure plus legume stover returned (1/2NPKOM+L, and (6 chemical fertilizers plus legume stover returned (NPKL. Results showed that, compared to the control, NPK treatment showed no significant effect on soil organic matter (SOM, total N (TN, total P (TP, total K (TK, available N (AN, available K (AK and tea yields, but showed the lowest bacterial Shannon index of 1.714 and the lowest value of 2.002 for fungal Shannon index. Organic manure treatment had the richest diversity of soil bacterial community with Shannon index of 2.542, and the highest levels of soil essential nutrients, including SOM (30.03%, TN (2.90 g kg-1, TP (1.35 g kg-1, AN (245.30 mg kg-1, AP (57.00 mg kg-1, and AK (271.80 mg kg-1, followed by 1/2NPKOM+L, which appeared the maximal tea yields of 6772 kg ha-1. Organic manure amendment was a key factor in determining soil properties and productivity. Base on soil quality and tea yields, both OM and 1/2NPKOM+L treatments were recommended as better choices of fertilization practices for tea soils in southeastern China. These findings provided a better understanding of the importance of fertilizations in promoting soil fertility, crop yields, and altering soil microbial diversity, leading to selection of scientific fertilization practices for sustainable development of agroecosystems.

  14. Soil organic phosphorus characterisation on a glacial chronosequence (Damma, Switzerland)

    Jarosch, Klaus A.; Requejo, María I.; Bünemann, Else K.


    Soil organic phosphorus (P) may play a significant role in ecosystem P dynamics, yet, little is known about the development of different organic P classes over time. According to the commonly accepted model, relative proportions of organic P are expected to increase quickly after the commencement of soil development, subsequently remaining relatively stable over time. We tested this hypothesis on a young soil chronosequence in the Damma glacier forefield (Switzerland), where we examined the development of different organic P classes over time. In detail, we hypothesized that organic P compounds resistant against broadly active phosphatase-enzymes would increase with soil age. Soil samples (0-5 cm) were taken on 21 sites with 6 to 136 years of soil development. Using enzyme addition assays to soil extracts (0.25 M NaOH / 0.05 M EDTA), four organic P classes were detected: a) Monoester-like P (organic P hydrolysed by an acid phosphatase), b) DNA-like P (organic P hydrolysed by a nuclease in combination with an acid phosphatase, minus monoester-like P), c) Inositol Phosphate-like P (organic P hydrolysed by a phytase, minus monoester like P) and d) Enzyme stable P (difference between total extracted organic P and the three enzyme labile P classes a, b and c). NaOH-EDTA extractable inorganic and organic P increased with soil age from 4.2 and 5.2 mg kg-1 at the youngest sites to 23.9 and 64.5 mg kg-1 at the oldest sites, respectively. On all sites, more organic than inorganic P was extracted. We observed a strong linear relationship between organic and inorganic P along the chronosequence. Between 60 and 100% of extractable organic P was hydrolysed by the added enzymes, without a clear trend with respect to soil age. On most sites, Inositol phosphate-like P was the most prominent organic P class (1.8-24.3 mg kg-1). However, on some sites higher amounts of monoester-like P were detected (0.4-23.4 mg kg-1). DNA-like P ranged from nil to 12.9 mg kg-1. Thus, we observed a

  15. Degradation of Soil Nutrients in Southeast China


    A total of 2190 soil nutrient data in the Second National Soil Survey of China were collected to assess the degradation of soil nutrients in the hilly region of Southeast China. The definition of soil nutrient degradation is suggested firstly, then the evaluation criteria are set up and the current status of degradation of red soil and latosol is assessed. The percentages of areas in four grades of soil nutrient degradation, i.e., slightly deficient, medium deficient, severely deficient and extremely deficient, were 21.3%, 43.3%, 16.2% and 3.0% for soil total N; 0.7%, 6.4%, 16.7% and 76.2% for soil available P; and 25.4%, 26.3%, 8.6% and 5.0% for soil available K, respectively. The severity of soil nutrient degradation was in the order of P > N > K. The major factors leading to the degradation of soil nutrients in quantity include soil erosion, leaching and the consumption by crops. And the principal factor affecting the degradation of soil nutrients in availability is the fixation of N, P and K, especially the fixation of phosphorus. The average amount of P fixed by soils is 408 mg kg-1, and upland soils can fix more P than paddy soils.

  16. [Moisture and nutrient characteristics of deep layer soil in apple orchards on the Luochuan highland of Shaanxi, Northwest China].

    Cao, Yu; Jumahan, Kasimu; Fan, Peng; Zhang, Li-Na; Li, Jun


    Taking the 11-, 15-, 20-, and 43 years old apple orchards on the Luochuan highland of Shaanxi, Northwest China as test objects, this paper measured the moisture content in 0-1500 cm soil layer and the organic matter and total and available nitrogen, phosphorous, and potassium contents in 0-300 cm soil layer, with the soil moisture and nutrient regimes as well as their variation characteristics with apple tree age and soil depth analyzed. The moisture content in 0-1500 cm soil layer in 11-, 15-, 20-, and 43 years old apple orchards was averagely 18.6%, 13.7%, 17.0%, 11.5%, and 13.1%, respectively, and decreased with apple tree age. Soil desiccation did not occurr in the orchards with supplementary irrigation, but a slight or medium soil desiccation occurred in the rainfed orchards. Nevertheless, the moisture content in 0-300 cm soil layer in the rainfed orchards was still higher than that in wheat field. The contents of organic matter and total and available nitrogen in 0-300 cm soil layer in the five apple orchards were less than 10, 0.75 g. kg-1, and 50, respectively, all at shortage level, whilst the content of available phosphorous in 0-300 cm soil layer was 3.30-6.42, being moderate in upper soil layer and scarce in deep soil layer. The content of available potassium in 0-300 cm soil layer was 78.09-98.31, presenting abundant. The contents of nutrients were all higher in 0-100 cm soil layer than in 100-300 cm soil layer. The soil organic matter and total and available nitrogen contents and the soil nutrient index (SNI) all presented a trend of decrease after an initial increase with the increasing apple tree age. The contents of the test nutrients except total potassium in 0-100 cm soil layer all decreased rapidly with soil depth, while those in deeper soil layers kept relatively stable. There existed significant correlations between the contents of soil organic matter, total nitrogen, available nitrogen, total phosphorous

  17. Evaluación de la toxicidad de cobre en suelos a través de biomarcadores de estrés oxidativo en eisenia foetida Assessment of copper toxicity in soils using biomarkers of oxidative stress in eisenia foetida

    Hernán Gaete


    Full Text Available Copper toxicity in soil was evaluated using biomarkers of oxidative stress (catalase enzyme activity, superoxide dismutase and lipid peroxidation in the earthworm Eisenia foetida. Agricultural topsoils from mining areas of the Aconcagua river basin were collected. Total copper concentrations were in the range of 94-959 mg kg-1, while the exchangeable copper concentrations were in the range of 46-2225 µg kg-1. Earthworms exposed to soil with exchangeable copper concentrations above 32 µg kg-1 showed an increase in catalase activity. Parameters of antioxidant activity were more sensitive than the weight change and thus can be used as appropriate biomarkers in Eisenia foetida.

  18. [Growth responses of six leguminous plants adaptable in Northern Shaanxi to petroleum contaminated soil].

    Shan, Bao-Qin; Zhang, Yong-Tao; Cao, Qiao-Ling; Kang, Zhen-Yan; Li, Shu-Yuan


    To select appropriate native species in Northern Shaanxi for phytoremediation, the growth index of six kinds of leguminous plants planted in petroleum contaminated soils were investigated through pot culture. Petroleum concentrations were set at 0, 5 000, 10 000, 20 000, 40 000 mg x kg(-1) respectively with three replicates. Using different levels of seed germination rate, germination time, individual height, wilting rate, dry weight and chlorophyll content in leaves of tested plants as the ecological indicator. The results showed that tested plants have significantly different responses to petroleum pollution. Compared with those planted in clean soils, seed germination rate and individual height were promoted when petroleum concentration was lower than 5000 mg x kg(-1), but inhibition occurred when petroleum concentrations were higher than 10000 mg x kg(-1). Strong endurance of Medicago sativa was observed to petroleum polluted soil, especially at lower petroleum concentration. Leaf wilting of Robinia pseudoacacia was unobserved even when petroleum concentration was 40 000 mg x kg(-1), thus displaying the potential of remediating petroleum contaminated soils. The petroleum concentration was significantly and negatively correlated with seed germination rate, individual height and dry weight, but positively correlated with chlorophyll content in leaves.

  19. Effect of plant growth on copper solubility and speciation in soil solution samples

    Romkens, PFAM; Bouwman, LA; Boon, GT


    The effect of plant growth on copper solubility and speciation was studied in a 10-week pot experiment. A copper-tolerant grass variety (Agrostis capillaris L. var. Parys Mountain) was grown in pots that contained either clean (copper-total approx. 30 mg kg(-1)) or copper contaminated soil

  20. Effect of plant growth on copper solubility and speciation in soil solution samples

    Romkens, PFAM; Bouwman, LA; Boon, GT


    The effect of plant growth on copper solubility and speciation was studied in a 10-week pot experiment. A copper-tolerant grass variety (Agrostis capillaris L. var. Parys Mountain) was grown in pots that contained either clean (copper-total approx. 30 mg kg(-1)) or copper contaminated soil (copper-t

  1. Effect of plant growth on copper solubility and speciation in soil solution samples

    Romkens, PFAM; Bouwman, LA; Boon, GT


    The effect of plant growth on copper solubility and speciation was studied in a 10-week pot experiment. A copper-tolerant grass variety (Agrostis capillaris L. var. Parys Mountain) was grown in pots that contained either clean (copper-total approx. 30 mg kg(-1)) or copper contaminated soil (copper-t

  2. Effect of calcium on growth performance and essential oil of vetiver grass (Chrysopogon zizanioides) grown on lead contaminated soils.

    Danh, Luu Thai; Truong, Paul; Mammucari, Raffaella; Foster, Neil


    The aim of this study was to investigate effect of calcium on growth, survival, essential oil yield and chemical compositions of vetiver grass grown on lead contaminated soils. Calcium inform of CaCO3 (0, 2000, 4000, 6000 mg Ca kg(-1)) was added to river sand soils containing 4000 mg Pb kg(-1) dry soil. Results showed that, in the absence of calcium treatment, no plants survived after 2 weeks of cultivation, while the rest grew well to the end of the experimental period (42 weeks). Calcium treatments generally resulted in a slight decrease in biomass. Interestingly, an increase in calcium over 2000 mg kg(-1) did not result in a decrease in accumulation of lead in vetiver roots and shoots. The levels of lead in roots and shoots under calcium treatments were around 2000 and 90 mg kg(-1) dry weight, respectively. The addition of CaCO3 did not improve vetiver essential oil yield and chemical composition compared to the control. A level of applied CaCO3 about half of the lead concentration in soils was sufficient to improve vetiver growth and survival, and accumulate high concentrations of lead in the roots. This finding can be applied for re-vegetation of lead contaminated soils using vetiver.

  3. Toxicity of the ionophore antibiotic lasalocid to soil-dwelling invertebrates: avoidance tests in comparison to classic sublethal tests.

    Žižek, Suzana; Zidar, Primož


    Lasalocid is a veterinary ionophore antibiotic used for prevention and treatment of coccidiosis in poultry. It enters the environment with the use of contaminated manure on agricultural land. Despite its extensive use, the effects of lasalocid on non-target soil organisms are poorly explored. We used classical subleathal ecotoxicity tests to assess the effects of lasalocid on earthworms (Eisenia andrei) and isopods (Porcellio scaber) and compared the results with tests using avoidance behaviour as the endpoint. The results showed that avoidance is a much more sensitive endpoint. For earthworms, EC50 for avoidance (12.3 mg kg(-1) dry soil) was more than five times lower than EC50 for reproduction (69.6 mg kg(-1) dry soil). In isopods the sensitivity of the behavioural response test was even higher. While the highest lasalocid concentration 202 mg kg(-1) had no significant effects on isopod growth or survival, already the lowest used concentration in the behavioural assay (4.51 mg kg(-1)) caused significant impact on isopod behaviour. Using the avoidance test results for calculating the predicted no-effect concentration (PNEC) of lasalocid to soil invertebrates, the value is close to the predicted environmental concentration (PEC). This indicates that the use of lasalocid-contaminated manure could potentially impair the habitat function of agricultural soils.

  4. Sparingly-soluble phosphate rock induced significant plant growth and arsenic uptake by Pteris vittata from three contaminated soils.

    Lessl, Jason T; Ma, Lena Q


    We evaluated the ability of As-hyperaccumulator Pteris vittata (PV) to remove As from As-contaminated soils over five harvests in 2.5 years in raised beds (162 kg soil/bed). We tested the hypothesis that a P-limiting environment would enhance PV growth and As uptake owing its unique ability to uptake P under As-rich environment. In Dec. 2009, PV was transplanted to three As-contaminated soils (pH of 5.5-7.2) containing 25-129 mg kg(-1) As, which was amended with sparingly-soluble phosphate rock (PR-soil) or soluble P fertilizer (P-soil). During the 2.5-year, PV obtained sufficient P (1882 vs 2225 mg kg(-1)) from PR-soils, with increased root biomass (33%) and root exudation (53%) compared to P-soils. In addition, its frond biomass increased by 20% consecutively with each harvest (six month interval) from 18 to 36 g plant(-1). Its frond biomass in PR-soils (52.2 g plant(-1) year(-1) or ∼12 mt ha(-1) year(-1)) averaged 39% more than that in P-soils. To our knowledge, this represented the largest PV frond biomass reported, demonstrating the unique ability of PV in using insoluble P from PR in alkaline soils. In addition to biomass increase, PV from PR-soils had ∼1.5 times more As in fronds (2540, 780, and 920 mg kg(-1)) than those from P-soils (1740, 570, and 400 mg kg(-1)), with soils containing 129, 25, and 30 mg kg(-1) As, respectively. The low available P in PR-soils induced substantial plant growth and As uptake by PV. This translated into significantly more As removal from soil, averaging 48% reduction in PR-soils and 36% in P-soils in 2.5 years. With multiple harvests and PR amendments, our results showed As removal by PV from contaminated soils was ∼7 times faster than published studies.

  5. The effect of EDTA on Helianthus annuus uptake, selectivity, and translocation of heavy metals when grown in Ohio, New Mexico and Colombia soils.

    Turgut, Cafer; Pepe, M Katie; Cutright, Teresa J


    The use of two EDTA concentrations for enhancing the bioavailability of cadmium, chromium, and nickel in three natural soils (Ohio, New Mexico and Colombia) was investigated. The resulting uptake, translocation and selectivity with Helianthus annuus after mobilization were also examined. In general, plants grown in the sandy-loam Ohio soil had a higher uptake that resulted in a selectivity and total metal content of Cd>Cr>Ni and 0.73 mg and Cr>Cd>Ni and 0.32 mg for 0.1 and 0.3 g kg-1 EDTA, respectively. With the silty-loam New Mexico soil, although the total metal uptake was not statistically different the EDTA level did alter the selectivity; Cd>Cr>Ni (0.1 g kg-1 EDTA) and Cd>Cr>Ni (0.3 g kg-1 EDTA). Conversely, with the Colombian (sandy clay loam) soil increasing the EDTA level resulted in a higher total metal uptake (0.62 mg) than the 0.1 g kg-1 (0.59 mg) treatment. For all three soils, the translocation of Cd was limited. Evaluating the mobile metal fraction with and without EDTA determined that the chelator was capable of overcoming mass transfer limitations associated with the expandable clay fraction in the soils. Root wash results and root biomass concentrations indicated that Cd sorption was occurring. Therefore limited Cd translocation was attributed to insufficient phytochelatin levels.

  6. Variability in soil micronutrients extracted by DTPA and Mehlich-3 at the plot scale in an acidic environment

    Paz-Ferreiro, Jorge; Lado, Marcos; de Abreu, Cleide A.


    Land use practices affect soil properties and nutrient supply. Very limited data are available on micronutrient extractability in northwest Spain. The aim of this study was to analyse long-term effects of land use on the concentration, variability and spatial distribution of soil nutrients. To this end, neighboring forest and cultivated stands were compared. The study was carried out in an acid, rich in organic matter soil developed over sediments at the province of Lugo, northwestern of Spain. Adjacent plots with a surface of 100 m2 were marked on regular square grids with 2-m spacing. Fe, Mn, Zn and Cu were extracted both by Mehlich-3 and DTPA solutions and determined by ICP-MS. General soil chemical and physical properties were routinely analyzed. In arable land, microelement concentration ranges were as follows: Fe (100 and 135 mg kg-1), Mn (7.6 and 21.5 mg kg-1), Zn (0.6 and 3.7 mg kg-1), and Cu (0.2 and 0.7 mg kg-1). In forest land, these ranges were: Fe (62 and 309 mg kg-1), Mn (0.2 and 2.1 mg kg-1), Zn (0.2 and 2.9 mg kg-1), and Cu (0.1 and 0.2 mg kg-1). With the exception of Fe-DTPA, microelement concentrations extracted both with DTPA and Mehlich-3 were higher in the cultivated than in the forest stand. Coefficients of variation were higher for the microelement content of the soil under forest. Principal component analysis was performed to evaluate associations between extractable microelements and general physico-chemical properties. At the studied scale, nutrient management was the main factor affecting the agricultural site, whereas soil-plant interactions were probably responsible for the higher variation within the forest site. Patterns of spatial variability of the studied nutrients at the small plot scale also were assessed by geostatistical techniques. Results were discussed in the frame of sustainable land use and organic matter decline with conventional tillage and sustainable land use

  7. Simultaneous adsorption/desorption of quaternary ammonium herbicides by acid vineyard soils

    Conde Cid, Manuel; Paradelo Núñez, Remigio; Fernández Calviño, David; Nóvoa Muñoz, Juan Carlos; Arias Estévez, Manuel


    Competitive adsorption and desorption of three quaternary ammonium herbicides (paraquat, diquat, and difenzoquat) have been studied in four sandy-loam acid vineyard soils from NW Spain and Portugal. The soils present organic matter contents between 3 and 48 g kg-1 and copper contents ranging from 25 to 107 mg kg-1. Adsorption has been studied under equilibrium conditions in batch experiments, and kinetics were studied in a stirred-flow chamber. Adsorption and desorption followed a Freundlich model and kinetics were well described by the pseudo-first-order model. The retention capacity for the pesticides by the four soils followed the sequence: paraquat > diquat > difenzoquat. The different adsorption capacities of each soil were not related to pH, clay or organic matter contents, as could be expected, but rather to soil copper content. The results show that competition with copper for adsorption sites is an important factor in quaternary ammonium herbicides retention in soils with these characteristics.

  8. Tropical soils cultivated with tomato: fractionation and speciation of Al.

    Nogueirol, Roberta Corrêa; Monteiro, Francisco Antonio; Azevedo, Ricardo Antunes


    Soil acidity and the associated problems of aluminum (Al) toxicity and scarce exchangeable bases are typically the most important limiting factors of agricultural yield in wet tropical regions. The goals of this study were to test how soil lime rates affect the forms and distribution of Al in the soil fractions and how different levels of bioavailable Al affect two tomato genotypes grown in wet tropical soils. The tomato genotypes CNPH 0082 and Calabash Rouge were grown in two wet tropical soils in a greenhouse. Soil lime rates of 0, 560, and 2240 mg kg(-1) soil (clay soil) and 0, 280, and 1120 mg kg(-1) soil (sandy soil) were applied to modify Al concentrations. Dry mass production and Al concentrations were determined in shoots and roots. Al was fractionated in the soil, and the soil solution was speciated after cultivation. The Calabash Rouge genotype possesses mechanisms to tolerate Al3+, absorbed less Al, exhibited smaller reduction in growth, and lower Al concentrations in plant parts than the CNPH 0082. Increased soil pH reduced the exchangeable Al fraction and increased the fraction mainly linked to organic matter. Al in the soil in the form of complexes with organic compounds and Al(SO4)+ (at the highest lime rate) did not affect plant development. Soil acidity can be easily neutralized by liming the soil, which transforms toxic Al3+ in the soil into forms that do not harm tomato plants, thereby avoiding oxidative stress in the plants. Al-induced stress in tomatoes varies with genotypes and soil type.

  9. Micronutrient Availability in Relation to Selected Soil Properties and landscape Position in Calcareous Soils of Golpayegan

    Mojtaba Fathi


    Full Text Available Introduction: Variety of soil reactions govern the distribution of metal micronutrients that includes complexation with organic and inorganic ligands, ion exchange, adsorption and desorption processes, precipitation and dissolution of solids and acid-based equilibria. The relative importance of these reactions depends on many factors such as soil physical, chemical, and mineralogical properties and the nature of metal ions. Environmental factors such as climate, physiographic position, and soil development may affect variability of some soil properties and thereby nutrient availability. The present research was conducted to find relationships between Iron, manganese, zinc, and copper availability and some major soil properties, physiographic condition and soil development. Materials and Methods: Golpayegan region is located in northwest of Isfahan province in central Iran. The mean elevation of the studied area is 1790 above sea level. Annual precipitation was about 244mm and mean monthly temperature ranges from -6 in January to 34°C in August. The soils were developed on different physiographic conditions including piedmont plains, alluvial-fan, plateaus, and flood plains belonging to Entisols and Aridisols. Soil samples (0–60 cm were collected from 98 grid points with 2000m distance in the agricultural area of Golpayegan. Particle size distribution, calcium carbonate, organic carbon, available potassium and phosphorus of the soils were measured by SWRI standard methods. Available Zn, Cu, Mn, and Fe were determined by addition of 10 g soil to 20mL 0.005M diethylentriaminepentacetic‏. The solutions were shaken for 2 h at 25°C, centrifuged, filtered, and Fe, Mn, Zn, and Cu concentrations were measured by an atomic absorption spectrophotometer. Results Discussion: Studied soils were developed on calcareous material and about 60% of samples have more than 20% of calcium carbonate. Available Fe ranged from 1.4 to 6.5 mg kg-1 (mean 15.8 mg kg-1

  10. Ecotoxicological effects on the earthworm Eisenia fetida following exposure to soil contaminated with imidacloprid.

    Zhang, Qingming; Zhang, Baohua; Wang, Caixia


    Imidacloprid, a neonicotinoid insecticide, has been used widely in agriculture worldwide. The adverse effects of imidacloprid on exposed biota have brought it increasing attention. However, knowledge about the effects of imidacloprid on antioxidant defense systems and digestive systems in the earthworm is vague and not comprehensive. In the present study, the changes in the activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), cellulase, reactive oxygen species (ROS), and malondialdehyde (MDA) in the earthworm Eisenia fetida exposed to artificial soil treated with imidacloprid were examined systematically. The results showed that the activity of these biomarkers was closely related to the dose and duration of the exposure to imidacloprid. The activity of SOD was stimulated significantly at doses of 0.66 and 2 mg kg(-1) imidacloprid but markedly inhibited at a dose of 4 mg kg(-1) imidacloprid with prolonged exposure. The activities of CAT and POD increased irregularly at 0.2-4 mg kg(-1) imidacloprid over different exposure times. The level of ROS at a dose of 2 or 4 mg kg(-1) imidacloprid was significantly increased over the entire exposure period. When the concentration of imidacloprid was above 0.66 mg kg(-1), the balance of the activity of the antioxidant enzymes and ROS level was interrupted. The activity of cellulase decreased significantly with prolonged exposure. At the stress of 4 mg kg(-1) imidacloprid, the content of MDA was significantly increased with increasing exposure time. The results of the present study suggest that imidacloprid has a potentially harmful effect on E. fetida and may be helpful for assessment of the risk of imidacloprid to the soil ecosystem environment. However, to obtain more comprehensive toxicity data, it is necessary to investigate the effects of imidacloprid on earthworm using native soils in the future work.

  11. [Effects of nitrogen fertilization on soil respiration during maize growth season].

    Li, Jian-Min; Ding, Wei-Xin; Cai, Zu-Cong


    In order to understand how nitrogen (N) fertilization affects soil respiration, a pot experiment with splitting-root compartment and by root-cutting was conducted in a greenhouse. The experiment had four treatments, i. e., unplanted and N-unfertilized (CKO), unplanted but fertilized with 150 mg N x kg(-1) CKN), planted maize (Zea mays L.) but N-unfertilized (MO), and planted maize and fertilized with 150 mg N x kg(-1) (MN). Soil respiration, soil basal respiration, root respiration, and rhizospheric microbial respiration were measured simultaneously. In unplanted soils (treatments CKO and CKN), soil respiration rate (soil basal respiration) ranged from 13.41 to 77.27 mg C x m(-2) x h(-1), and N fertilization had less effect; while in planted soils, the averaged soil respiration rate in treatment MN amounted to 138.54 mg C x m(-2) x h(-1), and was 17.7% higher (P < 0.05) than that in treatment MO. This increment mainly occurred at tasselling and flowering stages. During maize growth season, the contribution of soil basal respiration, root respiration, and rhizospheric microbial respiration to soil respiration in treatments MN and MO was 36.2%, 45.9%, and 17.9%, and 35.5%, 36.9%, and 37.6%, respectively.

  12. Effects of myclobutanil on soil microbial biomass, respiration, and soil nitrogen transformations.

    Ju, Chao; Xu, Jun; Wu, Xiaohu; Dong, Fengshou; Liu, Xingang; Zheng, Yongquan


    A 3-month-long experiment was conducted to ascertain the effects of different concentrations of myclobutanil (0.4 mg kg(-1) soil [T1]; 1.2 mg kg(-1) soil [T3]; and 4 mg kg(-1) soil [T10]) on soil microbial biomass, respiration, and soil nitrogen transformations using two typical agricultural soils (Henan fluvo-aquic soil and Shanxi cinnamon soil). Soil was sampled after 7, 15, 30, 60, and 90 days of incubation to determine myclobutanil concentration and microbial parameters: soil basal respiration (RB), microbial biomass carbon (MBC) and nitrogen (MBN), NO(-)3-N and NH(+)4-N concentrations, and gene abundance of total bacteria, N2-fixing bacteria, fungi, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB). The half-lives of the different doses of myclobutanil varied from 20.3 to 69.3 d in the Henan soil and from 99 to 138.6 d in the Shanxi soil. In the Henan soil, the three treatments caused different degrees of short-term inhibition of RB and MBC, NH(+)4-N, and gene abundance of total bacteria, fungi, N2-fixing bacteria, AOA, and AOB, with the exception of a brief increase in NO(-)3-N content during the T10 treatment. The MBN (immobilized nitrogen) was not affected. In the Shanxi soil, MBC, the populations of total bacteria, fungi, and N2-fixing bacteria, and NH(+)4-N concentration were not significantly affected by myclobutanil. The RB and MBN were decreased transitorily in the T10 treatment. The NO(-)3-N concentrations and the abundance of both AOA and AOB were erratically stimulated by myclobutanil. Regardless of whether stimulation or suppression occurred, the effects of myclobutanil on the two soil types were short term. In summary, myclobutanil had no long-term negative effects on the soil microbial biomass, respiration, and soil nitrogen transformations in the two types of soil, even at 10-fold the recommended dosage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Improving the prediction of arsenic contents in agricultural soils by combining the reflectance spectroscopy of soils and rice plants

    Shi, Tiezhu; Wang, Junjie; Chen, Yiyun; Wu, Guofeng


    Visible and near-infrared reflectance spectroscopy provides a beneficial tool for investigating soil heavy metal contamination. This study aimed to investigate mechanisms of soil arsenic prediction using laboratory based soil and leaf spectra, compare the prediction of arsenic content using soil spectra with that using rice plant spectra, and determine whether the combination of both could improve the prediction of soil arsenic content. A total of 100 samples were collected and the reflectance spectra of soils and rice plants were measured using a FieldSpec3 portable spectroradiometer (350-2500 nm). After eliminating spectral outliers, the reflectance spectra were divided into calibration (n = 62) and validation (n = 32) data sets using the Kennard-Stone algorithm. Genetic algorithm (GA) was used to select useful spectral variables for soil arsenic prediction. Thereafter, the GA-selected spectral variables of the soil and leaf spectra were individually and jointly employed to calibrate the partial least squares regression (PLSR) models using the calibration data set. The regression models were validated and compared using independent validation data set. Furthermore, the correlation coefficients of soil arsenic against soil organic matter, leaf arsenic and leaf chlorophyll were calculated, and the important wavelengths for PLSR modeling were extracted. Results showed that arsenic prediction using the leaf spectra (coefficient of determination in validation, Rv2 = 0.54; root mean square error in validation, RMSEv = 12.99 mg kg-1; and residual prediction deviation in validation, RPDv = 1.35) was slightly better than using the soil spectra (Rv2 = 0.42, RMSEv = 13.35 mg kg-1, and RPDv = 1.31). However, results also showed that the combinational use of soil and leaf spectra resulted in higher arsenic prediction (Rv2 = 0.63, RMSEv = 11.94 mg kg-1, RPDv = 1.47) compared with either soil or leaf spectra alone. Soil spectral bands near 480, 600, 670, 810, 1980, 2050 and

  14. Occurrence and sorption of fluoroquinolones in poultry litters and soils from São Paulo State, Brazil.

    Leal, Rafael Marques Pereira; Figueira, Rafael Fernandes; Tornisielo, Valdemar Luiz; Regitano, Jussara Borges


    Animal production is one of the most expressive sectors of Brazilian agro-economy. Although antibiotics are routinely used in this activity, their occurrence, fate, and potential impacts to the local environment are largely unknown. This research evaluated sorption-desorption and occurrence of four commonly used fluoroquinolones (norfloxacin, ciprofloxacin, danofloxacin, and enrofloxacin) in poultry litter and soil samples from São Paulo State, Brazil. The sorption-desorption studies involved batch equilibration technique and followed the OECD guideline for pesticides. All compounds were analyzed by HPLC, using fluorescence detector. Fluoroquinolones' sorption potential to the poultry litters (K(d) ≤65 L kg(-1)) was lower than to the soil (K(d) ~40,000 L kg(-1)), but was always high (≥69% of applied amount) indicating a higher specificity of fluoroquinolones interaction with soils. The addition of poultry litter (5%) to the soil had not affected sorption or desorption of these compounds. Desorption was negligible in the soil (≤0.5% of sorbed amount), but not in the poultry litters (up to 42% of sorbed amount). Fluoroquinolones' mean concentrations found in the poultry litters (1.37 to 6.68 mg kg(-1)) and soils (22.93 μg kg(-1)) were compatible to those found elsewhere (Austria, China, and Turkey). Enrofloxacin was the most often detected compound (30% of poultry litters and 27% of soils) at the highest mean concentrations (6.68 mg kg(-1) for poultry litters and 22.93 μg kg(-1) for soils). These results show that antibiotics are routinely used in poultry production and might represent one potential source of pollution to the environment that has been largely ignored and should be further investigated in Brazil.

  15. Heavy metal and nutrient concentration in soil and plants growing on a metalliferous chromite minespoil.

    Samantaray, S; Rout, G R; Das, P


    Metal contamination in soil and plant samples from a chromite mine and its adjoining regions was determined. The metal concentration varied in stem, leaf and root of different tree species. In the case of shrubs, the highest concentration of iron (18.5 mg kg(-1) was detected in the stem of Combretum roxburghii. The concentration of aluminium varied from 1.8 - 5.3 mg kg(-1) dry weight, whereas the nickel content was found to be the highest in the stem of Calotropis gigantea. In the case of herbs, chromium concentration was highest (60.9 mg kg(-1) dry weight) in Evovulus alsenoides and the lowest (18.8 mg kg(-1) dry weight) in Andrographis paniculata. There was a significant correlation observed between chromium in soil with the root of tree species like Lagerstroemia parviflora, Madhuca longifolia, Anogeissus latifolia and Haldina cordyfolia. Nickel in soil was significantly correlated with the stem and leaf of all the tree species except Chlroxylon sweitenta. Iron in soil showed correlation with the stem and leaf of Chloroxylon sweitenia. Among the shrubs (Calotropis gigantea, Combretum roxburghii and Smilax zeylancia), chromium in soil showed a correlation with the root. Nickel in soil was positively correlated with the stem and leaf of Calotropis gigantea and Combretum roxburghii. Among the herbs, chromium in the whole plant of Evolvulus alsenoids, Solanum surattense and Phyllanthus fraternus showed significant positive correlation with soil; nickel in Solanum surattense showed significant positive correlation with soil. The positive correlation coefficient was observed between iron in the whole plant and soil on Phyllanthus virgatus, Phyllanthus fraternus and Andrographis paniculata. The above information would be useful for the establishment of a vegetation cover on the minewaste heaps.

  16. Effect of Rare Earths on Fractionation and Transformation of Soil Available Nitrogen

    丁士明; 梁涛; 张自立; 孙琴; 张朝生


    The effect of rare earths (RE) on fractionation and transformation of available nitrogen (N) in a yellow cinnamon soil was studied with soil cultivation. The results show that under the dry condition, when the extraneous RE are added to the soil, both concentrations of soil ammonium N and hydrolysable N increase, and the concentrations of soil nitric N decrease. The concentrations of soil available N increase with the increase of RE concentrations in soils when the RE concentrations are low, but it decreases with the increase of high RE concentrations in soils. The NOEC (no observed effect concentration) of the extraneous RE to available N in the soils is 443.8 mg*kg-1. Under the inundated condition, low RE concentrations in soil has no significant effect on soil ammonium N and hydrolysable N. However, when the soil RE concentrations are high, both of them decrease with the increase of RE concentrations. The NOEC of the extraneous RE to soil ammonium N and hydrolysable N are 171.2 and 256.9 mg*kg-1, respectively.

  17. Remediation of PAH-contaminated soil by the combination of tall fescue, arbuscular mycorrhizal fungus and epigeic earthworms.

    Lu, Yan-Fei; Lu, Mang


    A 120-day experiment was performed to investigate the effect of a multi-component bioremediation system consisting of tall fescue (Festuca arundinacea), arbuscular mycorrhizal fungus (AMF) (Glomus caledoniun L.), and epigeic earthworms (Eisenia foetida) for cleaning up polycyclic aromatic hydrocarbons (PAHs)-contaminated soil. Inoculation with AMF and/or earthworms increased plant yield and PAH accumulation in plants. However, PAH uptake by tall fescue accounted for a negligible portion of soil PAH removal. Mycorrhizal tall fescue significantly enhanced PAH dissipation, PAH degrader density and polyphenol oxidase activity in soil. The highest PAH dissipation (93.4%) was observed in the combination treatment: i.e., AMF+earthworms+tall fescue, in which the soil PAH concentration decreased from an initial value of 620 to 41 mg kg(-1) in 120 days. This concentration is below the threshold level required for Chinese soil PAH quality (45 mg kg(-1) dry weight) for residential use.

  18. Long-term manure amendment increases organic C storage and stabilization in Loess soil

    Liang, B.; Zhao, W.; Yang, X.; Zhou, J.


    Soil is the largest terrestrial pool for organic carbon in the biosphere. Therefore, sequestration of C in soils is often seen as a 'win-win' proposition. The long-term combined application of manure with chemical fertilizers had increased the accumulation of organic carbon in soil (SOC); and the results from the application of chemical fertilizers on the stock of SOC in soil were inconsistent. Furthermore, less studies have been conducted to evaluate the effect of different fertilization, especially the application of N fertilizer, on the stabilization of SOC in the different fertilized soils. In this study, we hypothesized that the long-term different fertilization not only affect organic C storage, but also its stabilization in soil. Therefore, we conducted an incubation experiment with the soils from a long-term fertilization trials. Soil samples were collected from the three fertilized plots, ((1) no fertilizer, NF soil, (2) inorganic NPK fertilizers, NPK soil; and (3) Manure + NPK fertilizers, MNPK soil) of a long-term fertilization experiment initiated in 1990 in Shaanxi, China. The soils were incubated at 28o C for 30 days with the different treatments, i.e., (1) control with no addition (CK), (2) added 200 mg N kg-1 soil (+ NH4-N), (3) added 1000 mg C kg-1 soil (+ glucose), and (4) added 200 mg N kg-1 soil + 1000 mg C kg-1 soil (+glucose + NH4-N). The evolved CO2 was determined by titration of the excess NaOH with 0.1 M HCl. Decomposition of SOC in the different soils was evaluate with the accumulation of released CO2-C based on dry soil (in mg C kg-1 soil), and the decomposition rate of SOC during the incubation (in % of total organic C in soil). Long-term different fertilization treatments (NPK, and MNPK soil) significantly increased the organic C storage in 0-100 cm soil profile. SOC storage in MNPK soil (83.0 t ha-1) was significantly higher than NPK soil (80.8 t ha-1), and both were significantly higher than the no fertilizer soil. The decomposition

  19. Distribution of persistent organic pollutants, polycyclic aromatic hydrocarbons and trace elements in soil and vegetation following a large scale landfill fire in northern Greece.

    Chrysikou, Loukia; Gemenetzis, Panagiotis; Kouras, Athanasios; Manoli, Evangelia; Terzi, Eleni; Samara, Constantini


    Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), including hexaclorocyclohexanes (HCHs) and DDTs, as well as trace elements were determined in soil and vegetation samples collected from the surrounding area of the landfill "Tagarades", the biggest in northern Greece, following a large scale fire involving approximately 50,000 tons of municipal waste. High concentrations of total PAHs, PCBs and heavy metals were found inside the landfill (1475 microg kg(-1) dw, 399 microg kg(-1) dw and 29.8 mg kg(-1) dw, respectively), whereas concentrations in the surrounding soils were by far lower ranging between 11.2-28.1 microg kg(-1) dw for PAHs, 4.02-11.2 microg kg(-1) dw for PCBs and 575-1207 mg kg(-1) dw for heavy metals. The distribution of HCHs and DDTs were quite different since certain soils exhibited equal or higher concentrations than the landfill. In vegetation, the concentrations of PAHs, PCBs, HCHs and DDTs ranged from 14.1-34.7, 3.64-25.9, 1.41-32.1 and 0.61-4.03 microg kg(-1) dw, respectively, while those of heavy metals from 81 to 159 mg kg(-1) dw. The results of the study indicated soil and vegetation pollution levels in the surroundings of the landfill comparable to those reported for other Greek locations. The impact from the landfill fire was not evident partially due to the presence of recent and past inputs from other activities (agriculture, vehicular transport, earlier landfill fires).

  20. Optimization of ultrasonic extraction and analyses methodology by HPLC for determination of diuron and its metabolites in soil cultivation of sugar cane

    Maria Josefa Santos Yabe


    Full Text Available Diuron, N-(3,4-dichlorophenyl-N, N-dimethylurea can be transformed into the soil through the biodegradation of 3-(3,4-dichlorophenyl-3-methylurea (DCPMU, 3.4-diclorofenilureia (DCPU and 3,4-dichloroaniline (DCA. This study aimed to optimize and validate a method of extraction and analysis of these substances in the soil by HPLC/DAD. There was extracted with methanol in the bath ultrasonic and analysis in a liquid chromatograph/detector brand Waters. The condition of analysis optimized for separation of analytes was mobile phase methanol: water 50:50 (v / v, flow 1 mL min-1. Wavelength of 240 nm was selected for the DCA and 254 nm for diuron, DCPMU and DCPU. It was used column and pre column Waters Xterra RP18, 5 um, 4.6 and 3.9 x 150 mm x 20 mm. The calibration curve was obtained from the fortification of the soil with the mixture of patterns in the range of 5 mg Kg-1 to 200 mg Kg-1 of soil. The recovery was obtained in two concentration levels of 5 and 200 mg. Kg-1 of soil was between 85 and 99%. The repeatability was 0.78%, 2.20%, 2.17% and 1.72% and intermediate precision was 2.48%, 2.11%, 3.10% and 2.77% for diuron, DCPMU, DCPU and DCA, respectively. The limit of quantification was 1.25 mg Kg-1 soil. The concentration of diuron found in some bioaugmented soil samples ranged from 5.5 to 8.9 mg Kg-1 soil, but was not detected the presence of their metabolites.

  1. [Rare earth elements content in farmland soils and crops of the surrounding copper mining and smelting plant in Jiangxi province and evaluation of its ecological risk].

    Jin, Shu-Lan; Huang, Yi-Zong; Wang, Fei; Xu, Feng; Wang, Xiao-Ling; Gao, Zhu; Hu, Ying; Qiao Min; Li, Jin; Xiang, Meng


    Rare earth elements content in farmland soils and crops of the surrounding copper mining and smelting plant in Jiangxi province was studied. The results showed that copper mining and smelting could increase the content of rare earth elements in soils and crops. Rare earth elements content in farmland soils of the surrounding Yinshan Lead Zinc Copper Mine and Guixi Smelting Plant varied from 112.42 to 397.02 mg x kg(-1) and 48.81 to 250.06 mg x kg(-1), and the average content was 254.84 mg x kg(-1) and 144.21 mg x kg(-1), respectively. The average contents of rare earth elements in soils in these two areas were 1.21 times and 0.68 times of the background value in Jiangxi province, 1.36 times and 0.77 times of the domestic background value, 3.59 times and 2.03 times of the control samples, respectively. Rare earth elements content in 10 crops of the surrounding Guixi Smelting Plant varied from 0.35 to 2.87 mg x kg(-1). The contents of rare earth elements in the leaves of crops were higher than those in stem and root. The contents of rare earth elements in Tomato, lettuce leaves and radish leaves were respectively 2.87 mg x kg(-1), 1.58 mg x kg(-1) and 0.80 mg x kg(-1), which were well above the hygienic standard limit of rare earth elements in vegetables and fruits (0.70 mg x kg(-1)). According to the health risk assessment method recommended by America Environmental Protection Bureau (USEPA), we found that the residents' lifelong average daily intake of rare earth elements was 17.72 mg x (kg x d)(-1), lower than the critical value of rare earth elements damage to human health. The results suggested that people must pay attention to the impact of rare earth elements on the surrounding environment when they mine and smelt copper ore in Jiangxi.

  2. Is the inherent potential of maize roots efficient for soil phosphorus acquisition?

    Yan Deng

    Full Text Available Sustainable agriculture requires improved phosphorus (P management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L. roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg(-1, and the threshold indicating a significant environmental risk was about 15 mg kg(-1, which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg(-1, indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots.

  3. Assessment of the ecological security of immobilized enzyme remediation process with biological indicators of soil health.

    Zhang, Ying; Dong, Xiaonan; Jiang, Zhao; Cao, Bo; Ge, Shijie; Hu, Miao


    This study used the enzymes extracted from an atrazine-degrading strain, Arthrobacter sp. DNS10, which had been immobilized by sodium alginate to rehabilitate atrazine-polluted soil. Meanwhile, a range of biological indices were selected to assess the ecological health of contaminated soils and the ecological security of this bioremediation method. The results showed that there was no atrazine detected in soil samples after 28 days in EN+AT (the soil containing atrazine and immobilized enzyme) treatment. However, the residual atrazine concentration of the sample in AT (the soil containing atrazine only) treatment was about 5.02 ± 0.93 mg kg(-1). These results suggest that the immobilized enzyme exhibits an excellent ability in atrazine degradation. Furthermore, the immobilized enzyme could relieve soil microbial biomass carbon and soil microbial respiration intensity to 772.33 ± 34.93 mg C kg(-1) and 5.01 ± 0.17 mg CO(2) g(-1) soil h(-1), respectively. The results of the polymerase chain reaction-degeneration gradient gel electrophoresis experiment indicated that the immobilized enzyme also could make the Shannon-Wiener index and evenness index of the soil sample increase from 1.02 and 0.74 to 1.51 and 0.84, respectively. These results indicated that the immobilized enzymes not only could relieve the impact from atrazine on the soil, but also revealed that the immobilized enzymes did no significant harm on the soil ecological health.

  4. Effectiveness of 3,4-Dimethylpyrazole Phosphate as Nitrification Inhibitor in Soil as Influenced by Inhibitor Concentration,Application Form,and Soil Matric Potential



    The efficacy of nitrification inhibitors depends on soil properties and environmental conditions.The nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) was investigated in a sandy loam and a loamy soil to study its effectiveness as influenced by inhibitor concentration,application form,and soil matric potential.DMPP was applied with concentrations up to 34.6 mg DMPP kg-1 soil as solution or as ammonium-sulfate/ammonium-nitrate granules formulated with DMPP.DMPP inhibited the oxidation of ammonium in both soils,but this effect was more pronounced in the sandy loam than in the loamy soil When applied as solution,increasing DMPP concentrations up to 7 mg DMPP kg-1 soil had no influence on the inhibition.The effectiveness of DMPP formulated as fertilizer granules was superior to the liquid application of DMPP and NH+,particularly in the loamy soil.Without DMPP,a decline in soil matric potential down to -600 kPa decreased nitrification in both soils,but this effect was more pronounced in the sandy loam than in the loamy soil.DMPP was most effective in the sandy loam particularly under conditions of higher soil moisture,i.e.,under conditions favorable for nitrate leaching.

  5. Distribution patterns of typical enzyme activities in tundra soils on the Fildes Peninsula of maritime Antarctica

    DING Wei; WANG Qing; ZHU Renbin; MA Dawei


    Soil enzyme activities can be used as indicators of microbial activity and soil fertility. In this paper, the activities of invertase (IA), phosphatase (PA) and urease (UA) were investigated in tundra soils collected from marine animal colonies, areas of human activity and background areas on Fildes Peninsula, maritime Antarctica. Soil enzyme activities were in the range of 1.0–82.7 mg·kg-1·h-1 for IA, 0.2–8.2 mg·kg-1·h-1 for PA and 0.2–39.8 mg·kg-1·h-1 for UA. The spatial distribution patterns for soil enzyme activities corresponded strongly with marine animal activity and human activity. Significantly higher soil IA and PA activities occurred in penguin colony soils, whereas seal colony soils showed higher UA activity. Statistical analysis indicated that soil IA activity was controlled by the levels of soil nutrients (TOC, TN and TP), PA activity was closely related with TP, and UA activity was affected by the soil pH. Overall, the deposition amount of penguin guano or seal excreta could impact the distribution of enzyme activity in Antarctic tundra soils. Multiple stepwise regression models were established between the enzyme activities, soil physicochemical properties and heavy metals Cu and Zn ([IA]=0.7[TP]–0.2[Cu]+22.3[TN]+15.1, [PA]=0.3[TP]+0.03[Mc]+0.2, [UA]=16.7[pH]–0.5[Cu]+ 0.4[Zn]–72.6). These models could be used to predict enzyme activities in the tundra soils, which could be helpful to study the effects of marine animal activity and environmental change on tundra ecosystems in maritime Antarctica.

  6. Mercury speciation and effects on soil microbial activities.

    Tazisong, Irenus A; Senwo, Zachary N; Williams, Miranda I


    To study Hg toxicity on soil microbes and their activities, it is necessary to understand its various forms in soils. The objectives of this study were to investigate Hg speciation in four soil types spiked with Hg (300 mg kg(-1) soil) and its effects on soil microbial respiration and enzymes (amidohydrolases and phosphatase) activities. An assessment of the chemical forms, amounts, reactions, and mobility of Hg in soils and sediments is of significant importance to improve and maintain soil and environmental health and sustainability. Mercury speciation analysis was investigated under acidic and alkaline conditions using a modified sequential procedure, which differentiates Hg into the four distinct fractions. Soil microbial respiration and enzymes activities were determined under laboratory settings, by incubating the soils at 25°C for 30 days, and then determining the amount of CO(2) evolved. Speciation results revealed that the water soluble form was the least, with soil types investigated irrespective of the pH condition, while the residual fraction was the most abundant (> 80%) in Canisteo, Houston, and Ketona soils under acidic conditions and soil. Under alkaline conditions, the residual fraction was ≤ 70% in Canisteo, Houston, and ketona and ≤ 29% in Decatur soil. The exchangeable fraction was the second most abundant fraction in the soils used ranging from 3.7-50.0% under acid conditions and 16.9-52.1% under alkaline conditions indicating that Hg desorption was found to be more favorable under alkaline than acidic conditions. Soil respiration was suppressed by Hg especially at the 100 mg kg(-1) concentration level. Amidohydrolases and phosphatases' response in the presence of Hg was variable. Amidohydrolases were more sensitive to Hg (18-90%) than phosphatase (0-35%) in all soils. This study demonstrated that the forms in which Hg exist in soils may determine its bioavailability and toxicity. Also microbial respiration and enzyme activities are

  7. The effect of plowing under green manure on the soil microorganism and fertility in tobacco cultivation red soil%绿肥翻压对烟地红壤微生物及土壤养分的影响

    陈晓波; 官会林; 郭云周; 洪丽芳; 任石所; 曹卫东


    To explore the biological mechanisms of the green manure to improve fertility of tobacco cultivation red soil, the effects of purple green manure plowing and wheat stubble plowing on microorganisms, soil enzyme activity and nutrient content of tobacco cultivation red soil were studied with the control of fallow land. The results showed that: bacteria, actinomy-cetes, soil enzyme activity, soil organic matter and nutrient content of green manure treated soil were higher than those of wheat stubble treated land and those of fallow land, changes in differences were significant (p <0.05) or highly significant (p <0. 01) , and fungi of wheat stuble were higher than those. Green manure plowing land , wheat stubble plowing land and fallow land to compare; soil bacteria in Yuezhou test area were increased 1.74 × 10 6 , 2. 61 × 10 6 cfu · g-1, actinomy-cetes increased 1. 35 × 10 4, 0.65 × 10 4 cfu · g-1. Soil urease increased 1.50, 1.68 mg · g-1, acid phosphatase increased 2. 90, 3. 09 mg · g-1, catalase increased 1.20, 2. 54 Ml · g-1, polyphenol oxidase enzyme increased 1.91, 7. 58 mg ? Kg-1, soil organic matter increased 16. 36, 26. 22 g · kg-1, soil available N increased 42. 52, 54.31 mg- kg-1, soil a-vaikble P increased 6.22, 7. 57 mg · kg-1, soil bacteria in Jinning test area increased 2. 52 × 10 6, 3.95 × l0 6 cfu ? G-1 , actinomycetes increased 1.17 × 10 4, 1. 62 × 10 4 cfu · g-1, soil urease increased 1. 77 , 2. 00 mg · g-1, acid phosphatase increased 1. 13, 1. 24 mg · g-1, catalase increased 1.45, 2.19 Ml · g-1, polyphenol oxidase increased 4. 81, 11. 34 mg · kg-1, soil organic matter increased 10.18, 19.43 g · kg-1, soil available N increased 41. 34, 54. 43 mg · kg-1, soil available P increased 4.79, 5. 86 mg · kg-1.%为探讨绿肥对烟地红壤改良培肥的生物机制,试验以冬闲地为对照,研究了紫花苕绿肥翻压及麦茬翻压对烟地红壤微生物、土壤酶活性及养分含量的影响.结果表明,绿肥翻

  8. Response of Tomato on Calcareous Soils to Different Seedbed Phosphorus Application Rates

    ZHANG Xiao-Sheng; LIAO Hong; CHEN Qing; P. CHRISTIE; LI Xiao-Lin; ZHANG Fu-Suo


    Field experiments were conducted with five rates (0, 75, 150, 225, and 450 kg P2O5 ha-1) of seedbed P fertilizer application to investigate the yield of tomato in response to fertilizer P rate on calcareous soils with widely different levels of Olsen P (13-142 mg kg-1) at 15 sites in some suburban counties of Beijing in 1999. Under the condition of no P fertilizer application, tomato yield generally increased with an increase in soil test P levels, and the agronomic level for soil testing P measured with Olsen method was 50 or 82 mg kg-1 soil to achieve 85% or 95% of maximum tomato yield, respectively. With regard to marketable yield, in the fields where Olsen-P levels were < 50 mg kg-1, noticeable responses to applied P were observed. On the basis of a linear plateau regression, the optimum seedbed P application rate in the P-insufficient fields was 125 kg P2O5 ha-1 or about 1.5-2 times the P removal from harvested tomato plants. In contrast, in fields with moderate (50 < Olsen P < 90 mg kg-1) or high (Olsen P > 90 mg kg-1) available P, there was no marked effect on tomato fruit yield. Field survey data indicated that in most fields with conventional P management, a P surplus typically occurred. Thus, once the soil test P level reached the optimum for crop yield, it was recommended that P fertilizer application be restricted or eliminated to minimize negative environmental effects.

  9. Soil biochemical properties in brown and gray mine soils with and without hydroseeding

    Thomas, C.; Sexstone, A.; Skousen, J.


    Surface coal mining in the eastern USA disturbs hundreds of hectares of land every year and removes valuable and ecologically diverse eastern deciduous forests. Reclamation involves restoring the landscape to approximate original contour, replacing the topsoil, and revegetating the site with trees and herbaceous species to a designated post-mining land use. Re-establishing an ecosystem of ecological and economic value as well as restoring soil quality on disturbed sites are the goals of land reclamation, and microbial properties of mine soils can be indicators of restoration success. Reforestation plots were constructed in 2007 using weathered brown sandstone or unweathered gray sandstone as topsoil substitutes to evaluate tree growth and soil properties at Arch Coal's Birch River mine in West Virginia, USA. All plots were planted with 12 hardwood tree species and subplots were hydroseeded with a herbaceous seed mix and fertilizer. After 6 years, the average tree volume index was nearly 10 times greater for trees grown in brown (3853 cm3) compared to gray mine soils (407 cm3). Average pH of brown mine soils increased from 4.7 to 5.0, while gray mine soils declined from 7.9 to 7.0. Hydroseeding doubled tree volume index and ground cover on both mine soils. Hydroseeding doubled microbial biomass carbon (MBC) on brown mine soils (8.7 vs. 17.5 mg kg-1), but showed no effect on gray mine soils (13.3 vs. 12.8 mg kg-1). Hydroseeding also increased the ratio of MBC to soil organic C in both soils and more than tripled the ratio for potentially mineralizable nitrogen (PMN) to total N. Brown mine soils were a better growth medium than gray mine soils and hydroseeding was an important component of reclamation due to improved biochemical properties and microbial activity in mine soils.

  10. Phosphate fertilizer affected rhizospheric soils: speciation of cadmium and phytoremediation by Chlorophytum comosum.

    Wang, Youbao; Zhu, Chengfeng; Yang, Hongfei; Zhang, Xiaowei


    Experiments were conducted to investigate the effect of phosphate fertilization on chemical speciation of cadmium (Cd) in the rhizospheric soil of Chlorophytum comosum, a potential cadmium hyperaccumulator. The results revealed that when 200 mg kg(-1) phosphate was applied into the soil, the Cd contents in the exchangeable fraction (EXC), carbonate-binding fraction (CA), and Fe-Mn oxides-binding fraction (Fe-Mn) were the highest, and the Cd content in the residual fraction (RES) was the lowest. Phosphate fertilization could enhance Cd conversion from RES into CA and weak RES, thereby improving the bioavailability of Cd and enhancing Cd enrichment and adsorption by C. comosum. The total Cd content in the soil was reduced by 10.15 mg kg(-1) in the planted group, which was significantly different from the control group (p soil by C. comosum.

  11. Rare earth elements and titanium in plants, soils and groundwaters in the alkaline-ultramafic complex of Salitre, MG Brazil

    Ceccantini, G. [Instituto de Biociencias, Sao Paulo, (Brazil). Dept. de Botanica; Figueiredo, A.M.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Radioquimica; Sondag, F.; Soubies, F. [ORSTOM, 93 - Bondy (France); Soubies, F. [Universite Paul Sabatier, 31 - Toulouse (France)


    The contents of rare earth elements (REE) and titanium in various plant species, in groundwaters and in soils from the alkaline-ultramafic complex of Salitre, have been determined. Due to the the particular mineralogy of the bedrock, REE and Ti exhibit high concentrations in the soils. Despite this, plants generally present REE concentrations within the ranges usually found in plants, and the transfer factor from soil to plant is at least ten times below the range reported in the literature, confirming that the concentrations of REE in the plants are widely independent of the soil content. All species present normalized patterns similar to those of the soils, characterized by an enrichment in light REE. Several plants show Ti concentrations about three times higher than the reference values. It is suggested that in the studied ecosystem, the plant metabolism affect the REE distribution in the groundwaters, leading to an enrichment of the superficial waters in heavy REE

  12. Copper content and its distribution in soils of Tibet


    The copper (Cu) content in 205 soil samples (0-20 cm) of Tibet, covering 5 soil classes,were analyzed. The results showed as follows: (1) the average content of Cu was 19.6 mg kg-1 (CV=49.28%); (2) the content of Cu in Tibetan soils was lower than the average level of China; (3) the content of Cu gradually decreased from the southeast to the northwest which was consistent with the direction of changes in the zonal successions of soil in Tibet; (4) Cu contents in Tibetan soils varied with soil properties, particularly soil parent materials that Cu contents were remarkably enriched in soils derived from shale materials.

  13. Survival, growth, detoxifying and antioxidative responses of earthworms (Eisenia fetida) exposed to soils with industrial DDT contamination.

    Shi, Yajuan; Zhang, Qiangbin; Huang, Dunqi; Zheng, Xiaoqi; Shi, Yajing


    The survival, growth, activity of the biotransformation system phase II enzyme glutathione-S-transferase (GST) and the oxidative defense enzyme catalase (CAT) of earthworms exposed to the contaminated soils from a former DDT plant and reference soils were investigated, and compared with the corresponding indicators in simulated soil-earthworm system, unpolluted natural soils with spiked-in DDT series, to identify the toxic effects of DDT on earthworms and their cellular defense system in complex soil system. The results indicated that DDT level in the contaminated soils was significantly higher than that in the reference soils with similar level of other pollutants and soil characters. The mortality, growth inhibition rates, GST and CST activities of earthworms exposed to the contaminated soils were significantly higher than that in reference soils. The contribution of historical DDT in contaminated soils to earthworms was confirmed by the DDT spiked tests. DDT spiked in soils at rates of higher than 200 mg·kg(-1) was significantly toxic to both the survival and the growth of earthworms. DDT significantly stimulated GST and CAT activity in earthworms after 14 days. The CAT and GST activities were also stimulated by DDT exposure at rates of 100 mg·kg(-1) after chronic exposure (42 days). The results provide implications for validating the extrapolation from laboratory simulated soils criteria to contaminated soils and for making site risk assessments.

  14. Stabilising metal(loid)s in soil with iron and aluminium-based products: microbial, biochemical and plant growth impact.

    Garau, Giovanni; Silvetti, Margherita; Castaldi, Paola; Mele, Elena; Deiana, Pietrino; Deiana, Salvatore


    Four iron and aluminium-based products, including red mud (RM), hematite (Fe2O3), an iron-rich water treatment residual (Fe-WTR) and amorphous Al hydroxide (Al-OH), were evaluated for their effectiveness at stabilising As and heavy metals (i.e. Cd, Cu, Pb, Zn) in a circumneutral contaminated soil [As (2105 mg kg(-1)), Cd (18 mg kg(-1)), Cu (264 mg kg(-1)), Pb (710 mg kg(-1)), Zn (522 mg kg(-1))]. Treatment impacts on soil microbial and biochemical features (i.e. microbial biomass-C, microbial counts, 16S rRNA PCR-TTGE of culturable bacteria, dehydrogenase, urease and β-glucosidase activity, Biolog derived parameters-AWCD and richness) as well as bean (Phaseolus vulgaris) and wheat (Triticum vulgare) growth were also assessed. After 6 months equilibration, all the amendments (application rate 3% w/w) but RM reduced labile As while only Al-OH reduced the concentration of water-soluble heavy metals. Despite the highest bioavailability of contaminants, most of the soil microbial and biochemical features monitored (i.e. microbial biomass-C, total bacterial counts, dehydrogenase activity and AWCD) were significantly higher in the RM-soil. Bean germination was completely inhibited in RM-soil while wheat growth was similar to that of the control. The Al-OH treatment was best overall, promoting microbial abundance, diversity and activity while increasing bean and wheat growth and reducing As accumulated in plant shoots. Results suggest that Al-OH is a suitable candidate for field evaluations while the use of RM in the remediation of circumneutral or subalkaline contaminated soils should be reconsidered.

  15. Versatility of Streptomyces sp. M7 to bioremediate soils co-contaminated with Cr(VI) and lindane.

    Aparicio, JuanDaniel; Solá, María Zoleica Simón; Benimeli, Claudia Susana; Amoroso, María Julia; Polti, Marta Alejandra


    The aim of this work was to study the impact of environmental factors on the bioremediation of Cr(VI) and lindane contaminated soil, by an actinobacterium, Streptomyces sp. M7, in order to optimize the process. Soil samples were contaminated with 25 µg kg(-1) of lindane and 50 mg kg(-1) of Cr(VI) and inoculated with Streptomyces sp. M7. The lowest inoculum concentration which simultaneously produced highest removal of Cr(VI) and lindane was 1 g kg(-1). The influence of physical and chemical parameters was assessed using a full factorial design. The factors and levels tested were: Temperature: 25, 30, 35°C; Humidity: 10%, 20%, 30%; Initial Cr(VI) concentration: 20, 50, 80 mg kg(-1); Initial lindane concentration: 10, 25, 40 µg kg(-1). Streptomyces sp. M7 exhibited strong versatility, showing the ability to bioremediate co-contaminated soil samples at several physicochemical conditions. Streptomyces sp. M7 inoculum size was optimized. Also, it was fitted a model to study this process, and it was possible to predict the system performance, knowing the initial conditions. Moreover, optimum temperature and humidity conditions for the bioremediation of soil with different concentrations of Cr(VI) and lindane were determined. Lettuce seedlings were a suitable biomarker to evaluate the contaminants mixture toxicity. Streptomyces sp. M7 carried out a successful bioremediation, which was demonstrated through ecotoxicity test with Lactuca sativa.

  16. Heavy metal distribution and chemical speciation in tailings and soils around a Pb-Zn mine in Spain.

    Rodríguez, L; Ruiz, E; Alonso-Azcárate, J; Rincón, J


    Soil pollution by lead, zinc, cadmium and copper was characterized in the mine tailings and surrounding soils (arable and pasture lands) of an old Spanish Pb-Zn mine. Sixty soil samples were analyzed, determining the total metal concentration by acid digestion and the chemical fractionation of Pb and Zn by the modified BCR sequential extraction method. Samples belonging to mine waste areas showed the highest values, with mean concentrations of 28,453.50 mg kg(-1) for Pb, 7000.44 mg kg(-1) for Zn, 20.57 mg kg(-1) for Cd and 308.48 mg kg(-1) for Cu. High concentrations of Pb, Zn and Cd were found in many of the samples taken from surrounding arable and pasture lands, indicating a certain extent of spreading of heavy metal pollution. Acidic drainage and wind transport of dust were proposed as the main effects causing the dispersion of pollution. Sequential extraction showed that most of the Pb was associated with non-residual fractions, mainly in reducible form, in all the collected samples. Zn appeared mainly associated with the acid-extractable form in mine tailing samples, while the residual form was the predominant one in samples belonging to surrounding areas. Comparison of our results with several criteria reported in the literature for risk assessment in soils polluted by heavy metals showed the need to treat the mine tailings dumped in the mine area.

  17. From soil to leaves--aluminum fractionation by single step extraction procedures in polluted and protected areas.

    Frankowski, Marcin; Zioła-Frankowska, Anetta; Siepak, Jerzy


    The paper presents the fractionation of aluminum in the samples of soil and plants of different species using a selective single-step extraction method. The study was conducted in the area located near a chemical plant, which for many years served as a post-crystallization leachate disposal site storing chemical waste (sector I), and in the area around the site: in Wielkopolski National Park, Rogalin Landscape Park and toward the infiltration ponds at the "Dębina" groundwater well-field for the city of Poznań (Poland) (sector II). The results of aluminum fractionation in samples of soil, leaves and plants showed heavy pollution with aluminum, especially in the water soluble aluminum fraction - Alsw (maximum concentration of aluminum in soil extract was 234.8 ± 4.8 mg kg(-1), in the leaves of Betula pendula it was 107.4 ± 1.8 mg kg(-1) and in the plants of Artemisia vulgaris (root) and Medicago sativa (leaves) it amounted to 464.7 ± 10.7 mg kg(-1)and 146.8 ± 1.2 mg kg(-1) respectively). In addition, the paper presents the problem of organic aluminum fractionation in biological samples and it shows the relationship between aluminum concentration in soil and the analysed woody and herbaceous species.

  18. Bioremediation of Cd and carbendazim co-contaminated soil by Cd-hyperaccumulator Sedum alfredii associated with carbendazim-degrading bacterial strains.

    Xiao, Wendan; Wang, Huan; Li, Tingqiang; Zhu, Zhiqiang; Zhang, Jie; He, Zhenli; Yang, Xiaoe


    The objective of this study was to develop a bioremediation strategy for cadmium (Cd) and carbendazim co-contaminated soil using a hyperaccumulator plant (Sedum alfredii) combined with carbendazim-degrading bacterial strains (Bacillus subtilis, Paracoccus sp., Flavobacterium and Pseudomonas sp.). A pot experiment was conducted under greenhouse conditions for 180 days with S. alfredii and/or carbendazim-degrading strains grown in soil artificially polluted with two levels of contaminants (low level, 1 mg kg(-1) Cd and 21 mg kg(-1) carbendazim; high level, 6 mg kg(-1) Cd and 117 mg kg(-1) carbendazim). Cd removal efficiencies were 32.3-35.1 % and 7.8-8.2 % for the low and high contaminant level, respectively. Inoculation with carbendazim-degrading bacterial strains significantly (P soil microbial biomass, dehydrogenase activities and microbial diversities by 46.2-121.3 %, 64.2-143.4 %, and 2.4-24.7 %, respectively. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis revealed that S. alfredii stimulated the activities of Flavobacteria and Bradyrhizobiaceae. The association of S. alfredii with carbendazim-degrading bacterial strains enhanced the degradation of carbendazim by changing microbial activity and community structure in the soil. The results demonstrated that association of S. alfredii with carbendazim-degrading bacterial strains is promising for remediation of Cd and carbendazim co-contaminated soil.

  19. Effect of silver nano-particles on soil microbial growth, activity and community diversity in a sandy loam soil.

    Samarajeewa, A D; Velicogna, J R; Princz, J I; Subasinghe, R M; Scroggins, R P; Beaudette, L A


    Silver nano-particles (AgNPs) are widely used in a range of consumer products as a result of their antimicrobial properties. Given the broad spectrum of uses, AgNPs have the potential for being released to the environment. As a result, environmental risks associated with AgNPs need to be assessed to aid in the development of regulatory guidelines. Research was performed to assess the effects of AgNPs on soil microbial activity and diversity in a sandy loam soil with an emphasis on using a battery of microbial tests involving multiple endpoints. The test soil was spiked with PVP coated (0.3%) AgNPs at the following concentrations of 49, 124, 287, 723 and 1815 mg Ag kg(-1) dry soil. Test controls included an un-amended soil; soil amended with PVP equivalent to the highest PVP concentration of the coated AgNP; and soil amended with humic acid, as 1.8% humic acid was used as a suspension agent for the AgNPs. The impact on soil microbial community was assessed using an array of tests including heterotrophic plate counting, microbial respiration, organic matter decomposition, soil enzyme activity, biological nitrification, community level physiological profiling (CLPP), Ion Torrent™ DNA sequencing and denaturing gradient gel electrophoresis (DGGE). An impact on microbial growth, activity and community diversity was evident from 49 to 1815 mg kg(-1) with the median inhibitory concentrations (IC50) as low as 20-31 mg kg(-1) depending on the test. AgNP showed a notable impact on microbial functional and genomic diversity. Emergence of a silver tolerant bacterium was observed at AgNP concentrations of 49-287 mg kg(-1) after 14-28 days of incubation, but not detectable at 723 and 1815 mg kg(-1). The bacterium was identified as Rhodanobacter sp. The study highlighted the effectiveness of using multiple microbial endpoints for inclusion to the environmental risk assessment of nanomaterials.

  20. Changes in Soil Phosphorus Fractions Following Woody Plant Invasion of Grassland

    Boutton, T. W.; Kantola, I. B.; Filley, T. R.


    Many grass-dominated ecosystems around the world have experienced woody plant encroachment over the last century due to livestock grazing, fire suppression, and/or changes in climate and atmospheric chemistry. In the Rio Grande Plains of Texas, subtropical thorn woodlands dominated by N-fixing tree legumes have largely replaced grasslands and altered the biogeochemistry of this region. The purpose of this study was to assess the impact of this grassland-to-woodland transition on the size, distribution, and availability of soil P pools. A modified Hedley method was employed to fractionate soil P into pools based on organic and inorganic forms and relative plant-availability. Soil samples (0-10 cm) were collected in remnant grasslands and near the centers of woody plant clusters ranging in age from 14 to 86 yrs in a subtropical savanna parkland in southern Texas. Soil P was fractionated into resin-extractable inorganic P, bicarbonate-extractable organic and inorganic P, hydroxide-extractable organic and inorganic P, acid-extractable inorganic P, and residual inorganic P forms. P concentrations in these fractions were determined by colorimetry, and soil total P was determined by lithium fusion. Organic P was calculated from the difference between total and inorganic P. Total P in whole soils increased dramatically from 98 mg P kg-1 soil in remnant grasslands to 168 mg P kg-1 soil in the oldest woody plant stands (70-85 yrs). P concentrations in all pools increased linearly with increasing woody plant stand age except acid-extractable phosphorus. The most dramatic increases were observed in the resin-extractable fraction (plant-available P), which increased from 3 to 13 mg P kg-1 soil, and in hydroxide-extractable P (the majority of the organic P in the system), which increased from 15 mg P kg-1 soil in grasslands to 26 mg P kg-1 soil in the wooded clusters. Although the exact mechanisms by which soil P increases following woody invasion remain unknown, we suggest that

  1. Effect of various amendments on heavy mineral oil bioremediation and soil microbial activity.

    Lee, Sang-Hwan; Oh, Bang-Il; Kim, Jeong-gyu


    To examine the effects of amendments on the degradation of heavy mineral oil, we conducted a pilot-scale experiment in the field for 105 days. During the experiment, soil samples were collected and analyzed periodically to determine the amount of residual hydrocarbons and evaluate the effects of the amendments on microbial activity. After 105 days, the initial level of contamination (7490+/-480 mg hydrocarbon kg(-1) soil) was reduced by 18-40% in amended soils, whereas it was only reduced by 9% in nonamended soil. Heavy mineral oil degradation was much faster and more complete in compost-amended soil than in hay-, sawdust-, and mineral nutrient-amended soils. The enhanced degradation of heavy mineral oil in compost-amended soil may be a result of the significantly higher microbial activity in this soil. Among the studied microbial parameters, soil dehydrogenase, lipase, and urease activities were strongly and negatively correlated with heavy mineral oil biodegradation (Pamended soil.

  2. Optimization of phytoremediation in Cd- contaminated soil by using Taguchi method in Spinacia oleracea

    Shirin Jahanbakhshi


    Full Text Available Phytoremediation is an environmental friendly technique to the cleanup of polluted soils, which combines the disciplines of plant, soil and microbiology. In this study, four factors including: cow manure, compost, urea fertilizer and Cd-resistant bacteria with three different levels in soils contaminated with cadmium using 50 mg kg-1 cadmium chloride (CdCl2.H2O were used to optimize of phytoremediation by Spinacia oleracea. Taguchi method has been used for experimental design. Results showed that significant factors in the order of importance were: cow manure, Cd- resistant batteries, urea fertilizer and compost. The optimum conditions for the selected levels were inoculate three types of bacteria (CC3, CC4, CC5, compost = 10 (g kg-1, urea fertilizer = 0.05 (g kg-1 and cow manure = 40 (g kg-1. The performance of` these conditions were estimated at 257.27 (mg kg-1. Cow manure is the most contribution to efficiency of phytoremediation in Spinacia oleracea.

  3. Modification of an existing in vitro method to predict relative bioavailable arsenic in soils.

    Whitacre, Shane; Basta, Nicholas; Stevens, Brooke; Hanley, Valerie; Anderson, Richard; Scheckel, Kirk


    The soil matrix can sequester arsenic (As) and reduces its exposure by soil ingestion. In vivo dosing studies and in vitro gastrointestinal (IVG) methods have been used to predict relative bioavailable (RBA) As. Originally, the Ohio State University (OSU-IVG) method predicted RBA As for soils exclusively from mining and smelting sites with a median of 5,636 mg As kg(-1). The objectives of the current study were to (i) evaluate the ability of the OSU-IVG method to predict RBA As for As contaminated soils with a wider range of As content and As contaminant sources, and (ii) evaluate a modified extraction procedure's ability to improve prediction of RBA As. In vitro bioaccessible (IVBA) by OSU-IVG and California Bioaccessibility Method (CAB) methods, RBA As, speciation, and properties of 33 As contaminated soils were determined. Total As ranged from 162 to 12,483 mg kg(-1) with a median of 73 mg kg(-1). RBA As ranged from 1.30 to 60.0% and OSU-IVG IVBA As ranged from 0.80 to 52.3%. Arsenic speciation was predominantly As(V) adsorbed to hydrous ferric oxide (HFO) or iron (Fe), manganese (Mn), and aluminum (Al) oxides. The OSU-IVG often extracted significantly less As in vitro than in vivo RBA As, in particularly for soils from historical gold mining. The CAB method, which is a modified OSU-IVG method extracted more As than OSU-IVG for most soils, resulting in a more accurate predictor than OSU-IVG, especially for low to moderately contaminated soils (<1,500 mg As kg(-1)) with RBA As = 0.81 IVBA As + 3.2, r(2) = 0.91. Copyright © 2017. Published by Elsevier Ltd.

  4. Heavy metals in vegetables and respective soils irrigated by canal, municipal waste and tube well waters.

    Ismail, Amir; Riaz, Muhammad; Akhtar, Saeed; Ismail, Tariq; Amir, Mamoona; Zafar-ul-Hye, Muhammad


    Heavy metal contamination in the food chain is of serious concern due to the potential risks involved. The results of this study revealed the presence of maximum concentration of heavy metals in the canal followed by sewerage and tube well water. Similarly, the vegetables and respective soils irrigated with canal water were found to have higher heavy metal contamination followed by sewerage- and tube-well-watered samples. However, the heavy metal content of vegetables under study was below the limits as set by FAO/WHO, except for lead in canal-water-irrigated spinach (0.59 mg kg(-1)), radish pods (0.44 mg kg(-1)) and bitter gourd (0.33 mg kg(-1)). Estimated daily intakes of heavy metals by the consumption of selected vegetables were found to be well below the maximum limits. However, a complete estimation of daily intake requires the inclusion of other dietary and non-dietary exposure sources of heavy metals.

  5. Arsenic in residential soil and household dust in Cornwall, south west England: potential human exposure and the influence of historical mining.

    Middleton, Daniel R S; Watts, Michael J; Beriro, Darren J; Hamilton, Elliott M; Leonardi, Giovanni S; Fletcher, Tony; Close, Rebecca M; Polya, David A


    Exposure to arsenic (As) via residential soil and dust is a global concern, in regions affected by mining or with elevated concentrations present in underlying geology. Cornwall in south west England is one such area. Residential soil (n = 127) and household dust (n = 99) samples were collected from across Cornwall as part of a wider study assessing exposure to environmental As. Samples were analysed for total As (soil and dust samples) and human ingestion bioaccessible As (soil samples from properties with home-grown produce). Arsenic concentrations ranged from 12 to 992 mg kg(-1) in soil and 3 to 1079 mg kg(-1) in dust and were significantly higher in areas affected by metalliferous mineralisation. Sixty-nine percent of soils exceeded the 37 mg kg(-1) Category 4 Screening Level (C4SL), a generic assessment criteria for As in residential soils in England, which assumes 100% bioavailability following ingestion. The proportion of exceedance was reduced to 13% when the bioavailability parameter in the CLEA model was changed to generate household specific bioaccessibility adjusted assessment criteria (ACBIO). These criteria were derived using bioaccessibility data for a sub-set of individual household vegetable patch soils (n = 68). Proximity to former As mining locations was found to be a significant predictor of soil As concentration. This study highlights the value of bioaccessibility measurements and their potential for adjusting generic assessment criteria.

  6. Measured soil water concentrations of cadmium and zinc in plant pots and estimated leaching outflows from contaminated soils

    Holm, P.E.; Christensen, T.H.


    Soil water concentrations of cadmium and zinc were measured in plant pots with 15 contaminated soils which differed in origin, texture, pH (5.1-7.8) and concentrations of cadmium (0.2-17 mg Cd kg(-1)) and zinc (36-1300 mg Zn kg(-1)). The soil waters contained total concentrations of 0.5 to 17 mu g...... Cd L(-1) and 9 to 3600 mu g Zn L(-1), which were dominated by free metal ions as measured by an ion exchange-resin method. Annual leaching outflows were estimated from soil water concentrations to be 0.5-17 g Cd ha(-1) y(-1) and 9-3600 g Zn ha(-1) y(-1) per 100 mm of net percolation, corresponding...... to 0.1% per year of the total soil content of cadmium and zinc. The measured soil water concentrations of cadmium and zinc did not correlate linearly with the corresponding soil concentrations but correlated fairly well with concentrations measured in Ca(NO(3))(2) extracts of the soils and with soil...

  7. Effects of aluminium water treatment residuals, used as a soil amendment to control phosphorus mobility in agricultural soils.

    Ulén, Barbro; Etana, Ararso; Lindström, Bodil


    Phosphorus (P) leaching from agricultural soils is a serious environmental concern. Application of aluminium water treatment residuals (Al-WTRs) at a rate of 20 Mg ha(-1) to clay soils from central Sweden significantly increased mean topsoil P sorption index (PSI) from 4.6 to 5.5 μmol kg(-1) soil. Mean degree of P saturation in ammonium lactate extract (DPS-AL) significantly decreased from 17 to 13%, as did plant-available P (P-AL). Concentrations of dissolved reactive P (DRP) decreased by 10-85% in leaching water with Al-WTR treatments after exposure of topsoil lysimeters to simulated rain. Soil aggregate stability (AgS) for 15 test soils rarely improved. Three soils (clay loam, silty loam and loam sand) were tested in greenhouse pot experiments. Aluminium-WTR application of 15 or 30 ton ha(-1) to loam sand and a clay loam with P-AL values of 80-100 mg kg(-1) soil significantly increased growth of Italian ryegrass when fertilised with P but did not significantly affect growth of spring barley on any soil. Al-WTR should only be applied to soils with high P fertility where improved crop production is not required.

  8. Influence of ameliorating soil acidity with dolomite on the priming of soil C content and CO2 emission.

    Shaaban, Muhammad; Wu, Lei; Peng, Qi-An; van Zwieten, Lukas; Chhajro, Muhammad Afzal; Wu, Yupeng; Lin, Shan; Ahmed, Muhammad Mahmood; Khalid, Muhammad Salman; Abid, Muhammad; Hu, Ronggui


    Lime or dolomite is commonly implemented to ameliorate soil acidity. However, the impact of dolomite on CO2 emissions from acidic soils is largely unknown. A 53-day laboratory study was carried out to investigate CO2 emissions by applying dolomite to an acidic Acrisol (rice-rapeseed rotation [RR soil]) and a Ferralsol (rice-fallow/flooded rotation [RF soil]). Dolomite was dosed at 0, 0.5, and 1.5 g 100 g(-1) soil, herein referred to as CK, L, and H, respectively. The soil pH(H2O) increased from 5.25 to 7.03 and 7.62 in L and H treatments of the RR soil and from 5.52 to 7.27 and 7.77 in L and H treatments of the RF soil, respectively. Dolomite application significantly (p ≤ 0.001) increased CO2 emissions in both RR and RF soils, with higher emissions in H as compared to L dose of dolomite. The cumulative CO2 emissions with H dose of dolomite were greater 136% in the RR soil and 149% in the RF soil as compared to CK, respectively. Dissolved organic carbon (DOC) and microbial biomass carbon (MBC) increased and reached at 193 and 431 mg kg(-1) in the RR soil and 244 and 481 mg kg(-1) in the RF soil by H treatments. The NH4(-)-N and NO3(-)-N were also increased by dolomite application. The increase in C and N contents stimulated microbial activities and therefore higher respiration in dolomite-treated soil as compared to untreated. The results suggest that CO2 release in dolomite-treated soils was due to the priming of soil C content rather than chemical reactions.

  9. Effect of soil metal contamination on glyphosate mineralization: role of zinc in the mineralization rates of two copper-spiked mineral soils.

    Kim, Bojeong; Kim, Young Sik; Kim, Bo Min; Hay, Anthony G; McBride, Murray B


    A systematic investigation into lowered degradation rates of glyphosate in metal-contaminated soils was performed by measuring mineralization of [(14)C]glyphosate to (14)CO(2) in two mineral soils that had been spiked with Cu and/or Zn at various loadings. Cumulative (14)CO(2) release was estimated to be approximately 6% or less of the amount of [(14)C]glyphosate originally added in both soils over an 80-d incubation. For all but the highest Cu treatments (400 mg kg(-1)) in the coarse-textured Arkport soil, mineralization began without a lag phase and declined over time. No inhibition of mineralization was observed for Zn up to 400 mg kg(-1) in either soil, suggesting differential sensitivity of glyphosate mineralization to the types of metal and soil. Interestingly, Zn appeared to alleviate high-Cu inhibition of mineralization in the Arkport soil. The protective role of Zn against Cu toxicity was also observed in the pure culture study with Pseudomonas aeruginosa, suggesting that increased mineralization rates in high Cu soil with Zn additions might have been due to alleviation of cellular toxicity by Zn rather than a mineralization specific mechanism. Extensive use of glyphosate combined with its reduced degradation in Cu-contaminated, coarse-textured soils may increase glyphosate persistence in soil and consequently facilitate Cu and glyphosate mobilization in the soil environment.

  10. Heavy metal accumulation by poplar in calcareous soil with various degrees of multi-metal contamination: implications for phytoextraction and phytostabilization.

    Hu, Yahu; Nan, Zhongren; Su, Jieqiong; Wang, Ning


    The object of this study was to assess the capacity of Populus alba L. var. pyramidalis Bunge for phytoremediation of heavy metals on calcareous soils contaminated with multiple metals. In a pot culture experiment, a multi-metal-contaminated calcareous soil was mixed at different ratios with an uncontaminated, but otherwise similar soil, to establish a gradient of soil metal contamination levels. In a field experiment, poplars with different stand ages (3, 5, and 7 years) were sampled randomly in a wastewater-irrigated field. The concentrations of cadmium (Cd), Cu, lead (Pb), and zinc (Zn) in the poplar tissues and soil were determined. The accumulation of Cd and Zn was greatest in the leaves of P. pyramidalis, while Cu and Pb mainly accumulated in the roots. In the pot experiment, the highest tissue concentrations of Cd (40.76 mg kg(-1)), Cu (8.21 mg kg(-1)), Pb (41.62 mg kg(-1)), and Zn (696 mg kg(-1)) were all noted in the multi-metal-contaminated soil. Although extremely high levels of Cd and Zn accumulated in the leaves, phytoextraction using P. pyramidalis may take at least 24 and 16 years for Cd and Zn, respectively. The foliar concentrations of Cu and Pb were always within the normal ranges and were never higher than 8 and 5 mg kg(-1), respectively. The field experiment also revealed that the concentrations of all four metals in the bark were significantly higher than that in the wood. In addition, the tissue metal concentrations, together with the NH4NO3-extractable concentrations of metals in the root zone, decreased as the stand age increased. P. pyramidalis is suitable for phytostabilization of calcareous soils contaminated with multiple metals, but collection of the litter fall would be necessary due to the relatively high foliar concentrations of Cd and Zn.

  11. Soil biochemical properties after six years in amended brown and gray mine soils in West Virginia

    Thomas, C.; Sexstone, A.; Skousen, J.


    Surface coal mining in the eastern USA disturbs hundreds of hectares of land every year and removes valuable and ecologically diverse eastern deciduous forests. Reclamation involves restoring the landscape to approximate original contour, replacing the topsoil, and revegetating the site with trees and herbaceous species to a designated post-mining land use. Re-establishing an ecosystem of ecological and economic value as well as restoring soil quality on disturbed sites are the goals of land reclamation, and microbial properties of mine soils can be indicators of restoration success. Reforestation plots were constructed in 2007 using weathered brown sandstone or unweathered gray sandstone as topsoil substitutes to evaluate tree growth and soil properties at Arch Coal's Birch River Mine in West Virginia, USA. All plots were planted with 12 hardwood tree species and subplots were hydroseeded with an herbaceous seed mix and fertilizer. After six years, average tree volume index was nearly ten times greater for trees grown in brown (3853 cm3) compared to gray mine soils (407 cm3). Average pH of brown mine soils increased from 4.7 to 5.0, while gray mine soils declined from 7.9 to 7.0. Hydroseeding doubled tree volume index and ground cover on both mine soils. Hydroseeding doubled microbial biomass carbon (MBC) on brown mine soils (8.7 vs. 17.5 mg kg-1), but showed no effect on gray (13.3 vs. 12.8 mg kg-1). Hydroseeding also increased the ratio of MBC to soil organic C in both soils and more than tripled the ratio for potentially mineralizable nitrogen (PMN) to total N. Brown mine soils were a better growth medium than gray mine soils and hydroseeding was an important component of reclamation due to improved biochemical properties and microbial activity in mine soils.

  12. Concentration and distribution of Cr and Ni in soils of Talcahuano, Chile.

    Tume, Pedro; Gonzalez, Elizabeth; King, Robert; Alvarez, Manuel; Roca, Nuria; Bech, Jaume


    Urban soils can serve as a recipient for a large amount of trace elements from multiple sources, including, municipal wastes, vehicular emissions and industrial wastes.Several researchers have pointed out the need for a better understanding of urban soils in order to assist in developing strategies to protect urban environments and human health against the longterm accumulation of trace elements.The objectives of this study were to (1) define the background levels of chromium (Cr) and nickel (Ni) in soil of Talcahuano; (2) evaluate the site contaminated by trace metals.In this study, 140 soil plots (420 samples: TS:0-10 cm; SS:10-20 cm and BS:150 cm) located approximately in a 1 km regular grid covering the Talcahuano city(94 square km) have been examined. Soil samples (Atomic Absorption Spectrophotometry. The median concentrations (mg kg-1) obtained include: Cr 134 (range 66.6 - 657) and Ni 56.1 (26.4 - 137). In weakly developed urban soils, Ni follows the same pattern without any real distinguishing features. Chromium displays slight surface enrichment (Cr content in topsoil (mg kg-1): 145±70; Cr content in basement (mg kg-1): 138 ± 53 ). However, the differences are not significative. Different methods were evaluated in order to facilitate the best diagnosis of contamination. First, the trace metal geochemical background was determined using basic descriptive statistics. The upper limit (Upper Whisker value) of the background content in mg•kg-1is 266 for Cr and 112 for Ni. Secondly, the basic descriptive statistics were then compared with Dutch guidelines, in order to evaluate whether the concentrations measured in soils were abnormally high or not. By comparing the results of the different methods, we estimate that 5% of the soils demonstrate anthropogenic signatures of Cr and Ni.The greatest enrichment anomalies in heavy metals were detected in top soil due to an unauthorized rubbish dump.

  13. Heavy metal distribution between contaminated soil and Paulownia tomentosa, in a pilot-scale assisted phytoremediation study: influence of different complexing agents.

    Doumett, S; Lamperi, L; Checchini, L; Azzarello, E; Mugnai, S; Mancuso, S; Petruzzelli, G; Del Bubba, M


    The distribution of Cd, Cu, Pb and Zn between a contaminated soil and the tree species Paulownia tomentosa was investigated in a pilot-scale assisted phytoremediation study. The influence of the addition of EDTA, tartrate and glutamate at 1, 5 and 10mM concentrations on metal accumulation by the plant and on metal mobilization in soil was evaluated. Root/shoot metal concentration ratios were in the range of 3-5 for Zn, 7-17 for Cu, 9-18 for Cd and 11-39 for Pb, depending on the type and concentration of complexing agent. A significant enhancement of metal uptake in response to complexing agent application was mainly obtained in roots for Pb (i.e. 359 mg kg(-1) for EDTA 10mM and 128 mg kg(-1) for the control), Cu (i.e. 594 mg kg(-1) for glutamate 10mM and 146 mg kg(-1) for the control) and, with the exception of glutamate, also for Zn (i.e. 670 mg kg(-1) for tartrate 10mM and 237 mg kg(-1) for the control). Despite its higher metal mobilization capacity, EDTA produced a metal accumulation in plants quite similar to those obtained with tartrate and glutamate. Consequently the concentration gradient between soil pore water and plant tissues does not seem to be the predominant mechanism for metal accumulation in Paulownia tomentosa and a role of the plant should be invoked in the selection of the chemical species taken up. Metal bioavailability in soil at the end of the experiment was higher in the trials treated with EDTA than in those treated with tartrate and glutamate, the latter not being significantly different from the control. These findings indicated the persistence of a leaching risk associated to the use of this chelator, while an increase of the environmental impact is not expected when glutamate and tartrate are applied.

  14. Accumulation of oxytetracycline and norfloxacin from saline soil by soybeans.

    Boonsaner, M; Hawker, D W


    Soil of former shrimp aquaculture facilities in Thailand may be contaminated by antibiotics (e.g. oxytetracycline and norfloxacin) and have elevated salinity. Therefore, reuse of this land can be problematic. The utility of soybean (Glycine max (L.) Merr.) for phytoremediation was investigated. The rate of germination and seedling emergence in prepared contaminated soil (conductivity 17.7 dS m(-1) from adding 70 mg sodium chloride g(-1) dry weight, 105 mg kg(-1) dry weight oxytetracycline and 55 mg kg(-1) dry weight norfloxacin) in sunlight was approximately 80% that of uncontaminated soil. This reduction was largely due to the high salinity. The antibiotics of interest degraded relatively rapidly in soil (half-life removal of NaCl from soil adjacent to plant roots was observed, most within two days. Wilting and defoliation occurred, but plants recovered after 10 days and maximum salt levels in plants exceeded 20,000 mg g(-1) dry weight with translocation from root to shoot tissue noted. Soybean plants also accumulated the antibiotics from prepared contaminated saline soil, but translocation from the roots was not observed. The results showed that soybean can be valuable for phytoremediation in these situations.

  15. [Effects of low molecular weight organic acids on speciation of exogenous Cu in an acid soil].

    Huang, Guo-Yong; Fu, Qing-Ling; Zhu, Jun; Wan, Tian-Ying; Hu, Hong-Qing


    In order to ascertain the effect of LMWOA (citric acid, tartaric acid, oxalic acid) on Cu-contaminated soils and to investigate the change of Cu species, a red soil derived from quartz sandstone deposit was added by Cu (copper) in the form of CuSO4 x 5H2O so as to simulate soil Cu pollution, keeping the additional Cu concentrations were 0, 100, 200, 400 mg x kg(-1) respectively. After 9 months, different LMWOA was also added into the simulated soil, keeping the additional LMWOAs in soil were 0, 5, 10, 20 mmol x kg(-1) respectively. After 2 weeks incubation, the modified sequential extraction method on BCR (European Communities Bureau of Reference) was used to evaluate the effects of these LMWOAs on the changes of copper forms in soil. The result showed that the percentage of weak acid dissolved Cu, the most effective form in the soil increased with three organic acids increase in quantity in the simulated polluted soil. And there was a good activation effect on Cu in the soil when organic acid added. Activation effects on Cu increased with concentration of citric acid increasing, but it showed a rise trend before they are basically remained unchanged in the case of tartaric acid and oxalic acid added in the soil. On the contrary, the state of the reduction of copper which was regarded as a complement for effective state decreased with the increased concentration of organic acid in the soil, especially with citric acid. When 20 mmol x kg(-1) oxalic acid and citric acid were added into the soil, the activation effect was the best; whereas for tartaric, the concentration was 10 mmol x kg(-1). In general, the effect on the changes of Cu forms in the soil is citric acid > tartaric acid > oxalic acid.

  16. Chelant soil-washing technology for metal-contaminated soil.

    Voglar, David; Lestan, Domen


    We demonstrate here, in a pilot-scale experiment, the feasibility of ethylenediaminetetraacetate (EDTA)based washing technology for soils contaminated with potentially toxic metals. Acid precipitation coupled to initial alkaline toxic metal removal and an electrochemical advanced oxidation process were used for average recovery of 76 +/- 2% of EDTA per batch and total recycle of water in a closed process loop. No waste water was generated; solid wastes were efficiently bitumen-stabilized before disposal. The technology embodiment, using conventional process equipment, such as a mixer for soil extraction, screen for soil/gravel separation, filter chamber presses for soil/liquid and recycled EDTA separation and soil rinsing, continuous centrifuge separator for removal of precipitated metals and electrolytic cells for process water cleansing, removed up to 72%, 25% and 66% of Pb, Zn and Cd from garden soil contaminated with up to 6960, 3797 and 32.6 mg kg(-1) of Pb, Zn and Cd, respectively, in nine 60kg soil batches. Concentrations of Pb and Zn remaining in the remediated soil and bioaccessible from the simulated human intestinal phase soil were reduced by 97% and 96% and were brought under the level of determination for Cd. In the most cost-effective operation mode, the material and energy costs of remediation amounted to 50.5 Euros ton(-1) soil and the total cost to 299 Euros ton(-1).

  17. Integrated micro-biochemical approach for phytoremediation of cadmium and zinc contaminated soils.

    Mani, Dinesh; Kumar, Chitranjan; Patel, Niraj Kumar


    The integrated potential of oilcake manure (OM), elemental sulphur (S(0)), Glomus fasciculatum and Pseudomonas putida by growing Helianthus annuus L for phytoremediation of cadmium and zinc contaminated soils was investigated under pot experiment. The integrated treatment (2.5 g kg(-1) OM, 0.8 g kg(-1) S(0) and co-inoculation with G. fasciculatum and P. putida promoted the dry biomass of the plant. The treatment was feasible for enhanced cadmium accumulation up to 6.56 and 5.25 mg kg(-1) and zinc accumulation up to 45.46 and 32.56 mg kg(-1) in root and shoot, respectively, which caused maximum remediation efficiency (0.73 percent and 0.25 percent) and bioaccumulation factor (2.39 and 0.83) for Cd and Zn, respectively showing feasible uptake (in mg kg(-1) dry biomass) of Cd (5.55) and Zn (35.51) at the contaminated site. Thus, authors conclude to integrate oilcake manure, S(0) and microbial co-inoculation for enhanced clean-up of cadmium and zinc-contaminated soils. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Rare earth element transfer from soil to navel orange pulp (Citrus sinensis Osbeck cv. Newhall) and the effects on internal fruit quality.

    Cheng, Jinjin; Ding, Changfeng; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang


    The effects of soil rare earth element (REE) on navel orange quality and safety in rare earth ore areas have gained great attention. This study investigated the transfer characteristics of REE from soil to navel orange pulp (Citrus sinensis Osbeck cv. Newhall) and examined the effects of soil REE on internal fruit quality in Xinfeng County, Jiangxi province, China. Path analysis showed that soil REE, pH, cation exchange capacity (CEC), and Fe oxide (Feox) significantly affected pulp REE concentrations. A Freundlich-type prediction model for pulp REE was established: log[REEpulp] = -1.036 + 0.272 log[REEsoil] - 0.056 pH - 0.360 log[CEC] + 0.370 log[Feox] (n = 114, R2 = 0.60). From the prediction model, it was inferred that even when soil REE and Feox were as high as 1038 mg kg-1 and 96.4 g kg-1, respectively, and pH and CEC were as low as 3.75 and 5.08 cmol kg-1, respectively, pulp REE concentrations were much lower than the food limit standard. Additionally, soil REE levels were significantly correlated with selected fruit quality indicators, including titratable acidity (r = 0.52, P soil REE ranging from 38.6 to 546 mg kg-1 had improved in internal fruit quality.

  19. Effect of Lanthanum Accumulation on Cation Exchange Capacity and Solution Composition of Red Soil


    Pot and adsorption-exchange experiments were carried out by collecting the soil samples from the surface layer (0~15 cm) of red soil at the Ecological Experiment Station of Red Soil, the Chinese Academy of Sciences, in Jiangxi Province of China. When concentration of the exogenous La3+ exceeded 400 mg kg-1, there was less non-exchangeable La3+ than exchangeable La3+ in the soil. Cation exchange capacity of the soil changed slightly with increasing concentration of the exogenous La3+ in both experiments. However, in the adsorption-exchange experiment, when concentration of the exogenous La3+ was higher than 300 mg kg-1, exchangeable basic cations decreased significantly, while exchangeable hydrogen and exchangeable aluminum increased significantly compared with the control treatments. The amounts of base cations (Ca2+, Mg2+, K+ and Na+) exchanged by La3+ in the supernatant solution increased with the concentration of the exogenous La3+, especially when concentration of the exogenous La3+ was higher than 50 mg kg-1.

  20. [Soil organic carbon variation of de-farming and wasteland during alteration of ecosystem in Billabong].

    Tu, Cheng-long; Liu, Cong-qiang; Wu, Yong-feng


    Four soil profile samples were collected in the middle of de-farming and wasteland billabong and around slopes, located at typical karst district of Guizhou province. Soil organic matter (SOC) content and delta Corg, were determined. SOC content ranged from 6.0 mg x kg(-1) to 92.3 mg x kg(-1), and decreased with depth at slope soil profiles. The range of value was bigger than that at billabong soil profile (6.3-26.7 mg x kg(-1)). The value of detla13 Corg, at slope profiles was between - 25.103% per hundred and - 23.666% per hundred, but variation direction of three slope soil profiles was different. The value of delta 13Corg, in billabong soil profile was between - 23.495% per hundred and - 20.809% per hundred, and increased with depth. The correlation between delta13 Csoc and C4-C,C3-C was significant (R = 0.884, n=7), influenced by new C3-C.

  1. Affects of mining activities on Cd pollution to the paddy soils and rice grain in Hunan province, Central South China.

    Du, Yan; Hu, Xue-Feng; Wu, Xiao-Hong; Shu, Ying; Jiang, Ying; Yan, Xiao-Juan


    Located in Central South China, Hunan province is rich in mineral resources. To study the influence of mining on Cd pollution to local agricultural eco-system, the paddy soils and rice grain of Y county in northern Hunan province were intensively monitored. The results were as follows: (1) Total Cd (T-Cd) content in the soils of the county ranges from 0.13 to 6.02 mg kg(-1), with a mean of 0.64 mg kg(-1), of which 57.5% exceed the allowable limit specified by the China Soil Environmental Quality Standards. T-Cd in the soils varies largely, with the coefficient of variation reaching 146.4%. The spatial distribution of T-Cd in the soils quite matches with that of mining and industries. The content of HCl-extractable Cd (HCl-Cd) in the soils ranges from 0.02 to 2.17 mg kg(-1), with a mean of 0.24 mg kg(-1). A significant positive correlation exists between T-Cd and HCl-Cd in the soils (r = 0.770, ρ soils (r = 0.091, ρ > 0.05), which suggests that the amount of Cd accumulating in the rice is more affected by its availability in the soils, rather than the total content. (4) The dietary intake of Cd via rice consumption in Y county is estimated to be 179.9 μg day(-1) person(-1) on average, which is far beyond the allowable limit specified by FAO/WHO and the target hazard quotients of Cd much higher than 1, suggesting the high risk on human health from Cd exposure.

  2. Disponibilidad de cinc, cobre, hierro y manganeso extraíble con DTPA en suelos de córdoba (Argentina y variables edáficas que la condicionan Availability of DTPA extractable zinc, copper, iron and manganese in Córdoba (Argentina soils and its relationship with other properties

    Eduardo Volmer Buffa


    Full Text Available Se midió el contenido en suelo de Cu, Zn, Fe y Mn extraíbles con DTPA y se relacionó con la materia orgánica, pH, tenor salino y cantidad de carbonatos en Molisoles, Entisoles y Alfisoles de la llanura chaco-pampeana, en la provincia de Córdoba, Argentina. Las muestras de suelo, colectadas en 48 situaciones, correspondientes a distintas condiciones texturales (desde franco limoso a franco arenoso, de acidez (débil acidez a alta alcalinidad y con salinidad baja a media, fueron contrastadas con valores de suficiencia para microelementos, obtenidos de la bibliografía. Se encontraron valores muy bajos de Cu en suelos arenosos (0,1-1 mg kg-1 y los mayores correspondieron a Argiudoles (PO (1,5 -2,5 mg kg-1. El Zn estuvo por debajo de 1 mg kg-1 en la mayoría de los sitios. El Mn presentó un rango de 23 a 85 mg kg-1 y el Fe de 21 a 68 mg kg-1, valores superiores a los considerados críticos y con los máximos en Argiudoles (PO. Las variables acidez y carbonatos se asociaron con el Cu, la materia orgánica y la salinidad con el Zn, todas con signo positivo.Cu, Zn, Fe and Mn DTPA extractable content and it relationship with organic matter, pH, salinity and lime were studied in 48 soils (Mollisol, Entisol and Alfisol from some geomorphic regions of the Chaco-Pampean plain of Cordoba (Argentina. Soils ranged from silty loam to loamy sandy texture, weak acidity to strong alcalinity, and low to medium salinity, they were sampled from 0 to 60 cm depth. Copper were at its critical range (0,1-1 only in sandy soils, with the highest contents (1.5 -2.5 mg kg-1 in Argiudolls. Zinc was below 1 mg kg-1 in most regions. Manganese (23-85 mg kg-1 and Fe (21-68 mg kg-1 were above their respective critical content in all regions, with highest contents in Argiudolls for both micronutrients. Zn, Cu and Mn distribution in depth profile, was associated with organic matter content. Soil variables lime and pH for Cu, and OM and salinity for Zn, were positively

  3. Exposure to inorganic arsenic in soil increases urinary inorganic arsenic concentrations of residents living in old mining areas.

    Hinwood, Andrea L; Sim, Malcolm R; Jolley, Damien; de Klerk, Nick; Bastone, Elisa B; Gerostamoulos, Jim; Drummer, Olaf H


    The short term human exposure studies conducted on populations exposed to high concentrations of inorganic arsenic in soil have been inconsistent in demonstrating a relationship between environmental concentrations and exposure measures. In Australia there are many areas with very high arsenic concentrations in residential soil most typically associated with gold mining activities in rural areas. This study aimed to investigate the relationship between environmental arsenic and urinary inorganic arsenic concentrations in a population living in a gold mining area (soil arsenic concentrations between 9 and 9900 mg kg(-1)), and a control population with low arsenic levels in soil (between 1 and 80 mg kg(-1)). Risk factors for increased urinary arsenic concentrations were also explored. There was a weak but significant relationship between soil arsenic concentrations and inorganic urinary arsenic concentration with a Spearman correlation coefficient of 0.39. When participants with greater than 100 mg kg(-1) arsenic in residential soil were selected, the coefficient increased to 0.64. The geometric mean urinary inorganic arsenic concentration for the exposed group was 1.64 microg L(-1) (risk factors. These results show that high concentrations of arsenic in soil can make a contribution to urinary inorganic arsenic concentrations.

  4. A study on zinc distribution in calcareous soils for cowpea (Vigna Unguiculata L.) and barely ( Hordeum Vulgare L.)

    Boroomand, Naser; Maleki, Mohammad Reza


    Compared to other cereals, such as wheat and barley cultivars which have low sensitivity to Zn deficiency, cowpea is sensitive to zinc (Zn) deficiency, however it extensively grows even in soils with deficient in Zn. A 8-week greenhouse experiment was conducted to study the response of cowpea and barely to Zn in calcareous soils with different DTPA- Zn. The soil samples were taken from soil surface up to 0.3 m in which their DTPA- Zn ranged from 0.5 to 3.5 mg kg-1. Shoot dry matter, concentration and uptake of Zn were found to be significantly correlated with soil DTPA- Zn in cowpea and barely. Critical deficiency level of Zn in cowpea was 1.3 mg kg-1 in soil and 28.5 mg kg-1 in shoot dry matter, however, to barely symptoms of Zn deficiency was not observed and concentration of Zn was higher than the critical level reported in literatures. Organic carbon (OC), calcium carbonate equivalent (CCE), pH and field capacity soil moisture content(FC) were significantly correlated with plant responses to Zn which were the most influenced characteristics to Zn uptake by plants.

  5. [Characteristics of Adsorption Leaching and Influencing Factors of Dimethyl Phthalate in Purple Soil].

    Wang, Qiang; Song, Jiao-yan; Zeng, Wei; Wang, Fa


    The typical soil-purple soil in Three Gorges Reservoir was the tested soil, the characteristics of adsorption leaching of dimethyl phthalate (DMP) in contaminated water by the soil, and the influencing factors in the process were conducted using soil column leaching experiment. The results showed that the parabolic equation was the best equation describing adsorption kinetics of DMP by soils. The concentration of DMP in the leaching solution had significant effect on the adsorption amounts of DMP. With the increasing concentration of DMP in the leaching solution, the adsorption capacities of DMP by purple soil increased linearly. The ionic strength and pH in leaching solution had significant effects on adsorption of DMP. On the whole, increasing of the ionic strength restrained the adsorption. The adsorption amounts at pH 5.0-7.0 were more than those under other pH condition. The addition of exogenous organic matter (OM) in purple soil increased the adsorption amount of DMP by purple soil. However, the adsorption amount was less than those with other addition amounts of exogenous OM when the addition of exogenous OM was too high (> or = 30 g x kg(-1)). The addition of surfactant sodium dodecylbenzene sulfonic acid (SDBS) in purple soil increased the adsorption amount of DMP by purple soil. The adsorption amount was maximal when the addition amount of SDBS was 50 mg x kg(-1). However, the adsorption amounts decreased with increasing addition amounts of SDBS although the adsorption amounts were still more than that of the control group, and the adsorption amount was almost equal to that of the control group when the addition amount of SDBS was 800 mg x kg(-1). Continuous leaching time affected the vertical distribution of DMP in the soil column. When the leaching time was shorter, the upper soil column adsorbed more DMP, while the DMP concentrations in upper and lower soil columns became similar with the extension of leaching time.

  6. Green manure addition to soil increases grain zinc concentration in bread wheat.

    Forough Aghili

    Full Text Available Zinc (Zn deficiency is a major problem for many people living on wheat-based diets. Here, we explored whether addition of green manure of red clover and sunflower to a calcareous soil or inoculating a non-indigenous arbuscular mycorrhizal fungal (AMF strain may increase grain Zn concentration in bread wheat. For this purpose we performed a multifactorial pot experiment, in which the effects of two green manures (red clover, sunflower, ZnSO4 application, soil γ-irradiation (elimination of naturally occurring AMF, and AMF inoculation were tested. Both green manures were labeled with 65Zn radiotracer to record the Zn recoveries in the aboveground plant biomass. Application of ZnSO4 fertilizer increased grain Zn concentration from 20 to 39 mg Zn kg-1 and sole addition of green manure of sunflower to soil raised grain Zn concentration to 31 mg Zn kg-1. Adding the two together to soil increased grain Zn concentration even further to 54 mg Zn kg-1. Mixing green manure of sunflower to soil mobilized additional 48 µg Zn (kg soil-1 for transfer to the aboveground plant biomass, compared to the total of 132 µg Zn (kg soil-1 taken up from plain soil when neither green manure nor ZnSO4 were applied. Green manure amendments to soil also raised the DTPA-extractable Zn in soil. Inoculating a non-indigenous AMF did not increase plant Zn uptake. The study thus showed that organic matter amendments to soil can contribute to a better utilization of naturally stocked soil micronutrients, and thereby reduce any need for major external inputs.

  7. Biological Activity Assessment in Mexican Tropical Soils with Different Hydrocarbon Contamination Histories.

    Riveroll-Larios, Jessica; Escalante-Espinosa, Erika; Fócil-Monterrubio, Reyna L; Díaz-Ramírez, Ildefonso J

    The use of soil health indicators linked to microbial activities, such as key enzymes and respirometric profiles, helps assess the natural attenuation potential of soils contaminated with hydrocarbons. In this study, the intrinsic physicochemical characteristics, biological activity and biodegradation potential were recorded for two soils with different contamination histories (>5 years and contaminated soil samples. Soil suspensions were tested as microbial inocula in biodegradation potential assays using contaminated perlite as an inert support. The basal respiratory rate of the recently contaminated soil was 15-38 mg C-CO2 kg(-1) h(-1), while the weathered soil presented a greater basal mineralisation capacity of 55-70 mg C-CO2 kg(-1) h(-1). The basal levels of lipase and dehydrogenase were significantly greater than those recorded in non-contaminated soils (551 ± 21 μg pNP g(-1)). Regarding the biodegradation potential assessment, the lipase (1000-3000 μg pNP g(-1) of perlite) and dehydrogenase (~3000 μg INF g(-1) of perlite) activities in the inoculum of the recently contaminated soil were greater than those recorded in the inoculum of the weathered soil. This was correlated with a high mineralisation rate (~30 mg C-CO2 kg(-1) h(-1)) in the recently contaminated soil and a reduction in hydrocarbon concentration (~30 %). The combination of an inert support and enzymatic and respirometric analyses made it possible to detect the different biodegradation capacities of the studied inocula and the natural attenuation potential of a recently contaminated soil at high hydrocarbon concentrations.

  8. Arsenic and Antimony Content in Soil and Plants from Baia Mare Area, Romania

    Gabriela Oprea


    Full Text Available Problem statement: The objective of this research was to evaluate the degree of soil contamination with arsenic and antimony in Baia Mare, a nonferrous mining and metallurgical center located in the North West region of Romania. The soil in the area is affected by the emissions of powders containing metals from metallurgical factories. Previous studies indicated the soil contamination with copper, zinc, cadmium and lead, but there is few data about the actual level of soil pollution with arsenic and antimony. Approach: The soil samples were collected from 2 districts of Baia Mare: Ferneziu, which is located in the proximity of a lead smelter and Săsar district which is located along the Sasar River in the preferential direction of the wind over a metallurgical factory producing lead. As reference was considered Dura area located in a less polluted hilly area, in the west part of the town. Samples of soil and plants from the residential area of Ferneziu, Săsar and Dura districts were collected. The arsenic determination was carried out by inductively coupled plasma atomic emission spectrometry and the antimony determination by inductively coupled plasma mass spectrometry. Results: In Ferneziu area, the concentration of arsenic in soil ranged between 0.25 and 255 mg kg-1. In Săsar district the arsenic concentration in the soil ranged between 5.5 and 295 mg kg-1. Regarding antimony, in Ferneziu area the concentration ranged between 5.3 and 40.6 mg kg-1; while in Săsar, antimony soils concentrations vary in the range: 0.9-18.4. Arsenic and antimony concentrations in plants were low for almost of the samples, both in Ferneziu and Săsar area indicating a low mobility of these elements in the studied soils. Conclusion: This study indicated the soil pollution with arsenic both in Ferneziu district and in Săsar district. The soil pollution with antimony was found especially in Ferneziu district.

  9. Effect of Simulated Acid Rain on Potential Carbon and Nitrogen Mineralization in Forest Soils

    OUYANG Xue-Jun; ZHOU Guo-Yi; HUANG Zhong-Liang; LIU Ju-Xiu; ZHANG De-Qiang; LI Jiong


    Acid rain is a serious environmental problem worldwide. In this study, a pot experiment using forest soils planted with the seedlings of four woody species was performed with weekly treatments of pH 4.40, 4.00, 3.52, and 3.05 simulated acid rain (SAR) for 42 months compared to a control of pH 5.00 lake water. The cumulative amounts of C and N mineralization in the five treated soils were determined after incubation at 25 ℃ for 65 d to examine the effects of SAR treatments.For all five treatments, cumulative CO2-C production ranged from 20.24 to 27.81 mg kg-1 dry soil, net production of available N from 17.37 to 48.95 mg kg-1 dry soil, and net production of NO-3-N from 9.09 to 46.23 mg kg-1 dry soil. SAR treatments generally enhanced the emission of CO2-C from the soils; however, SAR with pH 3.05 inhibited the emission.SAR treatments decreased the net production of available N and NO3-N. The cumulative CH4 and N2O productions from the soils increased with increasing amount of simulated acid rain. The cumulative CO2-C production and the net production of available N of the soil under Acmena acuminatissima were significantly higher (P≤0.05) than those under Schima superba and Cryptocarya concinna. The mineralization of soil organic C was related to the contents of soil organic C and N, but was not related to soil pH. However, the overall effect of acid rain on the storage of soil organic matter and the cycling of important nutrients depended on the amount of acid deposition and the types of forests.

  10. Nitrogen, carbon and phosphorus mineralization in soils from semi-arid highlands of central Mexico amended with tannery sludge.

    Barajas-Aceves, M; Dendooven, L


    Tannery sludge contains valuable nutrients and could be used as a fertilizer to pioneering vegetation in heavily eroded soils of the semi-arid highlands of central Mexico. Soil collected under and outside the canopy of mesquite (Prosopis laeviginata), huizache (Acacia tortuoso) and catclaw (Mimosa biuncifera), and cultivated with maize (Zea mays) and beans (Phaesolus vulgaris) was amended with 1.5 g tannery sludge kg-1 soil or 210 kg dry sludge ha-1 or left unamended. Amended and unamended soils were incubated aerobically for 70 days at 22 +/- 2 degrees C and CO2 production, available P, and inorganic N concentrations were monitored. The CO2 production rate, total C and P, available P, biomass C and P were larger under the canopy of the vegetation than outside of the canopy. The soils were depleted of N as more than 50 mg N kg-1 soil could not be accounted for in the first days of the incubation. Nitrification showed a lag, which lasted 28 days, and concentration of available P remained constant or increased slightly. Application of tannery sludge to soil increased CO2 production with 6.5 mg CO2 kg-1 soil d-1 and inorganic N with 30 mg N kg-1 soil after 70 days, but available P did not increase. Application of tannery sludge increased C and N mineralization and could thus provide valuable nutrients to a pioneer vegetation. Although no inhibitory effects on the biological functioning of the soil were found, further investigation into possible long-term environmental effects are necessary.

  11. X-ray CT Scanning Reveals Long-Term Copper Pollution Effects on Functional Soil Structure

    Naveed, Muhammad; Møldrup, Per; Homstrup, Martin

    Soil structure plays the main role in the ability of the soil to fulfill essential soil functions such as the root growth, rate of water infiltration and retention, transport of gaseous and chemicals/pollutants through the soil. Soil structure is a dynamic soil property and affected by various...... factors such as soil type, land use, and soil contamination. In this study, we quantified the soil structure using X-ray CT scanning and revealed the effect of a long history of Copper (Cu) pollution on it. A fallow field at Hygum Denmark provides this opportunity as it had a long history of Copper...... sulphate contamination in a gradient with Cu content varies from 21 mg kg-1 to 3837 mg kg-1. Total 20 intact soil columns (diameter of 10 cm and height of 8 cm) were sampled at five locations along the Cu-gradient from a depth of 5 to 15 cm below surface level. The soil columns were scanned at a voxel...

  12. Effect of pH on boron adsorption in some soils of Paraná, Brazil

    Fábio Steiner


    Full Text Available Temporary B deficiency can be triggered by liming of acid soils because of increased B adsorption at higher soil pH. Plants respond directly to the activity of B in soil solution and only indirectly to B adsorbed on soil constituents. Because the range between deficient and toxic B concentration is relatively narrow, this poses difficulty in maintaining appropriate B levels in soil solution. Thus, knowledge of the chemical behavior of B in the soil is particularly important. The present study investigated the effect of soil pH on B adsorption in four soils of Paraná State, and to correlate these values with the physical and chemical properties of the soils. Surface samples were taken from a Rhodic Hapludox, Arenic Hapludalf, Arenic Hapludult, and one Typic Usthorthent. To evaluate the effect of pH on B adsorption, subsamples soil received the application of increasing rates of calcium carbonate. Boron adsorption was accomplished by shaking 2.0 g soil, for 24 h, with 20 mL of 0.01 mol L¹ NaCl solution containing different concentrations (0.0, 0.1, 0.2, 0.4, 0.8, 1.2, 1.6, 2.0, and 4.0 mg B L-1. Sorption was fitted to non-linear form of the Langmuir adsorption isotherm. Boron adsorption increased as concentration increased. Boron adsorption was dependent on soil pH, increasing as a function of pH in the range between 4.6 and 7.4, although the bonding energy has decreased. Maximum adsorption capacity (MAC of B was observed in the Arenic Hapludalf (49.8 mg B kg-1 soil followed by Arenic Hapludult (22.5 mg kg-1, Rhodic Hapludox (17.4 mg kg-1, and Typic Usthorthent (7.0 mg kg-1. The organic matter content, clay content, and aluminum oxide content (Al2O3 were the soils properties that affecting the B adsorption on Paraná soils.

  13. Sorption of organic carbon compounds to the fine fraction of surface and Subsurface Soils

    Jagadamma, Sindhu [ORNL; Mayes, Melanie [ORNL; Zinn, Yuri [Federal University of Lavras, Brazil; Gisladottir, Gudrun [University of Iceland; Ann, Russell [Iowa State University


    Dissolved organic carbon (DOC) transported from the soil surface is stabilized in deeper soil profiles by physicochemical sorption processes. However, it is unclear how different forms of organic carbon (OC) compounds common in soil organic matter interact with soil minerals in the surface (A) and subsurface (B) horizons. We added four compounds (glucose, starch, cinnamic acid and stearic acid) to the silt- and clay-sized fraction (fine fraction) of A and B horizons of eight soils from varying climates (3 temperate, 3 tropical, 1 arctic and 1 sub-arctic). Equilibriumbatch experiments were conducted using 0 to 100 mg C L 1 of 14C-labeled compounds for 8 h. Sorption parameters (maximum sorption capacity, Qmax and binding coefficient, k) calculated by fitting sorption data to the Langmuir equation showed that Qmax of A and B horizons was very similar for all compounds. Both Qmax and k values were related to sorbate properties, with Qmax being lowest for glucose (20 500 mg kg 1), highest for stearic acid (20,000 200,000 mg kg 1), and intermediate for both cinnamic acid (200 4000 mg kg 1) and starch (400 6000 mg kg 1). Simple linear regression analysis revealed that physicochemical properties of the sorbents influenced the Qmax of cinnamic acid and stearic acid, but not glucose and starch. The sorbent properties did not show predictive ability for binding coefficient k. By using the fine fraction as sorbent, we found that the mineral fractions of A horizons are equally reactive as the B horizons irrespective of soil organic carbon content.

  14. Soil pollution assessment and identification of hyperaccumulating plants in chromated copper arsenate (CCA) contaminated sites, Korea.

    Usman, Adel R A; Lee, Sang Soo; Awad, Yasser M; Lim, Kyoung Jae; Yang, Jae E; Ok, Yong Sik


    In recent decades, heavy metal contamination in soil adjacent to chromated copper arsenate (CCA) treated wood has received increasing attention. This study was conducted to determine the pollution level (PL) based on the concentrations of Cr, Cu and As in soils and to evaluate the remediative capacity of native plant species grown in the CCA contaminated site, Gangwon Province, Korea. The pollution index (PI), integrated pollution index (IPI), bioaccumulation factors (BAF(shoots) and BAF(roots)) and translocation factor (TF) were determined to ensure soil contamination and phytoremediation availability. The 19 soil samples from 10 locations possibly contaminated with Cr, Cu and As were collected. The concentrations of Cr, Cu and As in the soil samples ranged from 50.56-94.13 mg kg(-1), 27.78-120.83 mg kg(-1), and 0.13-9.43 mg kg(-1), respectively. Generally, the metal concentrations decreased as the distance between the CCA-treated wood structure and sampling point increased. For investigating phytoremediative capacity, the 19 native plant species were also collected in the same area with soil samples. Our results showed that only one plant species of Iris ensata, which presented the highest accumulations of Cr (1120 mg kg(-1)) in its shoot, was identified as a hyperaccumulator. Moreover, the relatively higher values of BAF(shoot) (3.23-22.10) were observed for Typha orientalis, Iris ensata and Scirpus radicans Schk, suggesting that these plant species might be applicable for selective metal extraction from the soils. For phytostabilization, the 15 plant species with BAF(root) values>1 and TF values<1 were suitable; however, Typha orientalis was the best for Cr. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Spatial distribution and accumulation of Hg in soil surrounding a Zn/Pb smelter.

    Wu, Qingru; Wang, Shuxiao; Wang, Long; Liu, Fang; Lin, Che-Jen; Zhang, Lei; Wang, Fengyang


    Nonferrous metal smelting is an important atmospheric mercury (Hg) emission source that has significant local and global impacts. To quantify the impact of Hg emission from non-ferrous metal smelter on the surrounding soil, an integrated model parameterizing the processes of smelter emission, air dispersion, atmospheric deposition and Hg accumulation in soil was developed. The concentrations of gaseous elemental Hg (GEM) around the smelter and the spatial distribution of Hg in the surrounding soil were measured and compared with the model results. Atmospheric deposition of Hg emitted from the smelter was identified as the main source of Hg accumulation in the surrounding soil. From 1960 to 2011, the smelter emitted approximately 105 t of Hg into the atmosphere, of which 15 t deposited locally and resulted in an increase of Hg concentration in soil from 0.12 to 1.77 mg kg(-1). A detailed examination of wind rose and model data suggested that the area within 1.0-1.5 km northwest and southeast of the smelter was most severely impacted. It was estimated that the smelter operation from 1969 to 1990, when large scale emission controls were not implemented, resulted in 6450 μg m(-2)yr(-1) of Hg net deposition and a model simulated increase of 0.40 mg kg(-1) of Hg accumulation in the soil. During the period from 1991 to 2011, atmospheric Hg emission from the smelter alone increased the average concentration in soil from 0.41 mg kg(-1) to 0.45 mg kg(-1). In the past 50 years, over 86% of Hg emitted from this smelter went into the global pool, indicating the importance of controlling Hg emissions from non-ferrous metal smelters.

  16. Effects of calcium peroxide on arsenic uptake by celery (Apium graveolens L.) grown in arsenic contaminated soil.

    Liu, Chuan-ping; Luo, Chun-ling; Xu, Xiang-hua; Wu, Chuang-an; Li, Fang-bai; Zhang, Gan


    The ability of calcium peroxide (CaO(2)) to immobilize As of contaminated soil was studied using pot and field experiments. In pot experiment, CaO(2) applied at 2.5 and 5 g kg(-1) significantly increased celery shoot weight and decreased shoot As accumulation, which was ascribed to the formation of stable crystalline Fe and Al oxides bound As and the reduction of labile As fractions in the soil. The labile As fractions were pH dependent and it followed a "V" shaped profile with the change of pH. In field experiment, the dose of CaO(2) application at 750 kg ha(-1) was optimal and at which the celery was found to produce the highest biomass (63.4 Mg ha(-1)) and lowest As concentration (0.43 mg kg(-1)). CaO(2) probably has a promising potential as soil amendment to treat As contaminated soils.

  17. Depth distribution of available micronutrients in cultivated soil

    Vukašinović Ivana Ž.


    Full Text Available This paper presents a study of the profile distribution of available micronutrients Fe, Mn, Cu and Zn and radionuclide 137Cs in cultivated soil at the experimental field "Radmilovac" (property of Agricultural Faculty, Belgrade University in the vicinity of Vinĉa Institute of Nuclear Sciences. The soil belongs to the anthrosol class of anthropogenic soils according to FAO (2006. At first, the deep plowing was performed while preparing soil for planting peach trees followed by cultivation of soil for 12 years. All agricultural treatments at the experimental field ceased for three years. After that period, soil sampling was carried out. Contents of DTPA-extracted Fe, Mn, Cu and Zn were in the range of (mg kg-1: 5.8-41.6; 9.2-34.2; 1-7.6 and 0.2-1.3, respectively. Detected activity concentration (Bq kg-1 for 137Cs ranged from 1.8 to 35. It was noticed that distribution patterns of 137Cs radionuclide and available Cu and Zn along soil depth were very similar and they were analyzed by simple linear regression; mutual affinity for the soil organic matter might affect their distribution in soil. Contents of available Fe and Mn exhibited different, more constant distribution within a soil horizon.

  18. Alleviating aluminium toxicity on an acid sulphate soils in Peninsular Malaysia with application of calcium silicate

    Elisa, A. A.; Ninomiya, S.; Shamshuddin, J.; Roslan, I.


    A study was conducted to alleviate Al toxicity of an acid sulphate soils collected from paddy cultivation area in Kedah, Peninsular Malaysia. For this purpose, the collected acid sulphate soils were treated with calcium silicate. The treated soils were incubated for 120 days in submerged condition in a glasshouse. Subsamples were collected every 30 days throughout the incubation period. Soil pH and exchangeable Al showed positive effect; soil pH increased from 2.9 to 3.5, meanwhile exchangeable Al was reduced from 4.26 to 0.82 cmolc kg-1, which was well below the critical Al toxicity level for rice growth of 2 cmolc kg-1. It was noted that the dissolution of calcium silicate (CaSiO3) supplied substantial amount of Ca2+ and H4SiO42- ions into the soil, noted with increment in Si (silicate) content from 21.21 to 40 mg kg-1 at day 30 and reduction of exchangeable Al at day 90 from 4.26 to below 2 cmolc kg-1. During the first 60 days of incubation, Si content was positively correlated with soil pH, while the exchangeable Al was negatively correlated with Si content. It is believed that the silicate anions released by calcium silicate were active in neutralizing H+ ions that governs the high acidity (pH 2.90) of the acid sulphate soils. This scenario shows positive effect of calcium silicate to reduce soil acidity, therefore creates a favourable soil condition for good rice growth during its vegetative phase (30 days). Thus, application of calcium silicate to alleviate Al toxicity of acid sulphate soils for rice cultivation is a good soil amendment.

  19. Free Cu2+ Ions, Cu Fractionation and Microbial Parameters in Soils from Apple Orchards Following Long-Term Application of Copper Fungicides

    ZHOU Dong-Mei; WANG Quan-Ying; CANG Long


    Soil samples were collected from apple orchards 5, 15, 20, 30, and 45 years old, and one adjacent forest soil was used as reference to investigate the free Cu2+ ion activity in soil solution and the soil Cu fractionation in the solid phase following long-term application of copper fungicide, Bordeaux mixture, in apple orchards and to investigate the relationships among soil free Cu2+ ions, Cu fractionation and soil microbial parameters. The total Cu concentration in the orchard soils varied from 21.8 to 141 mg kg-l, increasing with the orchard age, and the value for the reference soil was 12.5 mg kg-1. The free Cu2+ ion concentrations in the soil solutions extracted by 0.01 mol L-1 KNO3 ranged from 3.13 × 10-8 (reference) to 4.08 × 10-6 mol L-1 (45 years-old orchard). The concentration of Cu complexed in the fulvic fraction increased with orchard age from 5.16 to 52.5 mg kg-1. This was also the case for other soil Cu fractions except the residual one. The residual soil Cu remained practically constant, ranging from 4.28 to 5.66 mg kg-1, suggesting that anthropogenic soil Cu mainly existed in the more labile active fractions. Regression analyses revealed that both the free Cu2+ ions in the soil solution and the humic acid-complexed Cu fraction in the solid phase were strongly related with soil microbial parameters.

  20. Enhanced dissipation of polycyclic aromatic hydrocarbons in the rhizosphere of the Athel tamarisk (Tamarix aphylla L. Karst.) grown in saline-alkaline soils of the former lake Texcoco.

    Betancur-Galvis, Liliana A; Carrillo, Hernando; Luna-Guido, Marco; Marsch, Rodolfo; Dendooven, Luc


    Remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated alkaline saline soil with phreatophyte or "water loving plants" was investigated by spiking soil from the former lake Texcoco with 100 mg phenanthrene (Phen) kg(-1) soil, 120 mg anthracene (Ant)kg(-1) soil and 45 mg benzo(a)pyrene (BaP) kg(-1) soil and vegetating it with Athel tamarisk (Tamarix aphylla L Karst.). The growth of the Athel tamarisk was not affected by the PAHs. In soil cultivated with Athel tamarisk, the leaching of PAHs to the 32-34 cm layer decreased 2-fold compared to the uncultivated soil. The BaP concentration decreased to 39% of the initial concentration at a distance smaller than 3 cm from the roots and to 45% at a distance larger than 3cm, but 59% remained in unvegetated soil after 240 days. Dissipation of Ant and Phen decreased with depth, but not BaP. The biodegradation of PAHs was affected by their chemical properties and increased in the presence of T. aphylla, but decreased with depth.

  1. Physicochemical and biological quality of soil in hexavalent chromium-contaminated soils as affected by chemical and microbial remediation.

    Liao, Yingping; Min, Xiaobo; Yang, Zhihui; Chai, Liyuan; Zhang, Shujuan; Wang, Yangyang


    Chemical and microbial methods are the main remediation technologies for chromium-contaminated soil. These technologies have progressed rapidly in recent years; however, there is still a lack of methods for evaluating the chemical and biological quality of soil after different remediation technologies have been applied. In this paper, microbial remediation with indigenous bacteria and chemical remediation with ferrous sulphate were used for the remediation of soils contaminated with Cr(VI) at two levels (80 and 1,276 mg kg(-1)) through a column leaching experiment. After microbial remediation with indigenous bacteria, the average concentration of water-soluble Cr(VI) in the soils was reduced to less than 5.0 mg kg(-1). Soil quality was evaluated based on 11 soil properties and the fuzzy comprehensive assessment method, including fuzzy mathematics and correlative analysis. The chemical fertility quality index was improved by one grade using microbial remediation with indigenous bacteria, and the biological fertility quality index increased by at least a factor of 6. Chemical remediation with ferrous sulphate, however, resulted in lower levels of available phosphorus, dehydrogenase, catalase and polyphenol oxidase. The result showed that microbial remediation with indigenous bacteria was more effective for remedying Cr(VI)-contaminated soils with high pH value than chemical remediation with ferrous sulphate. In addition, the fuzzy comprehensive evaluation method was proven to be a useful tool for monitoring the quality change in chromium-contaminated soils.

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

    Dian Siswanto


    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.

  3. Contribution for the derivation of a soil screening value (SSV for uranium, using a natural reference soil.

    Ana Luisa Caetano

    Full Text Available In order to regulate the management of contaminated land, many countries have been deriving soil screening values (SSV. However, the ecotoxicological data available for uranium is still insufficient and incapable to generate SSVs for European soils. In this sense, and so as to make up for this shortcoming, a battery of ecotoxicological assays focusing on soil functions and organisms, and a wide range of endpoints was carried out, using a natural soil artificially spiked with uranium. In terrestrial ecotoxicology, it is widely recognized that soils have different properties that can influence the bioavailability and the toxicity of chemicals. In this context, SSVs derived for artificial soils or for other types of natural soils, may lead to unfeasible environmental risk assessment. Hence, the use of natural regional representative soils is of great importance in the derivation of SSVs. A Portuguese natural reference soil PTRS1, from a granitic region, was thereby applied as test substrate. This study allowed the determination of NOEC, LOEC, EC20 and EC50 values for uranium. Dehydrogenase and urease enzymes displayed the lowest values (34.9 and <134.5 mg U Kg, respectively. Eisenia andrei and Enchytraeus crypticus revealed to be more sensitive to uranium than Folsomia candida. EC50 values of 631.00, 518.65 and 851.64 mg U Kg were recorded for the three species, respectively. Concerning plants, only Lactuca sativa was affected by U at concentrations up to 1000 mg U kg(1. The outcomes of the study may in part be constrained by physical and chemical characteristics of soils, hence contributing to the discrepancy between the toxicity data generated in this study and that available in the literature. Following the assessment factor method, a predicted no effect concentration (PNEC value of 15.5 mg kg-1dw was obtained for U. This PNEC value is proposed as a SSV for soils similar to the PTRS1.

  4. Assessing spatial variability of soil petroleum contamination using visible near-infrared diffuse reflectance spectroscopy.

    Chakraborty, Somsubhra; Weindorf, David C; Zhu, Yuanda; Li, Bin; Morgan, Cristine L S; Ge, Yufeng; Galbraith, John


    Visible near-infrared (VisNIR) diffuse reflectance spectroscopy (DRS) is a rapid, non-destructive method for sensing the presence and amount of total petroleum hydrocarbon (TPH) contamination in soil. This study demonstrates the feasibility of VisNIR DRS to be used in the field to proximally sense and then map the areal extent of TPH contamination in soil. More specifically, we evaluated whether a combination of two methods, penalized spline regression and geostatistics could provide an efficient approach to assess spatial variability of soil TPH using VisNIR DRS data from soils collected from an 80 ha crude oil spill in central Louisiana, USA. Initially, a penalized spline model was calibrated to predict TPH contamination in soil by combining lab TPH values of 46 contaminated and uncontaminated soil samples and the first-derivative of VisNIR reflectance spectra of these samples. The r(2), RMSE, and bias of the calibrated penalized spline model were 0.81, 0.289 log(10) mg kg(-1), and 0.010 log(10) mg kg(-1), respectively. Subsequently, the penalized spline model was used to predict soil TPH content for 128 soil samples collected over the 80 ha study site. When assessed with a randomly chosen validation subset (n = 10) from the 128 samples, the penalized spline model performed satisfactorily (r(2) = 0.70; residual prediction deviation = 2.0). The same validation subset was used to assess point kriging interpolation after the remaining 118 predictions were used to produce an experimental semivariogram and map. The experimental semivariogram was fitted with an exponential model which revealed strong spatial dependence among soil TPH [r(2) = 0.76, nugget = 0.001 (log(10) mg kg(-1))(2), and sill 1.044 (log(10) mg kg(-1))(2)]. Kriging interpolation adequately interpolated TPH with r(2) and RMSE values of 0.88 and 0.312 log(10) mg kg(-1), respectively. Furthermore, in the kriged map, TPH distribution matched with the expected TPH variability of the study site. Since the

  5. Impacts of geology and land use on magnetic susceptibility and selected heavy metals in surface soils of Mashhad plain, northeastern Iran

    Karimi, Alireza; Haghnia, Gholam Hosain; Ayoubi, Shamsollah; Safari, Tayebeh


    Magnetic susceptibility is a fast, inexpensive and reliable technique for estimating and monitoring the anthropogenic contamination of soil with heavy metals. However, it is essential to determine the factors affecting magnetic susceptibility before applying this technique to environmental studies. The objectives of this study were to investigate i) the effect of parent materials and land use on the magnetic susceptibility and concentrations of Fe, Ni, Pb and Zn, and ii) capability of magnetic susceptibility as an indicator of anthropogenic heavy metals contamination of soil in Mashhad plain, northeastern Iran. One hundred seventy-eight composite surface soil samples (0-10 cm) were taken. The aqua-regia extractable concentrations of Fe, Ni, Zn and Pb were determined by atomic absorption spectroscopy. Magnetic susceptibility at low and high frequency (χlf and χhf) were measured and frequency dependent susceptibility (χfd) was calculated. The average concentrations of Fe, Ni, Pb and Zn were 22,812, 61.4, 74.1 and 31.6 mg kg- 1, respectively. The highest contents of Pb (69.1 mg kg- 1) and Zn (149 mg kg- 1) were observed in urban area. The highest concentration of Ni was 41,538 mg kg- 1 observed in the soils developed from ultramafic rocks. Magnetic susceptibility varied from 20.3 on marly sediments to 311.8 × 10- 8 m3 kg- 1 on ultramafic rocks. A positive strong correlation (Pvalue < 0.01, r = 0.88) was obtained between Ni and χlf. There were no significant relationships between Zn and Pb with χlf, therefore it seems that magnetic susceptibility has not been affected significantly by anthropogenic activities which enhanced Pb and Zn concentrations in urban soils. The results indicated that magnetic susceptibility was mainly controlled by Ni containing minerals with lithogenic origin. Therefore, in the soils studied, magnetic susceptibility could not be employed as indicator of anthropogenic contamination of soil with heavy metals.

  6. Soil Cadmium Regulates Antioxidases in Sorghum

    LIU Da-lin; ZHANG Shu-pan; CHEN Zheng; QIU Wei-wei


    The regulatory mechanism of soil cadmium(Cd)on antioxidases in sorghum was studied using 3 sorghum species viz.,sweet sorghum[Sorghum bicolor(L.)],sorghum hybrid sudangrass(Sorghum bicolor × S.sudanense,cv.Everlush)and sudangrass[Sorghum sudanense(Piper)Stapf cv.Xinjiang].The results showed that low concentrations of Cd2+(≤10 mg kg-1)induced the activities of 4 antioxidases in leaves of the 3 species of sorghum,but high Cd2+concentrations(≥50 mg kg-1)significantly reduced the activities of all the four antioxidases.The glutathione(GSH)contents in leaves of the 3 species of sorghum correlated positively with the Cd2+concentrations.The maximum antioxidase activities were observed at the elongation stage of sorghum during the whole growth period.

  7. The uptake of Cs and Sr from soil to radish (Raphanus sativus L.)- potential for phytoextraction and remediation of contaminated soils.

    Wang, Dan; Wen, Fangping; Xu, Changhe; Tang, Yunlai; Luo, Xuegang


    The (133)Cs and (88)Sr uptake by plant Raphanus sativus L. was studied during cultivation in outdoor potted-soil. The distribution, accumulation of (133)Cs, (88)Sr and the antioxidant responses in plants were measured after 30 and 60 days of cultivation. The results showed that the uptake capacity of radish for (88)Sr was far higher than that for (133)Cs when the concentration of (88)Sr was as the same as that of (133)Cs in the soil (The concentration of (88)Sr or (133)Cs in the soil was from 2.5 mg kg(-1) to 40 mg kg(-1)). The highest (88)Sr accumulation was 239.18 μg g(-1) dw, otherwise, the highest (133)Cs accumulation was 151.74 μg g(-1) dw (The concentration of (88)Sr in the soil was 40 mg kg(-1)), and the lowest (88)Sr accumulation was 131.03 μg g(-1) dw, otherwise, the lowest (133)Cs accumulation was 12.85 μg g(-1) dw (The concentration of (88)Sr in the soil is 5 mg kg(-1)). The (88)Sr and (133)Cs TF values were 1.16-1.72 and 0.24-0.60, respectively. There was little influence of high concentration of (88)Sr on the total biomass of plants, so the radish is one of the ideal phytoremediation plant for Sr polluted soils. The important physiological reasons that radish had good tolerance to (88)Sr stress were that the MDA content was higher under the (88)Sr stress than that under the (133)Cs stress, and the activities of POD and CAT were lower under the (88)Sr stress than that under (133)Cs stress.

  8. Brassica juncea tested on urban soils moderately contaminated by lead: Origin of contamination and effect of chelates.

    Bouquet, Dorine; Braud, Armelle; Lebeau, Thierry


    Urban garden soils are a potential repository of heavy metal pollution, resulting from either anthropogenic or geogenic origin. The efficiency of phytoextraction was compared on two garden soils with the same texture and topsoil Pb concentration (170 mg kg(-1)) but not the same origin: one geogenic, the other anthropogenic. Two varieties of Brassica juncea were tested with citric acid (25 mmol kg(-1)) or ethylenediaminetetraacetic acid (EDTA, 2.5 mmol kg(-1)). Geogenic Pb was shown to be two times less available than anthropogenic Pb, as a result of which the phytoextraction efficiency was reduced by 59%. Pb mobility in the soil was solely enhanced with EDTA, which increased the Pb concentration in shoots of B. juncea by between 14 and 26 times in comparison with the control. The highest Pb concentration in shoots still remained low, however (i.e., 45 mg kg(-1) dry weight). Regardless of the chelates introduced, B. juncea 426308 accumulated roughly twice as much lead as B. juncea 211000, but only for the anthropogenic contaminated soil. Under these conditions, the amount of Pb accumulated by B. juncea (even when assisted by EDTA) was not high enough to envision achieving soil clean-up within a reasonable time frame.

  9. Behaviour of metalaxyl as copper oxychloride-metalaxyl commercial formulation vs. technical grade-metalaxyl in vineyards-devoted soils.

    Pose-Juan, E; Rial-Otero, R; Paradelo, M; Simal-Gándara, J; Arias, M; López-Periago, J E


    The objective of this work is to asses the sorption of metalaxyl applied as a copper oxychloride (CO)-metalaxyl formulation, for a set of selected soils devoted to vineyards. The method involved batch incubation of soils suspended with a commercial copper oxychloride-metalaxyl-based fungicide in 0.01M CaCl(2). Afterwards, the metalaxyl concentration remaining in solution was determined by high-performance liquid chromatography (HPLC). The amount of dissolved metalaxyl in the fungicide suspension depends mainly on the soil pH, its potential acidity, and the cation exchange capacity. Of the approx. 20% metalaxyl retained by the solid colloids, the effect of organic matter colloids in soils (15-20 mg kg(-1)) had a poor contribution (six times lower) than the copper oxychloride colloids (40%, w/w) in the commercial fungicide formulation (100-130 mg kg(-1)). When comparing these retention data with the behaviour of metalaxyl used as a technical grade fungicide of about 100% purity (10-15 mg kg(-1) in solids), it is clear that the commercial formulation increases a 30% retention of metalaxyl by soil (15-20 mg kg(-1) in solids). The overall effect of the metalaxyl formulation plus soil show values of 10 times higher retention than technical grade-metalaxyl plus soil. Commercial formulation can decrease the mobility of soluble metalaxyl in agricultural soils with regard to the expected values obtained from batch studies using analytical grade-metalaxyl. Therefore, the effect of surfactants should be considered in the assessment of water contamination by the pesticides used in agriculture.

  10. Nitrogen utilization pathways of soil microorganisms

    Pinggera, J.; Geisseler, D.; Merbach, I.; Ludwig, B.


    Nitrogen (N) is an essential nutrient for all organisms. In terrestrial ecosystems N occurs predominantly in the form of organic matter. Here, soil microorganisms can use two possible mechanisms for the uptake of organic N: the direct route and the mobilization-immobilization-turnover (MIT) route. In the direct route simple organic molecules are taken up directly into the cell. The deamination occurs inside the cell and only the surplus N is released into the soil solution. In the second route, the deamination occurs outside the cell and all N is mineralized before assimilation. To determine the importance of the different N uptake pathways of soil microorganisms an incubation experiment (21 days, 20°C) is currently being carried out. Corn leaves with different C to N ratios (20, 40) and (NH4)2SO4 have been added to three soils (Haplic Chernozem, FAO) with different fertilization histories (300dt/ha farmyard manure every second year, mineral NPK fertilizer, no fertilization) from the long-term experiment at Bad Lauchstädt. Contents of NH4+, NO3- and microbial biomass C (Cmic) and N (Nmic), CO2 production, potential protease activity, gross N mineralization and mineralization of added amino acids will be determined after 3, 7 and 21 days. Preliminary results show that the protease activity (without addition of corn residues) decreased in the order manure-fertilized soil (18.26 mg tyrosine kg-1 soil h-1) > Soil with mineral NPK fertilizer (17.45 mg tyrosine kg-1 soil h-1) > unfertilized soil (11.34 mg tyrosine kg-1 oven dry soil h-1). The turnover of amino acids after 24h was higher for the manure-fertilized soil (99.5% of the added amino acids were consumed) than for the NPK- fertilized and unfertilized soils (76%). The effects of the fertilization histories on the temporal dynamics of the different biological properties (Cmic, Nmic), CO2 production, protease activity and N mineralization rates will be presented.

  11. Key indicator tools for shallow slope failure assessment using soil chemical property signatures and soil colour variables.

    Othman, Rashidi; Hasni, Shah Irani; Baharuddin, Zainul Mukrim; Hashim, Khairusy Syakirin Has-Yun; Mahamod, Lukman Hakim


    Slope failure has become a major concern in Malaysia due to the rapid development and urbanisation in the country. It poses severe threats to any highway construction industry, residential areas, natural resources and tourism activities. The extent of damages that resulted from this catastrophe can be lessened if a long-term early warning system to predict landslide prone areas is implemented. Thus, this study aims to characterise the relationship between Oxisols properties and soil colour variables to be manipulated as key indicators to forecast shallow slope failure. The concentration of each soil property in slope soil was evaluated from two different localities that consist of 120 soil samples from stable and unstable slopes located along the North-South Highway (PLUS) and East-West Highway (LPT). Analysis of variance established highly significant difference (P < 0.0001) between the locations, the total organic carbon (TOC), soil pH, cation exchange capacity (CEC), soil texture, soil chromaticity and all combinations of interactions. The overall CIELAB analysis leads to the conclusion that the CIELAB variables lightness L*, c* (Chroma) and h* (Hue) provide the most information about soil colour and other related soil properties. With regard to the relationship between colour variables and soil properties, the analysis detected that soil texture, organic carbon, iron oxide and aluminium concentration were the key factors that strongly correlate with soil colour variables at the studied area. Indicators that could be used to predict shallow slope failure were high value of L*(62), low values of c* (20) and h* (66), low concentration of iron (53 mg kg(-1)) and aluminium oxide (37 mg kg(-1)), low soil TOC (0.5%), low CEC (3.6 cmol/kg), slightly acidic soil pH (4.9), high amount of sand fraction (68%) and low amount of clay fraction (20%).

  12. Dechlorination of polychlorinated biphenyl-contaminated soil via anaerobic composting with pig manure.

    Zhang, Chi; Du, Yao; Tao, Xiao-Qing; Zhang, Kun; Shen, Dong-Sheng; Long, Yu-Yang


    Anaerobic dechlorination is an effective degradation pathway of higher chlorinated polychlorinated biphenyls (PCBs). The efficiency of anaerobic composting remediation of PCB-contaminated soil using pig manure was determined. The results show that the dechlorination of PCB-contaminated soil via anaerobic composting with pig manure is feasible. PCB concentration is the most critical factor. Elevated PCB concentrations can inhibit dechlorination but does not disrupt the anaerobic fermentation process. At 1 mg kg(-1) PCBs, the degradation rate of five or more chlorinated biphenyls is 43.8%. The highest dechlorination performance in this experiment was obtained when the soil-to-organic waste ratio, carbon-to-nitrogen ratio, moisture content, and PCB concentration were 2:3, 20, 60%, and 1 mg kg(-1), respectively.

  13. Accumulation of mercury and methylmercury by mushrooms and earthworms from forest soils.

    Rieder, Stephan R; Brunner, Ivano; Horvat, Milena; Jacobs, Anna; Frey, Beat


    Accumulation of total and methyl-Hg by mushrooms and earthworms was studied in thirty-four natural forest soils strongly varying in soil physico-chemical characteristics. Tissue Hg concentrations of both receptors did hardly correlate with Hg concentrations in soil. Both total and methyl-Hg concentrations in tissues were species-specific and dependent on the ecological groups of receptor. Methyl-Hg was low accounting for less than 5 and 8% of total Hg in tissues of mushrooms and earthworms, respectively, but with four times higher concentrations in earthworms than mushrooms. Total Hg concentrations in mushrooms averaged 0.96 mg Hg kg(-1) dw whereas litter decomposing mushrooms showed highest total Hg and methyl-Hg concentrations. Earthworms contained similar Hg concentrations (1.04 mg Hg kg(-1) dw) whereas endogeic earthworms accumulated highest amounts of Hg and methyl-Hg.

  14. Nitrogen utilization and transformation in red soil fertilized with urea and ryegrass

    WuGang; HeZhen-Li


    The influence of fertilization with urea and ryegrass on nitrogen utilization and transformation in red soil has been studied by using 15N tracer method.When urea and ryegrass were applied alone or in combination,the percentage of N uptaken by ryegrass from labelled urea was 3 and 1.7 times that from labelled ryegrass for the application rate of and,respectively;combining application of ryegrass and ureareduced uptake of urea N and increased uptake of ryegrass N by ryegrass plant,but the percentage of N residued in soil increased for urea and decreased for ryegrass.when urea and ryegrass were applied alone,the percentage of N residued in soil from labelled ryegrass was more than 69% while that from labelled urea was less than 25%,and much more ryegrass N was incorporated into humus than urea N.

  15. Long-Term Effects of Legacy Copper Contamination on Microbial Activity and Soil Physical Properties

    Arthur, Emmanuel; Møldrup, Per; Holmstrup, Martin

    Soils heavily contaminated with copper (Cu) are considered unsuitable for agricultural use due to adverse impacts on microbial activity, soil physical properties, and direct toxicity to crops. This study investigated effects of Cu pollution from timber preservation activities between 1911 and 1924......, Denmark. Soil samples obtained from the fallow field were used to determine total microbial activity using fluorescein diacetate and dehydrogenase assays. The physical properties measured included water-dispersible clay, bulk density, air permeability and air-filled porosity. Significant differences...... in microbial activity (for both assays) were observed at Cu concentrations >500 mg kg-1. Although, unfavorable changes in all physical properties were obvious for Cu concentrations >500 mg kg-1, significant increases in bulk density and water dispersible-clay, together with decreases in total porosity, air...

  16. Total soil electrical conductivity and critical soil K+ to Ca2+ and Mg2+ ratio for potato crops Condutividade elétrica e níveis críticos da relação entre K+ e Ca+ + Mg+ no solo para cultura da batata

    Roberto Anjos Reis Jr.


    Full Text Available Soil K+ to Ca2+ and Mg2+ ratio as well as the total salinity were evaluated in response to potassium fertilizer application onto potato. Potassium was applied at six different rates (0, 60, 120, 240, 480 and 960 kg ha-1 of K2O, as K2SO4, and was placed during planting time in the furrow. Soil from the 0-200 mm layer was collected in the furrow, 20 and 48 days after plant emergence (DAE to evaluate soil pH, K+, Ca2+ and Mg2+ contents and the total electrical conductivity (EC. A factorial design (6x2, with six K rates and two sampling times was set up in a randomized block design with four replications. The application of K fertilizer increased exchangeable K, did not affect pH and exchangeable Ca and Mg contents, but caused a linear increase of the soil K+/(Ca2++Mg2+1/2 ratio as well as EC. At 20 DAE, the critical soil K+/(Ca2++Mg2+1/2ratio and the EC associated with maximum tuber yield (30.5 Mg.ha-1, with 353.4 kg ha-1 of K2O were 1.79 and 1.6 dS m-1, respectively. The highest soil K+/(Ca2++Mg2+1/2 ratio and EC were obtained with the highest application of K fertilizer, which led to a reduction in the potato tuber yield.Com o objetivo de avaliar a relação entre K e Ca + Mg e a salinidade no solo em resposta à adubação potássica no cultivo da batateira (cultivar Baraka, foi instalado experimento fatorial a nível de campo com seis doses de potássio (0, 60, 120, 240, 480 e 960 kg ha-1 de K2O e duas épocas de amostragem, 20 e 48 dias após a emergência das plantas, (DAE delineado em blocos casualizados com quatro repetições. O potássio foi aplicado como K2SO4 no sulco de plantio. O solo foi amostrado (0-200 mm de profundidade para avaliar o pH, a condutividade elétrica e os teores de K, Ca e Mg. A adubação potássica aumentou o K trocável, não afetou o pH e os teores de Ca e Mg trocáveis no solo, e elevou linearmente a condutividade elétrica e a relação K+/(Ca2++ Mg2+1/2. Aos 20 DAE, a máxima produção de tubérculos foi

  17. Mercury speciation in highly contaminated soils from chlor-alkali plants using chemical extractions.

    Neculita, Carmen-Mihaela; Zagury, Gérald J; Deschênes, Louise


    A four-step novel sequential extraction procedure (SEP) was developed to assess Hg fractionation and mobility in three highly contaminated soils from chlor-alkali plants (CAPs). The SEP was validated using a certified reference material (CRM) and pure Hg compounds. Total, volatile, and methyl Hg concentrations were also determined using single extractions. Mercury was separated into four fractions defined as water-soluble (F1), exchangeable (F2) (0.5 M NH4Ac-EDTA and 1 M CaCl2 were tested), organic (F3) (successive extractions with 0.2 M NaOH and CH3COOH 4% [v/v]), and residual (F4) (HNO3 + H2SO4 + HClO4). The soil characterization revealed extremely contaminated (295 +/- 18 to 11 500 +/- 500 mg Hg kg(-1)) coarse-grained sandy soils having an alkaline pH (7.9-9.1), high chloride concentrations (5-35 mg kg(-1)), and very low organic carbon content (0.00-18.2 g kg(-1)). Methyl Hg concentrations were low (0.2-19.3 microg kg(-1)) in all soils. Sequential extractions indicated that the majority of the Hg was associated with the residual fraction (F4). In Soils 1 and 3, however, high percentages (88-98%) of the total Hg were present as volatile Hg. Therefore, in these two soils, a high proportion of volatile Hg was present in the residual fraction. The nonresidual fraction (F1 + F2 + F3) was most abundant in Soil 1 (14-42%), suggesting a higher availability of Hg in this soil. The developed and validated SEP was reproducible and efficient for highly contaminated samples. Recovery ranged between 93 and 98% for the CRM and 70 and 130% for the CAP-contaminated soils.

  18. Biodegradation of imidacloprid by consortium of two soil isolated Bacillus sp.

    Sharma, Smriti; Singh, Balwinder; Gupta, V K


    Imidacloprid degradation potential of bacterial cultures from sugarcane growing soils was studied in liquid culture and Bacillus aerophilus and Bacillus alkalinitrilicus showed maximum potential to degrade imidacloprid. Hence, into a clay loam soil imidacloprid was added at 50, 100, and 150 mg kg(-1) along with 45 × 10(7) cells g(-1) soil of both species under autoclaved and unautoclaved conditions. Under autoclaved conditions imidacloprid residues were degraded after 56 days to 3.18, 5.83 and 10.48 mg kg(-1) and under unautoclaved conditions to 5.17, 6.23 and 10.31 mg kg(-1). 6-chloronicotinic acid, nitrosimine and imidacloprid-NTG metabolites were detected in measurable concentrations under both conditions. Dissipation pattern of imidacloprid did not follow first order kinetics under both sets of conditions. The half life value of imidacloprid ranged from 13 to 16 days after bacterial inoculation. This is first report of use of mixed culture of native soil bacterial isolates for remediation of imidacloprid contaminated soils.

  19. Quantifying nickel in soils and plants in an ultramafic area in Philippines.

    Susaya, Janice P; Kim, Ki-Hyun; Asio, Victor B; Chen, Zueng-Sang; Navarrete, Ian


    In this study, concentrations of nickel (Ni) were quantified in the soils and plants in the agricultural areas of Salcedo watershed in Eastern Samar Island, Philippines. The quantity of total Ni in soils (TS-Ni) was significantly high with a mean of 1,409 mg kg(-1), while the soil available Ni (SA-Ni) was low with a mean of 8.66 mg kg(-1). As the levels of TS-Ni in the Salcedo watershed greatly exceeded the maximum allowable concentrations for agricultural soils, the site is not suitable for agricultural purposes. Despite significant TS-Ni levels, SA-Ni levels were very low due to tight binding between Ni and soil components. Consequently, all plants investigated did not meet the criterion for a Ni hyperaccumulator plant with low Ni contents (mean TP-Ni of 14.7 mg kg(-1)). Comparison of Ni levels between food plants and its recommended daily intake (RDI) suggests that consumption of food-plants grown in the study area is unlikely to pose health risks. However, caution must be taken against combined consumption of food plants with high Ni levels or their prolonged consumption, as it can induce accumulation of Ni above RDI.

  20. Chemical Criteria to Assess Risk of Phosphorus Leaching from Urban Soils

    ZHANG Gan-Lin; W. BURGHARDT; YANG Jin-Ling


    Soils from urban and suburban areas are normally enriched with phosphorus (P). Sixteen urban soils with a wide range of total P concentrations under typical urban land uses were sampled and analyzed for extractable P concentrations using water, sodium bicarbonate and citric acid. Meanwhile the soils were artificially leached in columns and P concentrations in the leachates were determined. With linear regression a two-stage linear relationship was found to exist between concentrations of P in the leachates and soil P contents obtained by various chemical measurements, i.e., there was a "change-point" denoting the critical threshold value for extractable P between the regression lines, above which concentrations of P in leachates increased substantially. These threshold "change-point" values were 1.5 mg kg-1 for water-soluble P and CaC12-P, 25 mg kg-1 for Olsen-P, and 250-350 mg kg-1 for citric acid-P with the sharpest change and the best predictor [r2 (upper) = 0.928, r2 (lower)= 0.807] appearing for Olsen-P. These "change-points" were considered important criteria in assessing the risk of P leaching from urban soils and could be used as standards to delineate and target hazardous areas in urban and suburban areas.

  1. Enhanced accumulation of Cd in castor (Ricinus communis L) by soil-applied chelators.

    Chhajro, Muhammad Afzal; Rizwan, Muhammad Shahid; Guoyong, Huang; Jun, Zhu; Kubar, Kashif Ali; Hongqing, Hu


    Phytoextraction has been identified as one of the most propitious methods of phytoremediation. This pot experiment were treated with varying amounts of (ethylenediamine triacetic acid) EDTA 3-15, (Nitriloacetic acid) NTA 3-10, (Ammonium citrate) NH4 citrate 10 - 25 mmol and one mg kg(-1)Cd, filled with 5 kg soil. The addition of chelators significantly increased Cd concentration in soil and plant. The results showed that maximum Cd uptake was noted under root, shoot and leaf of castor plant tissue (2.26, 1.54, and 0.72 mg kg(-1)) under EDTA 15, NTA 10, and NH4 citrate 25 mmol treatments respectively, and in soil 1.08, 1.06 and 0.52 mg kg(-1) pot(-1) under NH4 citrate 25, NTA 10 and EDTA 15 mmol treatments respectively, as against to control (p < 0.05). Additions of chelators reduction biomass under the EDTA 15 mmol as compared to other treatments, However, Bioconcentration factor (BCF), translocation factor (TF) and remediation factor (RF) were significantly increased under EDTA 15 and NH4 citrate 25 mmol as against control. Our results demonstrated that castor plant proved satisfactory for phytoextraction on contaminated soil, and EDTA 15 and NH4 citrate 25 mmol had the affirmative effect on the Cd uptake in the artificial Cd-contaminated soil.

  2. Monitoring arsenic contamination in agricultural soils with reflectance spectroscopy of rice plants.

    Shi, Tiezhu; Liu, Huizeng; Wang, Junjie; Chen, Yiyun; Fei, Teng; Wu, Guofeng


    The objective of this study was to explore the feasibility and to investigate the mechanism for rapidly monitoring arsenic (As) contamination in agricultural soils with the reflectance spectra of rice plants. Several data pretreatment methods were applied to improve the prediction accuracy. The prediction of soil As contents was achieved by partial least-squares regression (PLSR) using laboratory and field spectra of rice plants, as well as linear regression employing normalized difference spectral index (NDSI) calculated from fild spectra. For laboratory spectra, the optimal PLSR model for predicting soil As contents was achieved using Savitzky-Golay smoothing (SG), first derivative and mean center (MC) (root-mean-square error of prediction (RMSEP)=14.7 mg kg(-1); r=0.64; residual predictive deviation (RPD)=1.31). For field spectra, the optimal PLSR model was also achieved using SG, first derivative and MC (RMSEP=13.7 mg kg(-1); r=0.71; RPD=1.43). In addition, the NDSI with 812 and 782 nm obtained a prediction accuracy with r=0.68, RMSEP=13.7 mg kg(-1), and RPD=1.36. These results indicated that it was feasible to monitor the As contamination in agricultural soils using the reflectance spectra of rice plants. The prediction mechanism might be the relationship between the As contents in soils and the chlorophyll-a/-b contents and cell structure in leaves or canopies of rice plants.

  3. Phytoremediation of heavy metal-contaminated soils: natural hyperaccumulation versus chemically enhanced phytoextraction.

    Lombi, E; Zhao, F J; Dunham, S J; McGrath, S P


    A pot experiment was conducted to compare two strategies of phytoremediation: natural phytoextraction using the Zn and Cd hyperaccumulator Thlaspi caerulescens J. Presl & C. Presl versus chemically enhanced phytoextraction using maize (Zea mays L.) treated with ethylenediaminetetraacetic acid (EDTA). The study used an industrially contaminated soil and an agricultural soil contaminated with metals from sewage sludge. Three crops of T. caerulescens grown over 391 d removed more than 8 mg kg(-1) Cd and 200 mg kg(-1) Zn from the industrially contaminated soil, representing 43 and 7% of the two metals in the soil. In contrast, the high concentration of Cu in the agricultural soil severely reduced the growth of T. caerulescens, thus limiting its phytoextraction potential. The EDTA treatment greatly increased the solubility of heavy metals in both soils, but this did not result in a large increase in metal concentrations in the maize shoots. Phytoextraction of Cd and Zn by maize + EDTA was much smaller than that by T. caerulescens from the industrially contaminated soil, and was either smaller (Cd) or similar (Zn) from the agricultural soil. After EDTA treatment, soluble heavy metals in soil pore water occurred mainly as metal-EDTA complexes, which were persistent for several weeks. High concentrations of heavy metals in soil pore water after EDTA treatment could pose an environmental risk in the form of ground water contamination.

  4. Can Membrane Inlet Mass Spectrometer Measure Short-term Denitrification Enzyme Activity and Denitrification Potentials of Soils?

    Khalil, M. I.; Richards, K. G.


    Denitrifier population size and potential activity combined with the relevant environmental factors regulate the rates of denitrification in terrestrial and aquatic ecosystems. Due to the high atmospheric background of di-nitrogen (N2), denitrification enzyme activity (DEA) in soils is traditionally measured using the acetylene block or stable isotope techniques under non-limiting substrates and anaerobic/saturated conditions for periods from a few hours to several days so as to estimate denitrification potential (DP). This research investigated the estimation of DEA and DP by quantifying the N2/Ar ratio changes in waters/sediments using membrane inlet mass spectrometry (MIMS). Two experiments were conducted with soils of A, B and C horizons collected from grazed grassland to obtain optimal NO3- and available carbon (C) rates. In experiment 1, 30 g soil (oven dry basis) followed by helium-flushed deionized water was taken in triplicate 160 mL glass bottles and sealed with rubber stoppers without any air entrapments. Then N as potassium nitrate (0 to 120 mg NO3 - N kg-1 soil) and readily available C as glucose (0 to 240 mg glucose-C) plus 30 mg NO3 - N, kg-1 soil were amended. Laboratory incubation was performed in the dark at 21oC under water to reduce the risk of N2 contamination. After six hours, the treated water samples were transferred into 12 mL exetainers and kept under water at 4oC before analysis using MIMS. The N2/Ar ratios, representing DEA, varied between soil horizons and declined with decreasing soil depths. The maximum peak for N2/Ar ratios were observed with the 30 mg NO3 - N kg-1 soil in all soil horizons and coupled with the 60 mg glucose-C kg-1 soil for C horizon, and 120 mg glucose-C kg-1 for A and B horizons. Experiment 2 was conducted to assess simulated unsaturated and saturated subsoil (C horizon) denitrification capacity (NO3 - Nonly amendment), and DP (both C and N amendment) using the same methodology as experiment 1 and incubated for 3

  5. Uptake and speciation of vanadium in the rhizosphere soils of rape (Brassica juncea L.).

    Tian, Li-Yan; Yang, Jin-Yan; Huang, Jen-How


    The response of rape (Brassica juncea L.) to different vanadium (V) speciation in rhizosphere soils was investigated in pot experiments using an agricultural soil containing 147 mg V kg(-1) supplemented with 0-500 mg V kg(-1) of pentavalent V [V(V)] and a mining soil containing 774 mg V kg(-1). Tetravalent V [V(IV)] accounted for 76.1 and 85.9 % of total V in the untreated agricultural soil and mining soil, respectively. The proportion of both V(V) and water-extractable V increased with increasing concentrations of V(V) in the agricultural soil. The growth of rape substantially reduced the concentrations of V(V) but not V(IV) in the rhizosphere soil, suggesting that V(V) was actively involved in the soil-rape interaction of V. Both soil V(V) and water-extractable V were negatively related to the total rape biomass, but were positively correlated with the concentration of root V. No such relationships were found for total V and soil V(IV). Together, these results indicate that soil V(V) and water-extractable V might better reflect the toxicity of V in soils than total V and soil V(IV). Rape accumulated V in the sequence: roots > > stem > leaf > seed. As indicated by the remarkably low root bioconcentration factor of V(V) (0.41-7.24 %), rape had a lower ability to accumulate V than other plants reported in the literature (14.6-298 %). Only a small fraction of V in rape roots was translocated to the aboveground organs (the translocation factor was 3.57-46.9 %). No V was detectable in seeds in the soils at 147 and 197 mg V kg(-1), and no seed was produced in the soils at higher V concentrations. Thus, the risk of V intake by humans via the consumption of rapeseed-based foods under normal conditions is considered to be lower than that of other plants.

  6. Fate of Fluazinam in Pepper and Soil After Application

    DONG Feng-shou; YANG Shuang; LIU Xin-gang; SUN Jian-peng; ZHENG Yong-quan; LI Chong-jiu; YAO Jian-ren


    To discover the fate of fluazinam after its application in pepper field,an efficient residual analytical method for determining fluazinam in pepper and soil was developed.The samples were extracted by acetone,cleaned up by solid-phase extraction (SPE)florisil cartridge,and determined by gas chromatography with electronic capture detector(ECD).The recoveries ranged from 80 to 94.6%,with repeatability relative standard deviation ≤9.3% at spiking levels of 0.1-1 mg kg-1.The residue dynamics of fluazinam in pepper and soil were studied in a field plot.The experiment data showed that the halflives of fluazinam in peppers and soils were 2.5-3.7 days and 1.2-4.2 days,respectively.When the pepper was treated by fluazinam 50% suspension concentrate(SC)at 495 g ha-1 4 times at 7-day intervals,the fluazinam in pepper on the 7th day after the last application was all below 0.06 mg kg-1,which was below the maximum residue limit(MRL)fixed in Korea(0.3mg kg-1).It is implied that fluazinam in pepper is nonpersistent.The results suggested that fluazinam 50% SC should be used in a pepper field at most for 4 times,and the pre-harvest interval should be 7 days.

  7. 福建省蔬菜产地土壤汞污染状况及其影响因素%Mercury Pollution and its Influencing Factors of Vegetable Soils in Fujian Province, China

    洪曾纯; 郭永玲; 王果


    An investigation on mercury pollution of the soils was carried out over the vegetable fields at the suburbs of 12 countries of Fujian Province. The main soil properties which influenced the accumulation and the availability of soil mercury were discussed. Results showed that soil total mercury of the vegetable fields was 0.038~1.81 mg·kg-1, and 33.04%of the total soil mercury of the soil samples exceeded the Na-tional Secondary Standard for acidic agricultural soils. Total soil mercury had significant and positive correlations with the contents of clay, silt, organic matter, as well as CEC of the soils, indicating that these soil properties were in favour of the accumulation of mercury in the soils. The available soil mercury was between 0.003 mg·kg-1 and 0.095 mg·kg-1, showing a significant and positive correlation with total soil mer-cury. The availability factions of soil mercury decreased with increasing soil organic matter, suggesting that organic matter was the major soil property which influenced the availability of mercury in the soils.%研究了福建省12个县(市、区)郊区部分菜地土壤的汞污染状况,讨论了影响土壤汞累积及汞有效性的主要土壤学性质。结果表明:调查的菜地土壤全汞含量范围为0.038耀1.81 mg·kg-1,其中有33.04%的土壤全汞含量超出国家土壤环境质量二级标准。土壤全汞含量与土壤粘粒、粉粒、有机质含量及CEC之间均呈极显著的正相关,说明这些土壤性质有利于汞在土壤中的累积。土壤有效汞含量范围为0.003耀0.095 mg·kg-1,与土壤全汞含量之间呈极显著的线性正相关。土壤汞有效度随土壤有机质的增加而降低,表明有机质是影响土壤汞有效性的主要土壤学性质。

  8. Soil microbial activity and nutrients of evergreen broad-leaf forests in mid-subtropical region of China

    Zhangquan Zeng; Silong Wang; Canming Zhang; Hong Tang; Xiquan Li; Zijian Wu; Jia Luo


    To better understand the effects of forest suc-cession on soil microbial activity, a comparison of soil microbial properties and nutrients was conducted between three forest types representing a natural forest succession chronosequence. The study compared a pine (Pinus mas-soniana) forest (PF), a pine and broadleaf mixed forest (MF) and an evergreen broadleaf forest (BF), in the Yingzuijie Biosphere Reserve, Hunan Province, China. Results showed that soil nutrients in the MF and BF plots were higher than in the PF plots. The range in microbial biomass carbon followed a similar pattern with BF having the greatest values, 522–1022 mg kg-1, followed by MF 368–569 mg kg-1, and finally, PF 193–449 mg kg-1. Soil nutrients were more strongly correlated with microbial biomass carbon than basal respiration or metabolic quo-tient. Overall, forest succession in the study site improved soil microbial properties and soil fertility, which in turn can increase primary productivity and carbon sequestration.

  9. Soil-to-plant transfer of native selenium for wild vegetation cover at selected locations of the Czech Republic.

    Száková, Jiřina; Tremlová, Jana; Pegová, Kristýna; Najmanová, Jana; Tlustoš, Pavel


    Total selenium (Se) contents were determined in aboveground biomass of wild plant species growing in two uncultivated meadows at two different locations. The soils in these locations had pseudototal (Aqua Regia soluble) Se in concentration ranges of between 0.2 and 0.3 mg kg(-1) at the first location, and between 0.7 and 1.4 mg kg(-1) at the second location. The plant species represented 29 plant families where the most numerous ones were Poaceae, Rosaceae, Fabaceae , and Asteraceae. The selenium contents in the plants varied between undetectable levels (Aegopodium podagraria, Achillea millefolium, Lotus corniculatus) and 0.158 mg kg(-1) (Veronica arvensis, Veronicaceae). The Se levels were roughly one order of magnitude lower compared to other elements with similar soil content, such as cadmium and molybdenum. The transfer factors of Se, quantifying the element transfer from soil to plants, varied between <0.001 and 0.146 with no significant differences between the locations, confirming the limited soil-plant selenium transfer regardless of location, soil Se level, and plant species. Among the plant families, no unambiguous trend to potential elevated Se uptake was observed. Low Se content in the soil and its plant availability was comparable to other Se-deficient areas within Europe.

  10. Comparison of Metals and Tetracycline as Selective Agents for Development of Tetracycline Resistant Bacterial Communities in Agricultural Soil.

    Song, Jianxiao; Rensing, Christopher; Holm, Peter E; Virta, Marko; Brandt, Kristian K


    Environmental selection of antibiotic resistance may be caused by either antibiotic residues or coselecting agents. Using a strictly controlled experimental design, we compared the ability of metals (Cu or Zn) and tetracycline to (co)select for tetracycline resistance in bacterial communities. Soil microcosms were established by amending agricultural soil with known levels of Cu, Zn, or tetracycline known to represent commonly used metals and antibiotics for pig farming. Soil bacterial growth dynamics and bacterial community-level tetracycline resistance were determined using the [(3)H]leucine incorporation technique, whereas soil Cu, Zn, and tetracycline exposure were quantified by a panel of whole-cell bacterial bioreporters. Tetracycline resistance increased significantly in soils containing environmentally relevant levels of Cu (≥365 mg kg(-1)) and Zn (≥264 mg kg(-1)) but not in soil spiked with unrealistically high levels of tetracycline (up to 100 mg kg(-1)). These observations were consistent with bioreporter data showing that metals remained bioavailable, whereas tetracycline was only transiently bioavailable. Community-level tetracycline resistance was correlated to the initial toxicant-induced inhibition of bacterial growth. In conclusion, our study demonstrates that toxic metals in some cases may exert a stronger selection pressure for environmental selection of resistance to an antibiotic than the specific antibiotic itself.

  11. Reducing soil phosphorus fertility brings potential long-term environmental gains: A UK analysis

    Withers, Paul J. A.; Hodgkinson, Robin A.; Rollett, Alison; Dyer, Chris; Dils, Rachael; Collins, Adrian L.; Bilsborrow, Paul E.; Bailey, Geoff; Sylvester-Bradley, Roger


    Soil phosphorus (P) fertility arising from historic P inputs is a major driver of P mobilisation in agricultural runoff and increases the risk of aquatic eutrophication. To determine the environmental benefit of lowering soil P fertility, a meta-analysis of the relationship between soil test P (measured as Olsen-P) and P concentrations in agricultural drainflow and surface runoff in mostly UK soils was undertaken in relation to current eutrophication control targets (30-35 µg P L-1). At agronomic-optimum Olsen P (16-25 mg kg-1), concentrations of soluble reactive P (SRP), total dissolved P (TDP), total P (TP) and sediment-P (SS-P) in runoff were predicted by linear regression analysis to vary between 24 and 183 µg L-1, 38 and 315 µg L-1, 0.2 and 9.6 mg L-1, and 0.31 and 3.2 g kg-1, respectively. Concentrations of SRP and TDP in runoff were much more sensitive to changes in Olsen-P than were TP and SS-P concentrations, which confirms that separate strategies are required for mitigating the mobilisation of dissolved and particulate P forms. As the main driver of eutrophication, SRP concentrations in runoff were reduced on average by 60 µg L-1 (71%) by lowering soil Olsen-P from optimum (25 mg kg-1) to 10 mg kg-1. At Olsen-P concentrations below 12 mg kg-1, dissolved hydrolysable P (largely organic) became the dominant form of soluble P transported. We concluded that maintaining agronomic-optimum Olsen-P could still pose a eutrophication risk, and that a greater research focus on reducing critical soil test P through innovative agro-engineering of soils, crops and fertilisers would give long-term benefits in reducing the endemic eutrophication risk arising from legacy soil P. Soil P testing should become compulsory in priority catchments suffering, or sensitive to, eutrophication to ensure soil P reserves are fully accounted for as part of good fertiliser and manure management.

  12. Agronomic efficiency of polymer-coated triple superphosphate in onion cultivated in contrasting texture soils

    Wantuir Filipe Teixeira Chagas


    Full Text Available ABSTRACT Information related to phosphate fertilization and coated phosphate fertilizer in onion is scarce. Thus, this study was carried out to evaluate agronomic efficiency, production and nutritional characteristics of triple superphosphate coated with polymers in onion cultivated in contrasting texture soils. Two experiments were carried out under protected conditions in pots containing 5 kg soil. The experimental design was completely randomized with treatments arranged in a 2 x 5 factorial: triple superphosphate (TSP and polymer-coated triple superphosphate (TSP+P applied in five phosphorus rates: Dystroferric Red Latosol (LVdf (clayey = 0; 100; 200; 400; 800 mg P2O5 kg-1, and Quartzarenic Neosol (sandy = 0; 75; 150; 300; 600 mg P2O5 kg-1, with three replications. Results indicated that polymer-coated TSP showed no difference for bulb mass and agronomic efficiency for phosphorus fertilization. Agronomic efficiency of phosphorus fertilization decreased with the increase in the amount of phosphorus applied. Phosphorus accumulation for onion bulb cultivated in Dystroferric Red Latosol (LVdf was higher with the use of polymer-coated triple superphosphate. Growth, production and nutritional characteristics in onion were affected by phosphorus. The highest bulbs mass production and phosphorus accumulation occurred at the doses of 783; 629 mg kg-1 P2O5 (Dystroferric Red Latosol - LVdf, and of 406; 600 mg kg-1 P2O5 (Quartzarenic Neosol -RQ.

  13. Biodegradation of polycyclic aromatic hydrocarbons in soil contaminated with coal tar

    Ondrej Tischler


    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are a group of serious contaminants of air, water soil and sediments. Persistence and accumulation of PAHs in the environment is due to their hydrophobicity and hence low solubility and bioavailability to microbial action. This work presents an evidence of biodegradation of PAHs in a soil sample taken from a coal gasification plant contaminated with coal tar. The degradation of the contaminant by indigenous microorganisms was studied under aerobic conditions at 15 ºC in a laboratory glass column. The oxidation kinetic of organic carbon was monitored by measuring the oxygen consumption rate and the carbon dioxide production rate. The biodegradation rates observed were in the range of 0.2 to 7 mg C kg-1 h-1. Approximately 14 000 mg kg-1 of the total organic carbon was completely mineralized to CO2 during 6 months. The sum of 16 EPA PAHs decreased from the initial concentration of 21 331 mg kg-1 to the value of 2 774 mg kg-1after 6 months of biodegradation. The thermogravimetric analysis revealed a 34 % weight decrease of organic mater content during the 6-month degradation period.

  14. Determination of total mercury in aluminium industrial zones and soil contaminated with red mud.

    Rasulov, Oqil; Zacharová, Andrea; Schwarz, Marián


    This study investigated total mercury contents in areas impacted by aluminium plants in Tajikistan and Slovakia and in one area flooded with red mud in Hungary. We present the first determination of total mercury contents in the near-top soil (0-10 and 10-20 cm) in Tajikistan and the first comparative investigation of Tajikistan-Slovakia-Hungary. The Tajik Aluminium Company (TALCO) is one of the leading producers of primary aluminium in Central Asia. In the past 30 years, the plant has been producing large volumes of industrial waste, resulting in negative impacts on soil, groundwater and air quality of the surrounding region. Mercury concentrations were significant in Slovakia and Hungary, 6 years after the flooding. In studied areas in Slovakia and Hungary, concentrations of total mercury exceeded the threshold limit value (TLV = 0.5 mg Hg kg(-1)). However, in Tajikistan, values were below the TLV (0.006-0.074 mg kg(-1)) and did not significantly vary between depths. Total Hg in Slovakia ranged from 0.057 to 0.668 mg kg(-1) and in Hungary from 0.029 to 1.275 mg kg(-1). However, in the plots near to the red mud reservoir and the flooded area, Hg concentrations were higher in the upper layers than in the lower ones.

  15. Evidence for the importance of litter as a co-substrate for MCPA dissipation in an agricultural soil.

    Saleh, Omar; Pagel, Holger; Enowashu, Esther; Devers, Marion; Martin-Laurent, Fabrice; Streck, Thilo; Kandeler, Ellen; Poll, Christian


    Environmental controls of 2-methyl-4-chlorophenoxyacetic acid (MCPA) degradation are poorly understood. We investigated whether microbial MCPA degraders are stimulated by (maize) litter and whether this process depends on concentrations of MCPA and litter. In a microcosm experiment, different amounts of litter (0, 10 and 20 g kg(-1)) were added to soils exposed to three levels of the herbicide (0, 5 and 30 mg kg(-1)). The treated soils were incubated at 20 °C for 6 weeks, and samples were taken after 1, 3 and 6 weeks of incubation. In soils with 5 mg kg(-1) MCPA, about 50 % of the MCPA was dissipated within 1 week of the incubation. Almost complete dissipation of the herbicide had occurred by the end of the incubation with no differences between the three litter amendments. At the higher concentration (30 mg kg(-1)), MCPA endured longer in the soil, with only 31 % of the initial amount being removed at the end of the experiment in the absence of litter. Litter addition greatly increased the dissipation rate with 70 and 80 % of the herbicide being dissipated in the 10 and 20 g kg(-1) litter treatments, respectively. Signs of toxic effects of MCPA on soil bacteria were observed from related phospholipid fatty acid (PLFA) analyses, while fungi showed higher tolerance to the increased MCPA levels. The abundance of bacterial tfdA genes in soil increased with the co-occurrence of litter and high MCPA concentration, indicating the importance of substrate availability in fostering MCPA-degrading bacteria and thereby improving the potential for removal of MCPA in the environment.

  16. Landslide-induced changes in soil phosphorus speciation and availability in Xitou, Central Taiwan

    Cheng, Chih-Hsin; Hsiao, Sheng-Che; Huang, Yu-Sheng; Chen, Chiu-Ping; Menyailo, Oleg


    Phosphorus is an important nutrient in forest ecosystem. In tropical/subtropical areas, phosphorus is generally limited because of strong soil weathering but its speciation and availability can be changed by disturbances, such as the geological landslide events. In this study, we evaluated the changes in soil P speciation and availability after landslide in a mountainous forest ecosystem in Xitou, central Taiwan. Five soil pedons along a landslide/nonlanslide affected sequence from deep landslide deposit to nonlandslide were collected. The Hedley's sequential extraction procedure and synchrotron-based phosphorus x-ray adsorption near edge structure (XANES) spectroscopy were applied for the surface 0-10 cm and 10-20 cm soils to provide information concerning chemical and structural composition of phosphorus. The results indicated that plant available P (Resin-P + NaHCO3 extract P) and total P were reduced after landslide, from 150 and 500 mg kg-1, respectively, at nonlandsliding sites to 50 and 350 mg kg-1 at landsliding sites. However, the apatite-type P was significantly increased after landslide, from about 70 mg kg-1 at nonlandsliding sites to around 200 mg kg-1 at landsliding sites. Similar trend of enhanced apatite-type P after landslide was also observed in the XANES spectra. The ryegrass pot experiment confirmed that the landsliding soils were less fertile and had less growth rate. However, both nitrogen and phosphorus nutrients were limited at landsliding sites. The results demonstrated that soil P speciation and availability were significantly altered after landslide; these resultant changes are expected to influence functions in forest ecosystems.

  17. Effects of birch tar oils on soil organisms and plants



    Full Text Available The use of birch tar oil (BTO is a new innovation in plant and animal protection working against various weeds, harmful insects and rodents. Due to its novelty as a biocide/repellent/plant protection product, no comprehensive information on the effects of BTO on non-target soil organisms is available. In this study we examined the impact of BTO on non-target soil organisms (enchytraeids, nematodes and soil microbes and plants using laboratory toxicity tests and field experiments. In addition, we determined the LC50 value of BTO to the earthworm Aporrectodea caliginosa and the EC50 value of BTO to the offspring production of the collembolan Folsomia candida. The effects of BTO on soil fauna were mostly insignificant. BTO seemed to be detrimental to the growth of plants directly after application, but this effect was short-term; after a period of 2.5 months, the growth of most of the plant species recovered completely from the application. The LC50 for A. caliginosa was 6560 mg BTO kg-1 dry soil and EC50 for juvenile production of F. candida was 5100 mg BTO kg-1 dry soil. The results indicate that the risk caused by BTOs (concentration 500-1360 L ha-1 to the soil environment is insignificant and short-term as compared to the many chemical products applied for similar purposes.;

  18. Dissipation of glyphosate from grapevine soils in Sonora, Mexico

    Norma J. Salazar López


    Full Text Available Grapevine is one of the important crops in Sonora, due to revenue generation from its export to foreign countries. Among the most widely used herbicides for this crop is glyphosate, which is considered moderately toxic and persistent. The present research evaluates the dissipation of glyphosate in grapevine planted soil at three depths (5, 30 and 60 cm. Sampling was carried out before glyphosate application, and 5, 10, 18, 27, and 65 days after. Glyphosate was extracted from soil samples using ammonium hydroxide. The derivate extracts were partitioned with dichloromethane and analyzed using gas chromatography with pulsed flame photometric detector (PFPD. The results showed that average glyphosate residues are significantly greater at 5 cm (0.09 mg kg-1 than the other depths (30 and 60 cm, having a difference of 0.078 mg kg-1 between them (P < 0.03. Glyphosate concentration time profiles were similar; it reached maximum soil concentration in a range of 10 to 18 days after application. The half-life of glyphosate in soil has an average of 39 days at all depths. Our data suggests that the release in soil of glyphosate applied to weeds delays its transference to soil by 14 days, and extends residue half life to 55 days after application. These results could be the basis for further research, including more environmental parameters that could affect the dissipation or degradation process in soil.


    Marija Tomasic


    Full Text Available The study was conducted on 18 locations and 11 dominant soil types in the Republic of Croatia including their evolution-genetic horizons. In total, 51 soil samples were examined. Analysis of soil was done by saturating patterns using barium chloride solution in three replications. Descriptive statistics of the analyzed data was conducted. Basic statistical parameters were calculated, and functional dependence between the base saturation (V% of analyzed soil samples and their pH was observed. The correlation coefficient (r between base saturation (V% and pH for all examined soils was r=0.79 (n=51; very strong correlation. For acid soils it was r=0.82 (n=17; very strong correlation, for neutral soils r=0.75 (n=8; very strong correlation, and finally for alkaline soils r=0.15 (n=26; very weak correlation. Cation exchange capacity values ranged from 2.39 cmol+*kg-1 to 33.8 cmol+*kg-1 depending on soil type, pH, organic content and other soil parameters. The content of exchangeable cations in the sum of basic cations ranged from: Ca2+ (16% - 94%, Mg2+ (2% - 41%, K+ (1% - 68% and Na+ (<0.01% also depending on soil type, depth, location and other physical and chemical soil parameters.

  20. Phytoavailability of cadmium (Cd) to Pak choi (Brassica chinensis L.) grown in Chinese soils: a model to evaluate the impact of soil Cd pollution on potential dietary toxicity.

    Rafiq, Muhammad Tariq; Aziz, Rukhsanda; Yang, Xiaoe; Xiao, Wendan; Stoffella, Peter J; Saghir, Aamir; Azam, Muhammad; Li, Tingqiang


    Food chain contamination by soil cadmium (Cd) through vegetable consumption poses a threat to human health. Therefore, an understanding is needed on the relationship between the phytoavailability of Cd in soils and its uptake in edible tissues of vegetables. The purpose of this study was to establish soil Cd thresholds of representative Chinese soils based on dietary toxicity to humans and develop a model to evaluate the phytoavailability of Cd to Pak choi (Brassica chinensis L.) based on soil properties. Mehlich-3 extractable Cd thresholds were more suitable for Stagnic Anthrosols, Calcareous, Ustic Cambosols, Typic Haplustalfs, Udic Ferrisols and Periudic Argosols with values of 0.30, 0.25, 0.18, 0.16, 0.15 and 0.03 mg kg-1, respectively, while total Cd is adequate threshold for Mollisols with a value of 0.86 mg kg-1. A stepwise regression model indicated that Cd phytoavailability to Pak choi was significantly influenced by soil pH, organic matter, total Zinc and Cd concentrations in soil. Therefore, since Cd accumulation in Pak choi varied with soil characteristics, they should be considered while assessing the environmental quality of soils to ensure the hygienically safe food production.

  1. Migration and Enrichment of Arsenic in the Rock-Soil-Crop Plant System in Areas Covered with Black Shale, Korea

    Ji-Min Yi


    Full Text Available The Okchon black shale, which is part of the Guryongsan Formation or the Changri Formation of Cambro-Ordovician age in Korea provides a typical example of natural geological materials enriched with potentially toxic elements such as U, V, Mo, As, Se, Cd, and Zn. In this study, the Dukpyung and the Chubu areas were selected to investigate the migration and enrichment of As and other toxic elements in soils and crop plants in areas covered with black shale. Rock and soil samples digested in 4-acid solution (HCl+HNO3+HF+HClO4 were analyzed for As and other heavy metals by ICP-AES and ICP-MS, and plant samples by INAA. Mean concentration of As in Okchon black shale is higher than those of both world average values of shale and black shale. Especially high concentration of 23.2 mg As kg-1 is found in black shale from the Dukpyung area. Mean concentration of As is highly elevated in agricultural soils from the Dukpyung (28.2 mg kg-1 and the Chubu areas (32.6 mg kg-1. As is highly elevated in rice leaves from the Dukpyung (1.14 mg kg-1 and the Chubu areas (1.35 mg kg-1. The biological absorption coefficient (BAC of As in plant species decreases in the order of rice leaves > corn leaves > red pepper = soybean leaves = sesame leaves > corn stalks > corn grains. This indicates that leafy plants tend to accumulate As from soil to a greater degree than cereal products such as grains.

  2. Concentrations of arsenic, copper, cobalt, lead and zinc in cassava (Manihot esculenta Crantz) growing on uncontaminated and contaminated soils of the Zambian Copperbelt

    Kříbek, B.; Majer, V.; Knésl, I.; Nyambe, I.; Mihaljevič, M.; Ettler, V.; Sracek, O.


    The concentrations of arsenic (As), copper (Cu), cobalt (Co), lead (Pb) and zinc (Zn) in washed leaves and washed and peeled tubers of cassava (Manihot esculenta Crantz, Euphorbiaceae) growing on uncontaminated and contaminated soils of the Zambian Copperbelt mining district have been analyzed. An enrichment index (EI) was used to distinguish between contaminated and uncontaminated areas. This index is based on the average ratio of the actual and median concentration of the given contaminants (As, Co, Cu, mercury (Hg), Pb and Zn) in topsoil. The concentrations of copper in cassava leaves growing on contaminated soils reach as much as 612 mg kg-1 Cu (total dry weight [dw]). Concentrations of copper in leaves of cassava growing on uncontaminated soils are much lower (up to 252 mg kg-1 Cu dw). The concentrations of Co (up to 78 mg kg-1 dw), As (up to 8 mg kg-1 dw) and Zn (up to 231 mg kg-1 dw) in leaves of cassava growing on contaminated soils are higher compared with uncontaminated areas, while the concentrations of lead do not differ significantly. The concentrations of analyzed chemical elements in the tubers of cassava are much lower than in its leaves with the exception of As. Even in strongly contaminated areas, the concentrations of copper in the leaves and tubers of cassava do not exceed the daily maximum tolerance limit of 0.5 mg kg-1/human body weight (HBW) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The highest tolerable weekly ingestion of 0.025 mg kg-1/HBW for lead and the highest tolerable weekly ingestion of 0.015 mg kg-1/HBW for arsenic are exceeded predominantly in the vicinity of smelters. Therefore, the preliminary assessment of dietary exposure to metals through the consumption of uncooked cassava leaves and tubers has been identified as a moderate hazard to human health. Nevertheless, as the surfaces of leaves are strongly contaminated by metalliferous dust in the polluted areas, there is still a potential hazard

  3. Effects of pig manure compost and nonionic-surfactant Tween 80 on phenanthrene and pyrene removal from soil vegetated with Agropyron elongatum.

    Cheng, K Y; Lai, K M; Wong, J W C


    This paper evaluates the effects of pig manure compost (PMC) and Tween 80 on the removal of phenanthrene (PHE) and pyrene (PYR) from soil cultivated with Agropyron elongatum. Soils spiked with about 300 mg kg(-1) of PHE and PYR were individually amended with 0%, 2.5%, 5% and 7.5% (dry wt) of PMC or 0, 20 and 100 mg kg(-1) of Tween 80. Unplanted and sterile microcosms were prepared as the controls. PAH concentration, total organic matter (TOM), dissolved organic carbon (DOC), total heterotrophic and PAH degrading microbial populations in soil were quantified before and after 60d period. The results indicated that A. elongatum could significantly enhance PYR removal (from 46% to 61%) but had less impact on PHE removal (from 96% to 97%). Plant uptake of the PAHs was insignificant. Biodegradation was the key mechanism of PAH removals (Tween 80 levels increased the removal of PYR but not of PHE. Maximal PYR removal of 79% and 92% were observed in vegetated soil receiving 100 mg kg(-1) Tween 80 and 7.5% PMC, respectively. Enhanced PYR removal in soil receiving PMC could be explained by the elevated levels of DOC, TOM and microbial populations as suggested by Pearson correlation test. While the positive effect of Tween 80 on PYR removal could probably due to its capacities to enhance PYR bioavailability in soil. This paper suggests that the addition of either PMC or nonionic-surfactant Tween 80 could facilitate phytoremediation of PAH contaminated soil.

  4. Dynamics of microbial community during bioremediation of phenanthrene and chromium(VI)-contaminated soil microcosms.

    Ibarrolaza, Agustín; Coppotelli, Bibiana M; Del Panno, María T; Donati, Edgardo R; Morelli, Irma S


    The combined effect of phenanthrene and Cr(VI) on soil microbial activity, community composition and on the efficiency of bioremediation processes has been studied. Biometer flask systems and soil microcosm systems contaminated with 2,000 mg of phenanthrene per kg of dry soil and different Cr(VI) concentrations were investigated. Temperature, soil moisture and oxygen availability were controlled to support bioremediation. Cr(VI) inhibited the phenanthrene mineralization (CO(2) production) and cultivable PAH degrading bacteria at levels of 500-2,600 mg kg(-1). In the bioremediation experiments in soil microcosms the degradation of phenanthrene, the dehydrogenase activity and the increase in PAH degrading bacteria counts were retarded by the presence of Cr(VI) at all studied concentrations (25, 50 and 100 mg kg(-1)). These negative effects did not show a correlation with Cr(VI) concentration. Whereas the presence of Cr(VI) had a negative effect on the phenanthrene elimination rate, co-contamination with phenanthrene reduced the residual Cr(VI) concentration in the water exchangeable Cr(VI) fraction (WEF) in comparison with the soil microcosm contaminated only with Cr(VI). Clear differences were found between the denaturing gradient gel electrophoresis (DGGE) patterns of each soil microcosm, showing that the presence of different Cr(VI) concentrations did modulate the community response to phenanthrene and caused perdurable changes in the structure of the microbial soil community.

  5. Thresholds of copper phytotoxicity in field-collected agricultural soils exposed to copper mining activities in Chile.

    Verdejo, José; Ginocchio, Rosanna; Sauvé, Sébastien; Salgado, Eduardo; Neaman, Alexander


    It has been argued that the identification of the phytotoxic metal thresholds in soil should be based on field-collected soil rather than on artificially-contaminated soils. However, the use of field-collected soils presents several difficulties for interpretation because of mixed contamination and unavoidable covariance of metal contamination with other soil properties that affect plant growth. The objective of this study was to estimate thresholds of copper phytotoxicity in topsoils of 27 agricultural areas historically contaminated by mining activities in Chile. We performed emergence and early growth (21 days) tests (OECD 208 and ISO 11269-2) with perennial ryegrass (Lolium perenne L.). The total Cu content in soils was the best predictor of plant growth and shoot Cu concentrations, while soluble Cu and pCu(2+) did not well correlate with these biological responses. The effects of Pb, Zn, and As on plant responses were not significant, suggesting that Cu is a metal of prime concern for plant growth in soils exposed to copper mining activities in Chile. The effects of soil nutrient availability and shoot nutrient concentrations on ryegrass response were not significant. It was possible to determine EC10, EC25 and EC50 of total Cu in the soil of 327 mg kg(-1), 735 mg kg(-1) and 1144 mg kg(-1), respectively, using the shoot length as a response variable. However, the derived 95% confidence intervals for EC10, EC25 and EC50 values of total soil Cu were wide, and thus not allowing a robust assessment of metal toxicity for agricultural crops, based on total soil Cu concentrations. Thus, plant tests might need to be performed for metal toxicity assessment. This study suggests shoot length of ryegrass as a robust response variable for metal toxicity assessment in contaminated soils with different nutrient availability.

  6. Nitrification Potential of Soils Under Liquid Incubation Conditions

    YUAN Fei; RAN Wei; SHEN Qi-Rong


    A red soil, a fluvo-aquic soil and a permeable paddy soil were used in a long-term investigation to study changes in nitrification with treatments: 1) soil incubation, 2) liquid incubation inoculated with soil samples, and 3) liquid incubation inoculated with ammonia-oxidizing bacteria (AOB) from the soils. There were significant differences (P < 0.001) in nitrification rates among the three soils when measured for 28 days by adding (NH4)2SO4 at the rate of 154 mg N kg-1 dry soil to fresh soil. However, the amounts of nitrifying bacteria in the three soils were not related to soil nitrification capacity. When the soil samples or the isolates of AOB enriched from the corresponding soil were incubated in liquid with pH 5.8, 7.0 and 8.0 buffers and 10 mmol L-1 ammonium nitrogen, there were no significant nitrification differences in the same soil type at each pH. The ability to oxidize ammonia through AOB from different types of soils in a homogeneous culture medium was similar, and the soil nitrification capacity could reflect the inherent properties of a soil. Altering the culture medium pH of individual soil type also showed that acidification of an alkaline fluvo-aquic soil decreased nitrification capacity, whereas alkalinization of the acidic red soil and permeable paddy soil increased their nitrification. For a better insight into factors influencing soil nitrification processes, soil properties including texture and clay composition should be considered.

  7. Soils

    Emily Moghaddas; Ken Hubbert


    When managing for resilient forests, each soil’s inherent capacity to resist and recover from changes in soil function should be evaluated relative to the anticipated extent and duration of soil disturbance. Application of several key principles will help ensure healthy, resilient soils: (1) minimize physical disturbance using guidelines tailored to specific soil types...

  8. Grain yield and arsenic uptake of upland rice inoculated with arbuscular mycorrhizal fungi in As-spiked soils.

    Wu, Fuyong; Hu, Junli; Wu, Shengchun; Wong, Ming Hung


    A pot trial was conducted to investigate the effects of three arbuscular mycorrhizal (AM) fungi species, including Glomus geosporum BGC HUN02C, G. versiforme BGC GD01B, and G. mosseae BGC GD01A, on grain yield and arsenic (As) uptake of upland rice (Zhonghan 221) in As-spiked soils. Moderate levels of AM colonization (24.1-63.1 %) were recorded in the roots of upland rice, and up to 70 mg kg(-1) As in soils did not seem to inhibit mycorrhizal colonization. Positive mycorrhizal growth effects in grain, husk, straw, and root of the upland rice, especially under high level (70 mg kg(-1)) of As in soils, were apparent. Although the effects varied among species of AM fungi, inoculation of AM fungi apparently enhanced grain yield of upland rice without increasing grain As concentrations in As-spiked soils, indicating that AM fungi could alleviate adverse effects on the upland rice caused by As in soils. The present results also show that mycorrhizal inoculation significantly (p < 0.05) decreased As concentrations in husk, straw, and root in soils added with 70 mg kg(-1) As. The present results suggest that AM fungi are able to mitigate the adverse effects with enhancing rice production when growing in As-contaminated soils.

  9. Trichoderma harzianum Rifai 1295-22 mediates growth promotion of crack willow (Salix fragilis) saplings in both clean and metal-contaminated soil.

    Adams, P; De-Leij, F A A M; Lynch, J M


    We investigated if the plant growth promoting fungus Trichoderma harzianum Rifai 1295-22 (also known as "T22") could be used to enhance the establishment and growth of crack willow (Salix fragilis) in a soil containing no organic or metal pollutants and in a metal-contaminated soil by comparing this fungus with noninoculated controls and an ectomycorrhizal formulation commercially used to enhance the establishment of tree saplings. Crack willow saplings were grown in a temperature-controlled growth room over a period of 5 weeks' in a garden center topsoil and over 12 weeks in a soil which had been used for disposal of building materials and sewage sludge containing elevated levels of heavy metals including cadmium (30 mg kg(-1)), lead (350 mg kg(-1)), manganese (210 mg kg(-1)), nickel (210 mg kg(-1)), and zinc (1,100 mg kg(-1)). After 5 weeks' growth in clean soil, saplings grown with T. harzianum T22 produced shoots and roots that were 40% longer than those of the controls and shoots that were 20% longer than those of saplings grown with ectomycorrhiza (ECM). T. harzianum T22 saplings produced more than double the dry biomass of controls and more than 50% extra biomass than the ECM-treated saplings. After 12 weeks' growth, saplings grown with T. harzianum T22 in the metal-contaminated soil produced 39% more dry weight biomass and were 16% taller than the noninoculated controls. This is the first report of tree growth stimulation by application of Trichoderma to roots, and is especially important as willow is a major source of wood fuel in the quest for renewable energy. These results also suggest willow trees inoculated with T. harzianum T22 could be used to increase the rate of revegetation and phytostabilization of metal-contaminated sites, a property of the fungus never previously demonstrated.

  10. [Quantifying soil autotrophic microbes-assimilated carbon input into soil organic carbon pools following continuous 14C labeling].

    Shi, Ran; Chen, Xiao-Juan; Wu, Xiao-Hong; Jian, Yan; Yuan, Hong-Zhao; Ge, Ti-Da; Sui, Fang-Gong; Tong, Cheng-Li; Wu, Jin-Shui


    Soil autotrophic microbe has been found numerous and widespread. However, roles of microbial autotrophic processes and the mechanisms of that in the soil carbon sequestration remain poorly understood. Here, we used soils incubated for 110 days in a closed, continuously labeled 14C-CO2 atmosphere to measure the amount of labeled C incorporated into the microbial biomass. The allocation of 14C-labeled assimilated carbon in variable soil C pools such as dissolved organic C (DOC) and microbial biomass C (MBC) were also examined over the 14C labeling span. The results showed that significant amounts of 14C-SOC were measured in paddy soils, which ranged from 69.06-133.81 mg x kg(-1), accounting for 0.58% to 0.92% of the total soil organic carbon (SOC). The amounts of 14C in the dissolved organic C (14C-DOC) and in the microbial biomass C (14C-MBC) were dependent on the soils, ranged from 2.54 to 8.10 mg x kg(-1), 19.50 to 49.16 mg x kg(-1), respectively. There was a significantly positive linear relationship between concentrations of 14C-SOC and 14C-MBC (R2 = 0.957**, P < 0.01). The 14C-DOC and 14C-MBC as proportions of total DOC, MBC, were 5.65%-24.91% and 4.23%-20.02%, respectively. Moreover, the distribution and transformation of microbes-assimilated-derived C had a greater influence on the dynamics of DOC and MBC than that on the dynamics of SOC. These data provide new insights into the importance of microorganisms in the fixation of atmospheric CO2 and of the potentially significant contributions made by microbial autotrophy to terrestrial C cycling.

  11. Initial copper stress strengthens the resistance of soil microorganisms to a subsequent copper stress.

    Li, Jing; Zheng, Yuan-Ming; Liu, Yu-Rong; Ma, Yi-Bing; Hu, Hang-Wei; He, Ji Zheng


    To improve the prediction of essential ecosystem functioning under future environmental disturbances, it is of significance to identify responses of soil microorganisms to environmental stresses. In this study, we collected polluted soil samples from field plots with eight copper levels ranging from 0 to 3,200 mg Cu kg(-1) soil. Then, the soils with 0 and 3,200 mg Cu kg(-1) were selected to construct a microcosm experiment. Four treatments were set up including Cu0-C and Cu3200-C without further Cu addition, and Cu0-A and Cu3200-A with addition of 57.5 mg Cu kg(-1) soil. We measured substrate-induced respiration (SIR) and potential nitrification rate (PNR). Furthermore, the abundance of bacterial, archaeal 16S rRNA genes, ammonia-oxidizing bacteria and archaea amoA genes were determined through quantitative PCR. The soil microbial communities were investigated by terminal restriction fragment length polymorphism (T-RFLP). For the field samples, the SIR and PNR as well as the abundance of soil microorganisms varied significantly between eight copper levels. Soil microbial communities highly differed between the low and high copper stress. In the microcosm experiment, the PNR and SIR both recovered while the abundance of soil microorganisms varied irregularly during the 90-day incubation. The differences of microbial communities measured by pairwise Bray-Curtis dissimilarities between Cu0-A and Cu0-C on day 0 were significantly higher after subsequent stress than before. However, the differences of microbial communities between Cu3200-A and Cu3200-C on day 0 changed little between after subsequent stress and before. Therefore, initial copper stress could increase the resistance of soil microorganisms to subsequent copper stress.

  12. Effects of Heavy Metal Contamination on Microbial Biomass and Community Structure in Soils

    杨元根; 刘丛强; 徐磊; 吴攀; 张国平


    Zinc smelting near Magu Town, Hezhang County, Guizhou Province, resulted in vegetation destruction and the accumulation of heavy metals, to varying extent, in adjacent soils, where up to 162.2-877.9 mg·kg+-1 Zn, 37.24-305.6 mg·kg+-1 Pb, and 0.50-16.43 mg·kg+-1 Cd, were detected. These values greatly exceed the background levels of these elements in soils. The concentrations of heavy metals (particularly Pb, Zn) were positively correlated with the contents of Fe-2O-3 and Al-2O-3 in the soils, showing that Fe and Al oxides play an important role in retaining heavy metals. Chemical fractionation indicates that Pb and Zn were associated mainly with Fe and Mn oxides and minerals, whereas Cd was dominated by exchangeable form. Microbial biomass in the soils was relatively low, in the range of 57.00-388.0μg C·g+-1, and was negatively correlated with heavy metal concentrations in the soils. The correlation coefficient of microbial biomass C to Zn concentrations in the soils was as high as -0.778 (p<0.01), indicating that the heavy metal contamination has toxic effects on microorganisms in soil. The results of Biolog measurements demonstrated that there were no significant changes in microbial community structure in the heavy metal contaminated soils. Gene fragments were similar to one another after the DNA was extracted from soil microbes and experienced PCR (polymerase chain reaction) and DGGE (denaturing gradient gel electrophoresis) reactions. These results indicated that light heavy-metal pollution may not result in any change in soil microbial community structure.

  13. Assessment of heavy metal pollution in vegetables and relationships with soil heavy metal distribution in Zhejiang province, China.

    Ye, Xuezhu; Xiao, Wendan; Zhang, Yongzhi; Zhao, Shouping; Wang, Gangjun; Zhang, Qi; Wang, Qiang


    There are increasing concerns on heavy metal contaminant in soils and vegetables. In this study, we investigated heavy metal pollution in vegetables and the corresponding soils in the main vegetable production regions of Zhejiang province, China. A total of 97 vegetable samples and 202 agricultural soil samples were analyzed for the concentrations of Cd, Pb, As, Hg, and Cr. The average levels of Cd, Pb, and Cr in vegetable samples [Chinese cabbage (Brassica campestris spp. Pekinensis), pakchoi (Brassica chinensis L.), celery (Apium graveolens), tomato (Lycopersicon esculentum), cucumber (Colletotrichum lagenarium), cowpea (Vigna unguiculata), pumpkin (Cucurbita pepo L.), and eggplant (Solanum melongena)] were 0.020, 0.048, and 0.043 mg kg(-1), respectively. The Pb and Cr concentrations in all vegetable samples were below the threshold levels of the Food Quality Standard (0.3 and 0.5 mg kg(-1), respectively), except that two eggplant samples exceeded the threshold levels for Cd concentrations (0.05 mg kg(-1)). As and Hg contents in vegetables were below the detection level (0.005 and 0.002 mg kg(-1), respectively). Soil pollution conditions were assessed in accordance with the Chinese Soil Quality Criterion (GB15618-1995, Grade II); 50 and 68 soil samples from the investigated area exceeded the maximum allowable contents for Cd and Hg, respectively. Simple correlation analysis revealed that there were significantly positive correlations between the metal concentrations in vegetables and the corresponding soils, especially for the leafy and stem vegetables such as pakchoi, cabbage, and celery. Bio-concentration factor values for Cd are higher than those for Pb and Cr, which indicates that Cd is more readily absorbed by vegetables than Pb and Cr. Therefore, more attention should be paid to the possible pollution of heavy metals in vegetables, especially Cd.

  14. Implication of zinc excess on soil health.

    Wyszkowska, Jadwiga; Boros-Lajszner, Edyta; Borowik, Agata; Baćmaga, Małgorzata; Kucharski, Jan; Tomkiel, Monika


    This study was undertaken to evaluate zinc's influence on the resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease. The experiment was conducted in a greenhouse of the University of Warmia and Mazury (UWM) in Olsztyn, Poland. Plastic pots were filled with 3 kg of sandy loam with pHKCl - 7.0 each. The experimental variables were: zinc applied to soil at six doses: 100, 300, 600, 1,200, 2,400 and 4,800 mg of Zn(2+) kg(-1) in the form of ZnCl2 (zinc chloride), and species of plant: oat (Avena sativa L.) cv. Chwat and white mustard (Sinapis alba) cv. Rota. Soil without the addition of zinc served as the control. During the growing season, soil samples were subjected to microbiological analyses on experimental days 25 and 50 to determine the abundance of organotrophic bacteria, actinomyces and fungi, and the activity of dehydrogenases, catalase and urease, which provided a basis for determining the soil resistance index (RS). The physicochemical properties of soil were determined after harvest. The results of this study indicate that excessive concentrations of zinc have an adverse impact on microbial growth and the activity of soil enzymes. The resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease decreased with an increase in the degree of soil contamination with zinc. Dehydrogenases were most sensitive and urease was least sensitive to soil contamination with zinc. Zinc also exerted an adverse influence on the physicochemical properties of soil and plant development. The growth of oat and white mustard plants was almost completely inhibited in response to the highest zinc doses of 2,400 and 4,800 mg Zn(2+) kg(-1).

  15. Hyphomicrobium sp.MAP-1菌株修复甲胺磷乙酰甲胺磷和水胺硫磷污染土壤的实验研究%Bioremediation on the Soil Contaminated by Methamidophos, Acephate and Isocarbophos by Hyphomicrobium sp.MAP-1

    王莉; 凌琪; 伍昌年; 李顺鹏; 蒋建东; 王敏


    在实验室条件下,评估了菌株Hyphomicrobium sp.MAP-1对甲胺磷、乙酰甲胺磷和水胺硫磷污染土壤的修复能力.革兰氏阴性菌MAP-1在土壤中能很好的定殖,以1×107 CFU·g-1 soil的浓度接种于土壤,15d后菌株浓度仅下降了1个数量级.土壤非灭菌状态下,30℃pH 6.8,接种量为1×107 CFU·g-1soil时,9d内可分别将土壤100 mg· kg-1甲胺磷、100 mg·kg-1乙酰甲胺磷完全降解,13d内将50 mg·kg-1水胺硫磷完全降解.添加甲醇和加大接种量能促进土壤中三种有机磷农药降解,土壤是否处于淹水状态对其降解影响不大.在20~30℃之间,土壤中三种农药有比较好的去除效果.土壤投加菌株MAP-1,第10 d可使100 mg·kg-1甲胺磷和1 00 mg· kg-1乙酰甲胺磷抑制的土壤脱氢酶、蔗糖酶和脲酶活性恢复至施农药前水平,对50 mg· kg-1水胺硫磷抑制的这三种土壤酶活性也有较大的恢复作用.可见将菌株MAP-1应用于降低甲胺磷、乙酰甲胺磷和水胺硫磷对土壤的潜在风险是可接受的.%The ability of bioremediation on contamined soil by methamidophos, acephate, and isocarbophos for Hyphomicrobium sp. MAP-1 was assessed under laboratory conditions. It was found that the gram-stain-negative strain MAP-1 could well colonizated in soil, and concentration of MAP-1 only decreased by one order of magnitude after 15 days, when inculating MAP-1 into soil at the inculum size of lx107 CFU-g"1 soil. Under these conditions: non-sterilization soil, 30 ℃ pH 6.8, the inculum size of lx107 CFU-g-1 soil, the strain MAP-1 was able to completely respectively degradate 100 nig-kg1 methamidophos and 100 mg-kg1 acephate within 9 days, completely remove 50 mg-kg1 isocarbophos within 13 days. The addiation of methanol or increase of inoculum of strain MAP-1 in soil, could accelerate the degradation of three organophosphorus pesticides. Whether the soil was flooded or not, no notable effect on degradation was found. Between 20

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

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


    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

  17. How historical copper contamination affects soil structure and mobilization and transport of colloids

    Paradelo, Marcos; Møldrup, Per; Holmstrup, Martin;

    between 0.01 to 0.43 pore volumes, with longer times for the most contaminated point, likely related with its higher soil density and lower air permeability. The copper pollution affected colloid and tracer transport in the soil columns. The release of colloids especially in the most contaminated points......Copper is accumulated in soils due to human activities such as mining industry, agriculture practises, or waste deposals. High concentrations of copper can affect plants and soil organisms, and subsequently the soil structure and its inner space architecture. In this work we investigated the effect...... of copper concentration on the movement of an inert tracer, tritium, and the mobilization and transport of colloid particles in undisturbed soil cores (10 cm diameter and 8 cm height). The cores were sampled along a copper gradient of 21 to 3837 mg Cu kg-1 soil on an abandoned arable soil polluted by copper...

  18. Effect of pyrene and cadmium on microbial activity and community structure in soil.

    Lu, Mang; Xu, Kui; Chen, Jun


    In this study, a greenhouse experiment was conducted to investigate interactive effects of cadmium (Cd) × pyrene × plant treatments on soil microbial activity and community structure. The results demonstrated that the basal respiration, microbial biomass carbon and metabolic quotient in both unplanted and rhizosphere soil were significantly influenced by interaction of Cd and pyrene. The combined application of Cd and pyrene caused a significantly greater biocidal influence on the soil microorganisms than the single spiking of Cd or pyrene. The soil basal respiration increased with the spiking of 2.5 mg kg(-1) Cd in both unplanted and rhizosphere soil. The eco-physiological index of Cd-tolerant populations was significantly different among the unplanted soil, rhizoplane and rhizosphere soil of tall fescue, indicating a slightly uneven distribution of fast- and slow-growing tolerant bacteria. Obvious differences in microbial activity were observed among treatments due to different physicochemical characteristics of the rhizosphere soils depending on the plant species.

  19. Distributions and concentrations of thallium in Korean soils determined by single and sequential extraction procedures.

    Lee, Jin-Ho; Kim, Dong-Jin; Ahn, Byung-Koo


    The objectives of this study were to investigate the distribution of thallium in soils collected near suspected areas such as cement plants, active and closed mines, and smelters and to examine the extraction of thallium in the soils using 19 single chemical and sequential chemical extraction procedures. Thallium concentrations in soils near cement plants were distributed between 1.20 and 12.91 mg kg(-1). However, soils near mines and smelters contained relatively low thallium concentrations ranging from 0.18 to 1.09 mg kg(-1). Thallium extractability with 19 single chemical extractants from selected soils near cement plants ranged from 0.10% to 8.20% of the total thallium concentration. In particular, 1.0 M NH4Cl, 1.0 M (NH4)2SO4, and 1.0 M CH3COONH4 extracted more thallium than other extractants. Sequential fractionation results of thallium from different soils such as industrially and artificially contaminated soils varied with the soil properties, especially soil pH and the duration of thallium contamination.

  20. [Accumulation Characteristics and Evaluation of Heavy Metals in Soil-Crop System Affected by Wastewater Irrigation Around a Chemical Factory in Shenmu County].

    Qi, Yan-bing; Chu, Wan-lin; Pu, Jie; Liu, Meng-yun; Chang, Qing-rui


    Soil heavy metals Cu, Pb, Zn, and Cd, are regarded as "chemical time bombs" because of their propensity for accumulation in the soil and uptake by crops. This ultimately causes human toxicity in both the short and long-term, making farmland ecosystems dangerous to health. In this paper, accumulation and spatial variability of Cu, Zn, Pb and Cd in soil-crop system affected by wastewater irrigation around a chemical factor in northern Shaanxi province were analyzed. Results showed that wastewater irrigation around the chemical factory induced significant accumulation in soils compared with control areas. The average concentrations of available Cu and total Cu were 4.32 mg x kg(-1) and 38.4 mg x kg(-1), which were twice and 1.35 times higher than those of the control area, respectively. Soil Zn and Pb were slightly accumulated. Whereas soil Cd was significantly accumulated and was higher than the critical level of soil environmental quality (II), the available and total Cd concentrations were 0.248 mg x kg(-1) and 1.21 mg x kg(-1), which were 10 and 6.1 times higher than those of the control areas. No significant correlations were found between available and total heavy metals except between available Cd and total Cd. All the heavy metals were mainly accumulated in the top layer (0-10 cm). Spatially, soils and plants high in heavy metal concentration were distributed within the radius of about 100 m from the waste water outlet for Cu, Zn and Cd and about 200 m for Pb, and decreased exponentially with the distance from the factory. Affected by wastewater irrigation, contents of Cu, Pb and Cd in maize were 4.74, 0.129 and 0.036 mg x kg(-1) which were slightly higher than those in the control area. The content of Zn was similar to that in the control area. Affected by the vehicle exhaust, the over standard rate of Pb was 5.7% in maize. All the heavy metals did not show significant correlation between soil and crop, except Cd. The square correlation coefficients were 0

  1. Temperature Effect on Boron Adsorption—Desorption Kinetics in Soils



    The effect of temperature on the properties of boron adsorption-desorption in brown-red soil,yellowbrown soil and calcareous alluvial soil of Hubei Province was investigated with the mobile displacement technique.The experimental data of B adsorption-desorption amounts and reaction time at 25 and 40℃ were fitted by the zero-order,first-order and parabolic diffusion kinetic equations.The adsorption process was in conformity with the parabolic diffusion law at both the temperatures,and the values of rate constant of the parabolic diffusion equation in B adsorption were 0.138,0.124 and 0.105 mg kg-1 min-1/2 at 25℃,and 0.147,0.146and 0.135mg kg-1 min1/2 at 40℃ for the brown-red soil,yellow-brown soil,and calcareous alluvial soil,respectively,The relationship between amount of B desorption and reaction time could be well described by the first-order kinetic equation,and the corresponding values of rate constant were 0.0422,0.0563 and 0.0384min-1 at 25℃,and 0.0408,0.0423 and 0.0401min-1 at 40℃ for the brown-red soil,the yellow-brown soil and the calcareous alluvial soil,respectively.Therefore,the desorption process of B might be related to the amount of B adsorbed in soil,The higher th temperature,the lower the amount of B adsorption of the same soil in the same reaction time,The values of the apparent activation energy of B adsorption in the three soils calculated with the rate constants of parabolic diffusion equation were 3.27,8.44 and 12.99 kJ mol-1,respectively,based on the experimental data of B adsorption amounts and reaction time at and 40℃.

  2. Effects of nano-sized zero-valent iron (nZVI) on DDT degradation in soil and its toxicity to collembola and ostracods.

    El-Temsah, Yehia S; Joner, Erik J


    Nano-sized zero valent iron (nZVI) has been studied for in situ remediation of contaminated soil and ground water. However, little is known about its effects on organisms in soil and aquatic ecosystems. In this study, the effect of nZVI on degradation of DDT and its ecotoxicological effects on collembola (Folsomia candida) and ostracods (Heterocypris incongruens) were investigated. Two soils were used in suspension incubation experiments lasting for 7 and 30 d; a spiked (20 mg DDT kg(-1)) sandy soil and an aged (>50 years) DDT-polluted soil (24 mg DDT kg(-1)). These were incubated with 1 or 10 g nZVI kg(-1), and residual toxicity in soil and the aqueous phase tested using ecotoxicological tests with collembola or ostracods. Generally, addition of either concentration of nZVI to soil led to about 50% degradation of DDT in spiked soil at the end of 7 and 30 d incubation, while the degradation of DDT was less in aged DDT-polluted soil (24%). Severe negative effects of nZVI were observed on both test organisms after 7 d incubation, but prolonged incubation led to oxidation of nZVI which reduced its toxic effects on the tested organisms. On the other hand, DDT had significant negative effects on collembolan reproduction and ostracod development. We conclude that 1 g nZVI kg(-1) was efficient for significant DDT degradation in spiked soil, while a higher concentration was necessary for treating aged pollutants in soil. The adverse effects of nZVI on tested organisms seem temporary and reduced after oxidation.

  3. Evaluation of solid sampling for determination of Mo, Ni, Co, and V in soil by high-resolution continuum source graphite furnace atomic absorption spectrometry

    Babos, Diego Victor; Barros, Ariane Isis; Ferreira, Edilene Cristina; Neto, José Anchieta Gomes


    New methods are proposed for the determination of Mo, Ni, Co, and V in soils using high-resolution continuum source graphite furnace atomic absorption spectrometry with direct solid sampling. Cobalt and V were simultaneously determined, and different analytical lines of Ni and V were monitored to adjust sensitivity for each sample. Accuracy was checked by means of soil certified reference materials, and also by flame atomic absorption spectrometry as comparative technique. The results for Mo, Ni, Co, and V found by proposed methods were in agreement with certified values and with those obtained by the comparative technique at 95% confidence level. The concentrations found in different soil samples were in the ranges 0.19-1.84 mg kg- 1 (Mo), 9.2-22.7 mg kg- 1 (Ni), 1.1-10.7 mg kg- 1 (Co), and 35.6-426.1 mg kg- 1 (V). The relative standard deviations were in the ranges 3.2-10% (Mo), 2.8-9.8% (Ni), 4.0-9.2% (Co), and 1.2-8.0% (V). The limits of quantification for Mo, Ni, Co, and V were 0.027, 0.071, 0.15, and 1.43 ng, respectively.

  4. Effects of dicyandiamide and dolomite application on N2O emission from an acidic soil.

    Shaaban, Muhammad; Wu, Yupeng; Peng, Qi-an; Lin, Shan; Mo, Yongliang; Wu, Lei; Hu, Ronggui; Zhou, Wei


    Soil acidification is a major problem for sustainable agriculture since it limits productivity of several crops. Liming is usually adopted to ameliorate soil acidity that can trigger soil processes such as nitrification, denitrification, and loss of nitrogen (N) as nitrous oxide (N2O) emissions. The loss of N following liming of acidic soils can be controlled by nitrification inhibitors (such as dicyandiamide). However, effects of nitrification inhibitors following liming of acidic soils are not well understood so far. Here, we conducted a laboratory study using an acidic soil to examine the effects of dolomite and dicyandiamide (DCD) application on N2O emissions. Three levels of DCD (0, 10, and 20 mg kg(-1); DCD0, DCD10, and DCD20, respectively) were applied to the acidic soil under two levels of dolomite (0 and 1 g kg(-1)) which were further treated with two levels of N fertilizer (0 and 200 mg N kg(-1)). Results showed that N2O emissions were highest at low soil pH levels in fertilizer-treated soil without application of DCD and dolomite. Application of DCD and dolomite significantly (P ≤ 0.001) reduced N2O emissions through decreasing rates of NH4 (+)-N oxidation and increasing soil pH, respectively. Total N2O emissions were reduced by 44 and 13% in DCD20 and dolomite alone treatments, respectively, while DCD20 + dolomite reduced N2O emissions by 54% when compared with DCD0 treatment. The present study suggests that application of DCD and dolomite to acidic soils can mitigate N2O emissions.

  5. Microbial and enzymatic activity of soil contaminated with a mixture of diflufenican + mesosulfuron-methyl + iodosulfuron-methyl-sodium.

    Baćmaga, Małgorzata; Borowik, Agata; Kucharski, Jan; Tomkiel, Monika; Wyszkowska, Jadwiga


    The aim of this study was to determine the effect of three active substances, diflufenican, mesosulfuron-methyl and iodosulfuron-methyl-sodium, applied in combination, on soil microbial counts, the structure of soil microbial communities, activity of soil enzymes and their resistance to the tested product, the biochemical indicator of soil fertility, and spring wheat yield. Soil samples with the granulometric composition of sandy loam with pHKCl 7.0 were used in a pot experiment. The herbicide was applied to soil at seven doses: 0.057 (dose recommended by the manufacturer), 1.140, 2.280, 4.560, 9.120, 18.240 and 36.480 mg kg(-1) soil DM. Uncontaminated soil served as the control treatment. It was found that a mixture of the tested active substances increased the counts of total oligotrophic bacteria and spore-forming oligotrophic bacteria, organotrophic bacteria and actinomycetes, decreased the counts of Azotobacter and fungi, and modified the structure of soil microbial communities. The highest values of the colony development (CD) index and the ecophysiological (EP) index were observed in fungi and organotrophic bacteria, respectively. The herbicide applied in the recommended dose stimulated the activity of catalase, urease and acid phosphatase, but it had no effect on the activity of dehydrogenases, alkaline phosphatase, arylsulfatase and β-glucosidase. The highest dose of the analyzed substances (36.480 mg kg(-1)) significantly inhibited the activity of dehydrogenases, acid phosphatase, alkaline phosphatase and arylsulfatase. The values of the biochemical soil fertility indicator (BA21) decreased in response to high doses of the herbicide. Urease was most resistant and dehydrogenases were least resistant to soil contamination with a mixture of diflufenican + mesosulfuron-methyl + iodosulfuron-methyl-sodium. The analyzed herbicide had an adverse influence on spring wheat yield, and doses of 18.240 and 36.480 mg kg(-1) led to eventual death of plants.

  6. Degradation of metaflumizone in soil: impact of varying moisture, light, temperature, atmospheric CO2 level, soil type and soil sterilization.

    Chatterjee, Niladri Sekhar; Gupta, Suman; Varghese, Eldho


    Soil is a major sink for the bulk of globally used pesticides. Hence, fate of pesticides in soil under the influence of various biotic and abiotic factors becomes important for evaluation of stability and safety. This paper presents the impact of varying moisture, light, temperature, atmospheric CO(2) level, soil type and soil sterilization on degradation of metaflumizone, a newly registered insecticide in India. Degradation of metaflumizone in soil followed the first order reaction kinetics and its half life values varied from ~20 to 150 d. Under anaerobic condition, degradation of metaflumizone was faster (t(½) 33.4 d) compared to aerobic condition (t(½) 50.1 d) and dry soil (t(½) 150.4 d). Under different light exposures, degradation was the fastest under UV light (t(½) 27.3 d) followed by Xenon light (t(½) 43 d) and dark condition (t(½) 50.1 d). Degradation rate of metaflumizone increased with temperature and its half life values ranged from 30.1 to 100.3d. Elevated atmospheric CO(2) level increased the degradation in soil (t(½) 20.1-50.1 d). However, overall degradation rate was the fastest at 550 ppm atmospheric CO(2) level, followed by 750 ppm and ambient level (375 ppm). Degradation of metaflumizone was faster in Oxisol (pH 5.2, Total Organic Carbon 1.2%) compared to Inceptisol (pH 8.15, TOC 0.36%). In sterile soil, only 5% dissipation of initial concentration was observed after 90 d of sampling. Under various conditions, 4-cyanobenzoic acid (0.22-1.86 mg kg(-1)) and 4-trifluoromethoxy aniline (0.21-1.23 mg kg(-1)) were detected as major degradation products.

  7. Fixed Ammonium in Major Types of Paddy Soils in Hunan Province,China



    The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner method by laboratory and pot experiments. Results showed that the content of fixed ammoniumin the plough horizons ranged from 88.3 mg kg-1 to 388.1 mg kg-1, with 273.2 ± 77.7 mg kg-1 on average,accounting for 11.2% of total soil N on average. Content of fixed ammonium decreased in the order of newlylacustrine clayey paddy soil > alluvial sandy paddy soil > purple clayey paddy soil > newly alluvial sandypaddy soil > yellow clayey paddy soil > reddish-yellow clayey paddy soil > granitic sandy paddy soil. Therewere four distribution patterns of fixed ammonium in the profiles to 1-m depth, i.e., increase with the depth,decrease with increasing depth, no distinct change with the depth, and abrupt increase or decrease in somehorizon. Percentage of fixed ammonium in total N increased with the depth in most of the soils. Fixationof NH4+ by soil was higher at 30 ℃ than at 20 ℃ and 40 ℃, and continuous submergence benefited thefixation of NH4+ in newly alluvial sandy paddy soil, purple clayey paddy soil and alluvial sandy paddy soil,while alternating wetting and drying contributed to the fixation of NH4+ in yellow clayey paddy soil mostly.Fixed ammonium content in the test paddy soils was significantly correlated with < 0.01 mm clay content(P < 0.05), but not with < 0.001 mm clay content, total N, organic N and organic matter. Fixed ammoniumcontent varied with rice growth stages. Application of N fertilizer promoted fixation of NH4+ by soil, and Nuptake by rice plant promoted release of fixed ammonium from the soil. Recently fixed ammonium in paddysoil after N fertilizer application was nearly 100% available to rice plant, while native fixed ammonium wasonly partly available, varying with the soil type and rice type.

  8. Degradation of toxaphene in aged and freshly contaminated soil.

    Lacayo-Romero, Martha; van Bavel, Bert; Mattiasson, Bo


    Degradation of toxaphene in soil from both newly contaminated (from Sweden) and aged spills (from Nicaragua) were studied. The newly contaminated soil contained approximately 11 mg kg(-1) toxaphene while the aged Nicaraguan soil contained approximately 100 mg kg(-1). Degradation was studied in anaerobic bioreactors, some of which were supplied with lactic acid and others with Triton X-114. In this study we found that the lower isomers Parlar 11, 12 were degraded while the concentration of isomer Parlar 15 increased. This supported an earlier evaluation which indicated that less chlorinated isomers are formed from more heavily isomers. Lactic acid when added to the soil, interfere with the degradation of toxaphene. Lactic acid was added; several isomers appeared to degrade rather slowly in newly contaminated Swedish soil. The Swedish soil, without any external carbon source, showed the slowest degradation rate of all the compounds studied. When Triton X-114 at 0.4 mM was added, the degradation rate of the compounds increased. This study illustrates that biodegradation of toxaphene is a complex process and several parameters have to be taken into consideration. Degradation of persistent pollutants in the environment using biotechnology is dependent on bioavailability, carbon sources and formation of metabolites.

  9. Impact of pigeon pea biochar on cadmium mobility in soil and transfer rate to leafy vegetable spinach.

    Coumar, M Vassanda; Parihar, R S; Dwivedi, A K; Saha, J K; Rajendiran, S; Dotaniya, M L; Kundu, S


    Introduction of heavy metals in the environment by various anthropogenic activities has become a potential treat to life. Among the heavy metals, cadmium (Cd) shows relatively high soil mobility and has high phyto-mammalian toxicity. Integration of soil remediation and ecosystem services, such as carbon sequestration in soils through organic amendments, may provide an attractive land management option for contaminated sites. The application of biochar in agriculture has recently received much attention globally due to its associated multiple benefits, particularly, long-term carbon storage in soil. However, the application of biochar from softwood crop residue for heavy metal immobilization, as an alternative to direct field application, has not received much attention. Hence, a pot experiment was conducted to study the effect of pigeon pea biochar on cadmium mobility in a soil-plant system in cadmium-spiked sandy loam soil. The biochar was prepared from pigeon pea stalk through a slow pyrolysis method at 300 °C. The experiment was designed with three levels of Cd (0, 5, and 10 mg Cd kg(-1) soil) and three levels of biochar (0, 2.5, and 5 g kg(-1) soil) using spinach as a test crop. The results indicate that with increasing levels of applied cadmium at 5 and 10 mg kg(-1) soil, the dry matter yield (DMY) of spinach leaf decreased by 9.84 and 18.29 %, respectively. However, application of biochar (at 2.5 and 5 g kg(-1) soil) significantly increased the dry matter yield of spinach leaf by 5.07 and 15.02 %, respectively, and root by 14.0 and 24.0 %, respectively, over the control. Organic carbon content in the post-harvest soil increased to 34.9 and 60.5 % due to the application of biochar 2.5 and 5 g kg(-1) soil, respectively. Further, there was a reduction in the diethylene triamine pentaacetic acid (DTPA)-extractable cadmium in the soil and in transfer coefficient values (soil to plant), as well as its concentrations in spinach leaf and root, indicating that

  10. Propriedades físicas do solo, influenciadas pela distribuição de poros, de seis classes de solos da região de Lavras-MG Soil physical properties, influenced by pores distribution, of six soil classes in the region of Lavras-MG

    Kátia Daniela Ribeiro


    Full Text Available A distribuição de poros dos solos condiciona seu comportamento físico-hídrico. Assim, influencia os processos dinâmicos do ar e da solução do solo, bem como a potencialidade agrícola dos mesmos. Desta forma, com o presente trabalho, objetivou-se avaliar a influência da distribuição de poros sobre as propriedades físicas de seis classes de solos, sob vegetação natural, localizados na região de Lavras (MG. Coletaram-se amostras deformadas e indeformadas da camada superficial (0-20 cm para a caracterização física e a determinação da curva de distribuição de poros dos solos. Os resultados indicaram que as propriedades físicas dos solos não foram influenciadas pelos poros com diâmetro entre 0,03 e 0,0375 mm. Verificou-se, também, que os valores de macroporosidade foram diretamente proporcionais aos valores de condutividade hidráulica saturada dos solos estudados.The soil pores distribution conditions its physical-hydraulic behavior. Therefore, it influences the dynamic processes of air and solution of the soil, and also its agricultural potentiality. This work aimed at evaluating the influence of pores distribution on physical properties of six classes of soil, under natural vegetation, located in the region of Lavras (MG. Disturbed and undisturbed samples were collected from superficial layer (0-20 cm for physical characterization and determination of pores distribution curves. The results indicated that soil physical properties were not influenced by the pores with diameter between 0,03 and 0,0375 mm. It was also verified that macroporosity values were directly proportional to the hydraulic conductivity values of saturated soils.

  11. Mercury contamination in agricultural soils from abandoned metal mines classified by geology and mineralization.

    Kim, Han Sik; Jung, Myung Chae


    This survey aimed to compare mercury concentrations in soils related to geology and mineralization types of mines. A total of 16,386 surface soils (0~15 cm in depth) were taken from agricultural lands near 343 abandoned mines (within 2 km from each mine) and analyzed for Hg by AAS with a hydride-generation device. To meaningfully compare mercury levels in soils with geology and mineralization types, three subclassification criteria were adapted: (1) five mineralization types, (2) four valuable ore mineral types, and (3) four parent rock types. The average concentration of Hg in all soils was 0.204 mg kg(-1) with a range of 0.002-24.07 mg kg(-1). Based on the mineralization types, average Hg concentrations (mg kg(-1)) in the soils decreased in the order of pegmatite (0.250) > hydrothermal vein (0.208) > hydrothermal replacement (0.166) > skarn (0.121) > sedimentary deposits (0.045). In terms of the valuable ore mineral types, the concentrations decreased in the order of Au-Ag-base metal mines ≈ base metal mines > Au-Ag mines > Sn-W-Mo-Fe-Mn mines. For parent rock types, similar concentrations were found in the soils derived from sedimentary rocks and metamorphic rocks followed by heterogeneous rocks with igneous and metamorphic processes. Furthermore, farmland soils contained relatively higher Hg levels than paddy soils. Therefore, it can be concluded that soils in Au, Ag, and base metal mines derived from a hydrothermal vein type of metamorphic rocks and pegmatite deposits contained relatively higher concentrations of mercury in the surface environment.

  12. Effectiveness of vetiver grass (Vetiveria zizanioides L. Nash) for phytoremediation of endosulfan in two cotton soils from Burkina Faso.

    Abaga, Norbert Ondo Zue; Dousset, Sylvie; Munier-Lamy, Colette; Billet, David


    The influence of vetiver grass (Vetiveria zizanioides) on the fate of endosulfan was studied using a vertisol and a lixisol soils from cotton-growing areas of Burkina Faso. Endosulfan adsorption isotherms were prepared for planted and unplanted soils. Pot experiments were then conducted for six months. For both soils, endosulfan adsorption was higher on planted soils (K(f) = 6.53-9.73 mg(l-n) L(n) kg(-1)) than on unplanted soils (6.27-7.24 mg(l-n) L(n) kg(-1)). In unplanted soils, vertisol adsorbed more endosulfan than lixisol. From the pot experiments, the estimated half-lives of endosulfan in unplanted soils (40.6 to 43.1 days) were higher than in planted soils (34.5 to 40.6 days) containing a greater number of endosulfan-degrading microorganisms. Six months after treatment, endosulfan was not detected in soils. The effectiveness of vetiver in promoting adsorption and the disappearance of endosulfan in both studied soils should be validated on the cotton plot scale in Burkina Faso.

  13. The effects of simultaneous application of plant growth regulators and bioaugmentation on improvement of phytoremediation of pyrene contaminated soils.

    Rostami, Saeid; Azhdarpoor, Abooalfazl; Rostami, Majid; Samaei, Mohammad Reza


    Polycyclic aromatic hydrocarbons (PAHs) refer to a wide group of soil contaminants whose presence in the environment is a cause of concern. The present study aimed to evaluate the effects of Indole Acetic Acid (IAA) and Pseudomonas aeruginosa on the phytoremediation activities of sorghum bicolor and increase in pyrene removal efficiency in the soil. The initial concentration of pyrene was 150 and 300 mg kg(-1) in this experiment. The treatments included unplanted soil (T0), planted soil with sorghum (T1), planted soil with application of IAA (T2), planted soil with application of Pseudomonas sp. (T3), and planted soil with simultaneous application of IAA and Pseudomonas sp. (T4). The pyrene removal rate in the soil was measured every 30 days. Moreover, plant biomass and soil bacteria were measured after 90 days. The results showed that pyrene removal rate significantly increased in the planted treatments compared to the unplanted ones. After 90 days, at the initial concentration of 150-300 mg kg(-1), pyrene removal efficiency was 52-92% in T1-T4 and 35-47% in the unplanted treatment (T0). Application of IAA and Pseudomonas sp. significantly increased plant biomass, soil bacteria, and pyrene removal rate in T2, T3, and T4 compared to T1. Therefore, application of IAA in the planted treatments with sorghum could have a significant effect on increasing the removal efficiency of pyrene.

  14. Phytoremediation of soils contaminated by cadmium

    Watai, H.; Miyazaki, T.; Fujikawa, T.; Mizoguchi, M.


    Phytoremediation is a technique to clean up soils contaminated with heavy metals. Advantages of this method are that (1) This technique is suitable to cleanup soils slightly contaminated with heavy metals in relatively wide area. (2) The expense for clean up is lower than civil engineering techniques. (3) This method can remove heavy metals fundamentally from contaminated. (4) The heavy metals are able to recycle by ashing of plants. Many researches have been done on the phytoremediation up to now, but almost all these researches were devoted to clarify the phytoremediation from the view point of plants themselves. However, few efforts have been devoted to analyze the migrations of heavy metals in soils during the phytoremediation process. The objective of this study is to clarify the features of Cd migration when plant roots are absorbing Cd from the ambient soils. Especially, we focused on finding the Cd migration pattern by changing the soil condition such as plant growing periods, planting densities, and the initial Cd concentration in soils. We planted sunflowers in columns filled with Cd contaminated soils because sunflower is a well-known hyperaccumulator of Cd from soils. By cutting the shoots of plants at the soil surface, and by keeping the plant roots in the soils without disturbance, the Cd concentrations, moisture contents, pH distributions, EC distributions, and dry weight of residual roots in the soils were carefully analyzed. The experimental results showed that (1)The growth of the planted sunflowers were suffered by applying of Cd. (2)The decrease of suction was affected by water uptake by roots at the depth from 0 to 5 cm. Water contents with plants in soils decrease more than without plants. (3)Cd adsorption by roots was predominant within 5cm from soil surface. In addition, it was also shown that there was an optimal Cd concentration where Cd is most effectively adsorbed by the plant. In this experiment we found that 40 to 60 mg kg-1 was the

  15. Identification of Heavy Metal Pollution Derived From Traffic in Roadside Soil Using Magnetic Susceptibility.

    Yang, Pingguo; Ge, Jing; Yang, Miao


    The study integrates surface and vertical distribution of magnetic susceptibility and heavy metal contents (Pb, Cu, Zn and Fe) to characterize the signature of vehicle pollutants in roadside soils at Linfen city, China. Sites with reforestation and without vegetation cover were investigated. The results showed that magnetic susceptibility and heavy metal contents were higher at the roadside without trees than in the reforest belt. The variations of magnetic susceptibility and heavy metal contents decreased both with distance and with depth. The maximum value was observed at 5-10 m away from the roadside edge. The vertical distribution in soil revealed accumulation of pollutants in 0-5 cm topsoils. The average contents were higher than the background values and in the order Fe (107.21 g kg(-1)), Zn (99.72 mg kg(-1)), Pb (90.99 mg kg(-1)), Cu (36.14 mg kg(-1)). Coarse multi domain grains were identified as the dominating magnetic particles. Multivariate statistical and SEM/EDX analyses suggested that the heavy metals derived from traffic sources. Trees act as efficient receptors and green barrier, which can reduce vehicle derived pollution.

  16. Avaliação da fertilidade dos solos de sistemas agroflorestais com cafeeiro (Coffea arabica L. em Lavras-MG Evaluation of soil fertility in agroforest systems with coffee trees (Coffea arabica L. in Lavras-MG

    Bruno Grandi Salgado


    Full Text Available Com o objetivo de avaliar a fertilidade dos solos em um sistema agroflorestal composto por cafeeiros (Coffea arábica L. - Mundo Novo, ingazeiros (Inga vera Willd e grevíleas (Grevilea robusta A. Cunn, situado em Lavras, Minas Gerais, foi instalado o presente experimento. Usou-se um delineamento experimental inteiramente casualizado com três tratamentos e sete repetições. Os tratamentos foram: a cafeeiros a pleno sol, b cafeeiros consorciados com ingazeiros e c cafeeiros consociados com grevílea. Os espaçamentos dos cafeeiros nos três sistemas foi 4 x 1 m, para o ingazeiro 8 m x 15 m e para a grevílea 12 m x 10 m. Aos 15 anos de idade do cafeeiro e do ingazeiro e aos 9 anos da grevílea foram avaliadas as seguintes características dos solos, pH, acidez potencial (H+Al, alumínio trocável (Al+3, bases trocáveis (Ca+2 e Mg+2, potássio disponível (K+, fósforo disponível(P, enxofre (S, CTC efetiva (T, soma de bases (SB, saturação de bases (V e matéria orgânica (MO. Os resultados foram submetidos à analise de variância e as médias, comparadas pelo teste de Scott-Knott. Após a análise dos dados, concluiu-se que, embora tenha havido diferenças entre alguns elementos estudados, as características químicas dos solos nos três sistemas não foram severamente afetadas.The objective of this wark was to evaluat e the soil fertility in an agroforest system using coffee trees (Coffea arabica L - Mundo Novo, inga trees (Inga vera Wild and grevillea trees (Grevillea robusta A Cunn situated in Lavras, Minas Geris. A completely randomized experimental design with tree treatments and seven replicates was utilized. The treatments were : a coffee trees in full sunshine; b coffee trees mixed with inga trees and c coffee trees mixed with grevillea trees. Tree spacings in the three systems were 4 x 1m for coffee, 8 m x 15 m for inga and 12 x 10 m for grevillea. With coffee and inga trees at 15 years of age and grevillea trees at 9 years of age

  17. Characterization of bacteria in the rhizosphere soils of Polygonum pubescens and their potential in promoting growth and Cd, Pb, Zn uptake by Brassica napus.

    Jing, Yuan Xiao; Yan, Jun Lan; He, Huai Dong; Yang, Dan Jing; Xiao, Li; Zhong, Ting; Yuan, Ming; Cai, Xin De; Li, Shu Bin


    Microbe-enhanced phytoremediation has been considered as a promising measure for the remediation of metal-contaminated soils. In this study, two bacterial strains JYX7 and JYX10 were isolated from rhizosphere soils of Polygonum pubescens grown in metal-polluted soil and identified as of Enterobacter sp. and Klebsiella sp. based on 16S rDNA sequences, respectively. JYX7 and JYX10 showed high Cd, Pb and Zn tolerance and increased water-soluble Cd, Pb and Zn concentrations in culture solution and metal-added soils. Two isolates produced plant growth-promoting substances such as indole acetic acid, siderophore, 1-aminocyclopropane-1-carboxylic deaminase, and solubilized inorganic phosphate. Based upon their ability in metal tolerance and solubilization, two isolates were further studied for their effects on growth and accumulation of Cd, Pb, and Zn in Brassica napus (rape) by pot experiments. Rapes inoculated with JYX7 and JYX10 had significantly higher dry weights, concentrations and uptakes of Cd, Pb, Zn in both above-ground and root tissues than those without inoculation grown in soils amended with Cd (25 mg kg(-1)), Pb (200 mg kg(-1)) or Zn (200 mg kg(-1)). The present results demonstrated that JYX7 and JYX10 are valuable microorganism, which can improve the efficiency of phytoremediation in soils polluted by Cd, Pb, and Zn.

  18. Advantages and limitations of chemical extraction tests to predict mercury soil-plant transfer in soil risk evaluations.

    Monteiro, R J R; Rodrigues, S M; Cruz, N; Henriques, B; Duarte, A C; Römkens, P F A M; Pereira, E


    In this study, we compared the size of the mobile Hg pool in soil to those obtained by extractions using 2 M HNO3, 5 M HNO3, and 2 M HCl. This was done to evaluate their suitability to be used as proxies in view of Hg uptake by ryegrass. Total levels of Hg in soil ranged from 0.66 to 70 mg kg(-1) (median 17 mg kg(-1)), and concentrations of Hg extracted increased in the order: mobile Hg tests explained between 66 and 86 % of the variability of Hg contents in ryegrass shoots. Results indicated that all methods tested here can be used to estimate the plant total Hg pool at contaminated areas and can be used in first tier soil risk evaluations. This study also indicates that a relevant part of Hg in plants is from deposition of soil particles and that splashing of soil can be more significant for plant contamination than actual uptake processes. Graphical Abstract Illustration of potential mercury soil-plant transfer routes.

  19. The effects of lead sources on oral bioaccessibility in soil and implications for contaminated land risk management.

    Palmer, Sherry; McIlwaine, Rebekka; Ofterdinger, Ulrich; Cox, Siobhan F; McKinley, Jennifer M; Doherty, Rory; Wragg, Joanna; Cave, Mark


    Lead (Pb) is a non-threshold toxin capable of inducing toxic effects at any blood level but availability of soil screening criteria for assessing potential health risks is limited. The oral bioaccessibility of Pb in 163 soil samples was attributed to sources through solubility estimation and domain identification. Samples were extracted following the Unified BARGE Method. Urban, mineralisation, peat and granite domains accounted for elevated Pb concentrations compared to rural samples. High Pb solubility explained moderate-high gastric (G) bioaccessible fractions throughout the study area. Higher maximum G concentrations were measured in urban (97.6 mg kg(-1)) and mineralisation (199.8 mg kg(-1)) domains. Higher average G concentrations occurred in mineralisation (36.4 mg kg(-1)) and granite (36.0 mg kg(-1)) domains. Findings suggest diffuse anthropogenic and widespread geogenic contamination could be capable of presenting health risks, having implications for land management decisions in jurisdictions where guidance advises these forms of pollution should not be regarded as contaminated land.

  20. Organ-wise accumulation of fluoride in Prosopis juliflora and its potential for phytoremediation of fluoride contaminated soil.

    Saini, Poonam; Khan, Suphiya; Baunthiyal, Mamta; Sharma, Vinay


    Fluoride (F) contamination is a global environmental problem, as there is no cure of fluorosis available yet. Prosopis juliflora is a leguminous perennial, phreatophyte tree, widely distributed in arid and semi-arid regions of world. It extensively grows in F endemic areas of Rajasthan (India) and has been known as a "green" solution to decontaminate cadmium, chromium and copper contaminated soils. This study aims to check the tolerance potential of P. juliflora to accumulate fluoride. For this work, P. juliflora seedlings were grown for 75 d on soilrite under five different concentrations of F viz., control, 25, 50, 75 and 100 mg NaF kg(-1). Organ-wise accumulation of F, bioaccumulation factor (BF), translocation factor (TF), growth ratio (GR) and F tolerance index (TI) were examined. Plant accumulated high amounts of F in roots. The organ-wise distribution showed an accumulation 4.41 mg kg(-1)dw, 12.97 mg kg(-1)dw and 16.75 mg kg(-1)dw F, in stem, leaves and roots respectively. The results indicated significant translocation of F from root into aerial parts. The bioaccumulation and translocation factor values (>1.0) showed high accumulation efficiency and tolerance of P. juliflora to F. It is concluded that P. juliflora is a suitable candidate for phytoremediation purpose and can be explored further for the decontamination of F polluted soils.

  1. Toxicity of four veterinary pharmaceuticals on the survival and reproduction of Folsomia candida in tropical soils.

    Zortéa, Talyta; Segat, Julia C; Maccari, Ana Paula; Sousa, José Paulo; Da Silva, Aleksandro S; Baretta, Dilmar


    This study aimed to evaluate the effect of veterinary pharmaceuticals (VPs) used to control endo- and ectoparasites in ruminants, on the survival and reproduction of the collembolan species Folsomia candida. Standard ecotoxicological tests were conducted in Tropical Artificial Soil and the treatments consisted of increasing dosages of four commercial products with different active ingredients: ivermectin, fipronil, fluazuron and closantel. Ecotoxicological effects were related to the class and mode of action of the different compounds. Fipronil and ivermectin were the most toxic compounds causing a significant reduction in the number of juveniles at the lowest doses tested (LOECreprod values of 0.3 and 0.2 mg kg(-1) of dry soil, respectively) and similar low EC50 values (fipronil: 0.19 mg kg(-1) dry soil, CL95% 0.16-0.22; ivermectin: 0.43 mg kg(-1) dry soil, CL95% 0.09-0.77), although the effects observed in the former compound were possibly related to a low adult survival (LC50 of 0.62 mg kg(-1) dry soil; CL95%: 0.25-1.06). For the latter compound no significant lethal effects were observed. Fluazuron caused an intermediate toxicity (EC50 of 3.07 mg kg(-1) dry soil, CL95%: 2.26-3.87), and also here a decrease in adult survival could explain the effects observed at reproduction. Closantel, despite showing a significant reduction on the number of juveniles produced, no dose-response relationship nor effects higher than 50% were observed. Overall, all tested compounds, especially ivermectin, when present in soil even at sub-lethal concentrations, can impair the reproduction of collembolans and possibly other arthropods. However, the actual risk to arthropod communities should be further investigated performing tests under a more realistic exposure (e.g., by testing the dung itself as the contaminated matrix) and by deriving ecotoxicologically relevant exposure concentration in soil derived from the presence of cattle dung. Copyright © 2017 Elsevier Ltd

  2. Concentration and dissipation of chlorantraniliprole and thiamethoxam residues in maize straw, maize, and soil.

    He, Min; Song, Dan; Jia, Hong C; Zheng, Yongquan


    To study the dissipation rates and final residual levels of chlorantraniliprole and thiamethoxam in maize straw, maize, and soil, two independent field trials were conducted during the 2014 cropping season in Beijing and Anhui Provinces of China. A 40% wettable powder (20% chlorantraniliprole + 20% thiamethoxam) was sprayed onto maize straw and soil at an application rate of 118 g of active ingredient per hectare (g a.i.ha(-1)). The residual concentrations were determined by ultra-high-performance liquid chromatography-tandem mass spectrometry. The chlorantraniliprole half-lives in maize straw and soil were 9.0-10.8 and 9.5-21.7 days, respectively. The thiamethoxam half-lives in maize straw and soil were 8.4-9.8 and 4.3-11.7 days, respectively. The final residues of chlorantraniliprole and thiamethoxam in maize straw, maize, and soil were measured after the pesticides had been sprayed two and three times with an interval of 7 days using 1 and 1.5 times the recommended rate (72 g a.i. ha(-1) and 108 g a.i. ha(-1), respectively). Representative maize straw, maize, and soil samples were collected after the last treatment at pre-harvest intervals of 7, 14, and 28 days. The chlorantraniliprole residue was below 0.01 mg kg(-1) in maize, between 0.01 and 0.31 mg kg(-1) in maize straw, and between 0.03 and 1.91 mg kg(-1) in soil. The thiamethoxam residue concentrations in maize, maize straw, and soil were <0.01, <0.01, and 0.01-0.03 mg kg(-1), respectively. The final pesticide residues on maize were lower than the maximum residue limit (MRL) of 0.02 mg kg(-1) after a 14-day pre-harvest interval. Therefore, a dosage of 72 g a.i. ha(-1) was recommended, as it can be considered safe to human beings and animals.

  3. Concentration of cadmium in cacao beans and its relationship with soil cadmium in southern Ecuador.

    Chavez, E; He, Z L; Stoffella, P J; Mylavarapu, R S; Li, Y C; Moyano, B; Baligar, V C


    Cadmium (Cd) content in cacao beans above a critical level (0.6 mg kg(-1)) has raised concerns in the consumption of cacao-based chocolate. Little is available regarding Cd concentration in soil and cacao in Ecuador. The aim of this study was to determine the status of Cd in both, soils and cacao plants, in southern Ecuador. Soil samples were collected from 19 farms at 0-5, 5-15, 15-30, and 30-50 cm depths, whereas plant samples were taken from four nearby trees. Total recoverable and extractable Cd were measured at the different soil depths. Total recoverable Cd ranged from 0.88 to 2.45 and 0.06 to 2.59, averaged 1.54 and 0.85 mg kg(-1), respectively in the surface and subsurface soils whereas the corresponding values for M3-extractable Cd were 0.08 to 1.27 and 0.02 to 0.33 with mean values of 0.40 and 0.10 mg kg(-1). Surface soil in all sampling sites had total recoverable Cd above the USEPA critical level for agricultural soils (0.43 mg kg(-1)), indicating that Cd pollution occurs. Since both total recoverable and M3-extractable Cd significantly decreased depth wise, anthropogenic activities are more likely the source of contamination. Cadmium in cacao tissues decreased in the order of beans>shell>leaves. Cadmium content in cacao beans ranged from 0.02 to 3.00, averaged 0.94 mg kg(-1), and 12 out of 19 sites had bean Cd content above the critical level. Bean Cd concentration was highly correlated with M3- or HCl-extractable Cd at both the 0-5 and 5-15 cm depths (r=0.80 and 0.82 for M3, and r=0.78 and 0.82 for HCl; Pcacao beans and M3- or HCl-extractable Cd are suitable methods for predicting available Cd in the studied soils. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Home gardening near a mining site in an arsenic-endemic region of Arizona: assessing arsenic exposure dose and risk via ingestion of home garden vegetables, soils, and water.

    Ramirez-Andreotta, Monica D; Brusseau, Mark L; Beamer, Paloma; Maier, Raina M


    The human-health risk posed by gardening near a legacy mine and smelter in an arsenic-endemic region of Arizona was characterized in this study. Residential soils were used in a greenhouse study to grow common vegetables, and local residents, after training, collected soil, water, and vegetables samples from their home gardens. Concentrations of arsenic measured in water, soil, and vegetable samples were used in conjunction with reported US intake rates to calculate the daily dose, Incremental Excess Lifetime Cancer Risk (IELCR), and Hazard Quotient for arsenic. Relative arsenic intake dose decreased in order: water>garden soils>homegrown vegetables, and on average, each accounted for 77, 16, and 7% of a residential gardener's daily arsenic intake dose. The IELCR ranges for vegetables, garden soils, and water were 10(-8) to 10(-4), 10(-6) to 10(-4), and 10(-5) to 10(-2), respectively. All vegetables (greenhouse and home garden) were grouped by scientific family, and the risk posed decreased as: Asteraceae≫Fabaceae>Amaranthaceae>Liliaceae>Brassicaceae>Solanaceae≫Cucurbitaceae. Correlations observed between concentrations of arsenic in vegetables and soils were used to estimate a maximum allowable level of arsenic in soil to limit the excess cancer risk to 10(-6). The estimated values are 1.56 mg kg(-1), 5.39 mg kg(-1), 11.6 mg kg(-1) and 12.4 mg kg(-1) for the Asteraceae, Brassicaceae, Fabaceae, and Amaranthaceae families, respectively. It is recommended that home gardeners: sample their private wells annually, test their soils prior to gardening, and, if necessary, modify their gardening behavior to reduce incidental soil ingestion. This study highlights the importance of site-specific risk assessment, and the need for species-specific planting guidelines for communities. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata.

    Bañuelos, Gary S; Arroyo, Irvin S; Dangi, Sadikshya R; Zambrano, Maria C


    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton) three and 4 years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0-30 cm) were 1.65 mg kg(-1) and 88 μg L(-1), and 0.92 mg kg(-1) and 48.6 μg L(-1) at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg(-1) and 3.15 to 6.25 mg kg(-1) in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine) was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid fatty acid (PLFA) analyses showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi), actinomycetes and Gram-positive and bacterial PLFA at both 0-5 and 0-30 cm, respectively, 3 years later. Successfully producing Se-enriched broccoli and carrots 3 and 4 years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions.

  6. Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata

    Bañuelos, Gary S.; Arroyo, Irvin S.; Dangi, Sadikshya R.; Zambrano, Maria C.


    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton) three and 4 years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0–30 cm) were 1.65 mg kg-1 and 88 μg L-1, and 0.92 mg kg-1 and 48.6 μg L-1 at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg-1 and 3.15 to 6.25 mg kg-1 in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine) was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid fatty acid (PLFA) analyses showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi), actinomycetes and Gram-positive and bacterial PLFA at both 0–5 and 0–30 cm, respectively, 3 years later. Successfully producing Se-enriched broccoli and carrots 3 and 4 years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions. PMID:27602038

  7. Continued selenium biofortification of carrots and broccoli grown in soils once amended with Se-enriched S. pinnata

    Gary S. Bañuelos


    Full Text Available Selenium (Se biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton three and four years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0-30 cm were 1.65 mg kg-1 and 88 µg L-1, and 0.92 mg kg-1 and 48.6 µg L-1 at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg-1 and 3.15 to 6.25 mg kg-1 in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid analyses (PLFA showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi, actinomycetes and Gram-positive and bacterial PLFA at both 0-5 and 0-30 cm, respectively, three years later. Successfully producing Se-enriched broccoli and carrots three and four years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions.

  8. Effects of imidacloprid on soil microbial communities in different saline soils.

    Zhang, Qingming; Xue, Changhui; Wang, Caixia


    The effects of imidacloprid in the soil environment are a worldwide concern. However, the impact of imidacloprid on soil microorganisms under salt stress is almost unknown. Therefore, an indoor incubation test was performed, and the denaturing gradient gel electrophoresis (DGGE) approach was used to determine the response of different saline soil bacterial and fungal community structures to the presence of imidacloprid (0.4, 2, 10 mg kg(-1)). The results showed that the soil bacterial diversity slightly declined with increasing imidacloprid concentration in soils with low salinity. In moderately saline soils, a new band in the DGGE profile suggested that imidacloprid could improve the soil bacterial diversity to some degree. An analysis of variance indicated that the measured soil bacterial diversity parameters were significantly affected by dose and incubation time. Compared with the control, the soil fungal community structure showed no obvious changes in low and moderately saline soils treated with imidacloprid. The results of these observations provide a basic understanding of the potential ecological effects of imidacloprid on different microorganisms in saline soils.

  9. Sorption, degradation and mobility of ptaquiloside, a carcinogenic Bracken (Pteridium sp.) constituent, in the soil environment

    Rasmussen, Lars Holm; Lauren, Denis; Hansen, Hans Christian Bruun


    very low sorption affinity with distribution coefficients in the range 0.01–0.22 l kg1 at a solution concentration of 1 mg l1 except for the most acid soil; Freundlich affinity coefficients increased linearly with clay and organic matter contents. Negligible sorption was also observed in column studies......Ptaquiloside (PTA) is a carcinogenic norsesquiterpene glucoside produced by Bracken in amounts up to at least 13 500 mg m2. The toxin is transferred from Bracken to the underlying soil from where it may leach to surface and groundwaters impairing the quality of drinking water. The objectives...

  10. 田间土壤外源铜镍在小麦中的累积及其毒害研究%Toxicity and Accumulation of Copper and Nickel in Wheat Plants Cropped on Alkaline and Acidic Field Soils

    黄锦孙; 韦东普; 郭雪雁; 马义兵


    Field experiments were conducted to study the toxicity of added copper(Cu) and nickel(Ni) in soils to wheat and metal accumulation in wheat plants.The results showed that the yields of wheat straw and grain were decreased with the increasing concentration of Cu and Ni added to soils.The added Cu concentrations yielding 10% inhibition of wheat yield(EC10) were 499.6 mg·kg-1 for alkaline soils(Dezhou,pH 8.90),and 55.7 mg·kg-1 for acidic soils(Qiyang,pH 5.31).The toxicity of Cu or Ni in acidic soils were significantly higher than that in alkaline soils.With increasing addition of Cu or Ni,the contents of Cu in wheat grains initially increased and then keep at constant level,while the accumulation of Ni in grains linearly increased.The contents of Cu and Ni in Qiyang wheat grains were 6.07-9.26 mg·kg-1 and 0.53-31.78 mg·kg-1,and those of in Dezhou were 5.24-10.52 mg·kg-1 and 0.16-25.33 mg·kg-1.In both field experimental sites,the contents of Cu in wheat grains meet the national standard for food safety.These findings showed that Cu is more relevant to ecological risk assessments than to food safety assessments for wheat grown in soils that have been contaminated with Cu.%通过湖南祁阳和山东德州的田间试验,研究不同水平外源Cu、Ni在酸性和碱性土壤中经过老化之后对小麦的毒害及其在小麦植株内的累积状况.结果表明,小麦籽粒和秸秆的生物量随着土壤中Cu、Ni添加剂量增加而减少.酸性土壤(祁阳,pH 5.31)和碱性土壤(德州,pH 8.90)中外源Cu的对小麦的10%抑制效应含量(EC10)分别为55.7和,外源Cu、Ni在祁阳田间土壤中的毒性显著高于德州田间土壤.随着土壤重金属添加量的增加,Cu在祁阳小麦籽粒中的含量随土壤Cu添加量的增加而增加,后趋于稳定,Ni在德州小麦籽粒中的含量随土壤Ni添加量的增加呈线性增加;德州小麦籽粒中Cu、Ni含量范围分别为6.07~9

  11. Temporal changes of soil physic-chemical properties at different soil depths during larch afforestation by multivariate analysis of covariance.

    Wang, Hui-Mei; Wang, Wen-Jie; Chen, Huanfeng; Zhang, Zhonghua; Mao, Zijun; Zu, Yuan-Gang


    Soil physic-chemical properties differ at different depths; however, differences in afforestation-induced temporal changes at different soil depths are seldom reported. By examining 19 parameters, the temporal changes and their interactions with soil depth in a large chronosequence dataset (159 plots; 636 profiles; 2544 samples) of larch plantations were checked by multivariate analysis of covariance (MANCOVA). No linear temporal changes were found in 9 parameters (N, K, N:P, available forms of N, P, K and ratios of N: available N, P: available P and K: available K), while marked linear changes were found in the rest 10 parameters. Four of them showed divergent temporal changes between surface and deep soils. At surface soils, changing rates were 262.1 g·kg(-1)·year(-1) for SOM, 438.9 mg·g(-1)·year(-1) for C:P, 5.3 mg·g(-1)·year(-1) for C:K, and -3.23 mg·cm(-3)·year(-1) for bulk density, while contrary tendencies were found in deeper soils. These divergences resulted in much moderated or no changes in the overall 80-cm soil profile. The other six parameters showed significant temporal changes for overall 0-80-cm soil profile (P: -4.10 mg·kg(-1)·year(-1); pH: -0.0061 unit·year(-1); C:N: 167.1 mg·g(-1)·year(-1); K:P: 371.5 mg·g(-1) year(-1); N:K: -0.242 mg·g(-1)·year(-1); EC: 0.169 μS·cm(-1)·year(-1)), but without significant differences at different soil depths (P > 0.05). Our findings highlight the importance of deep soils in studying physic-chemical changes of soil properties, and the temporal changes occurred in both surface and deep soils should be fully considered for forest management and soil nutrient balance.

  12. Avaliação de contaminação por mercúrio em Descoberto, MG Evaluation of mercury contamination in Descoberto, MG

    Ana Amélia Paulino Tinôco


    Full Text Available O mercúrio, elemento químico considerado não essencial a qualquer processo metabólico, é facilmente acumulado na maioria dos organismos. Ocorre naturalmente em formas orgânicas e inorgânicas, nos estados sólido, dissolvido e gasoso. Seu ciclo biogeoquímico envolve processos que ocorrem no solo, na água e na atmosfera. Em 2002, descobriu-se mercúrio elementar na zona rural do município de Descoberto, Minas Gerais, onde moram cerca de 70 famílias, e sua origem parece estar associada à exploração de ouro, que existiu na região no século 19. Neste trabalho, foram escolhidas três áreas para identificar possível contaminação da água, solo, sedimento e peixes por mercúrio, bem como para estabelecer valores de referência local e contraprova de resultados obtidos anteriormente. Verificaram-se elevadas concentrações no solo (0,26 a 0,55, sedimentos (0,13 a 0,61 e água (Mercury is a chemical element considered unessential to any metabolic process; however, it is easily accumulated in most organisms. It is naturally found in both organic and inorganic forms in solid, liquid and vapor states. Its biogeochemical cycle involves processes occurring in the soil, water and the atmosphere. In 2002, elementary mercury was found in the city of Descoberto, Minas Gerais, Brazil, where 70 families live, and its origin may be related to gold exploration that happened in this region in the 19th century. In this work, three areas were chosen to identify a possible mercury contamination of water, soil, sediment and fish samples and to establish local reference values and counter-evidence of the data previously obtained. Based on the results, high mercury concentrations in soil (0.26 to 0.55, sediments (0.13 to 0.61 and water (< 0.2 to 2,10 µg.L-1 were verified.

  13. [Effects of different fertilizer application on soil active organic carbon].

    Zhang, Rui; Zhang, Gui-Long; Ji, Yan-Yan; Li, Gang; Chang, Hong; Yang, Dian-Lin


    The variation characteristics of the content and components of soil active organic carbon under different fertilizer application were investigated in samples of calcareous fluvo-aquic soil from a field experiment growing winter wheat and summer maize in rotation in the North China Plain. The results showed that RF (recommended fertilization), CF (conventional fertilization) and NPK (mineral fertilizer alone) significantly increased the content of soil dissolved organic carbon and easily oxidized organic carbon by 24.92-38.63 mg x kg(-1) and 0.94-0.58 mg x kg(-1) respectively compared to CK (unfertilized control). The soil dissolved organic carbon content under OM (organic manure) increased greater than those under NPK and single fertilization, soil easily oxidized organic carbon content under OM and NPK increased greater than that under single chemical fertilization. OM and NPK showed no significant role in promoting the soil microbial biomass carbon, but combined application of OM and NPK significantly increased the soil microbial biomass carbon content by 36.06% and 20.69%, respectively. Soil easily oxidized organic carbon, dissolved organic carbon and microbial biomass carbon accounted for 8.41% - 14.83%, 0.47% - 0.70% and 0.89% - 1.20% of the total organic carbon (TOC), respectively. According to the results, the fertilizer application significantly increased the proportion of soil dissolved organic carbon and easily oxidized organic carbon, but there was no significant difference in the increasing extent of dissolved organic carbon. The RF and CF increased the proportion of soil easily oxidized organic carbon greater than OM or NPK, and significantly increased the proportion of microbial biomass carbon. OM or RF had no significant effect on the proportion of microbial biomass carbon. Therefore, in the field experiment, appropriate application of organic manure and chemical fertilizers played an important role for the increase of soil active organic carbon

  14. Biodegradation of the herbicide Diuron in soil by indigenous actinomycetes.

    Esposito, E; Paulillo, S M; Manfio, G P


    Three actinomycete strains isolated from soil treated with 2,4-D were able to degrade the herbicide Diuron in vitro. Strain CCT 4916 was the most efficient, degrading up to 37% of applied Diuron (100 mg Kg-1 soil) in 7 days, as measured by HPLC and UV/VIS spectroscopy. All strains showed protease and urease activity; intracellular activity of metapyrocatechase and pyrocatechase were not found. Actinomycete strain CCT 4916 produced manganese peroxidase, which could be potentially related to degradation of Diuron.

  15. Effects of imazamox on soil carbon and nitrogen mineralization under Mediterranean climate

    KIZILDAĞ, Nacide; SAĞLIKER, Hüsniye; CENKSEVEN, Şahin; DARICI, Hüseyin Cengiz; KOÇAK, Burak


    Imazamox is an herbicide intensively used in the peanut fields of Turkey. Carbon and nitrogen mineralizations were determined at 20 °C to evaluate the effects of the herbicide in soils humidified to 60% and 80% of field capacity (FC) over 45 days. Three doses of this herbicide [recommended dose (RD, 10 mg kg-1), 2× RD, and 4× RD] were added to soils without any previous imazamox application (NI) and to peanut soils with previous applications of imazamox (I). Carbon mineralization, determined ...

  16. Geochemical background values for trace elements in arable soils developed from sedimentary rocks of glacial origin.

    Czarnowska, K; Gworek, B


    The total content of trace elements was examined in some arable soils developed from boulder loam and silt formations of the Middle Poland and Baltic glaciations (62 profiles). Mean element concentrations calculated on the basis of chemical and statistical analyses were as follows: Mn = 322; Zn = 36; Cr = 30; Ni = 12.7; Pb = 10.3; Cu = 8.8; Co = 4.7; and Cd = 0.27 in mg kg(-1) of soil dry weight. The authors propose to accept these figures as the geochemical background values for soils derived from sedimentary rocks of glacial origin.

  17. Potential ecological risk assessment and predicting zinc accumulation in soils.

    Baran, Agnieszka; Wieczorek, Jerzy; Mazurek, Ryszard; Urbański, Krzysztof; Klimkowicz-Pawlas, Agnieszka


    The aims of this study were to investigate zinc content in the studied soils; evaluate the efficiency of geostatistics in presenting spatial variability of zinc in the soils; assess bioavailable forms of zinc in the soils and to assess soil-zinc binding ability; and to estimate the potential ecological risk of zinc in soils. The study was conducted in southern Poland, in the Malopolska Province. This area is characterized by a great diversity of geological structures and types of land use and intensity of industrial development. The zinc content was affected by soil factors, and the type of land use (arable lands, grasslands, forests, wastelands). A total of 320 soil samples were characterized in terms of physicochemical properties (texture, pH, organic C content, total and available Zn content). Based on the obtained data, assessment of the ecological risk of zinc was conducted using two methods: potential ecological risk index and hazard quotient. Total Zn content in the soils ranged from 8.27 to 7221 mg kg(-1) d.m. Based on the surface semivariograms, the highest variability of zinc in the soils was observed from northwest to southeast. The point sources of Zn contamination were located in the northwestern part of the area, near the mining-metallurgical activity involving processing of zinc and lead ores. These findings were confirmed by the arrangement of semivariogram surfaces and bivariate Moran's correlation coefficients. The content of bioavailable forms of zinc was between 0.05 and 46.19 mg kg(-1) d.m. (0.01 mol dm(-3) CaCl2), and between 0.03 and 71.54 mg kg(-1) d.m. (1 mol dm(-3) NH4NO3). Forest soils had the highest zinc solubility, followed by arable land, grassland and wasteland. PCA showed that organic C was the key factor to control bioavailability of zinc in the soils. The extreme, very high and medium zinc accumulation was found in 69% of studied soils. There is no ecological risk of zinc to living organisms in the study area, and in 90

  18. Influence of heavy metals and PCBs pollution on the enzyme activity and microbial community of paddy soils around an e-waste recycling workshop.

    Tang, Xianjin; Hashmi, Muhammad Z; Long, Dongyan; Chen, Litao; Khan, Muhammad I; Shen, Chaofeng


    Due to the emerging environmental issues related to e-waste there is concern about the quality of paddy soils near e-waste workshops. The levels of heavy metals and PCBs and their influence on the enzyme activity and microbial community of paddy soils obtained from the immediate vicinity of an e-waste workshop were investigated in the present study. The results indicated that the heavy metal and PCB pollution did not differ significantly with an increase of the sampling point distances (5 to 30 m). The concentration of Cd (2.16 mg·kg-1) and Cu (69.2 mg·kg-1) were higher, and the PCB pollution was also serious, ranging from 4.9 to 21.6 μg·kg-1. The highest enzyme activity was found for urease compared to phosphatase and catalase, and a fluctuating trend in soil enzyme activity was observed in soils from different sampling sites. The microbial analysis revealed that there was no apparent correlation between the microbial community and the pollutants. However, a slight influence for soil microbial communities could be found based on DGGE, the Shannon index and PCA analysis. The present study suggests that the contamination stress of heavy metals and PCBs might have a slight influence on microbial activity in paddy soils. This study provides the baseline data for enzyme activities and microbial communities in paddy soil under the influence of mixed contamination.

  19. Influence of paint chips on lead concentration in the soil of public playgrounds in Tokyo.

    Takaoka, Michie; Yoshinaga, Jun; Tanaka, Atsushi


    Lead concentration in the surface soils from 31 playgrounds in a ward in Tokyo was measured to examine if paint chips, peeled off from playing equipment installed in the playgrounds, contribute to elevated Pb concentration in the soil of public playgrounds. Lead concentration in the paint chips sampled from playgrounds ranged from 0.003 to 8.9%. Lead concentration in the surface soil ranged from 15.2 to 237 mg kg(-1) (average, 55.5 mg kg(-1)) and higher Pb concentration was found in the soil near painted playing equipment indicating that paint chips from playing equipment contributed to increase soil Pb level of playgrounds in Tokyo. The degree of peeling-off of paint on the surface of playing equipment in the public playground (peeling-off index: POI) positively correlated with Pb concentration in the soil (Spearman rank-correlation coefficient, r = 0.366, p = 0.043). The stronger correlation between Pb concentration and isotope ratios (207Pb/206Pb and Pb conc., r = 0.536, p = 0.002, 208Pb/206Pb and Pb conc. r = 0.600, p playground-to-playground variation in soil Pb concentration. It was concluded that both gasoline Pb of the past and paint chips contributed to increased Pb concentration in the surface soil of playgrounds in Tokyo, though the contribution of paint chips is smaller than gasoline Pb.

  20. [Characteristics of Phthalic Acid Esters in Agricultural Soils and Products in Areas of Zhongshan City, South China].

    Li, Bin; Wu, Shan; Liang, Jin-ming; Liang, Wen-li; Chen, Gui-xian; Li, Yong-jun; Yang, Guo-yi


    In order to investigate and assess the pollution level of phthalic acid esters (PAEs) in farm soils and products from typical agricultural fields in areas of Zhongshan City, Guangdong Province, South China, 65 topsoil and 37 agricultural product samples were collected and contents of 6 PAEs compounds that classified by the U. S. Environmental Protection Agency (EPA) as priority pollutants were determined by the GC-FID. The results indicated that total contents of the PAEs (∑ PAEs) in soils ranged from 0. 14 to 1. 14 mg x kg(-1), and the mean value was 0.43 mg x kg(-1), with the detected ratio of 100%. Various concentrations of PAEs differed in three land-use types were ordered by vegetable soil > orchard soil > paddy soil. Comparing with six U.S. EPA priority pollutants of PAEs, the contents of Di-n-butyl phthalate (DBP) and Dimethyl phthalate ( DMP) in soils exceeded the control limits of PAEs in the American soil by 93.85% and 27.69% respectively, but the rest four PAEs compounds were lower than the control limits. Generally, the pollution level of soils contaminated by PAEs in agricultural fields of Zhongshan City was relatively low. The contents of 3 PAEs in agricultural products ranged from 0.15 to 3.15 mg x kg(-1) with the average of 1.12 mg x kg(-1), which was lower than the suggested standards in USA and Europe and with low health risk. Meanwhile, ∑ PAEs concentrations in vegetables were higher than those both in rice and fruits. DBP and DEHP were the main components of PAEs both in agricultural soils and products, with higher percentage contents and detected ratio. ∑ PAEs and DBP contents in various agricultural products-soils had a significantly positive correlation, with Pearson coefficients (r) in vegetables-vegetable soils were 0.81 (P = 0.000), 0.75 (P = 0.000), and corresponding r among rice-paddy soil and fruits-fruit soils were 0.74 (P = 0.036), 0.65 (P = 0.041) and 0.66 (P = 0.029), 0.78 (P = 0.045), respectively. Although there existed a

  1. Soil decontamination of 2,4,6- trinitrotoluene by alfalfa (Medicago sativa).

    Fallahi, S; Habibi-Rezaei, M; Khayami, M; Heydari, R


    Present study investigate the toxicity effect of 2,4,6-trinitrotoluene (TNT) on a terrestrial plant, alfalfa (Medicago sativa) in artificial soils. In this study, TNT toxicity assessment was performed on spiked silica with this nitroaromatic compound by determination of the percent of emergence and shoots and roots biomasses at the concentration range of 3.2-10000 mg kg(-1) Dry Weight (DW). The emergence was reduced by 22-32% after 5 days of exposure at TNT concentrations up to 100 mg kg(-1) DW; shoot and root biomasses were reduced by 48-50 and 63-74%, respectively after 30 days exposure at TNT concentrations alfalfa cultivation for 30 days, TNT was partially transformed at the extent of 15-27%. This transformation decreased at higher TNT soil concentrations. TNT is taken up and metabolized by plants to its downstream derivatives.

  2. The cumulative effect of three decades of phosphogypsum amendments in reclaimed marsh soils from SW Spain: (226)Ra, (238)U and Cd contents in soils and tomato fruit.

    Abril, José-María; García-Tenorio, Rafael; Enamorado, Santiago M; Hurtado, M Dolores; Andreu, Luis; Delgado, Antonio


    Phosphogypsum (PG), a by-product of the phosphate fertiliser industries, has been applied as soil amendment to reduce Na saturation in soils, as in the reclaimed marsh area from SW Spain, where available PG has a typical fingerprint of 710+/-40 Bq kg(-1) of (226)Ra, 165+/-15 Bq kg(-1) of (238)U and 2.8+/-0.4 mg kg(-1) of Cd. This work was focussed on the cumulative effects of PG amendments on the enrichment of these pollutants in cultivated soils and plants (Lycopersicum esculentum Mill L.) from the area studied, where PG has been applied since 1978 at recommended rates of 20-25 Mg ha(-1) every 2-3 years. A field experiment was conducted over three years to compare activity concentrations of (226)Ra ((214)Pb) and (238)U ((234)Th) in non-reclaimed soils, reclaimed soils with no additional PG application, and reclaimed soils with two additional PG applications. A non-significant effect of two PG amendments (in three years) was observed when compared with non-amended reclaimed plots. Nevertheless, a significant (p<0.05) enrichment of (226)Ra was observed in the surface horizon (0-30 cm) of reclaimed plots relative to deeper horizons and also when compared with the surface horizon of non-reclaimed soil (p<0.05), thereby revealing the cumulative effect of three decades of PG applications. Furthermore, the effect of a continuous application of PG was studied by analysing soils and tomato fruits from six commercial farms with different cumulative rates of PG applied. Cadmium concentrations in tomatoes, which were one order of magnitude higher than those found in tomatoes from other areas in South Spain, were positively correlated (r = 0.917) with (226)Ra-concentration in soils, which can be considered an accurate index of the cumulative PG rate of each farm.

  3. Effects of reforestation on soil chemical properties and microbial communities in a severely degraded sub-tropical red soil region%植被恢复对亚热带退化红壤区土壤化学性质与微生物群落的影响

    龚霞; 牛德奎; 赵晓蕊; 鲁顺保; 刘苑秋; 魏晓华; 郭晓敏


    利用1991年在江西省泰和县严重退化的丘陵红壤区建立的长期森林恢复实验基地,以自然恢复的荒草地为对照,分析了湿地松纯林、枫香纯林、湿地松-枫香混交林3种植被类型造林19年后土壤养分和微生物群落数量的变化.结果表明:枫香纯林和湿地松-枫香混交林的土壤有机碳含量(15.16±3.53和16.42±0.49 g·kg-1)显著高于荒草地(9.30±1.13g·kg-1);土壤全磷含量表现为荒草地(0.30±0.02 g·kg-1)>湿地松-枫香混交林(0.22±0.04g·kg-1)>枫香纯林(0.14±0.01 g·kg-1);土壤有效磷含量为枫香纯林(1.66±0.02mg·kg-1)、湿地松-枫香混交林(2.47 ±0.27 mg·kg-1)和湿地松纯林(1.15±0.71 mg·kg-1)显著高于荒草地(0.01±0.00 mg·kg-1);土壤的微生物总数、细菌数量及百分比、土壤无机解磷菌和有机解磷菌数量均为枫香纯林、湿地松-枫香混交林显著高于湿地松纯林和荒草地;真菌数量及百分比、放线菌百分比为枫香纯林、湿地松-枫香混交林显著低于荒草地;土壤有机碳含量与细菌百分比呈极显著正相关,与真菌和放线菌百分比呈显著负相关;土壤有效磷与有机解磷菌数量呈显著正相关,与无机解磷菌数量不相关.枫香纯林和湿地松-枫香混交林可以作为亚热带退化红壤区植被恢复的推荐模式.%Taking the long-term reforestation experimental base established in a severely degraded sub-tropical hilly red soil region in Taihe County of Jiangxi Province in 1991 as the object, this paper studied the changes of soil nutrients and microbial communities after 19 years reforestation of Pi-nus elliottii forest, Liquidambar formosana forest, and P. elliotti-L. formosana forest, with the naturally restored grassland as the control. The soil organic carbon content in the L. formosana and P. elliottii-L. formosana forests (15. 16±3.53 and 16.42±0. 49 g·kg-1, respectively) was significantly higher than that in the

  4. Changes in microbial activity of soils during the natural restoration of abandoned lands in central Russia

    Ovsepyan, Lilit; Mostovaya, Anna; Lopes de Gerenyu, Valentin; Kurganova, Irina


    Most changes in land use affect significantly the amount of soil organic carbon (SOC) and alter the nutrition status of soil microbial community. The arable lands withdrawal induced usually the carbon sequestration in soil, the significant shifts in quality of soil organic matter and structure of microbial community. This study was aimed to determine the microbial activity of the abandoned lands in Central Russia due to the process of natural self-restoration. For the study, two representative chronosequences were selected in Central Russia: (1) deciduous forest area, DFA (Moscow region, 54o49N'; 37o34'E; Haplic Luvisols) and (2) forest steppe area, FSA (Belgorod region 50o36'N, 36o01'E Luvic Phaeozems). Each chronosequence included current arable, abandoned lands of different age, and forest plots. The total soil organic carbon (Corg, automatic CHNS analyzer), carbon immobilized in microbial biomass (Cmic, SIR method), and respiratory activity (RA) were determined in the topsoil (0-5, 5-10, 10-20 and 20-30 cm layers) for each plots. Relationships between Corg, Cmic, and RA were determined by liner regression method. Our results showed that the conversion of croplands to the permanent forest induced the progressive accumulation Corg, Cmic and acceleration of RA in the top 10-cm layer for both chronosequences. Carbon stock increased from 24.1 Mg C ha-1 in arable to 45.3 Mg C ha-1 in forest soil (Luvic Phaeozems, Belgorod region). In Haplic Luvisols (Moscow region), SOC build up was 2 time less: from 13.5 Mg C ha-1 in arable to 27.9 Mg C ha-1 in secondary forest. During post-agrogenic evolution, Cmic also increased significantly: from 0.34 to 1.43 g C kg-1 soil in Belgorod region and from 0.34 to 0.64 g C kg-1 soil in Moscow region. RA values varied widely in soils studied: from 0.54-0.63 mg C kg-1h-1 in arable plots to 2.02-3.4 mg C kg-1h-1 in forest ones. The close correlations between Cmic, RA and Corg in the top 0-5cm layer (R2 = 0.81-0.90; PSports.

  5. Levantamento de reconhecimento com apoio digital dos solos do município de Nazareno-MG Digital reconnaissance soil survey of Nazareno, state of Minas Gerais

    Ivana de Marco Fonseca Horta


    Full Text Available Este trabalho foi realizado no Município de Nazareno-MG, que tem sido submetido a sérios problemas ambientais em razão do uso inadequado dos solos, os quais, como suporte dos ecossistemas e das atividades antrópicas sobre a terra, são importantes para explicar fenômenos de erosão e assoreamento. Objetivou-se produzir um levantamento de reconhecimento de média intensidade dos solos, visando a subsidiar futuros mapeamentos mais detalhados do local. A escolha da área de trabalho deveu-se ao elevado grau que os processos erosivos alcançaram no município. Os sistemas de informações geográficas (SIGs auxiliaram durante a investigação e a confecção dos mapas, minimizando custos e aumentando qualidade e precisão dos resultados. Foram definidas cinco unidades de mapeamento: Latossolo Vermelho-Amarelo distrófico típico (LVAd 1 a 4 (58%, predominante, seguida por Cambissolo Háplico Tb distrófico típico (CXbd 4 a 6 (16% e CXbd 1 a 3 (15%, a unidade Latossolo Vermelho distrófico típico (LVdf 1 a 4 (7% que ocorreu no norte do município e a unidade Gleissolo Háplico Tb distrófico típico (GXbd que ocupa a menor área (2%.This research was carried out in Nazareno County, State of Minas Gerais, which has been subjected to serious environmental problems due to inadequate soil use. Information about soils is necessary for the appropriate monitoring when implementing measures to mitigate or correct the problem. The objective of this work was to produce a soil recognition map. It is intended to subsidize future and more detailed mapping of the area. The choice of the work area was due to the high degree that the erosive processes reached in Nazareno. Geographic Information Systems (GIS aided the mapping process and the investigation, minimizing costs and increasing the quality and precision of the results. Five soil mapping units were defined: LVAd (58% was predominant, followed by CXbd2 (16%, and CXbd1 (15%. The unit LVdf (7% occurs in

  6. Thallium in French agrosystems--I. Thallium contents in arable soils.

    Tremel, A; Masson, P; Sterckeman, T; Baize, D; Mench, M


    The thallium (Tl) content of the upper horizons of 244 French soils was determined as the first step towards the creation of a reference data bank for total Tl content of arable soils. Forty soil samples were collected in the vicinity of potential anthropogenic sources of Tl, but the remainder came from rural areas. The distribution of Tl concentrations in soils was characterized by a median value of 0.29 mg Tl kg(-1) and a 90th percentile value of 1.54 mg Tl kg(-1). Very high pedogeochemical contents were found (up to 55 mg Tl kg(-1)) but none could be attributed to obvious anthropogenic pollution. Areas of very high Tl concentration belong to an epihercynian transgression zone with a contact between a sedimentary basin and a crystalline massif. This contact is associated with stratified mineralizations (Zn, Pb, F, Sb, Ba, Tl and pyrites). High Tl concentrations were common in limestone, marl or granite derived soils, and the Tl in limestones or marls is probably concentrated in the sulfides contained in these rocks because Tl has a high affinity to S. In granites, Tl may be in the micas and feldspars because Tl+ can replace K+ in these minerals. Silty or clay-silty soils showed the highest concentrations. These granulometric fractions contain the majority of the minerals, which are supposed to be the major hosts of Tl in soils, i.e. clay minerals, oxides and micas. Tl in the soils was positively correlated with Ba, V, Pb, Fe, Ni, Cd, Zn, Co, As and especially Mn. A significant proportion of Tl may be in the Mn oxides: in oxidizing conditions, Tl(III) could enter the Mn oxides by sorption, or Tl(I) could replace K(I) in the oxide.

  7. Toxicity of 2,4-dinitrotoluene to terrestrial plants in natural soils.

    Rocheleau, Sylvie; Kuperman, Roman G; Simini, Mike; Hawari, Jalal; Checkai, Ronald T; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I


    The presence of energetic materials (used as explosives and propellants) at contaminated sites is a growing international issue, particularly with respect to military base closures and demilitarization policies. Improved understanding of the ecotoxicological effects of these materials is needed in order to accurately assess the potential exposure risks and impacts on the environment and its ecosystems. We studied the toxicity of the nitroaromatic energetic material 2,4-dinitrotoluene (2,4-DNT) on alfalfa (Medicago sativa L.), barnyard grass (Echinochloa crusgalli L. Beauv.), and perennial ryegrass (Lolium perenne L.) using four natural soils varying in properties (organic matter, clay content, and pH) that were hypothesized to affect chemical bioavailability and toxicity. Amended soils were subjected to natural light conditions, and wetting and drying cycles in a greenhouse for 13 weeks prior to toxicity testing to approximate field exposure conditions in terms of bioavailability, transformation, and degradation of 2,4-DNT. Definitive toxicity tests were performed according to standard protocols. The median effective concentration (EC(50)) values for shoot dry mass ranged from 8 to 229 mg kg(-1), depending on the plant species and soil type. Data indicated that 2,4-DNT was most toxic in the Sassafras (SSL) and Teller (TSL) sandy loam soils, with EC(50) values for shoot dry mass ranging between 8 to 44 mg kg(-1), and least toxic in the Webster clay loam soil, with EC(50) values for shoot dry mass ranging between 40 to 229 mg kg(-1). The toxicity of 2,4-DNT for each of the plant species was significantly (p < or = 0.05) and inversely correlated with the soil organic matter content. Toxicity benchmark values determined in the present studies for 2,4-DNT weathered-and-aged in SSL or TSL soils will contribute to development of an Ecological Soil Screening Level for terrestrial plants that can be used for ecological risk assessment at contaminated sites.

  8. Communities of arbuscular mycorrhizal fungi in the roots of Pyrus pyrifolia var. culta (Japanese pear) in orchards with variable amounts of soil-available phosphorus.

    Yoshimura, Yuko; Ido, Akifumi; Iwase, Koji; Matsumoto, Teruyuki; Yamato, Masahide


    We examined the colonization rate and communities of arbuscular mycorrhizal fungi (AMF) in the roots of Pyrus pyrifolia var. culta (Japanese pear) in orchards to investigate the effect of phosphorus (P) fertilization on AMF. Soil cores containing the roots of Japanese pear were collected from 13 orchards in Tottori Prefecture, Japan. Soil-available P in the examined orchards was 75.7 to 1,200 mg kg(-1), showing the extreme accumulation of soil P in many orchards. The AMF colonization rate was negatively correlated with soil-available P (P orchard environment.

  9. Applicability and limitations of enzyme addition assays for the characterisation of soil organic phosphorus across a range of soil types

    Jarosch, Klaus; Doolette, Ashlea; Smernik, Ronald; Frossard, Emmanuel; Bünemann, Else K.


    Solution 31P NMR spectroscopy is a powerful tool for the characterisation and quantification of organic P classes in soil. Potential limitations are due to costs, equipment accessibility and the requirement of relatively large amounts of sample. A recent alternative approach for the quantification of specific organic P classes is the use of substrate-specific phosphohydrolase enzymes which cleave the inorganic orthophosphate from the organic moiety. The released orthophosphate is detectable by colorimetry. Conclusions about the hydrolysed class of organic P can be made based on the comparison of inorganic P concentrations in enzymatically treated and untreated samples. The aim of this study was to test the applicability of enzyme addition assays for the characterisation of organic P classes on a) NaOH-EDTA extracts, b) soil:water filtrates (0.2 μm) and c) soil:water suspensions. The organic P classes in NaOH-EDTA extracts were also determined by 31P NMR spectroscopy, enabling a comparison between methods. Ten topsoil samples from four continents (five cambisols, two ferralsols, two luvisols and one lixisol) with varying total P content (83 - 1,1560 mg kg-1), pHH2O (4.2 - 8.0) and land management (grassland or cropped land) were analysed. Four different classes of organic P were determined by the enzyme addition assay: 1) monoester like-P (by an acid phosphatase known to hydrolyse simple monoesters, pyrophosphate and ATP), 2) DNA-like P (by a nuclease in combination with an acid phosphatase), 3) inositol phosphate-like P (by a phytase known to hydrolyse all monoester like-P plus myo-inositol hexakisphosphate and scyllo-inositol hexakisphosphate) and 4) enzyme stable-P (enzymatically not hydrolysed organic P forms). In the ten topsoil samples, NaOH-EDTA-extractable organic P ranged from 6 - 1,115 mg P kg-1 soil. Of this, 33 - 92 % was enzyme labile, with inositol phosphate-like P being the largest organic P class in most soils (15 - 51%), followed by monoester

  10. Oxytetracycline Toxicity and its Effect on Phytoremediation by Sedum Plumbizincicola and Medicago Sativa in Metal Contaminated Soil.

    Ma, Tingting; Zhou, Liqiang; Chen, Li 'ke; Li, Zhu; Wu, Longhua; Christie, Peter; Luo, Yongming


    Excessive use of antibiotics potentially threatens human health, agricultural production and soil phytoremediation. This arouses concern over the potential adverse effects of a commonly used antibiotic, oxytetracycline (OTC), on plants used for soil remediation and possible stimulation of antibiotic resistance genes in soils. A greenhouse experiment was conducted to investigate different rates (0, 1, 5, and 25 mg kg-1) and frequencies (one single high and daily low application) of OTC addition to soil on phytoremediation of a heavy metal contaminated soil by Sedum plumbizincicola and/or Medicago sativa (alfalfa). After 90 days both Cd and Zn were substantially removed by phytoextraction into S. plumbizincicola shoots especially at the high OTC (25 mg kg-1) treatment which also led to inhibition of anti-oxidative enzyme activities in both plant species. Soil microbial activity decreased significantly with the addition of OTC and this was ameliorated by planting alfalfa and S. plumbizincicola together. OTC at Alfalfa exhibited greater detoxification ability and effectiveness in soil microbial activity promotion than S. plumbizincicola with intercropping. Phytoremediation by alfalfa and S. plumbizincicola in association can both promote the removal of heavy metals and also alleviate the toxic effects of pollutants to plants and soil microbes even at relatively high soil OTC concentrations.

  11. Changes in methane oxidation activity and methanotrophic community composition in saline alkaline soils.

    Serrano-Silva, Nancy; Valenzuela-Encinas, César; Marsch, Rodolfo; Dendooven, Luc; Alcántara-Hernández, Rocio J


    The soil of the former Lake Texcoco is a saline alkaline environment where anthropogenic drainage in some areas has reduced salt content and pH. Potential methane (CH4) consumption rates were measured in three soils of the former Lake Texcoco with different electrolytic conductivity (EC) and pH, i.e. Tex-S1 a >18 years drained soil (EC 0.7 dS m(-1), pH 8.5), Tex-S2 drained for ~10 years (EC 9.0 dS m(-1), pH 10.3) and the undrained Tex-S3 (EC 84.8 dS m(-1), pH 10.3). An arable soil from Alcholoya (EC 0.7 dS m(-1), pH 6.7), located nearby Lake Texcoco was used as control. Methane oxidation in the soil Tex-S1 (lowest EC and pH) was similar to that in the arable soil from Alcholoya (32.5 and 34.7 mg CH4 kg(-1) dry soil day(-1), respectively). Meanwhile, in soils Tex-S2 and Tex-S3, the potential CH4 oxidation rates were only 15.0 and 12.8 mg CH4 kg(-1) dry soil day(-1), respectively. Differences in CH4 oxidation were also related to changes in the methane-oxidizing communities in these soils. Sequence analysis of pmoA gene showed that soils differed in the identity and number of methanotrophic phylotypes. The Alcholoya soil and Tex-S1 contained phylotypes grouped within the upland soil cluster gamma and the Jasper Ridge, California JR-2 clade. In soil Tex-S3, a phylotype related to Methylomicrobium alcaliphilum was detected.

  12. Effects of Long-Term Combined Application of Organic and Mineral Fertilizers on Microbial Biomass, Soil Enzyme Activities and Soil Fertility

    LI Juan; ZHAO Bing-qiang; LI Xiu-ying; JIANG Rui-bo; So Hwat Bing


    Soil health is important for the sustainable development of terrestrial ecosystem.In this paper,we studied the relationship between soil quality and soil microbial properties such as soil microbial biomass and soil enzyme activities in order to illustrate the function of soil microbial properties as bio-indicators of soil health.In this study,microbial biomass C and N contents(Cmic&Nmic),soil enzyme activities,and soil fertility with different fertilizer regimes were carried out based on a 15-year long-term fertilizer experiment in Drab Fluvo-aquic soil in Changping County,Beijing,China.At this site,7 different treatments were established in 1991.They were in a wheat-maize rotation receiving either no fertilizer(CK),mineral fertilizers(NPK),mineral fertilizers with wheat straw incorporated(NPKW),mineral fertilizers with incremental wheat straw incorporated(NPKW+),mineral fertilizers plus swine manure(NPKM),mineral fertilizers plus incremental swine manure(NPKM+)or mineral fertilizers with maize straw incorporated(NPKS).In different fertilization treatments Cmic changed from 96.49 to 500.12 mg kg-1,and Nmic changed from 35.89 to 101.82 mg kg-1.Compared with CK,the other treatments increased Cmic&Nmic,Cmic/Corg(organic C)ratios,Cmic/Nmic,urease activity,soil organic matter(SOM),soil total nitrogen(STN),and soil total phosphorus(STP).All these properties in treatment with fertilizers input NPKM+ were the highest.Meantime,long-term combined application of mineral fertilizers with organic manure or crop straw could significantly decrease the soil pH in Fluvo-aquic soil(the pH around 8.00 in this experimental soil).Some of soil microbial properties(Cmic/Nmic,urease activity)were positively correlated with soil nutrients.Cmic/Nmic was significantly correlated with SOM and STN contents.The correlation between catalase activity and soil nutrients was not significant.In addition,except of catalase activity,the soil pH in this experiment was negatively correlated with soil

  13. Acid soil indicators in forest soils of the Cherry River Watershed, West Virginia.

    Farr, C; Skousen, J; Edwards, P; Connolly, S; Sencindiver, J


    Declining forest health has been observed during the past several decades in several areas of the eastern USA, and some of this decline is attributed to acid deposition. Decreases in soil pH and increases in soil acidity are indicators of potential impacts on tree growth due to acid inputs and Al toxicity. The Cherry River watershed, which lies within the Monongahela National Forest in West Virginia, has some of the highest rates of acid deposition in Appalachia. East and West areas within the watershed, which showed differences in precipitation, stream chemistry, and vegetation composition, were compared to evaluate soil acidity conditions and to assess their degree of risk on tree growth. Thirty-one soil pits in the West area and 36 pits in the East area were dug and described, and soil samples from each horizon were analyzed for chemical parameters. In A horizons, East area soils averaged 3.7 pH with 9.4 cmol(c) kg(-1) of acidity compared to pH 4.0 and 6.2 cmol(c) kg(-1) of acidity in West area soils. Extractable cations (Ca, Mg, and Al) were significantly higher in the A, transition, and upper B horizons of East versus West soils. However, even with differences in cation concentrations, Ca/Al molar ratios were similar for East and West soils. For both sites using the Ca/Al ratio, a 50% risk of impaired tree growth was found for A horizons, while a 75% risk was found for deeper horizons. Low concentrations of base cations and high extractable Al in these soils translate into a high degree of risk for forest regeneration and tree growth after conventional tree harvesting.

  14. Land contamination and soil evolution in abandoned mine areas (Italy)

    Bini, Claudio; Wahsha, Mohammad; Spiandorello, Massimo


    In Italy ore research and exploitation are nearly exhausted since the end of the last century, leaving on the land a huge amount of mine waste, therefore provoking evident environmental damage including landscape, vegetation and the food chain, and a potential threat to human health. The increasing environmental consciousness of general population compelled Public Administrators to set down effective legislation acts on this subject (e.g. D.L. 152/2006), and more generally on environmental contamination. In this work we present the results of a survey carried out at several mixed sulphides mine sites in Italy, exploited for at least a millennium, and closed in the '60s of the last century. Biogeochemical analyses carried out on 50 soil profiles (mostly Entisols and Inceptisols) and vegetation in the proximal and distal areas of ore exploitation show metal concentrations overcoming legislation limits on average (Cu up to 3160 mg kg-1 , Pb up to 23600 mg kg-1, Zn up to 1588 mg kg-1, Fe up to 52,30 %). Ni, Cr and Mn concentrations, instead, are generally below the reference levels. Metal concentrations in native vegetation of the examined areas are moderately to highly elevated. Significant amounts of Cu, Pb, Zn in roots of Plantago major and Silene dioica, in leaves of Taraxacum officinale, and Salix spp, have been recorded. Essential elements, in particular, present Translocation Coefficients (TC) >1, with Mn>Zn>Cu>Fe. Toxic elements (Cd, Cr, Pb), instead, present TCparks in these areas could enhance their educational and scientific value, contributing in the meantime to general population amusement and recreation. Finally, it is the occasion for soil scientists to submit to the scientific community new classification proposals of this new kind of soils. Key-words: mine waste, heavy metals, accumulator plants, phytoremediation, soil genesis, soil classification

  15. Residue Determination and Degradation of Sulfoxaflor in Cotton and Soil

    QIN Xu


    Full Text Available An analytical method with high performance liquid chromatography(HPLCwas established for determining sulfoxaflor residue in soil, cotton seeds and cotton leaves. The field residue decline study and final residue trials of sulfoxaflor in cotton in Tianjin City and Hangzhou City, were designed. The samples were extracted with acetonitrile, partitioned by n-hexane, purified using Florisil column, and de-termined by HPLC equipped with a variable wavelength detector(VWD. The results showed that when the spiked levels were 0.05 mg·kg-1 to 2.5 mg·kg-1, the average recovery of sulfoxaflor ranged from 76.81%to 94.43%with relative standard deviation (RSDof 0.54%to 7.20%;the limit of detection(LODof sulfoxaflor was 1 ng, and the limit of quantification(LOQwas 0.05 mg·kg-1 in soil, cotton seeds and cotton leaves. The degradation of sulfoxaflor in soil and cotton leaves could be described with an equation:Ct=C0e-kt. The half-life of sulfoxaflor were 1.36~5.10 d and 6.13~9.37 d in soil and cotton leaves, respectively. The wheat was sprayed with 50%water dispersible granule(WDGat dosage 0.6~0.9 g·30 m-2(2~3 timesat full-bloom stage, the interval period was 7 d, the final residues of sulfoxaflor were lower than LOQ in soil and cotton seeds.

  16. Nitrogen Mineralization Potentials of Upland Soils in Central China



    Nitrogen mineralization potentials of 15 soil samples were studied by the methods of soil aerobic incubation,and the correlation between the potentials and the amounts of nitrogen taken up by rye grass(Lolium,multiflorum Lam.) in pot culture was calculated.The soils were collected from Hubei Province in Central China.Soil nitrogen mineralization potentials(No) were calculated and optimized by a quick-BASIC program,No ranged from 60 mg kg-1 to 340mg kg-1,which accounted for 9.1%to 34.6% of the total nitrogen content.Among the examined soils,yellow-brown soil collected from Wuhan had the largest No and brown-red soil from Xianning had the smallest one.The mineralization rate constants(k) ranged from 0.00556d-1 to 0.01280d-1,in average 0.00882 d-1,Chao soil from Wuhan had the greatest k while yellowcinamon soil from Zhaoyang had the smallest one.There were apparent differences between mineralization parameters(NO and k) optimized and non-optimized ones,Optimized No had a better correlation than non-optimized No with the amount of nitrogen accumulated in the aerial parts of rye grass.No,No×k and Nt(accumulated mineralized nitrogen Within time t ) could be used as indexes of soil nitrogen supply,Among them Nt was the best,which was significantly correlated with the amounts of nirogen accumulated in the aerial parts of rye grass harvested at three different times.

  17. Cerium dioxide and zinc oxide nanoparticles alter the nutritional value of soil cultivated soybean plants.

    Peralta-Videa, Jose R; Hernandez-Viezcas, Jose A; Zhao, Lijuan; Diaz, Baltazar Corral; Ge, Yuan; Priester, John H; Holden, Patricia Ann; Gardea-Torresdey, Jorge L


    The aim of this study was to determine nutrient elements in soybean (Glycine max) plants cultivated in farm soil amended with nCeO2 at 0-1000 mg kg(-1) and nZnO at 0-500 mg kg(-1). Digested samples were analyzed by ICP-OES/MS. Compared to control, pods from nCeO2 at 1000 mg kg(-1) had significantly less Ca but more P and Cu, while pods from 100 mg kg(-1)nZnO had more Zn, Mn, and Cu. Plants treated with nZnO showed significant correlations among Zn, P, and S in pods with Zn in roots. Correlations among pod Zn/root Zn was r = 0.808 (p ≤ 0.01) and pod P/root P was r = 0.541 (p ≤ 0.05). The correlation among pod S/root S was r = -0.65 (p ≤ 0.01). While nCeO2 treatments exhibited significant correlations between pod Ca/root Ca (r = 0.645, p ≤ 0.05). The data suggest that nCeO2 and nZnO alter the nutritional value of soybean, which could affect the health of plants, humans, and animals.

  18. Soils organic C sequestration under poplar and willow agroforestry systems

    Gunina, Anna; Tariq, Azeem; Lamersdorf, Norbert


    Short rotation coppices (SRC) as monocultures or as agroforestry (AF) applications (e.g. alley cropping) are two techniques to implement forest into agricultural practices. Despite afforestation promotes soil carbon (C) accumulation, age and type of the tree stand can affect the C accumulation in different degrees. Here, we studied the impact of afforestation on C accumulation for: i) pure SCR of willow (Salix viminalis x Salix schwerinii) and poplar (Populus nigra x Populus maximowiczii) and ii) AF cropping system with willow. Forest systems have been established within the BEST agroforestry project in Germany. Adjacent agricultural field have been used as a control. Soil samples were collected in 2014, three years after plantation establishment, from three soil depths: 0-3, 3-20, and 20-30 cm. Total organic C, labile C (incubation of 20 g soil during 100 days with measuring of CO2) and aggregate structure were analysed. Additionally, density fractionation of the samples from 0-3 cm was applied to separate particulate organic matter (POM) and mineral fractions. Aggregates and density fractions were analyzed for C content. High input of plant litter as well as root exudates have led to increases of organic C in AF and SRC plots compare to cropland, mainly in the top 0-3 cm. The highest C content was found for willow SRC (18.2 g kg-1 soil), followed by willow-AF (15.6 g kg-1 soil), and poplar SRC (13.7 g kg-1 soil). Carbon content of cropland was 12.5 g kg-1 soil. Absence of ploughing caused increase portion of macroaggregates (>2000 μm) under SRC and AF in all soil layers as well as the highest percentage of C in that aggregate size class (70-80%). In contrast, C in cropland soil was mainly accumulated in small macroaggregates (250-2000 μm). Intensive mineralisation of fresh litter and old POM, taking place during first years of trees development, resulted to similar portions of free POM for willow AF, willow SRC and cropland (8%), and even lower ones for poplar

  19. Biodegradation of phthalate esters in compost-amended soil.

    Chang, B V; Lu, Y S; Yuan, S Y; Tsao, T M; Wang, M K


    In this study, we investigated the biodegradation of the phthalate acid esters (PAEs) di-n-butyl phthalate (DBP) and di-(2-ethyl hexyl) phthalate (DEHP) in compost and compost-amended soil. DBP (50 mg kg(-1)) and DEHP (50 mg kg(-1)) were added to the two types of compost (straw and animal manure) and subsequently added to the soil; they were tested as a single compound and in combination. Optimal PAE degradation in soil was at pH 7 and 30 degrees C. The degradation of PAE was enhanced when DBP and DEHP were simultaneously present in the soil. The addition of either of the two types of compost individually also improved the rate of PAE degradation. Compost samples were separated into fractions with various particle size ranges, which spanned from 0.1-0.45 to 500-2000 microm. We observed that the compost fractions with smaller particle sizes demonstrated higher PAE degradation rates. When the different compost fractions were added to soil, however, compost particle size had no significant effect on the rate of PAE degradation.

  20. Growth of four tropical tree species in petroleum-contaminated soil and effects of crude oil contamination.

    Pérez-Hernández, I; Ochoa-Gaona, S; Adams, R H; Rivera-Cruz, M C; Pérez-Hernández, V; Jarquín-Sánchez, A; Geissen, V; Martínez-Zurimendi, P


    Under greenhouse conditions, we evaluated establishment of four tree species and their capacity to degrade crude oil recently incorporated into the soil; the species were as follows: Cedrela odorata (tropical cedar), Haematoxylum campechianum (tinto bush), Swietenia macrophylla (mahogany), and Tabebuia rosea (macuilis). Three-month-old plants were planted in soil with three treatments of heavy petroleum and a control (C0 0 mg kg(-1); C1 18,000 mg kg(-1); C2 31,700 mg kg(-1); C3 47,100 mg kg(-1)) with four repetitions per treatment and species; the experiment was carried out for 245 days. Height and biomass of all species significantly diminished as petroleum concentration increased, although plant survival was not affected. The quantity of colony-forming units (CFU) of rhizospheric bacteria varied among tree species and treatments; petroleum stimulated bacterial CFU for S. macrophylla. The number of fungi CFU for S. macrophylla and T. rosea was significantly greater in C0 than in soil with petroleum, but among species and among different concentrations, no significant differences were found. The greatest percentage of total petroleum hydrocarbon (TPH) degradation was found in C1 for soil without plants (45 %). Differences from the remaining treatments (petroleum concentrations in soil and plant species) were not significant (P trees, H. campechianum had the greatest TPH degradation (32.5 % in C2). T. rosea (C1) and H. campechianum (C2) resulted in petroleum degradation at levels ranging from 20.5 to 32.5 %. On the basis of this experiment, the tree species used did not improve TPH degradation. However, all of them showed high rates of survival and vigor. So, as tree species provide goods and services, experiments with inoculation of hydrocarbonclastic microorganisms, addition of fertilizers, and mixture of tree and grasses are recommended.

  1. [Characteristics of soil microbial biomass carbon and nitrogen and their relationships with soil nutrients in Cunninghamia lanceolata plantations].

    He, Youjun; Wang, Qingkui; Wang, Silong; Yu, Xiaojun


    The study on the soil microbial biomass and nutrient status under native broadleaved forest and Cunninghamia lanceolata plantations at the Huitong National Research Station of Forest Ecosystem showed that after the native broadleaved forest was replaced by mono-cultured C. lanceolata or C. lanceolata was planted continuously, soil microbial biomass and nutrient pool decreased greatly. In 0 - 10 cm soil layer, the concentrations of soil microbial carbon and nitrogen in broadleaved forest were 800.5 and 84.5 mg x kg(-1) , being 1.90 and 1.03 times as much as those in the first rotation of C. lanceolata plantation, and 2.16 and 1.27 times as much as those in the second rotation of the plantation, respectively, while in 10 - 20 cm soil layer, the microbial carbon and nitrogen in broad-leaved forest were 475.4 and 63.3 mg x kg(-1), being 1.86 and 1.60 times as much as those in the first rotation, and 2.11 and 1.76 times as much as those in the second rotation, respectively. Soil nutrient pools such as total nitrogen, total potassium, NH4(+) -N, and available potassium also declined after the C. lanceolata plantation replaced native broad-leaved forest, or C. lanceolata was planted continuously. Less litter and its slower decay rate in pure C. lanceolata plantation were the crucial factors leading to the decrease of soil microbial biomass and nutrient pool in this area, and human disturbance, especially slash-burning and site preparation, was the another factor leading to the decrease. There were significant positive correlations between soil microbial carbon and nitrogen and soil nutrients. To improve soil quality and maintain sustainable productivity, some measures including planting mixed conifer with hardwood, preserving residues after harvest, and adopting scientific site preparation should be taken.

  2. In vitro assessment on the impact of soil arsenic in the eight rice varieties of West Bengal, India.

    Bhattacharya, Piyal; Samal, Alok C; Majumdar, Jayjit; Banerjee, Satabdi; Santra, Subhas C


    Rice is an efficient accumulator of arsenic and thus irrigation with arsenic-contaminated groundwater and soil may induce human health hazard via water-soil-plant-human pathway. A greenhouse pot experiment was conducted on three high yielding, one hybrid and four local rice varieties to investigate the uptake, distribution and phytotoxicity of arsenic in rice plant. 5, 10, 20, 30 and 40 mg kg(-1) dry weights arsenic dosing was applied in pot soil and the results were compared with the control samples. All the studied high yielding and hybrid varieties (Ratna, IET 4094, IR 50 and Gangakaveri) were found to be higher accumulator of arsenic as compared to all but one local rice variety, Kerala Sundari. In these five rice varieties accumulation of arsenic in grain exceeded the WHO permissible limit (1.0 mg kg(-1)) at 20 mg kg(-1) arsenic dosing. Irrespective of variety, arsenic accumulation in different parts of rice plant was found to increase with increasing arsenic doses, but not at the same rate. A consistent negative correlation was established between soil arsenic and chlorophyll contents while carbohydrate accumulation depicted consistent positive correlation with increasing arsenic toxicity in rice plant.


    Rodrigo Ferreira da Silva


    Full Text Available The ectomycorrhizal fungi symbiosis with native florestal essences may be an alternative to   revegetation of metal contaminated soils. The aim of this work was to determine canafístula seedlings behavior, inoculated to ectomycorrhizal fungi in soil with copper excess. The trial was conducted in greenhouse conditions. The ectomycorrhizal fungi used was Pisolithus microcarpus UFSC Pt116, cultivated on peat-vermiculite substrate (3:1. The canafístula seedlings were developed in washed  sand and transplanted, when showed two definitive leaves. Vase of 1L with 1 kg of soil were used as experimental unit. The inoculation was accomplished in the seedlings transplant, added 2g of inoculates for experimental unit. The experimental design was entirely casual in bi factorial scheme (2 x 4 qualitative in A, with and without fungi inoculum and quantitative in D being the control addition of 150 mg Kg -1, 300 mg Kg -1 and 450 mg Kg -1 of copper (CuSO4, with seven repetitions. Plant height, colon diameter, dry matter, copper content, mycorrhizal colonization percentage, superficial roots area and roots length were assessed. The increase of soil copper levels reduced roots length, specific superficial roots area, height and plant diameter of canafístula. Canafistula seedlings inoculated to ectomycorrhizal fungi showed low cooper amounts in their tissue and copper absortion reduced in high copper doses.

  4. Potential exposure to clothianidin and risk assessment of manual users of treated soil.

    Ren, JingXia; Tao, ChuanJiang; Zhang, LiYing; Ning, Jun; Mei, XiangDong; She, DongMei


    Treated soil is the second most prevalent application technique for all registered pesticides in China. Some developing countries also adopt this method. However, the safety of this scenario has not been reported in the literature. Experiments were therefore conducted to assess exposure using standard whole-body dosimetry and air sampling methodologies. Dermal deposition was the main route of exposure in this scenario. The total dermal unit exposure (UE) of operators to clothianidin-treated soil was 51.7 mg kg(-1) AI handled (SD = 20.59, n = 16), and hands accounted for 36%. Inhalation UE was 0.04 mg kg(-1) AI handled (SD = 0.02, n = 4), negligible compared with dermal exposure. Using an NOAEL (no observed adverse effect level) of 10 mg kg(-1) day(-1) , the margin of exposure was 773, i.e. greater than 100. For the first time, the scenario of treated soil exposure was assessed and was found to pose less risk than conventional pesticide application. These results can be used as a reference in pesticide management. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  5. Historical arsenic contamination of soil due to long-term phosphate fertiliser applications.

    Hartley, Tom N; Macdonald, Andy J; McGrath, Steve P; Zhao, Fang-Jie


    Archived samples from the Park Grass Experiment, established in 1856, were analysed to determine the impacts of long-term phosphate fertiliser applications on arsenic concentrations in soil and herbage. In plots receiving 35 kg P ha(-1) annually (+P), topsoil As concentrations almost doubled from an initial value of ∼10 mg kg(-1) during 1888-1947 and remained stable thereafter. The phosphate fertilisers used before 1948 contained 401-1575 mg As kg(-1), compared to 1.6-20.3 mg As kg(-1) in the later samples. Herbage samples from the +P plots collected during 1888-1947 contained significantly more As than those from the -P plots, but later samples did not differ significantly. Mass-balance calculations show that the increase in soil As can be explained by the As input from P fertiliser applications before 1948. The results demonstrate that the P fertilisers used on the Park Grass Experiment before 1948 caused substantial As contamination of the soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. [Effects of thiourea on pH and availability of metal ions in acid red soil].

    Yang, Bo; Wang, Wen; Zeng, Qing-Ru; Zhou, Xi-Hong


    Through the simulation research, the effects of application of thiourea and urea on pH and availability of metal ions in acid red soil were studied, and the results showed that after applying urea, the soil pH increased in the first experimental stage and then reduced gradually to a low level, however, decreased trends of soil pH values were inhibited by the application of thiourea, especially when the concentration of thiourea reached to 5.0 mmol x kg(-1) dry soil, the soil pH was stable at high level, which exceeded to 6.0. It proved that the application of thiourea could inhibit the soil acidification due to urea application. After applying urea with different concentrations of thiourea, the available contents of Zn and Al decreased with the increasing concentration of thiourea, nevertheless, when the concentration of thiourea reached to 5.0 mmol x kg(-1), the available content of Mn was stable at high level which was over 110 mg x kg(-1). In addition, the results showed a highly significant negative correlation between the soil pH and the available content of Cu, Zn and Al, but for Mn, no discipline was found between the soil pH and the availability after applying thiourea. Moreover, the soil pH became higher after applying urea with thiourea compared to add urea only, which led to the decreasing of available content of Al, and it was benefited for the control of the phytotoxic effect of Al. The available content of Mn in the soil not only depended on soil pH but also the content of thiourea due to its redox and complexing reaction with Mn.

  7. 锑矿土壤中As和Sb的分布、形态及生物可利用性%Distribution, speciation and bio-availability of arsenic(As) and antimony (Sb) in soils of antimony mine

    陈秋平; 胥思勤; 安艳玲; 陈洁薇; 吴贞术


    HG-AFS was applied to the determination of arsenic( As) and antimony ( Sb) in the soils near Qinglong antimony mine area with microwave assisted sample digestion. Tessier sequential extraction was used to investigate the distribution,speciation and bio-availability of As and Sb in the soils. Results showed that total arsenic content ( 17. 98-127. 85 mg·kg-1 ) and total antimony concentration (171.93-601.59 mg·kg-1) substantially exceeded their background level in Guizhou Province. The speciation of antimony and arsenic in the soils has the following distribution order:residual phase> Fe/Mn hydrous oxides, orgnic phase, carbonate fraction>cation exchangeable. The concentration of easily bioavailable antimony was 0. 60-3. 91 mg·kg-1 and the percentage was 0�33%-1.72%, while 0.15-0.48 mg·kg-1 and 0.09%-0.57% for arsenic.%采用微波消解-氢化物发生-原子荧光光谱法测定了晴隆锑矿区土壤中总砷和总锑,利用Tessier连续提取法分析土壤中不同形态砷和锑.结果表明,各采样点土壤 As、Sb 含量分别为17.98-127.85 mg·kg-1、171�93-601.59 mg·kg-1,远高于贵州省背景值;土壤中砷和锑的存在形态均以残渣态为主,其次是有机结合态、铁锰氧化物结合态和碳酸盐结合态,可交换态很少;土壤中生物可利用态锑占总和0.33%-1.72%,其含量为0.60-3.91 mg·kg-1,而土壤中生物可利用态砷占总和0.09%-0.57%,其含量为0.15-0.48 mg·kg-1

  8. Effect of soil texture on phytoremediation of arsenic-contaminated soils

    Pallud, C. E.; Matzen, S. L.; Olson, A.


    Soil arsenic (As) contamination is a global problem, resulting in part from anthropogenic activities, including the use of arsenical pesticides and treated wood, mining, and irrigated agriculture. Phytoextraction using the hyperaccumulating fern Pteris vittata is a promising new technology to remediate soils with shallow arsenic contamination with minimal site disturbance. However, many challenges still lie ahead for a global application of phytoremediation. For example, remediation times using P. vittata are on the order of decades. In addition, most research on As phytoextraction with P. vittata has examined As removal from sandy soils, where As is more available, with little research focusing on As removal from clayey soils, where As is less available. The objective of this study is to determine the effects of soil texture and soil fertilization on As extraction by P. vittata, to optimize remediation efficiency and decrease remediation time under complex field conditions. A field study was established 2.5 years ago in an abandoned railroad grade contaminated with As (average 85.5 mg kg-1) with texture varying from sandy loam to silty clay loam. Organic N, inorganic N, organic P, inorganic P, and compost were applied to separate sub-plots; control ferns were grown in untreated soil. In a parallel greenhouse experiment, ferns were grown in sandy loam soil extracted from the field (180 mg As kg-1), with similar treatments as those used at the field site, plus a high phosphate treatment and treatments with arbuscular mycorrhizal fungi. In the field study, fern mortality was 24% higher in clayey soil than in sandy soil due to waterlogging, while As was primarily associated with sandy soil. Results from the sandy loam soil indicate that soil treatments did not significantly increase As phytoextraction, which was lower in phosphate-treated ferns than in control ferns, both in the field and greenhouse study. Under greenhouse conditions, ferns treated with organic N were

  9. Effect of malachite green toxicity on non target soil organisms.

    Gopinathan, R; Kanhere, J; Banerjee, J


    Although malachite green (MG), is banned in Europe and US for its carcinogenic and teratogenic effect, the dye being cheap, is persistently used in various countries for fish farming, silk, dye, leather and textile industries. Current research, however, fails to elucidate adequate knowledge concerning the effects of MG in our ecosystem. In the present investigation, for the first time, an attempt has been made to study the effects of MG on soil biota by testing Bacillus subtilis, Azotobacter chroococcum, Saccharomyces cerevisiae, Penicillium roqueforti, Eisenia fetida and seeds of three crop plants of different families. Various tests were conducted for determining cytotoxicity, genotoxicity, acute toxicity, morphological and germination effect. Our data confirmed MG toxicity on fungi and bacteria (gram positive and gram negative organisms) showing elevated level of ROS. Genotoxicity caused in the microorganisms was detected by DNA polymorphism and fragmentation. Also, scanning electron microscopy data suggests that the inhibitory effect of MG to these beneficial microbes in the ecosystem might be due to pore formation in the cell and its eventual disruption. Filter paper and artificial soil test conducted on earthworms demonstrated a LC 50 of 2.6 mg cm(-2) and 1.45 mg kg(-1) respectively with severe morphological damage. However, seed germination of Mung bean, Wheat and Mustard was found to be unaffected in presence of MG up to 100 mL(-1) concentration. Thus, understanding MG toxicity in non target soil organisms and emphasis on its toxicological effects would potentially explicate its role as an environmental contaminant.

  10. Chromium fractionation and plant availability in tannery-sludge amended soil

    Allué, Josep; Moya Garcés, Alba; Bech, Jaume; Barceló, Juan; Poschenrieder, Charlotte


    The leather industry represents an important economic sector in both developed and developing countries. Chromium tanning is the major process used to obtain high quality leather. Within the REACH regulation the use of Cr, especially CrVI, in the tanning process is under discussion in Europe. High Cr concentration in shoes and other Cr-tanned leather products can cause contact dermatitis in sensitive population. Moreover, the high Cr concentration is the major limiting factor for the use of tannery sludge as a source of organic matter in agricultural soils. Interest in Cr, however is not limited to its potential toxic effects. Chromium III is used as a dietary supplement because there are reports, but also controversy, about the positive effects of Cr III in glucose tolerance and type-2 diabetes. Adequate intake levels for Cr by the diet have been established between 25 and 35 µg/day for adult females and males, respectively. Sufficient supply of Cr III by the diet is preferable to the use of CrIII-salt based dietary supplements. The objective of the present work was to investigate whether Cr from tannery sludge-amended soil is available to Trigonella foenum-graecum plants, a plant used both as a spice and as a medicinal herb, because of its hypoglucemic effects. For this purpose clay loam soil (pH 7.8) was sieved (2mm) and thoroughly mixed with tannery sludge from a depuration station (Igualadina Depuració i Recuperació S.L., Igualada, Barcelona, Spain). The sludge had a Cr concentration of 6,034mg kg-1 and a 0.73 % of NH4-nitrogen. All the Cr was in the form of CrIII. Three treatments were disposed. Control soil receiving no sludge, a 60 mg kg-1 Cr treatment (10 g fresh sludge kg-1 soil) and a 120 mg kg-1 Cr treatment (20 g fresh sludge kg-1 soil). Control soil and the soil treated with 10g kg-1 sludge received NPK fertilizer in the form of ammonium sulfate, superfosfate, and KCl to rise the N,P, and K concentrations to similar levels to those achieved in the

  11. Mobility of Arsenic and Heavy Metals in a Sandy-Loam Textured and Carbonated Soil



    The continued effect of the pyrite-tailing oxidation on the mobility of arsenic,lead,zinc,cadmium,and copper was studied in a carbonated soil under natural conditions,with the experimcntal plot preserved with a layer of tailing covering the soil during three years.The experimental area is located in Southern Spain and was affected by a pyrite-mine spill.The climate in the area is typically Mediterranean,which determines the rate of soil alteration and element mobility.The intense alteration processes that occurred in the soil during three years caused important changes in its morphology and a strong degradation of the main soil properties.In this period,lead concentrated in the first 5 mm of the soil,with concentrations higher than 1500 mg kg-1,mainly associated to the neoformation of plumbojarosite.Arsenic was partially leached from the first 5 mm and mainly concentrated between 5-10 mm in the soil,with maximum values of 1 239 mg kg-1;the retention of arsenates was related to the neoformation of iron hydroxysulfates (jarosite,schwertmannite) and oxyhydroxides (goethite,ferrihydrite),both with a variable degree of crystallinity.The mobility of Zn,Cd,and Cu was highly affected by pH,producing a stronger leaching in depth;their retention was related to the forms of precipitated aluminium and,in the case of Cu,also to the neoformation of hydroxysulfate.

  12. Phytotoxicity and uptake of nitroglycerin in a natural sandy loam soil.

    Rocheleau, Sylvie; Kuperman, Roman G; Dodard, Sabine G; Sarrazin, Manon; Savard, Kathleen; Paquet, Louise; Hawari, Jalal; Checkai, Ronald T; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I


    Nitroglycerin (NG) is widely used for the production of explosives and solid propellants, and is a soil contaminant of concern at some military training ranges. NG phytotoxicity data reported in the literature cannot be applied directly to development of ecotoxicological benchmarks for plant exposures in soil because they were determined in studies using hydroponic media, cell cultures, and transgenic plants. Toxicities of NG in the present studies were evaluated for alfalfa (Medicago sativa), barnyard grass (Echinochloa crusgalli), and ryegrass (Lolium perenne) exposed to NG in Sassafras sandy loam soil. Uptake and degradation of NG were also evaluated in ryegrass. The median effective concentration values for shoot growth ranged from 40 to 231 mg kg(-1) in studies with NG freshly amended in soil, and from 23 to 185 mg kg(-1) in studies with NG weathered-and-aged in soil. Weathering-and-aging NG in soil did not significantly affect the toxicity based on 95% confidence intervals for either seedling emergence or plant growth endpoints. Uptake studies revealed that NG was not accumulated in ryegrass but was transformed into dinitroglycerin in the soil and roots, and was subsequently translocated into the ryegrass shoots. The highest bioconcentration factors for dinitroglycerin of 685 and 40 were determined for roots and shoots, respectively. Results of these studies will improve our understanding of toxicity and bioconcentration of NG in terrestrial plants and will contribute to ecological risk assessment of NG-contaminated sites.

  13. Analysis of different management systems for water and soil conservation in experimental plots of "macauba" (Acrocomia aculeata) in Araponga (MG, Brazil)

    Batista Lúcio-Correa, João; Cristina-Tonello, Kelly; Taguas, Encarnación V.; Texeira-Dias, Herly C.


    In Brazil, the conservation of water resources and agricultural soil are key environmental and economic aspects to mantain land services and the quality of life people in rural and urban communities. The macaw - Acrocomia aculeata) (Jacq.) Lodd. (Ex Martius) - is a Brazilian native oleaginous palm, whose potential has been highlighted in the scientific community due to its high economic potential and its recent advances in crop farming. This study aims to quantify the runoff in macaw plantation, comparing different techniques of crop management for a period of one year (from September 2012 to August 2013). The data from this study were collected in the Experimental Farm of the Federal University of Viçosa (UFV) located in the municipality of Araponga, MG, Brazil. The seedlings took place in February 2009, in holes, spaced 5X5 in an area of 1.7 ha (680 plants) with a slope of 25%. Rainfall was monitored through three pluviometers with expose area of 162.86 cm² whereas the impact of different management systems on runoff was measured by using 10 plots of 63 m² each: 3 treatments with three repetitions plus the control plot. Each plot presented four macaw plants. The treatment one (T1), was formed by macaw plants without using any soil conservation technique; the treatment two (T2) consisted of macaws with a contour cord with 40 cm wide by 30 cm deep, located between the plantation lines; for the treatment three (T3) beans were planted forming vegetation strips; the control (T0) was represented by a portion without macaws plants, with spontaneous vegetation growing throughout the plot, which was not used any soil conservation technique. T2 presented the lowest values of runoff during the twelve months and at the same time, the greatest requirements of initial rainfall for runoff generation. In contrast, T3 showed the highest volumes of runoff for the study period, with a small reduction with the exception of January and February 2013, when the bean plants were well

  14. Dolomite application to acidic soils: a promising option for mitigating N2O emissions.

    Shaaban, Muhammad; Peng, Qi-An; Hu, Ronggui; Wu, Yupeng; Lin, Shan; Zhao, Jinsong


    Soil acidification is one of the main problems to crop productivity as well as a potent source of atmospheric nitrous oxide (N2O). Liming practice is usually performed for the amelioration of acidic soils, but the effects of dolomite application on N2O emissions from acidic soils are still not well understood. Therefore, a laboratory study was conducted to examine N2O emissions from an acidic soil following application of dolomite. Dolomite was applied to acidic soil in a factorial design under different levels of moisture and nitrogen (N) fertilizer. Treatments were as follows: dolomite was applied as 0, 1, and 2 g kg(-1) soil (named as CK, L, and H, respectively) under two levels of moisture [i.e., 55 and 90 % water-filled pore space (WFPS)]. All treatments of dolomite and moisture were further amended with 0 and 200 mg N kg(-1) soil as (NH4)2SO4. Soil properties such as soil pH, mineral N (NH4 (+)-N and NO3 (-)-N), microbial biomass carbon (MBC), dissolved organic carbon (DOC), and soil N2O emissions were analyzed throughout the study period. Application of N fertilizer rapidly increased soil N2O emissions and peaked at 0.59 μg N2O-N kg(-1) h(-1) under 90 % WFPS without dolomite application. The highest cumulative N2O flux was 246.32 μg N2O-N kg(-1) under 90 % WFPS without dolomite addition in fertilized soil. Addition of dolomite significantly (p ≤ 0.01) mitigated N2O emissions as soil pH increased, and H treatment was more effective for mitigating N2O emissions as compared to L treatment. The H treatment decreased the cumulative N2O emissions by up to 73 and 67 % under 55 and 90 % WFPS, respectively, in fertilized soil, and 60 and 68 % under 55 and 90 % WFPS, respectively, in unfertilized soil when compared to those without dolomite addition. Results demonstrated that application of dolomite to acidic soils is a promising option for mitigating N2O emissions.

  15. Dissipation of S-metolachlor in plant and soil and effect on enzymatic activities.

    Wołejko, Elżbieta; Kaczyński, Piotr; Łozowicka, Bożena; Wydro, Urszula; Borusiewicz, Andrzej; Hrynko, Izabela; Konecki, Rafał; Snarska, Krystyna; Dec, Dorota; Malinowski, Paweł


    The present study aimed at evaluating the dissipation of S-metolachlor (S-MET) at three doses in maize growing on diverse physico-chemical properties of soil. The effect of herbicide on dehydrogenase (DHA) and acid phosphatase (ACP) activity was estimated. A modified QuEChERS method using LC-MS/MS has been developed. The limit of quantification (0.001 mg kg(-1)) and detection (0.0005 mg kg(-1)) were very low for soil and maize samples. The mean recoveries and RSDs for the six spiked levels (0.001-0.5 mg kg(-1)) were 91.3 and 5.8%. The biggest differences in concentration of S-MET in maize were observed between the 28th and 63rd days. The dissipation of S-MET in the alkaline soil was the slowest between the 2nd and 7th days, and in the acidic soil between the 5th and 11th days. DT50 of S-MET calculated according to the first-order kinetics model was 11.1-14.7 days (soil) and 9.6-13.9 days (maize). The enzymatic activity of soil was higher in the acidic environment. One observed the significant positive correlation of ACP with pH of soil and contents of potassium and magnesium and negative with contents of phosphorus and organic carbon. The results indicated that at harvest time, the residues of S-MET in maize were well below the safety limit for maize. The findings of this study will foster the research on main parameters influencing the dissipation in maize ecosystems.

  16. Using Lead Concentrations and Stable Lead Isotope Ratios to Identify Contamination Events in Alluvial Soils

    Diane Saint-Laurent


    Full Text Available Soils contaminated with hydrocarbons (C10–C50, polycyclic aromatic hydrocarbons (PAHs, and other contaminants (e.g., As, Cd, Cu, Pb were recently discovered on the banks of the Saint-François and Massawippi rivers. Alluvial soils are contaminated over a distance of 100 kilometers, and the level of the contaminated-hydrocarbon layer in the soil profiles is among the highest at the Windsor and Richmond sites. Concentrations of lead and stable lead isotope ratios (204Pb/206Pb, 207Pb/206Pb, 208Pb/206Pb are also used to identify contamination events. The maximum and minimum values detected in soil profiles for arsenic, cadmium, and lead vary from 3.01 to 37.88 mg kg-1 (As, 0.11 to 0.81 mg kg-1 (Cd 12.32 to 149.13 mg kg-1 (Pb, respectively, while the 207Pb/206Pb isotopic ratio values are between 0.8545 and 0.8724 for all the profiles. The highest values of trace elements (As, Pb and Zn were detected in the hydrocarbon layer (C10–C50, most often located at the bottom of the profiles (160, 200, and 220 cm in depth. The various peaks recorded in the soils and the position of the profiles suggest that various contaminants were transported by the river on several occasions and infiltrated the soil matrix or deposited on floodplains during successive floods. Atmospheric particles which entered the river or deposited on riverbanks must also be considered as another source of pollution recorded in soils.

  17. Nitric oxide and greenhouse gases emissions following the application of different cattle slurry particle size fractions to soil

    Fangueiro, David; Coutinho, João; Cabral, Fernanda; Fidalgo, Paula; Bol, Roland; Trindade, Henrique


    The application to soil of different slurry particle size fractions may lead to variable gaseous soil emissions and associated differential environmental impacts. An incubation experiment was carried out during 70 d to assess the influence on nitric oxide (NO) and greenhouse gas (GHG; i.e. nitrous oxide, carbon dioxide and methane) emissions following incorporation of 4 particle size fractions, obtained through laboratorial separation from cattle slurry, to agricultural sandy loam soil (Dystric Cambisol). The response to these applied slurry fractions (>2000 μm, 2000-500 μm, 500-100 μm, emissions (6.3 mg NO-N kg -1 dry soil) were observed from the AS treatment. The cumulated amount of NO emitted (˜1 mg NO-N kg -1 dry soil) was not significantly different between slurry fractions, thereby indicating that slurry particle size had no effect on NO emissions. The largest slurry fraction (>2000 μm) induced significantly higher N 2O emissions (1.8 mg N 2O-N kg -1 dry soil) compared to the other smaller sized fractions (1.0 mg N 2O-N kg -1 dry soil). The >2000 μm, fraction, being more than 55% of the slurry by weight, was the major contributor to daily and cumulative N 2O emissions. Hence, for N 2O, the application of WS to agricultural soil is a better option that amendment with the >2000 μm, fraction. Low CH 4 emissions (emissions were short-lived and rates returned to control levels within 3 d after the slurry application. Higher CO 2 emissions were observed in soils amended with slurry fractions when compared to application with whole slurry. Clearly, slurry separation can increase soil CO 2 emissions relative to whole slurry application. Overall, N 2O contributed 10-30% to total GHG emissions, while that of methane was negligible. The present study suggested that mechanical separation of slurry into fractions and targeted application of the finest fractions to soil is a potential suitable management tool to reduce GHG emissions. However, the largest fractions

  18. Reflectance spectroscopy: a tool for predicting the risk of iron chlorosis in soils

    Cañasveras, J. C.; Barrón, V.; Del Campillo, M. C.; Viscarra Rossel, R. A.


    Chlorosis due to iron (Fe) deficiency is the most important nutritional problem a plant can have in calcareous soils. The most characteristic symptom of Fe chlorosis is internervial yellowing in the youngest leaves due to a lack of chlorophyll caused by a disorder in Fe nutrition. Fe chlorosis is related with calcium carbonate equivalent (CCE), clay content and Fe extracted with oxalate (Feo). The conventional technique for determining these properties and others, based on laboratory analysis, are time-consuming and costly. Reflectance spectroscopy (RS) is a rapid, non-destructive, less expensive alternative tool that can be used to enhance or replace conventional methods of soil analysis. The aim of this work was to assess the usefulness of RS for the determination of some properties of Mediterranean soils including clay content, CCE, Feo, cation exchange capacity (CEC), organic matter (OM) and pHw, with emphasis on those with a specially marked influence on the risk of Fe chlorosis. To this end, we used partial least-squares regression (PLS) to construct calibration models, leave-one-out cross-validation and an independent validation set. Our results testify to the usefulness of qualitative soil interpretations based on the variable importance for projection (VIP) as derived by PLS decomposition. The accuracy of predictions in each of the Vis-NIR, MIR and combined spectral regions differed considerably between properties. The R2adj and root mean square error (RMSE) for the external validation predictions were as follows: 0.83 and 37 mg kg-1 for clay content in the Vis-NIR-MIR range; 0.99 and 25 mg kg-1 for CCE, 0.80 and 0.1 mg kg-1 for Feo in the MIR range; 0.93 and 3 cmolc kg-1 for CEC in the Vis-NIR range; 0.87 and 2 mg kg-1 for OM in the Vis-NIR-MIR range, 0.61 and 0.2 for pHw in the MIR range. These results testify to the potential of RS in the Vis, NIR and MIR ranges for efficient soil analysis, the acquisition of soil information and the assessment of the

  19. Soil organic matter and fertility of anthropogenic dark earths (Terra Preta de Índio in the Brazilian Amazon basin Matéria orgânica e fertilidade de solos antropogênicos (Terra Preta De Índio da Bacia Amazônica brasileira

    Tony Jarbas Ferreira Cunha


    Full Text Available Fertility properties, total C (Ctot, and chemical soil organic matter fractions (fulvic acid fraction - FA, humic acid fraction - HA, humin fraction - H of anthropogenic dark earths (Terra Preta de Índio of the Amazon basin were compared with those of Ferralsols with no anthropogenic A horizon. Terra Preta soils had a higher fertility (pH: 5.1-5.4; Sum of bases, SB: 8.93-10.33 cmol c kg-1 , CEC: 17.2-17.5 cmol c kg-1 , V: 51-59 %, P: 116-291 mg kg-1 and Ctot (44.6-44.7 g kg-1 than adjacent Ferralsols (pH: 4.4; SB: 2.04 cmol c kg-1, CEC: 9.5 cmol c kg-1, V: 21 %, P 5 mg kg-1, C: 37.9 g kg-1. The C distribution among humic substance fractions (FA, HA, H in Terra Preta soils was also different, as shown by the ratios HA:FA and EA/H (EA=HA+FA (2.1-3.0 and 1.06-1.08 for Terra Preta and 1.2 and 0.72 for Ferralsols, respectively. While the cation exchange capacity (CEC, of Ferralsols correlated with FA (r = 0.97, the CEC of Terra Preta correlated with H (r = 0.82. The correlation of the fertility of Terra Preta with the highly stable soil organic matter fraction (H is highly significant for the development of sustainable soil fertility management models in tropical ecosystems.Propriedades de fertilidade, carbono total (Ctot e frações químicas da matéria orgânica (fração ácidos fúlvicos - FA, fração ácidos húmicos - HA e fração humina - HUM foram comparados entre solos antrópicos (Terra Preta de Índio e Latossolos sem horizonte A antrópico. Os solos antrópicos apresentaram maior fertilidade (pH: 5,1-5,4; S: 8,93-10,33 cmol c kg-1 ; CEC: 17,2-17,5 cmol c kg-1 ; V: 51-59 %; P: 116-291 mg kg-1 e maiores teores de carbono total (44,6-44,7 g kg-1 que os Latossolos (pH: 4,4; S: 2,04 cmol c kg-1; CEC: 9,5 cmol c kg-1; V: 21 %, P: 5 mg kg-1, Ctot: 37,9 g kg-1. Os solos antrópicos também tiveram distribuição diferenciada de C entre as frações das substâncias húmicas (FA, HÁ e HUM, expressa pelas razões HA:FA e EA:HUM (EA = HA + FA

  20. [Chlorine speciation and concentration in cultivated soil in the northeastern China studied by X-ray absorption near edge structure].

    Li, Jing; Lang, Chun-Yan; Ma, Ling-Ling; Xu, Dian-Dou; Zheng, Lei; Lu, Yu-Nanz; Cui Li-Rui; Zhang, Xiao-Meng


    A procedure has been proposed to determine chlorine speciation and concentration in soil with X-ray absorption near edge structure (XANES), and this method was applied to study the cultivated soil (bog, dark brown and black cultivated soil) in the Northeastern China. Qualitative analysis was carried out by least-squares fitting of sample spectra with standard spectra of three model compounds (NaCl, 3-chloropropionic acid, chlorophenol red). Linear correlation between the absolute fluorescence intensity of a series of NaCl standards and the Cl concentration was used as quantification standard for measuring the total Cl concentration in samples. The detection limits,relative standard deviation (RSD), recoveries were 2 mg · kg(-1), 0%-5% and 77%-133%, respectively. The average concentration of total Cl was 19 mg · kg(-1). The average relative content was as high as 61% of organochlorine with the concentration of 1-2 times as high as the concentration of inorganic chloride. The distribution trend of the total Cl, inorganic chloride and organic chlorine in different types of soil was: bog arable soil > dark brown soil > black soil. In conclusion, XANES is a reliable method to nondestructively characterize the speciation and concentration of chlorine in soil, which would provide some basic data for the future study of the chlorine's biogeochemical transformations.

  1. Removal of Anthracene and Fluoranthene by Waxy Corn, Long Bean and Okra in Lead-Contaminated Soil.

    Somtrakoon, Khanitta; Chouychai, Waraporn; Lee, Hung


    The ability of waxy corn, long bean and okra to remove two polycyclic aromatic hydrocarbons (PAHs) from soil containing 0.63 mg Pb kg(-1) dry soil was assessed. The presence of Pb did not reduce the ability of these plants to remove the PAHs from soil. About 49 % of anthracene and 77 % of fluoranthene were removed from Pb-spiked or non-spiked soil, respectively, after 30 days. Among the plants, okra was the most efficient at removing anthracene and fluoranthene in the presence or absence of Pb in soil after 30 days. Pb did not affect fluoranthene removal, but stimulated the removal of anthracene, by long bean, waxy corn and okra. However, growth of long bean and waxy corn was poor in Pb-spiked soil and waxy corn plants died around 22 days after transplantation. The results show some promise in using plants to remove PAHs from soil which is also co-contaminated with Pb.

  2. [Vertical distribution of soil active carbon and soil organic carbon storage under different forest types in the Qinling Mountains].

    Wang, Di; Geng, Zeng-Chao; She, Diao; He, Wen-Xiang; Hou, Lin


    Adopting field investigation and indoor analysis methods, the distribution patterns of soil active carbon and soil carbon storage in the soil profiles of Quercus aliena var. acuteserrata (Matoutan Forest, I), Pinus tabuliformis (II), Pinus armandii (III), pine-oak mixed forest (IV), Picea asperata (V), and Quercus aliena var. acuteserrata (Xinjiashan Forest, VI) of Qinling Mountains were studied in August 2013. The results showed that soil organic carbon (SOC), microbial biomass carbon (MBC), dissolved organic carbon (DOC), and easily oxidizable carbon (EOC) decreased with the increase of soil depth along the different forest soil profiles. The SOC and DOC contents of different depths along the soil profiles of P. asperata and pine-oak mixed forest were higher than in the other studied forest soils, and the order of the mean SOC and DOC along the different soil profiles was V > IV > I > II > III > VI. The contents of soil MBC of the different forest soil profiles were 71.25-710.05 mg x kg(-1), with a content sequence of I > V > N > III > II > VI. The content of EOC along the whole soil profile of pine-oak mixed forest had a largest decline, and the order of the mean EOC was IV > V> I > II > III > VI. The sequence of soil organic carbon storage of the 0-60 cm soil layer was V > I >IV > III > VI > II. The MBC, DOC and EOC contents of the different forest soils were significanty correlated to each other. There was significant positive correlation among soil active carbon and TOC, TN. Meanwhile, there was no significant correlation between soil active carbon and other soil basic physicochemical properties.

  3. Effect of Cl— on Behavior of Fertilizer Nitrogen, Number of Microorganisms and Enzyme Activities in Soils



    Pot experiments were conducted to study the effect of Cl- on transformation of fertilizer N,number of microorganisms and enzyme activities in soils.It is indicated that Cl- did not show significant influence on total number of bacteria,actinomyces and fungi,but significantly reduced the number of nitrosolbacteria, which led to decrease of NO3- content in the soil.Application of Cl- to soil could significantly enhance the adtivities of phosphatase and urease in the coastal saline soil and orthic aquisols,In hilly red soil,however,the application of Cl-1 at the rate of 500-1000mg Cl- kg-1 soil significantly decreased the activity of the two enzymes mentioned above.

  4. 西藏土壤中铜含量及分布%Content and distribution of copper in soils of Tibet.

    张晓平; 张玉霞; 王晶


    Cu content in soils sampled from different sites in Tibet was analyzed. The results showed that the average Cu content of soils was 19.6mg@ kg-1, lower than the average content in China. The content of Cu was distributed in Tibet with a total of gradually decreasing from the southeast to the northwest, which was consistent with the direction of change in the zonal successions of soil in Tibet. The variation of the content of Cu in the soils developed from different soil parent materials in Tibet was very remarkable, and the content of Cu in the soil developed from shale was greatly higher than that in the soil developed from other soil parent material.

  5. Influence of pH and soil copper on adsorption of metalaxyl and penconazole by the surface layer of vineyard soils.

    Arias, M; Paradelo, M; López, E; Simal-Gándara, J


    The upper horizons of old vineyard soils have substantial copper contents due to the traditional use of copper-based fungicides. Total copper levels in eight vineyard soils in the Rías Baixas area of Galicia (northwestern Spain) ranged from 60 to 560 mg kg(-1) (mean +/- SD = 206 +/- 170 mg kg(-1)). The adsorption of the fungicides metalaxyl (pK(a) = 1.41) and penconazole (pK(a) = 2.83) by these soils was determined using fungicide solutions of pH 2.5 and 5.5, and desorption of fungicide adsorbed at pH 5.5 was also determined. In all cases, Freundlich equations were fitted to the data with R (2) > 0.96. Penconazole was adsorbed and retained more strongly than metalaxyl, with K(F) values more than an order of magnitude greater. In the desorption experiments, both fungicides exhibited hysteresis. Soil copper content hardly affected the adsorption of metalaxyl, but K(F) values for adsorption of penconazole increased at a rate of about 0.1 mL(n) (microg of penconazole)(1-n) (microg of Cu)(-1), which is attributed to the formation of Cu(2+)-penconazole complexes with greater affinity for soil colloids than penconazole itself. Because the dependence of K(F) for penconazole adsorption on copper content was the same at both pH values, complex formation appears not to have been affected by the solubilization of 6-17% of soil copper at pH 2.5. A similar copper dependence, or lack of dependence, was observed when 100-1000 mg kg(-1) of copper was added as Cu(NO(3))(2).2H(2)O to the solutions from which the fungicides were adsorbed.

  6. Alleviation of Copper Toictiy to Maize by Phosphours Fertilizer in Purple Soil



    A pot experiment was conducted to evaluate the effects of phosphours fertilizer in inhibiting the copper toxicity to maizce(Zea mays L.) in neutral purple soil.Results indicated that the growth of the shoot and roots of maize plant was obviously reduced by copper and the height and biomass were significantly negatively correlated to the application levels of copper(r=-0.899**--0.994**) at no P and low P(100 mg kg-1).However,the maize biomass was relatively increased and the high Cu(100 and 200 mg kg-1) induced toxicity of maize was greatly alleviated in all treatments with medium P( 300mg kg-1) and high P (500mg kg-1). to maintain the normal growth of miaze plant(≥3.68 g pot-1),the critical application rates of phosphours fertilizer shouled be 160,210,300 and 500 mg P kg-1 at 10,50,100 and 200mg Cu kg-1 levels of the soil,respectively,The increases in polyphenol oxdase and catalase activities in maize leaf and dehydrogenase activity in roots by phosphorus fertilizer were in the order of medium P>high P>low P>no P.Activites of polyphenol oxidase an catalase were significantly positively correlated to the application levels of copper(r=0.892**-0.924**),whereas that of edhydrogenase was just rvers(r=-0.966**) at no P.Medium and high P represed the influence of copper on activities of three enzymes.Phosphorus fertilizer reduced the copper concentrations of maize roots and leaf and the change ranges of the P/Cu ratio of miaze roots and the P/Cu,N/Cu and K/Cu ratios of maize leaf ,The three ratios of maize leaf were 253±71.5 ,2643±839 and 1133±440 at normal growth of maize plant. respectively,Soil avaiable Cu could be markedly cut down by application of phosphours fertilizer ,especiallly at hight phosphorus level.

  7. Responses of lucerne (Medicago sativa L.) and rhizobia to copper-based fungicide application in two contrasting soils

    Schneider, Martin; Dober, Melanie; Jöchlinger, Lisa; Keiblinger, Katharina; Soja, Gerhard; Mentler, Axel; Zechmeister-Boltenstern, Sophie; Bruckner, Alexander; Golestani Fard, Alireza; Wenzel, Walter; Zehetner, Franz


    For more than 120 years, salts of copper (Cu) have been used in viticulture to prevent damages by fungal diseases. Due to restrictions in the use of synthetic fungicides and mineral fertilizers, organic viticulture depends on Cu as well as on biological nitrogen fixation. Here, we conducted an eco-toxicological pot experiment with an acidic, sandy soil and a calcareous, loamy soil and incrementally increasing fungicide application rates from 0 to 5000 mg Cu kg-1 soil. Lucerne (Medicago sativa L. cultivar. Plato) was grown in the pots for 3 months under greenhouse conditions. Acetylene reduction assays performed with harvested nodules showed no response to elevated soil Cu concentrations indicating that the nitrogen fixing capacity of rhizobia was not compromised by Cu in our experiment. Nevertheless, the nodule biomass was very sensitive to Cu and strongly decreased due to reduced amounts of fine roots and less energy supply by the plant. Legumes are known to be Cu-sensitive, and our contribution also showed a decrease in harvest by 50 % (EC50) at 21 mg kg-1 plant Cu tissue concentration in the acidic soil and at 30 mg kg-1 in the calcareous soil. This corresponded to diffusional fluxes measured by diffusive gradients in thin films (DGT) of 202 and 368 fmol cm-2 s-1, respectively. DGT measurements showed that in the acidic soil, Cu was 2 to 10 times more available for plants, depending on the concentration applied, than in the calcareous soil. A modeling approach for estimating the effective concentration (EC) by including the DGT-estimated plant Cu content and the pH produced more accurate values (NRMSE of 21.9 to 20.1 %) than EC directly estimated from DGT.


    Jean Dalmo de Oliveira Marques


    Full Text Available Organic matter plays an important role in many soil properties, and for that reason it is necessary to identify management systems which maintain or increase its concentrations. The aim of the present study was to determine the quality and quantity of organic C in different compartments of the soil fraction in different Amazonian ecosystems. The soil organic matter (FSOM was fractionated and soil C stocks were estimated in primary forest (PF, pasture (P, secondary succession (SS and an agroforestry system (AFS. Samples were collected at the depths 0-5, 5-10, 10-20, 20-40, 40-60, 60-80, 80-100, 100-160, and 160-200 cm. Densimetric and particle size analysis methods were used for FSOM, obtaining the following fractions: FLF (free light fraction, IALF (intra-aggregate light fraction, F-sand (sand fraction, F-clay (clay fraction and F-silt (silt fraction. The 0-5 cm layer contains 60 % of soil C, which is associated with the FLF. The F-clay was responsible for 70 % of C retained in the 0-200 cm depth. There was a 12.7 g kg-1 C gain in the FLF from PF to SS, and a 4.4 g kg-1 C gain from PF to AFS, showing that SS and AFS areas recover soil organic C, constituting feasible C-recovery alternatives for degraded and intensively farmed soils in Amazonia. The greatest total stocks of carbon in soil fractions were, in decreasing order: (101.3 Mg ha-1 of C - AFS > (98.4 Mg ha-1 of C - FP > (92.9 Mg ha-1 of C - SS > (64.0 Mg ha-1 of C - P. The forms of land use in the Amazon influence C distribution in soil fractions, resulting in short- or long-term changes.


    孙玉焕; 骆永明; 滕应; 李振高


    未经处理的污泥农业利用后,不仅会增加土壤中污染物的含量,而且会威胁人类和其他生物的健康.室内培养试验结果表明,污泥中的重金属进入土壤后,表现出先释放,后固定的变化趋势,而且随培养时间的增加,施污泥土壤中EDTA和CaCl_2提取态Cu和Zn含量逐渐增加,150 d时其含量达到最高.与对照处理相比,施污泥土壤中EDTA提取态Cu和Zn含量分别增加了21.4 mg kg~(-1)和26.1 mg kg~(-1),而CaCl_2提取态Cu和Zn含量分别增加了0.10 mg kg~(-1)和3.37 mg kg~(-1).重金属不合格的污泥农业利用存在一定程度的重金属污染风险, 且其风险大小与土壤类型、污泥种类和培养时间及污泥的土壤施用量等因素密切相关.选择适宜的土壤类型、污泥种类、施用时间及控制污泥施用量等,能够在一定程度上降低污泥中重金属农业利用的环境风险.%Concentrations of pollutants will increase if sewage sludge is applied to soil, thus posing a risk to the health of human. An incubation experiment was carried out with results showing that concentrations of EDTA and CaCl_2 extracted Cu and Zn in the sludge-amended soils increased with time and reached to maximum 150 days after the incubation. The average concentration of EDTA-extracted Cu and Zn was 30.0 mg kg~(-1) and 30.1 mg kg~(-1), and increased by 21.4 mg kg~(-1) and 26.1 mg kg~(-1) over the control, respectively. The average concentration of CaCl_2-extracted Cu and Zn was 0.11 mg kg~(-1) and 3.65 mg kg~(-1), about 0.10 mg kg~(-1) and 3.37 mg kg~(-1) higher, respectively, than in the control. Application of sewage sludge into the soil posed a potential risk of heavy metal pollution. Soil type, sludge characteristics and application time should be taken into account simultaneously for reducing the risk of heavy metal pollution of the soil in making agricultural use of sewage sludge.

  10. Enhanced biodegradation of anthracene in acidic soil by inoculated Burkholderia sp. VUN10013.

    Somtrakoon, Khanitta; Suanjit, Sudarat; Pokethitiyook, Prayad; Kruatrachue, Maleeya; Lee, Hung; Upatham, Suchart


    The ability of Burkholderia sp. VUN10013 to degrade anthracene in microcosms of two acidic Thai soils was studied. The addition of Burkholderia sp. VUN10013 (initial concentration of 10(5) cells g(-1) dry soil) to autoclaved soil collected from the Plew District, Chanthaburi Province, Thailand, supplemented with anthracene (50 mg kg(-1) dry soil) resulted in complete degradation of the added anthracene within 20 days. In contrast, under the same test conditions but using autoclaved soil collected from the Kitchagude District, Chanthaburi Province, Thailand, only approximately 46.3% of the added anthracene was degraded after 60 days of incubation. In nonautoclaved soils, without adding the VUN10013 inocula, 22.8 and 19.1% of the anthracene in Plew and Kitchagude soils, respectively, were degraded by indigenous bacteria after 60 days. In nonautoclaved soil inoculated with Burkholderia sp. VUN10013, the rate and extent of anthracene degradation were considerably better than those seen in autoclaved soils or in uninoculated nonautoclaved soils in that only 8.2 and 9.1% of anthracene remained in nonautoclaved Plew and Kitchagude soils, respectively, after 10 days of incubation. The results showed that the indigenous microorganisms in the pristine acidic soils have limited ability to degrade anthracene. Inoculation with the anthracene-degrading Burkholderia sp. VUN10013 significantly enhanced anthracene degradation in such acidic soils. The indigenous microorganisms greatly assisted the VUN10013 inoculum in anthracene degradation, especially in the more acidic Kitchagude soil.

  11. Modification of soil microbial activity and several hydrolases in a forest soil artificially contaminated with copper

    Bellas, Rosa; Leirós, Mā Carmen; Gil-Sotres, Fernando; Trasar-Cepeda, Carmen


    Soils have long been exposed to the adverse effects of human activities, which negatively affect soil biological activity. As a result of their functions and ubiquitous presence microorganisms can serve as environmental indicators of soil pollution. Some features of soil microorganisms, such as the microbial biomass size, respiration rate, and enzyme activity are often used as bioindicators of the ecotoxicity of heavy metals. Although copper is essential for microorganisms, excessive concentrations have a negative influence on processes mediated by microorganisms. In this study we measured the response of some microbial indicators to Cu pollution in a forest soil, with the aim of evaluating their potential for predicting Cu contamination. Samples of an Ah horizon from a forest soil under oakwood vegetation (Quercus robur L.) were contaminated in the laboratory with copper added at different doses (0, 120, 360, 1080 and 3240 mg kg-1) as CuCl2×2H2O. The soil samples were kept for 7 days at 25 °C and at a moisture content corresponding to the water holding capacity, and thereafter were analysed for carbon and nitrogen mineralization capacity, microbial biomass C, seed germination and root elongation tests, and for urease, phosphomonoesterase, catalase and ß-glucosidase activities. In addition, carbon mineralization kinetics were studied, by plotting the log of residual C against incubation time, and the metabolic coefficient, qCO2, was estimated. Both organic carbon and nitrogen mineralization were lower in polluted samples, with the greatest decrease observed in the sample contaminated with 1080 mg kg-1. In all samples carbon mineralization followed first order kinetics; the C mineralization constant was lower in contaminated than in uncontaminated samples and, in general, decreased with increasing doses of copper. Moreover, it appears that copper contamination not only reduced the N mineralization capacity, but also modified the N mineralization process, since in

  12. Biotransformation and accumulation of arsenic in soil amended with seaweed.

    Castlehouse, Hayley; Smith, Cassandra; Raab, Andrea; Deacon, Claire; Meharg, Andrew A; Feldmann, Jörg


    For many coastal regions of the world, it has been common practice to apply seaweed to the land as a soil improver and fertilizer. Seaweed is rich in arsenosugars and has a tissue concentration of arsenic up to 100 micro/g g(-1). These arsenic species are relatively nontoxic to humans; however, in the environment they may accumulate in the soil and decompose to more toxic arsenic species. The aim of this study was to determine the fate and biotransformation of these arsenosugars in soil using HPLC-ICP-MS analysis. Data from coastal soils currently manured with seaweeds were used to investigate if arsenic was accumulating in these soils. Long-term application of seaweed increased arsenic concentrations in these soils up to 10-fold (0.35 mg of As kg(-1) for nonagronomic peat, 4.3 mg of As kg(-1) for seaweed-amended peat). The biotransformation of arsenic was studied in microcosm experiments in which a sandy (machair) soil, traditionally manured with seaweed, was amended with Laminaria digitata and Fucus vesiculosus. In both seaweed species, the arsenic occurs in the form of arsenosugars (85%). The application of 50 g of seaweed to 1 kg of soil leads to an increase of arsenic in the soils, and the dominating species found in the soil pore water were dimethylarsinic acid (DMA(V)) and the inorganic species arsenate (As(V)) and arsenite (As(III)) after the initial appearance of arsenosugars. A proposed decomposition pathway of arsenosugars is discussed in which the arsenosugars are transformed to DMA(V) and further to inorganic arsenic without appreciable amounts of methylarsonic acid (MA(V)). Commercially available seaweed-based fertilizers contain arsenic concentration between 10 and 50 mg kg(-1). The arsenic species in these fertilizers depends on the manufacturing procedure. Some contain mainly arsenosugars while others contain mainly DMA(V) and inorganic arsenic. With the application rates suggested by the manufacturers, the application of these fertilizers is 2

  13. Does the Total Soil N Determined by Kjeldahl Method Include Fixed NH4+?

    ZHANG Chong-yu; LI Sheng-xiu


    Forty soils from top layer (0-20 cm) were sampled in different regions of China and Kjeldahl, HF-Kjeldahl and double treatment methods were used to determine total N, total N plus fixed ammonium, and total N and the residual fixed ammonium left in soil after determination of total N, respectively, to evaluate if Kjeldahl's method could include the fixed N by soil minerals. The fixed N by soil minerals was measured by Silva-Bremner procedure to make comparison. Results showed that total N determined by Kjeldahl's method averaged 1.622 g kg-1, while that by HF- Kjeldahl's method 1.633 g kg-1, and that by double procedure 1.666 g kg-1. Obviously results obtained by the last two methods, particularly the double treatment method, were higher than Kjeldahl's, showing that Kjeldahl's method could not or not fully release N fixed by 2:1 minerals in soil, and therefore the determined results would not be the true "total N" for soils that contained large amount of the fixed N. The mineral fixed N averaged 166 mg kg-1, accounting for 10.1% of the total N while the residual fixed N amounted to 30.4 mg kg-1, equivalent to 1.9% of the total N or 18.3% of the total fixed N. The residual fixed N was correlated neither to organic matter nor to total N, but closely related to the total fixed N with a correlation coefficient of 0.598 (n=40), showing that the fixed N was the sole source of the residues. Soils having high residues of the fixed N were just those containing high fixed N, and soils containing high fixed N were just those containing high amount of 2:1minerals. As a result, Kjeldahl's method could not give a true value of the total N for such soils. However, for those containing small or little amount of 2:1 minerals, there was no significant difference in results measured by these methods.

  14. Phytoremedial assessment of flora tolerant to heavy metals in the contaminated soils of an abandoned Pb mine in Central Portugal.

    Pratas, João; Favas, Paulo J C; D'Souza, Rohan; Varun, Mayank; Paul, Manoj S


    Significant accumulation of heavy metals in soils and flora exists around the abandoned Barbadalhos Pb mine in Central Portugal. Soil and plant samples [49 species] were collected from two line transects, LT 1 and LT 2, in the mineralized and non-mineralized area, respectively to gain a comprehensive picture of heavy metals in soils and flora to assess its potential for phytoremediation. Phytosociological inventories of the vegetation were made using the Braun-Blanquet cover-abundance scale. Metal concentrations in soil ranged from (in mg kg(-1)): 98-9330 [Pb], 110-517 [Zn], 7.1-50 [Co], 69-123 [Cr], 31-193 [Cu], 33400-98500 [Fe], 7.7-51 [Ni], 0.95-13 [Ag], 2.8-208 [As], and 71-2220 [Mn] along LT 1; and 24-93 [Pb], 30-162 [Zn], 3.7-34 [Co], 61-196 [Cr], 21-46 [Cu], 24100-59400 [Fe], 17-87 [Ni], 0.71-1.9 [Ag], 4.3-12 [As], and 44-1800 [Mn] along LT 2. Plant metal content ranged from (in mg kg(-1)): 1.11-548 [Pb], 7.06-1020 [Zn], 0.08-2.09 [Co], 0.09-2.03 [Cr], 2.63-38.5 [Cu], 10.4-4450 [Fe], 0.38-8.9 [Ni], and 0.03-1.9 [Ag] along LT 1; and 0.94-11.58 [Pb], 2.83-96.5 [Zn], 0.12-1.44 [Co], 0.21-1.49 [Cr], 1.61-22.7 [Cu], 4.6-2050 [Fe], 0.51-4.81 [Ni], and 0.02-0.31 [Ag] along LT 2. Plants with highest uptake of metals were: Cistus salvifolius (548 mg Pb kg(-1)), Digitalis purpurea (1017 mg Zn kg(-1) and 4450 mg Fe kg(-1)). Mentha suavolens and Ruscus ulmifolius were seen to hyperaccumulate Ag (1.9 and 1 mg Ag kg(-1), respectively). More metals and higher concentrations were traced in plants from LT 1, especially for Pb and Zn. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Trace elements contamination of agricultural soils affected by sulphide exploitation (Iberian Pyrite Belt, Sw Spain)