Estimation of Efficiency of Processing Soil Samples for Pesticide Residues Analysis

The efficiency of four sample processing methods was tested with eight different types of soils representing the major proportion of cultivated soils. The principle of sampling constant was applied for characterizing the efficiency of the procedures and testing the well-mixed status of the prepared soil. The test material was 14C-labeled atrazine that enabled keeping the random error of analyses ≤ about 1%. Adding water to the soil proved to be the most efficient and generally applicable procedure resulting in about 6% relative sample processing uncertainty for 20 g test portions. The expected error is inversely proportional to the mass of test portion. Smashing and manual mixing of soil resulted in about four times higher uncertainty than mixing with water. Grinding of soil is applicable for dry soils only, but the test procedure applied was not suitable for estimating a typical uncertainty of processing dry soil samples. Adding dry ice did not improve the efficiency of sample processing.     

Persistence and Movement of the Herbicide Propoxycarbazone-Sodium in Winter Wheat Crops

The new herbicide propoxycarbazone (sodium methyl 2-[[[(4,5-dihydro-4-methyl-5-oxo-3-propoxy-1H-1,2,4-triazole-1-yl)carbonyl]amino]sulfonyl]benzoate, 1 ) has been measured in the soil of winter wheat crops. In the soil extract, propoxycarbazone was separated from its potential soil metabolites by repeated TLC. Propoxycarbazone was methylated with diazomethane. In the GC and GC-MS apparatus, the N -methylpropoxycarbazone 2 (methyl 2-[[[(4,5-dihydro-4-methyl-5-oxo-3-propoxy-1H-1,2,4-triazole-1-yl)carbonyl]methylamino]sulfonyl]benzoate) generated N -methylsaccharin 4 (1-dioxy-2- N -methyl-3-keto-1,2-benzisothiazol) which was measured. Propoxycarbazone has been applied in the spring at the rate of 70 g ha m 1 post-emergence on winter wheat crops grown in several sites different as to their soil texture and composition. In the 0-10 cm surface soil layer of the winter wheat crops grown on sandy loam (Melle) or on clay loam (Zevekote) soils, the half-life of propoxycarbazone was 54 days. In the winter wheat crop grown on loam soil (Cortil-Noirmont), the propoxycarbazone soil half-life was 31 days. The difference between the propoxycarbazone soil half-lives at the different sites was related to the organic fertilizer treatments applied in the past. After the winter wheat harvest at the end of August, the concentration of propoxycarbazone in soil was very low at Cortil-Noirmont; at the end of September, propoxycarbazone was no more detected. At Melle and Zevekote, the concentration of propoxycarbazone in soil was very low in September, and disappeared completely at the end of October. Since the treatment and until the end of October, propoxycarbazone was not detected in the 10-15 and 15-20 cm surface soil layers of the three trials.     

When is a soil remediated? Comparison of biopiled and windrowed soils contaminated with bunker-fuel in a full-scale trial

A six month field scale study was carried out to compare windrow turning and biopile techniques for the remediation of soil contaminated with bunker C fuel oil. End-point clean-up targets were defined by human risk assessment and ecotoxicological hazard assessment approaches. Replicate windrows and biopiles were amended with either nutrients and inocula, nutrients alone or no amendment. In addition to fractionated hydrocarbon analysis, culturable microbial characterisation and soil ecotoxicological assays were performed. This particular soil, heavy in texture and historically contaminated with bunker fuel was more effectively remediated by windrowing, but coarser textures may be more amendable to biopiling. This trial reveals the benefit of developing risk and hazard based approaches in defining end-point bioremediation of heavy hydrocarbons when engineered biopile or windrow are proposed as treatment option.     

Degradation of Soil Environment in the Post‐Flooding Area: Content of Polycyclic Aromatic Hydrocarbons (PAHs) and S‐Triazine Herbicides

Impacts of flooding on the soil environment with regard to soil pollution with polycyclic aromatic hydrocarbons and s‐triazine (cyanazine, simazine, atriazine, propazine, prometryn) herbicides have been evaluated. No clear differences in the sum of the PAHs content were observed in the present studies. Only changes in the levels of individual PAHs were noted. In soils covered with flooding both at a depth of 0–20 and 20–40 high molecular weight PAHs were predominant (especially mutagenic and carcinogenic 5‐rings PAHs) whereas in non‐flooded areas, 2‐ and 3‐rings PAHs constituted over 80%. In the case of s‐triazine herbicides, no influence of flooding on the changes in their content in agriculturally used soils was noted. On the other hand, clearly lower levels of cyanazine, simazine and atriazine were not in the flooded forest soil as compared to the non‐flooded forest soil.     

Detecting Trends Using Spearman's Rank Correlation Coefficient

Spearman's rank correlation coefficient is a useful tool for exploratory data analysis in environmental forensic investigations. In this application it is used to detect monotonic trends in chemical concentration with time or space.     

Quantification of activated carbon contents in soils and sediments using chemothermal and wet oxidation methods

Activated carbon (AC) strongly sorbs organic pollutants and can be used for remediation of soils and sediments. A method for AC quantification is essential to monitor AC (re)distribution. Since AC is black carbon (BC), two methods for BC quantification were tested for AC mixed in different soils and sediments: i) chemothermal oxidation (CTO) at a range of temperatures and ii) wet-chemical oxidation with a potassium dichromate/sulfuric acid solution. For three soils, the amount of AC was accurately determined by CTO at 375 °C. For two sediments, however, much of the AC disappeared during combustion at 375 °C, which could probably be explained by catalytic effects by sediment constituents. CTO at lower temperatures (325-350 °C) was a feasible alternative for one of the sediments. Wet oxidation effectively functioned for AC quantification in sediments, with almost complete AC recovery (81-92%) and low remaining amounts of native organic carbon (5-16%).     

Spirulina platensis extract improves the production and defenses of the common bean grown in a heavy metals-contaminated saline soil

Plants have to cope with several abiotic stresses, including salinity and heavy metals (HMs). Under these stresses, several extracts have been used as effective natural biostimulants, however, the use of Spirulina platensis (SP) extract (SPE) remains elusive. The effects of SPE were evaluated as soil addition (SA) and/or foliar spraying (FS) on antioxidant defenses and HMs content of common bean grown in saline soil contaminated with HMs. Individual (40 or 80 mg SPE/hill added as SA or 20 or 40 mg SPE/plant added as FS) or integrative (SA+FS) applications of SPE showed significant improvements in the following order: SA-80+FS-40 > SA-80+FS-20 > SA-40+FS-40 > SA-40+FS-20 > SA-80 > SA-40 > FS-40 > FS-20 > control. Therefore, the integrative SA+FS with 40 mg SP/plant was the most effective treatment in increasing plant growth and production, overcoming stress effects and minimizing contamination of the edible part. It significantly increased plant growth (74%–185%) and yield (107%–227%) by enhancing net photosynthetic rate (78.5%), stomatal conductance (104%), transpiration rate (124%), and contents of carotenoids (60.0%), chlorophylls (49%–51%), and NPK (271%–366%). These results were concurrent with the marked reductions in malondialdehyde (61.6%), hydrogen peroxide (42.2%), nickel (91%–94%), lead (80%–9%), and cadmium (74%–91%) contents due to the improved contents of glutathione (87.1%), ascorbate (37.0%), and α-tocopherol (77.2%), and the activities of catalase (18.1%), ascorbate peroxidase (18.3%), superoxide dismutase (192%), and glutathione reductase (52.2%) as reinforcing mechanisms. Therefore, this most effective treatment is recommended to mitigate the stress effects of salinity and HMs on common bean production while minimizing HMs in the edible part.     

A Geochemical and Biological Basis for Marine Sediment Quality Guidelines

This document describes a basis for the establishment of marine sediment quality guidelines for regulatory applications. It outlines a geochemical basis for identifying potential anomalies in the presence of inorganic contaminants in marine sediments and a biological or ecotoxicological basis for determining concentrations unlikely to result in adverse biological effects. These approaches are discussed in an exploratory fashion. It is intended that both approaches could be combined in a manner that takes account of sedimentary nature and composition as a conceptual and practical approach to the establishment of guidelines for regulatory applications associated with the protection of the marine environment.     

Protection of Antarctic soil environments: A review of the current issues and future challenges for the Environmental Protocol

2016 marked the 25th anniversary of the Protocol on Environmental Protection to the Antarctic Treaty. Terrestrial ice-free areas constitute approximately 0.18% of Antarctica, but represent the most biologically active, historically rich, and environmentally sensitive sites. Antarctic soils are easily disturbed and environmental legacies of human activities are scattered across the continent; many are remnants of the 1950s-1980s when environmental protection was less comprehensive than today. Adoption of the Environmental Protocol in 1991 represented an important and proactive shift in Antarctic governance, securing environmental protection as a fundamental tenet of the Treaty System. Twenty five years on standards of environmental management have greatly improved, yet environmental pressures are compounding. Shortcomings in the implementation of the Environmental Protocol exist due to disparities in cultural values, operational realities, and inconsistent environmental impact assessments among governments and National Antarctic Programs. Non-native species management remains underdeveloped; and there is inadequate representation of all biogeographic regions within the Protected Area system; therefore jeopardizing conservation of Antarctic biodiversity and the integrity of the soil environment. Fundamental improvements are required to address the current shortcomings and ensure effective environmental protection for the next 25 years, including: (1) increased multinational and multidisciplinary collaboration to answer targeted research questions addressing contemporary management challenges, (2) effective communication of science to policy makers and environmental managers to inform decision- making, and (3) making the mandate of long-term monitoring of the terrestrial environment a high priority for all governments signatory to the Antarctic Treaty.