Search Results for: Soil

Abstract: One of the potential environmental effects of the recent rapid increase in the global agricultural area cultivated with transgenic crops is a change in soil microbially mediated processes and functions. Among the many essential functions of soil biota are soil organic matter decomposition, nutrient mineralization and immobilization, oxidation-reduction reactions, biological N fixation, and solubilization. …

Abstract: Transgenic or genetically modified plants possess novel genes that impart beneficial characteristics such as herbicide resistance. One of the least understood areas in the environmental risk assessment of genetically modified crops is their impact on soil- and plant-associated microbial communities. The potential for interaction between transgenic plants and plant residues and the soil microbial …

Abstract: A silty loam soil was incubated with the leaves and stems of two transgenic Bacillus thuringiensis (Bt) cotton varieties and nontransgenic Bt cotton to study the soil persistence of the Bt toxin from the decomposing transgenic Bt cotton tissues and its effect on soil enzyme activities. The results showed that after Bt cotton tissue …

Abstract: Translocation of glyphosate (N-(phosphonomethyl)glycine) to plant roots and its impact on detected herbicide residues in sandy loam soil were studied in a glasshouse pot experiment in Finland. Quinoa (Chenopodium quinoa, Willd) plants in two different growing phases (6–8 and 12–14 leaf stages, groups A and B, respectively) were sprayed with non-labelled glyphosate. Bare soil …

Abstract: Pyrolysis-gas (Py-GC) chromatography was used to characterize extractable lipids from Bt and non-Bt maize shoots and soils collected at time of harvesting. Py-GC-MS (mass spectrometry) showed that the concentrations of total alkenes identified in non-Bt shoots and soils were 47.9 and 21.3% higher than in Bt maize shoots and soils, respectively. N-alkanes identified were …

Abstract: The aim of this paper was to study in laboratory the degradation and the effects on biological properties in two soils after the addition of glyphosate, diflufenican and glyphosate+diflufenican. One hundred grams of sieved soil (<2 mm) were mixed with (i) 13 mL of Zarpa® (16% glyphosate and 4% diflufenican) prepared in a water …

Abstract: Recent applications of biotechnology, especially genetic engineering, have revolutionized crop improvement and increased the availability of valuable new traits. A current example is the use of the insecticidal Cry proteins from the bacterium, Bacillus thuringiensis (Bt), to improve crops, known as Btcrops, by reducing injury from various crop pests. The adoption of genetically modified …

Abstract: The effects of montmorillonite (M) or kaolinite (K) on the vertical movement of the insecticidal Cry1Ab protein of Bacillus thuringiensis subsp. kurstaki (Bt) were studied in repacked soil columns. The protein was added to the columns either in a purified form, as root exudates from growing plants of Bt corn, or within the biomass …

Abstract: The accumulation and persistence of the insecticidal toxins from Bacillus thuringiensis may result in environmental hazards, such as toxicity to nontarget species and the selection of toxin-resistant target species. Toxins from B. thuringiensis subsp. kurstaki were added to three soils [Kitchawan soil (which contains kaolinite but not montmorillonite) unamended or amended with montmorillonite or …

Abstract: The biochemical properties of soil have often been described as early and sensitive indicators of ecological changes in both natural soil and agroecosystem. In the current study, the impacts of the amendment of Bt-transgenic rice (KMD) straw on biological activities in water-flooded soil were investigated under laboratory conditions and compared with non-transgenic rice (Xiushui …

Abstract: Following application, pesticides can be intercepted and absorbed by weeds and/or crops. Plants containing pesticides residues may then reach the soil during the crop cycle or after harvest. However, the fate in soil of pesticides residues in plants is unknown. Two commonly used foliar herbicides, glyphosate and sulcotrione, (14)C-labeled, were applied on leaves of …

Abstract: The bioavailability of glyphosate from plant residues may be high in the soil matrix. In order to determine the impact of litter contaminated with glyphosate (GLY) on the growth and cocoon production of the earthworm Pontoscolex corethrurus as well as on acid and basic phosphatase activities and soil pH, a commercial glyphosate-based herbicide was …

Abstract: Glyphosate [(N-(phosphonomethyl)glycine)] is a widely used herbicide and it is known to compete for the same sorption sites in soil as phosphorus. Persistence and losses of glyphosate were monitored in a field with low phosphorus status and possible correlation between glyphosate and phosphorus leaching losses was studied. Glyphosate and its metabolite AMPA (aminomethyl phosphonic …

Summary: 1. A field study using transgenic plants with associated recombinant micro-organisms was conducted to assess the potential effects of genetically engineered organisms on soil ecosystems. Three genotypes of alfalfa plants (parental, transgenic aamylase-producing and transgenic lignin peroxidase-producing) were planted in an agricultural field plot. Immediately prior to planting, the roots of the alfalfa plants …

Abstract: Insecticidal proteins produced by various subspecies (kurstaki, tenebrionis, and israelensis) of Bacillus thuringiensis (Bt) bound rapidly and tightly on clays, both pure mined clay minerals and soil clays, on humic acids extracted from soil, and on complexes of clay and humic acids. Binding reduced susceptibility of the proteins to microbial degradation. However, bound proteins …

Abstract: Soil properties, microbial communities, and enzyme activities were studied in soil planted with transgenic or nontransgenic papaya under field conditions. The transgenic papaya contained a replicase (RP) mutant gene of the papaya ringspot virus (PRSV), which conferred resistance to the virus, the neomycin phosphotransferase II (NPT II) marker gene, which conferred Km resistance, and …

Abstract: An important aspect of the risk assessment of pesticidal transgenic plants is the potential for detrimental effects on the soil ecosystem from residual plant material following harvesting and tillage. We evaluated this concern by placing leaves of three different lines of cotton genetically engineered to produce the Bacillus thuringiensis var. kurstaki (B.t.k.) endotoxin in …

Abstract: Glyphosate and glyphosate-containing herbicides have an adverse effect on mammals, humans, and soil microbial ecosystems. Therefore, it is important to develop methods for enhancing glyphosate degradation in soil through bioremediation. We investigated the potential of glyphosate degradation and bioremediation in soil by Bacillus subtilis Bs-15. Bs-15 grew well at high concentrations of glyphosate; the …

Abstract: The aim of the experiment was to determine if temporal variations of belowground activity reflect the influence of the Cry1Ab protein from transgenic maize on soil bacteria and, hence, on a regulatory change of the microbial community (ability to metabolize sources belonging to different chemical guilds) and/or a change in numerical abundance of their …

Abstract: BACKGROUND: Repeated applications may have a greater impact on the soil microbial community than a single application of glyphosate. Experiments were conducted to study the effect of one, two, three, four or five applications of glyphosate on soil microbial community composition and glyphosate mineralization and distribution of (14)C residues in soil. RESULTS: Fatty acid …

Abstract: Bt plants are plants that have been genetically modified to express the insecticidal proteins (e.g. Cry1Ab, Cry1Ac, Cry3A) from subspecies of the bacterium, Bacillus thuringiensis (Bt), to kill lepidopteran pests that feed on corn, rice, tobacco, canola, and cotton and coleopteran pests that feed on potato. The biomass of these transgenic Bt plants (Bt+) …

Abstract: Some drinking water reservoirs under the vineyards of Burgundy are contaminated with herbicides. Thus the effectiveness of alternative soil management practices, such as grass cover, for reducing the leaching of glyphosate and its metabolite, AMPA, through soils was studied. The leaching of both molecules was studied in structured soil columns under outdoor conditions for …

Abstract: Before a genetically modified plant (GMP) can be placed on the market in the European Union (EU), an environmental risk assessment has to be conducted according to EU‐Directive 2001/18/EC or Regulation (EC) No. 1829/2003 of the European Parliament and of the Council. However, no harmonized concept for ecotoxicological testing is available today that considers …

Abstract: The widespread use of glyphosate‐resistant (GR) cropping systems may impact rhizosphere microbial associations and crop productivity. It was previously reported that glyphosate accumulation in the rhizosphere may stimulate colonization of soybean [Glycine max (L.) Merr.] roots by soilborne Fusarium. Field studies often reveal inconsistent root colonization by Fusarium, especially during growing seasons characterized by …