Impact of fertlizers and pesticides on soil and water quality

[ES]En la presente tesis se ha estudiado el impacto de diferentes fertilizantes y pesticidas utilizados en la Zona Vulnerable de Vitoria-Gasteiz en la calidad del suelo y las aguas de dicha zona. Se ha podido constatar que hoy en día siguen lixiviándose cantidades significativas de nitratos y pesticidas (e.g., etofumesato y difenoconazol) a las aguas de la Zona Vulnerable, durante el cultivo de remolacha azucarera (Beta vulgaris L.), muy característico de la zona de estudio. Se comprobó que el alto contenido en nitratos de las aguas subterráneas en la Zona Vulnerable es mitigado, al menos en parte, por la acción de la actividad microbiana desnitrificante que alberga la zona riparia del humedal de Salburua. Dicho proceso, sin embargo, supone la emisión a la atmósfera de importantes cantidades de gases de efecto invernadero (CO2 y N2O), y puede verse afectado negativamente por la presencia de pesticidas (e.g., deltametrina) en el medio.Por otra parte, hemos observado que diversos pesticidas (deltametrina, etofumesato, difenoconazol) aplicados en concentraciones similares a las dosis de aplicación en campo inducen cambios, de carácter limitado y transitorio, en las comunidades microbianas edáficas, siendo más significativos en el caso del fungicida difenoconazol. El efecto de los pesticidas fue más acusado a medida que aumentaba su concentración en el medio. Finalmente, encontramos que la aplicación de abonos orgánicos (avicompost), en lugar de los fertilizantes sintéticos tradicionales (NPK), además de mejorar la degradación de los pesticidas y disminuir el impacto de éstos sobre la calidad del suelo, podría ayudar a reducir las pérdidas de nitratos por lixiviación.

Pesticide Food Safety Act of 1988 [microform] : hearings before the Subcommittee on Department Operations, Research, and Foreign Agriculture of the Committee on Agriculture, House of Representatives, One Hundredth Congress, second session, on H.R. 4937, July 28 and September 7, 1988.

"Serial no. 100-99."

Federal Insecticide, Fungicide, and Rodenticide Act [microform] : hearing before the Subcommittee on Department Operations, Research, and Foreign Agriculture of the Committee on Agriculture, House of Representatives, Ninety-seventh Congress, second session, on H.R. 5203.

"Serial no. 97-R."

FIFRA extension [microform] : hearing before the Subcommittee on Agricultural Research and General Legislation of the Committee on Agriculture, Nutrition, and Forestry, United States Senate, Ninety-sixth Congress, first session, on S. 717 ... April 26, 1979.

Reuse of record except for individual research requires license from Congressional Information Service, Inc.

Vegetation Management Reform Act of 1981 [microform] : hearing before the Subcommittee on Forests, Family Farms, and Energy of the Committee on Agriculture, House of Representatives, Ninety-seventh Congress, first session, on H.R. 2900, April 16, 1981, Eugene, Oreg.

"Serial no. 97-I."

EPA pesticide regulatory program study [microform] : hearing before the Subcommittee on Department Operations, Research, and Foreign Agriculture of the Committee on Agriculture, House of Representatives, Ninety-seventh Congress, second session, December 17, 1982.

"Serial no. 97-NNNN."

Protection of man and the environment : supplemental report of the Committee on Agriculture and Forestry on H.R. 10729, Federal Environmental Pesticide Control Act of 1972.

On Federal Environmental Pesticide Control Act of 1972 to amend the Federal Insecticide, Fungicide, and Rodenticide Act.

The effects of two pesticides on Clarias gariepinus

Bioassays were carried out to determine the toxicity of two pesticides, Roundup and Gramoxone on Clarias gariepinus. The acute toxicity of both pesticides decreased towards the end of the bioassay period. The calculated safe concentrations for Roundup and Gramoxone are 0.99 ppm - 0.99 ppm and 0.09 ppm - 0.9 ppm respectively. Histological examination revealed that there were pathological changes in the gills and liver even when the fish were subjected to sub-lethal levels

The effect of pesticides on Byssus formation in the common mussel, Mytilus edulis

Seed mussels (Mytilus edulis) were exposed to a range of pesticides and PCBs, several of which caused a reduction in byssal attachment at higher concentrations. In queen scallops (Chlamys opercularis) byssus formation was similarly affected although this species was more sensitive than M. edulis. The sensitivity of mussels was greater at higher temperatures and decreased with increase in size. Of the compounds tested Endosulfan (organochlorine) was the most toxic, causing a 50% reduction in byssal attachment after 24 h at 0•45 mg/l. Trichlorphon (organophosphate) was the least toxic and did not affect byssal attachment at concentrations up to 30 mg/l. The probable cause of decreased byssal attachment is a reduction in pedal activity, although it is possible that direct interference with the synthesis or combination of byssus components may be involved. It is suggested that byssogenesis tests offer a rapid and convenient technique for the routine screening of potential marine pollutants.

Persistent negative effects of pesticides on biodiversity and biological control potential on European farmland

During the last 50 years, agricultural intensification has caused many wild plant and animal species to go extinct regionally or nationally and has profoundly changed the functioning of agro-ecosystems. Agricultural intensification has many components, such as loss of landscape elements, enlarged farm and field sizes and larger inputs of fertilizer and pesticides. However, very little is known about the relative contribution of these variables to the large-scale negative effects on biodiversity. In this study, we disentangled the impacts of various components of agricultural intensification on species diversity of wild plants, carabids and ground-nesting farmland birds and on the biological control of aphids.