The use of crop protection products (CPPs) is essential to improve crop production levels and feed the rising global population. Safety testing of CPPs is also essential to ensure that their use does not adversely affect human health or the environment. Currently, laboratory-based studies typically over-estimate the environmental persistence of CPPs in the environment. The inclusion of environmental variables that are currently omitted from laboratory studies, such as non-UV light, could reduce the disparity between laboratory and field degradation studies. The inclusion of light resulted in a significant reduction in extractable parent compound for benzovindiflupyr, chlorotoluron, prometryn, imidacloprid, and fludioxonil compared to dark conditions. In contrast, a significantly slower rate of cinosulfuron transformation was observed under light compared to dark conditions. In a separate experiment, terminal restriction fragment length polymorphism showed that under light conditions, the soil surface (0-3 mm) harboured distinct phototroph, bacterial and fungal communities compared to the underlying bulk soil (3-12 mm), or dark incubated soil. 454 pyrosequencing revealed that light selected for diazotrophs at the soil surface, including Nostoc punctiforme, in addition to heterotrophic bacteria, particularly within the phylum Firmicutes. Metatranscriptomic analysis showed that light also selected for actively transcribing photosynthetic eukaryotes at the soil surface, such as Chlorophyceae and Saccharomycetes, in addition to heterotrophs, such as Nostocaceae. Finally, light selected for major soil functions such as photosynthesis, and reduced the alpha and beta diversity of predicted protein coding regions at the soil surface. This work has important implications for CPP regulatory studies and soil surface management practices.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:606114 |
| Date | January 2013 |
| Creators | Davies, Lawrence O. |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/60282/ |
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