No description available.

No description available.

Revised / 2 pp.

Revised / 2 pp.

No description available.

No description available.

No description available.

No description available.

This thesis focuses on determining the potential of bio-energy crops to contribute to Europe’s future energy needs and to reduce future greenhouse gas emissions. This requires an end-to-end (seed to exhaust gas) analysis of the crop production and enabling technology in terms of energy use and greenhouse gas emissions. The starting point of this research was to consider which energy crops had the potential to grow in future European climate scenarios and to determine those for which models did not exist to make this prediction. <i>Miscanthus</i> was identified as a relatively new crop with 15 years of European growing experience but with limited previous model development.  MISCANMOD, a simple model of <i>Miscanthus</i> crop growth, was improved and rewritten in FORTRAN so that it could be interfaced to use climate scenario, soil property and land use data bases to predict energy yields for current and future climate scenarios. A greenhouse gas emissions and energy balance model was added to investigate the sustainability of <i>Miscanthus</i> as a bio-energy crop. This model was combined with data from other energy crop predictions to determine the energy yields and GHG mitigation of different crops for the various scenarios of future climate, each considering the soil conditions, land available and climatic conditions. We conclude that <i>Miscanthus</i> is the crop with the highest energy yield and largest carbon mitigation potential of all the available energy crops, and that the maximum amount of primary energy that could be produced by bio-energy crops in Europe would represent only 12% of EU 25’s primary energy needs. The carbon intensity of such energy is estimated to be 24% of that for gas. To achieve this level of energy production we show that it is necessary to develop drought and frost resistant hybrids to increase the range of the <i>Miscanthus</i> crop for current and future climate scenarios. This demonstrates that bio-energy is not a panacea but must be considered as part of the strategy to achieve sustainable energy whilst mitigating greenhouse gas emissions.

This is the first study to compare total arsenic (As) and other trace elements in the agricultural soils and grain of Eastern, Western and Southern Libya, North Africa and the Middle East (NA &amp; MIDEA). Soil pot experiments and field experiments were conducted to determine the levels of As within wheat grains in Libya. In the soil pot experiments, wheat genotypes were planted in similar soils and yet differences in grain As concentration were found among the cultivars. The highest As accumulation was found in <i>T. durum; </i>however, in the field data the highest levels were found in <i>T. aestrivum.</i> The levels of As and other trace elements found in agricultural soils from the Eastern Western and Southern regions of Libya are examined. Mean As concentrations in the clay mineral agricultural soils of the Eastern Region were nearly 4.8 and 4.1 times higher than in the southern and western regions, respectively. It is possible that the parent material of that region contains elevated levels of As, which are then exhibited in the overlying soil. Differences in the levels of As and other trace elements found in the irrigated agricultural soil of Southern Libya were compared with non-irrigated soil from the same region.  Concentrations of P, Zn and As in soil were higher in irrigated compared to non-irrigated soils, while the concentration of Cd is nearly the same in all soil samples. A market basket investigation was conducted to determine the total levels of As and Se in rice purchased from supermarkets. The average level of As in rice from NA &amp; MIDEA is 0.22 mg/kg, comparable with average levels in Australia.