Environmental impact and economic assessment for UK sugar beet production systems

It is important to understand and evaluate the environmental impacts of all crops if we are to develop more sustainable production systems. Understanding the impact of sugar beet (Beta vulgaris) is particularly important as there are alternative crops that can be used for sugar production and also because there is growing interest in its potential as a source for biofuel. This paper presents the findings of a research project to evaluate the environmental impact and economic viability of the range of sugar beet production systems in the UK. The study used 13 sugar beet production scenarios that represent those used throughout the UK. These scenarios differed in soil type, nutrients applied (inorganic and organic), crop protection (chemical and cultural) and use of irrigation. The assessment included an evaluation of inputs (nutrients, pesticides and energy) and their impact on the environment. A net margin for each scenario was also calculated to provide an economic assessment. An average of the assessment results for the different parameters across the scenarios was calculated (weighted by the sugar beet area each scenario represented) to provide a mean figure for sugar beet production in the UK. The results for this mean on a per ha basis were a yield of 52 t, a net margin of £560, consumption of 21.4 GJ of energy, emission of 1.4 equiv. t of carbon dioxide, 3.3 kg nitrogen leached, 15.2 kg nitrogen lost to denitrification and a pesticide ecotoxicity score of 26 (low). A sustainability profile, on a per ha and a per tonne basis, for each of the 13 scenarios was constructed enabling all scenarios to be compared in terms of their overall environmental and economic performance. This comparison showed that the most profitable scenario also had the best overall environmental performance. This scenario represented 18% of UK sugar beet area. Three other scenarios that represented 57% of the total area closely followed this performance. The overall performance of the organic scenario was equal to the best conventional scenario on a per ha basis, but on a per t basis its performance was lower (similar to the mean for sugar beet in the UK) due to its significantly lower yield. This study illustrates that a significant proportion of the UK crop is being grown in an economically efficient way whilst minimising environmental damage.