Most of the emissions associated with rice production are related to water management  and nitrogen fertilisers .Water and straw management related practices are the most effective in reducing emissions from paddy fields.Methane emissions depend on the combination of flooded and dry periods in the field, the management of straw and organic matter and the duration of the total cycle of production. Although they have no direct impact on energy consumption or on economic performance,these best practices would allow GHG emissions to be reduced by up to 23%. It also allows operative costs to be reduced and,hence, to improve economic performance. In our case study, for example, four of the nine farms presented a surplus of fertilizer use of between 17% and 37%.Best practises would reduce energy consumption by up to 8% and GHG emissions by up to 6% and thus save approximately 10% in fertiliser costs.

The optimisation of the number of seeds sown and the sharing of machineryfor various tasks are two measures that are related directly with a reduction in energy consumption. Both would result in an energy reduction of 2% and 4%,respectively. Although the two measures have a good impact on economic savings, they have almost no impact in reducing GHG emissions.As we can see, identifying best practises is not a linear process and involves a complex decision-making process that takes into account environmental and economic factors as well as the needs of the stakeholders. In this case study,farmers were most likely to accept suggestions that benefited their farms economically.GHG emissions and energy consumption were generally considered as being of secondary importance or disregarded altogether if they were not associated with any economic benefit. This suggests that for these farmers the value of any environmental impact is zero, as it is assumed to be in traditional accounting. As such, it is not only traditional accounting that undervalues the impact of human activities on climate change but also certain sectors of society-in this instance, one that is supposedly heavily engaged with the processes of nature.

This study has sought to overcome the general failure to measure the impacts of farming on climate change by analysing the relationship between energy consumption and rice paddy field emissions, on the one hand, and the productivity,sales revenues and income of rice production, on the other, in a sample of farms producing gleva and bomba rice varieties. Our results reinforce the idea that the higher productivity and higher revenues per hectare achieved thanks to the intensive use of fossil fuels and chemical inputs are closely linked with a higher impact on climate change.GHG emissions per hectare were consistently higher in the case of farms presenting above median economic indicators for both rice varieties farmed conventionally,while they were substantially lower in the case of the organic farm.As such, our results suggest that a better economic performance in conventional farming is achieved at the expense of a greater impact on climate change.Energy consumption has been analysed in terms of both direct and indirect energy sources. The latter enables us to assess the energy accumulated in the stages prior to actual rice production. It was found to be substantially higher than direct energy consumption in all the conventional farms and higher for farms with an above median economic performance. Here again the organic farm presents more environmentally friendly results with lower energy consumption values.

This means that conventional farms achieve higher productivity and profitability at the cost of overusing energy sources and, therefore, of an increased ecological foot print.The ratios between environmental and economic performance confirm that a higher environmental impact in terms of climate change is associated with a better economic performance. In producing one kg of rice, the less productive farms required less energy and were responsible for lower rates of emissions, a relationship that was stronger in the case of energy consumption than it was for GHG emissions. This might be attributable to the fact that methane emissions are unrelated to output but are rather determined by the size and flooding cycles of rice fields. Increasing impacts were recorded in the case of the intensification of the use of chemical inputs, fossil fuels and land. We have shown briefly how GHG emissions, energy consumption and economic costs can be reduced depending on the farming practises adopted, but we found that farmers were primarily interested in economic savings and less so in improving their environmental performance.We have found some evidence that sustainability accounting may well be useful to fill some of the gaps in the traditional accounting framework as regards the transparency of the reporting of the environmental impact of farming. Indeed,environmental impacts and, more importantly, indirect environmental impacts are not captured by traditional accounting methods.