Organic agriculture and energy conservation.

In the last decades the effects of oil crises on world economies along with the environmental impact cause by fossil fuels (e.g. climate change, emission of pollutants) led political leaders and scientists to search for alternative and sustainable energy sources (EC, 2005; EEA, 2006; IPPC, 2007; Goldemberg, 2007). One of these alternatives has been indicated in the use of biomass, in particular to supply biofuels (ethanol, biodiesel). In this chapter we will explore, instead, the possible role of alternative agriculture practices, referring in particular to organic agriculture, in contributing to energy saving and CO2 sequestration. If organic agriculture allow for improving energy efficiency and reducing CO2 and other Green House Gassess (GHGs) emission it would deserve much attention from policy makers and scientists alike and to be supported world wide. It has to be pointed out that organic agriculture provides many beneficial “by products” both for the environments (e.g. eliminating the use of agrochemical such as synthetic fertilisers and pesticides, increasing organic matter content and conservation of soil fertility, preservation of biodiversity, reduced water consumption) and for human heath (e.g. exposure to harmful chemicals, avoiding risks from possible side effects of Genetic Modified Organisms - GMO - use in agriculture). In this chapter we will review the literature concerning comparative analysis of energy use and CO2 emission from organic and conventional farming systems. The chapter is organised as follows: section (1) provides the reader with a definition of organic agriculture (and sustainable agriculture) and a brief history of the organic movement, this in order to help the reader to understand better what is presented later on; section (2) reviews a number of studies on energy efficiency in organic and conventional agriculture; section (3) compares CO2 emission from organic and conventional managed farming systems; section (4) analyses the possible use of agricultural “wastes” to produce cellulosic ethanol; section (5) provides some comments concerning the possible production of biofues from organically grown crops; section (6) concludes the cheaper presenting a summary of the review. We wish to underline that, whilst focusing mainly on the energetic performances of organic agriculture and its possible role in CO2 abatement, we are aware that a much more comprehensive treatment is necessary in order to assess the benefits and/or drawbacks of organic agriculture. Such an analysis is a difficult one, because of the complex nature of agroecosystems .