Energy use in organic, green and conventional pear producting systems - cases from China

The objective of this study was to evaluate the differences in the energy consumption between the production of certified organic pear, green food certified pear, and conventional pear in two areas in China. Data were collected from interviews with farmers during 2007 and 2008. Energy inputs were significantly higher in organic systems compared with conventional and green systems. Fertilizer was the most important contributor to energy consumption in all three farming systems. Three calculation methods for energy value of manure have been found in the literature: substitution method, by-product method, and thermal method. The choise of various calculation methods for estimating the energy value of manure turns out to have great influence on the results in terms of energy inputs and energy efficiency. Additionally, energy inputs and energy efficiency were also influenced by other agricultural inputs, such as machinery and corresponding fossil fuels, human labour, etc. Possible explanations for the three differences are discussed