The energy and water cost of sugar production in a semi-arid context: a comparative analysis of sugar beet and sugar cane production and processing in Morocco.

摘要

A comparative analysis of the production and processing of sugarbeet and sugarcane in Morocco was carried out with regards to energy and water use. Total agricultural energy inputs for sugarbeet were 33.79 GJ/ha and in the case of sugarcane were 59.33 GJ/ha for plant cane and 35.65 GJ/ha for ratoons. The major energy inputs for both were diesel fuel, electricity and fertilisers. In sugarbeet production fertiliser application accounted for more than 50% of total agricultural energy inputs. The mostenergy intensive operations in sugarcane production were irrigation (37%) and fertiliser application (29%). The input:output energy ratios were 1:3.2 for sugar beet and 1:3.7 for sugar cane. Total energy used in processing was 26.19 GJ/t white sugar (tws) from sugarbeet and 3.02 GJ/tws from sugar cane. Direct energy in processing was 22.51 GJ/tws for sugar beet and 1.27 GJ/t white sugar for sugarcane. Overall (production+processing) input:output energy ratio was 1:1.5 for sugarbeet and 1:4.2 for sugarcane. Overall analysis demonstrated that the production of sugar from sugarbeet is more energy intensive than from sugarcane while the sugarcane requires larger inputs of water.