Energy use efficiency of organic and conventional cropping systems of sugarcane

Analysis of energy use efficiency provides an assessment of non-renewable energy consumption; it is a useful indicator of environmental and long-term sustainability when comparing cropping systems. This study aimed to estimate the energy use efficiency of organic and conventional cropping systems of sugarcane for sugar production in central Cuba. Estimation of the energy use efficiency included analysis of four cropping systems. The energy input in the field until harvest and transport to the sugar mill was the limit of this analysis. The results showed that organic cropping systems were less efficient in energy use because of the greater number of field operations, mainly for weed control by manual and mechanical cultivation. Organic cropping systems also had lower yield compared with conventional systems due to their use of low doses of organic products, instead of agrochemical fertilizers, for plant nutrition. In all cropping systems evaluated, sugarcane used for seed was the largest part of the energy input due to the consumption of 12 t ha(-1) of seed, representing an average of 89% of the total energy input for the sugarcane cropping systems. The second largest part of the energy input was the fuel consumed during mechanized operations. Irrigation was the third largest part of the energy input for organic cropping systems and the second largest part of the energy input for conventional cropping systems.