Energy balance of wheat and barley under Moroccan conditions.

This study was carried out to establish the energy balance of barley and wheat, the main cultivated crops in Morocco. These crops cover about 5.3 million ha and cover 65% of the total arable area in Morocco [10]. The assessment of the energy requirements considers both direct inputs (electricity and diesel fuel) and indirect inputs (machinery, irrigation system, fertilizers, seeds and pesticides). Specific energy values were adapted from international literature and applied to national average data related to field operations. The results indicated that the total energy expenditure is 7480 MJ/ha for wheat and 3230 MJ/ha for barley. The energy efficiency in the case of wheat is 3.3 and 4.2 for barley without considering byproducts (straw, roots). The energy intensity is 4.9 MJ/kg for wheat grains and 3.7 MJ/kg for barley grains. Results revealed also that chemical fertilizers, seeds and diesel fuel consumed, respectively, 46.9 %, 18.2 % and 19.2 % of the total inputs for wheat and 20.5 %, 32.4 % and 25.5 % in the case of barley. Nitrogen represents 82% of fertilizers used; herbicides represented 87.4 % of pesticides used. Harvesting and threshing operation consumed 64.8 % and 68 %, respectively, of animal draft and manpower energy. Tillage operation consumed 46.2 % of diesel fuel.