A brand new study (2013) found that the projected energy demand (2035) in developing countries, can be covered with energy crops in surplus agricultural lands, then not competing with food production. The study, from the Department of Energy Technology, at Aalto University School of Engineering (Finland) was accepted by the sound scienfitc journal Renewable and Sustainable Energy Reviews.
The authors did first an extensive literature review considering current status on land availability, land use pattern, crops and energy production and their present and projected demands. Historical trends in land use changes, crop yields, per capita land use were also reviewed from statistical database and literature sources. In the second part, a set of assumptions were made based on the information and insight gained from the reviewed literature to determine the extents of land availability for growing selected energy crops to meet the projected demands.
Perennial plants can occupy pastures and degraded lands
The study focus all the assessment in perennial species and agricultural residues mostly. Regarding energy crop, this publication focused on scenario building with jatropha, willow, poplar, switchgrass and miscanthus.
Land use changes may exist, but there is enough land available for perennials.
The study concludes that there are sufficient land resources to grow food and other plant products to feed the population and meet other needs in developing countries including fiber and energy crops . The production of energy crops in the surplus agricultural lands can overall meet projected primary energy demand through 2035 in the developing countries considering four energy crop scenarios. The land availability and energy demand coincide for African and Latin American countries, which reduce the transportation risks of biomass. Asia, however, lags behind in providing surplus cropland required to deliver the projected energy demand.
The cropland can be surplus from cropland expansion, yield improvements or grassland upgradation. The dedicated energy crops can be grown in the tropical climate condition what actually the case in developing regions. The practice of growing energy crops are not wide spread in the developing counties, this might need serious effort from the governments, policy makers, and other stockholders to lay support for their dissemination. The productivity of crops in sub-Saharan Africa is very low, usually 1 t/ha, whereas in developed countries, it is 5 t/ha or more; therefore there is still big room to increase production without land expansion.
The study is basically very much complete and the only aspect to remark is that authors only considered 4 species when there is a broad large group of possible lignocellulosic energy crops including shrubs, short rotation forestry and perennial grasses in tropical, subtropical and temperate areas. Additionally the study does not consider agroforestry, double cropping systems, by-products or any combination in rotations that would eventually increase the potential land availability without food disruptions.
The published article can be obtained here.