The sustainability of growing crops for use as energy sources has been disputed for many years. A potentially attractive alternative is to use waste and residues from agricultural and forestry. However, using waste and other residues may have an impact on land use, biodiversity and food security. The additional sources of income from the sale of waste and other residues could prompt an increase in the production of crops and wood. LEI has investigated the potential impact of the large-scale use of waste from agriculture and forestry on land use and food security.
The use of crops as energy sources can have indirect land use change impacts (ILUC), generating greenhouse gas emissions and affecting biodiversity. The extra demand for crops increase food prices and lead to a deterioration in food security. In light of this, this year the European Commission decided to adjust the Renewable Energy Directive to limit the proportion of biofuels produced from agricultural crops to 7% of the total use of transport fuels.Use of waste and residues as an alternative to crops
An attractive alternative is the use of waste and residues from agriculture and forestry, such as straw, peels, husks and fruit stones. Various studies have demonstrated that the sustainable potential of residues and waste can supply a considerable amount of the future demand for biomass for energy production. These studies factored in theoretical, technical and economic factors that limit the potential of residues and waste. Allso, the future demand for waste and residues for other applications is considered, such as paper production and animal feed. These studies also assumed that part of the residues from agriculture must not be removed from the field in order to maintain the soil's fertility.Impact on land use, biodiversity and food security
The use of waste and residues from agriculture and forestry can have an impact on land use, biodiversity and food security. For instance, the use of straw from wheat boosts the profitability of wheat production. The extra income resulting from the sale of straw therefore creates an incentive to increase the production of wheat.Use of residues from agriculture results in lower ILUC impact and improved food security
Using the MAGNET computable general equilibrium (CGE) models, LEI calculated the impact of a large-scale use of crop residues from agriculture as energy sources on land use and food security in 2030. Results show that the use of residues from agriculture leads to a decrease of the price of crops and an increase of production and consumption. These effects are most notable in agricultural sectors and regions with high residue potential, such as maize production in North America and palm oil in Southeast Asia and Indonesia. Exports of crops and processed food from these regions are increasing and imports to these regions are decreasing. These effects trigger a decrease of prices and increase of consumption of crops and processed food in other parts of the world. The increase in crop production is realised through higher yields per hectare and an expansion of the area cropland. The expansion of cropland occurs at the expense of grasslands and consequently the net expansion of agricultural land land loss of natural vegetation is very limited. The effects of the changes in land use, which generate greenhouse gas emissions and affect biodiversity, are thus limited.Implications for policy
The use of waste and residues from agriculture and forestry as energy source results limited greenhouse gas emissions from land use change. The use of waste and residues also has an impact on food security. However, the uncertainties related to assessing the impact of the use of waste and residues from agriculture and forestry on land use and food security are large. Further, more attention needs to be paid to the impact on specific crops, regional effects and to the food security impacts on various groups of consumers and producers.