Modeling Energy and Agriculture Interactions: An Application to Bangladesh

Since many of the factors related to rural energy systems are gradually being quantified, there is a need to construct a model that integrates a number of these factors simultaneously in a consistent framework. Therefore, a general linear programming model is developed to capture energy and agricultural interactions existing in the rural areas of developing countries. Energy used for agriculture includes fertilizers, irrigation and mechanization. Several technological choices of each of the above are considered and so are several crop commodities, several types of livestock, and farmers of different groups along with their assets, i.e. land holdings, livestock, etc. The by-products of agriculture, i.e. biomass, such as crop residues, animal dung, wood, etc., can be used to generate energy. On the demand side the use of them for feed, fuel, and fertilizer must be considered. Thus, the household sector (which is the largest user of noncommercial energy), as well as the rural industries sector, is intimately related to the agriculture sector. Twelve different energy sources and several conversion technologies, such as biogas, charcoal kilns, alcohol distilleries, etc., are considered. The model is applicable to low-income, biomass-scarce developing countries. However, different types of countries will require different approximations, and their needs for detailing some aspects or other may vary. The model is suitable for policy purposes because it considers several income groups separately and considers how different changes affect each of them. The model is applied to Bangladesh for which the situation in 1976-1977 is simulated first. This base case provides insights into the present behavior of different income groups with regard to choices of fuels and allocation of biomass for various purposes. It is shown that, due to high needs and prices of fuels, the biomass allocation for fuels takes priority over feed and fertilizers. In fact, the landless burn all, and small farmers burn 80% of animal dung rather than use it for fertilizers. The model also shows that, unless substantial amounts of fertilizers are used, the small and middle farmers would have feed and fuel shortages on adopting high-yielding varieties (HYV) that minimize straw-grain ratios. Similarly, by 1990, when the population increases further, middle farmers also become vulnerable in meeting their feed, fuel, fertilizer requirements. To mitigate these effects, improved stoves and other measures would be necessary to increase biomass use efficiencies considerably. Since Bangladesh is a very low-income and resource-scarce country, the choice of biogas, charcoal kilns, and alcohol distilleries, and the choice of mechanization, all of which require investment, play a minor role