Abstract
The overall objective of this research was to develop a system dynamics computer model of agricultural mechanization in Bangladesh in order to evaluate the effectiveness of the agricultural mechanization policies showing its contributions in terms of rice production, food supply and employment generation. For this, rice production and policies affecting it were considered under a holistic framework to analyze the impacts of mechanized irrigation, HYV coverage, fertilizer coverage, draught power supply from cattle/mechanical sources, price-production-consumption behaviours and labour utilization due to mechanization. The model consists of five sub-models- population, rice production and consumption, employment and migration, cattle population and agricultural mechanization.A series of tests were conducted to build up confidence in the model. The simulated behaviours of population, rice production, rice import, cattle population, draught animals, land under rice, irrigated area and average yield per hectare in Bangladesh were in excellent agreement with reported data for the period of 1961-1991.The model was then simulated for the period of 1961-2030 to assess the impacts of thirteen alternative sets of agricultural mechanization policies. The simulated results show that the present irrigation-fertilizer-high yield variety technology is seriously restricted in achieving the desired production target due to an acute draught power shortage. A detailed analysis of the simulated results show that green revolution combined with a transparent policy on draught power has the potentiality to increase the internal rice production by about one and half times of the present level provided the price of rice is such that producers' expectation is not impaired. Draught power shortage is inherent and persistent, and introduction of mechanical power to supplement the draught power shortage is inevitable and beneficial. A policy of tractorization in association with green revolution shows the highest rural employment and a sustained near-subsistence level in the supply of rice in the long run and this policy is found to be the best one which deserves attention for implementation.None of the agricultural mechanization policies alone can effectively alleviate the food shortage problem in Bangladesh in the long run. The policies aimed at improving conditions in the short run are defeated in the long run because of the fact that the internal goal of the system to match population with food availability in the short run defeats any effort to enhance food availability in the long run. It further shows that policies aimed at relieving distress with external help would be more distressing and any interruption of such help is catastrophic in the long run.The results of the simulated policies are valuable guides for making rational choices amongst available alternatives and provide enormous potential for analyzing strategically important issues and can be used as a tool in the process of formulation of development plans.