R. C. Maheshwari
AICRP on Renewable Energy Sources Central Institute of Agricultural Engineering,
Bhopal 462018 (M. P.)
This paper deals with the animal energy flow in a village ecosystem, both with regards to its needs and supply. The animal system is able to generate so much energy that it can cope with 37.2% domestic energy needs, 17. 7% energy requirement for agricultural production and supplies 12.74% of food energy. The introduction of biogas technology can meet N P K requirement by 46, 22 and 23%. respectively, to make the village "elf-reliant in pulse and oilseed production which are presently in shortage by 23 and 72 percent, respectively. The animal conversion efficiency works aut to be 53% as compared to O.55%for human beings.
Both man and animal interact with soil, water, air and plant life to harness solar energy for their sustenance as represented in Fig 1. Both at micro and macro levels, there is energy and material balance in the ecosystem. Solar energy is used by green plants to synthesise organic compounds such as starch, sugar, cellulose and lignin. The annual utilization of solar radiation by earth’s plant life varies between 0.1 -0.3 percent. Out of the estimated total solar radiation of 29.96 x 1011 MJ (8.34 x 1011 kWh) received on the earth's surface annually, the vegetation utilizes 32 x 1014 MJ (8.9 x 1014 kWh) of energy to synthesise 1.785 x 1011 metric tonnes of carbon in the plants through photosynthesis (Pandya & Maheshwari; 1980). As per the ENERGY CENSUS of the Village Islamnagar carried out by the CIAE, Bhopal(Maheshwari, et al, 1981 ), the utilization of solar energy and its flow in the village ecosystem is illustrated in Fig 2. Out of the 46.6 x 103 T J of solar energy received by the geographical area (719.04 ha) of the village, only 40.44 T J is converted into food, feed and fuel thereby amounting to photosynthetic efficiency of 0,073 percent which is about half of the world's average of 0, 16 percent.