Energy input-output analysis of rice cultivation in the coastal region of Bangladesh

Abstract

An analysis of energy input-output in boro rice cultivation was undertaken for well recognized salinity classes (S1 -S5 ) and farm categories (landless, marginal, small, medium, and large) in south-west coastal Bangladesh. A total of 125 target farmers were surveyed by using structured questionnaire during the boro season (January-May 2011). Survey data were converted into energy by using the respective energy co-efficient equivalents. The results revealed that the sequences of total energy input were S1 > S5 > S2 > S4 > S3 and medium > large > landless > small > marginal among salinity regimes and farm categories, respectively. The seedbed stage consumed the highest energy followed by growing stage, and harvesting and threshing. Inorganic fertilizers accounted for a major share (59.98%) of energy input in rice field, while the lowest share was estimated for manpower (0.75%). Among fertilizers, nitrogen category was the most dominant source (54.94%) of energy input following phosphate (3.82%) and potassium (1.22%). The total output energy was in the sequences of S1 > S4 > S5 > S2 >S3 and landless > marginal > small > medium > large. Energy from main product (rice grains) was higher than that of byproduct (straw). The study also found that total output energy decreases with increases in farm size. In case of energy efficiency (output-input ratio), S4 was found to be the most energy efficient (2.43) regime followed by S3, S1, S5 and S2, whereas marginal sized farmers were the most energy efficient (2.12) followed by landless, small, medium and large. This study shows that increased energy input in rice cultivation is not always necessary to get higher output energy in the salinity affected coastal Bangladesh. Therefore, it is necessary to practice environmentally sound management systems for sustainable rice production.

Keywords

• energy input-output
• Boro rice
• salinity classes
• farm categories
• Coastal Bangladesh