Technological change, soil quality and land productivity: evidence from the rice-prawn gher farming system in Bangladesh.

摘要

This study aimed to determine the impact of the rice-prawn gher (RPG) farming system on the soil quality and land productivity of paddy fields cultivated with modern varieties (MV) of rice in Bangladesh. On average, the mean soil pH in rice fields in the RPG farming system at the beginning of transplanting and during harvesting was 6.6 and 6.0, respectively. On the other hand, mean soil pH in the year-round MV (YRMV) paddy fields increased from 6.5 during transplanting to 7.1 during harvesting. The mean value of the electrical conductivity (EC) of the soil under the RPG farming system was lower during the transplanting period compared with that in the YRMV paddy fields. However, the average values of EC during harvesting was almost the same for both farming systems. Total organic C and N content in soils of paddy fields under the RPG farming system was higher than that in the YRMV paddy fields. All input costs per hectare were lower in the RPG farming system compared with the YRMV farming system. Results indicate that the RPG farming system is better that the YRMV system in terms of improving soil quality and land productivity and reducing input cost.