Qualitative Analysis of Nitrogen Flows within Farms in Darusa, Bangladesh

To understand potential sources and losses of nitrogen from farming systems in Darusa, Bangladesh, a detailed survey of farming practices was conducted. A total of 100 households were randomly selected using demographic and agricultural information about the farmers in the study area. Data were used to stratify the farmers according to their operational land holding, livestock numbers (tropical livestock unit), use of irrigation, age, and educational level. Four clusters of farm households were identified, and nine households were randomly selected from each cluster for a total of 36 households. These 36 households completed more detailed surveys about their cropping and livestock. The surveys identified local practices of nitrogen management in different crops and types of livestock. Further information on traditional practices for soil fertility management was obtained by interviewing selected farmers. The results show that the major use for organic residues from crops and livestock is to provide fuel. Crop residues were used as fuel by 84% of farmers, with 23% using all of their crop residues as fuel. Some manure was used as fuel by all farmers, with 56% of farmers using most of their manure as fuel. As a result, 23% used no crop residues and 56% used less than half of their manure to improve soil fertility. This suggests that recycling of nitrogen in the study area is low. Soil analysis indicates that the organic matter and nitrogen contents of the soil in the study area were only 1.43% and 0.08%, respectively. Therefore, further recycling of organic residues should be practiced in order to reduce losses of available nitrogen from the system. More research is needed to quantify nitrogen lost by these practices and to draw up a full nitrogen budget for the study area.