To determine the efficiency of utilization of organic matter in agricultural production, nitrogen flow was estimated within a village-farm model in the west of Niger, West Africa. Nitrogen was focused on in this study as it is known to be a major nutrient component of organic matter and one of the limiting nutrients in Sahelian soil. Local practices regarding the use of organic matter and pertinent information on traditional practices for soil fertility management were determined by interviews with local farmers. To estimate nitrogen flow in farmlands and consumption in the village through various activities, quantitative measurements of crop yield and organic amendment were carried out. Data on human and livestock excreta were taken from published reports. The size and classification of farmlands were as follows: 0.5 ha adjacent farmland, 1.6 ha threshing farmland, 6.0 ha transported-manure farmland, 5.5 ha corralling farmland, and 86.5 ha extensively managed farmland (EMF). Levels of nitrogen flow from these farmlands to the studied villages were 0.9, 2.9, 9.6, 15.2, and 94.2 Mg, while the flows to these farmlands were 14.6, 6.3, 13.7, 17.5, and 26.3 Mg, respectively. Upon calculation of nitrogen balance -8 kg ha -1 year -1 was estimated in EMF, but there was a positive balance in other types of farmland, which ranged from 4 to 262 kg ha -1 year -1 , indicating inefficient use of nitrogen in the study area for crop production. The results indicated that nutrient flow in the study site was unequally distributed and nitrogen was not recycled. Therefore, efforts should be made to establish efficient utilization of available nutrients by reducing the loss from livestock feed and human consumption. At the

Most farmers in Niger live below the poverty line and require low-capital intensification to improve agricultural production. The purpose of this study was to evaluate local knowledge on less beneficial weed for future use in managing the soil fertility of the Sahel region. Sida cordifolia was utilized in a scientific procedure to verify how local farmers utilize this species and the nature of the important roles behind this wild plant in terms of soil fertility management. The results of a questionnaire showed that S. cordifolia was less frequently used than other wild plants found in the same area, but that local farmers recognized this plant as one of the indicators of soil fertility in millet fields. The results of soil analysis also revealed a significant coefficient of variance in certain parameters such as total acidity and aluminum saturation of the soil, while multiple regression analysis showed the high influence of total acidity and soil pH on plant height and dry matter weight, respectively. These results indicate that the significant difference in plant growth of S. cordifolia was mainly due to soil acidity rather than soil fertility. The application of organic matter is one effective approach to resolve this problem and it was shown that the poor growth of S. cordifolia is a particularly useful marker to identify patches where organic matter should be applied. Despite its simplicity, this technique is considered particularly beneficial to allocate limited resources efficiently for sustainable, improved production.