Objective To present the results of a research project on 6 heavy metals （Cd, Cu, Zn, Pb, Hg, and Cr） at 30 Fadama fields scattered around Kano. Methods Following a reconnaissance conducted, 30 representative Fadama...Objective To present the results of a research project on 6 heavy metals （Cd, Cu, Zn, Pb, Hg, and Cr） at 30 Fadama fields scattered around Kano. Methods Following a reconnaissance conducted, 30 representative Fadama lands being irrigated with wastewater were selected from zones of the city under residential, industrial, commercial, and mixed but largely residential landuses. Five additional Fadama lands not being irrigated with wastewater were selected to serve as control. Using grid sampling procedure, soil samples were selected from 0-15 cm and 20-30 cm depths and analyzed for the above listed heavy metals using atomic absorption spectrophotometry. T-test was used to compare the mean values of the metals for the Fadama lands under different landuse zones with those of the control. Results Analyses of the soil data collected showed that the metals were concentrated in higher amounts in the lower （20-30 cm） than the upper （0-15 cm） depths, which was an indication of downward movement of the metals in profile of the soils. In the two soil depths, Zn was generally the most abundant, followed by Cr, then Pb, Cu, and Cd while Hg was the least. The Fadama soils in areas of mixed landuses with industrial as the dominant ones maintained the highest concentrations of the various metals. Conclusions These results indicate clearly that the Fadama soils are significantly polluted by industrial and household wastewater and that there is a particular threat from Cr and Pb pollution. There is also evidence that the metals are accumulating at lower layers of the soil profile, suggesting that not only plants and soil, but even water bodies could be under the threat of heavy metal pollution in the area.展开更多
This study was conducted in Akwa Ibom, Bayelsa and Delta States of the Niger Delta, Nigeria. It examined the level of adoption of aquaculture technologies by Fadama Ⅲ beneficiaries and assessed the differences in ado...This study was conducted in Akwa Ibom, Bayelsa and Delta States of the Niger Delta, Nigeria. It examined the level of adoption of aquaculture technologies by Fadama Ⅲ beneficiaries and assessed the differences in adoption levels on sate basis. Five fish farmers were randomly selected on multiple stage bases from 18 Fadama Users＇ Groups （FUGs） amounting to 90 farmers as the sample size for this study （n=90）. Structured questionnaire was used to elicit information from respondents. Data collected were measured using descriptive and adoption Sigma method analysis. Results obtained revealed that of the 12 selected aquaculture based technologies recommended by Fadama Ⅲ, the ratio of adoption skills ranged from 1 high： 7 medium： 5 low. The adoption levels followed a sequence of earthen ponds preparation being the highest, and stocking density techniques being the lowest. The overall adoption level was 4.20 which implied that the aquaculture farmers were categorized as medium adopters using the Sigma method scale. It was recommended that farmers with adoption levels at medium and low ranges should be focused upon with more teaching sessions by community facilitators and that other extension workers should emulate the strategies used by Fadama Ⅲ in developing farmers.展开更多
Nigeria is a country endowed with alluvial aquifers that occur along major river valleys, in low lying areas which are frequent to flooding during the rainy season. They are scattered across the ecological zones of Gu...Nigeria is a country endowed with alluvial aquifers that occur along major river valleys, in low lying areas which are frequent to flooding during the rainy season. They are scattered across the ecological zones of Guinea savannah, Sudan savannah and the Sahel Savannah and are the thickest along the river Niger and river Benue. The irrigated flood plains (Fadama) are formed by the deposition of transported weathered exogenic terrigenous materials derived from the surrounding basement rocks. These shallow aquifers are mostly unconfined and are recharged through flash flooding events which make them hold great groundwater resources for dry season farming. The fertility of the soils with their residual moisture content makes them attractive for dry season farming. The potential and importance of Fadama agriculture for food production and economic development are crucial, given the recent rising food prices, climatic changes, environmental risks associated with “modern” agriculture, modelled farming systems and population growth. Fadama areas are therefore of critical importance to the survival and economic development of millions of rural dwellers. This paper reviews the groundwater potential of the Floodplains of Fadama for dry farming systems in semi-arid northern Nigeria.展开更多
文摘Objective To present the results of a research project on 6 heavy metals （Cd, Cu, Zn, Pb, Hg, and Cr） at 30 Fadama fields scattered around Kano. Methods Following a reconnaissance conducted, 30 representative Fadama lands being irrigated with wastewater were selected from zones of the city under residential, industrial, commercial, and mixed but largely residential landuses. Five additional Fadama lands not being irrigated with wastewater were selected to serve as control. Using grid sampling procedure, soil samples were selected from 0-15 cm and 20-30 cm depths and analyzed for the above listed heavy metals using atomic absorption spectrophotometry. T-test was used to compare the mean values of the metals for the Fadama lands under different landuse zones with those of the control. Results Analyses of the soil data collected showed that the metals were concentrated in higher amounts in the lower （20-30 cm） than the upper （0-15 cm） depths, which was an indication of downward movement of the metals in profile of the soils. In the two soil depths, Zn was generally the most abundant, followed by Cr, then Pb, Cu, and Cd while Hg was the least. The Fadama soils in areas of mixed landuses with industrial as the dominant ones maintained the highest concentrations of the various metals. Conclusions These results indicate clearly that the Fadama soils are significantly polluted by industrial and household wastewater and that there is a particular threat from Cr and Pb pollution. There is also evidence that the metals are accumulating at lower layers of the soil profile, suggesting that not only plants and soil, but even water bodies could be under the threat of heavy metal pollution in the area.
文摘This study was conducted in Akwa Ibom, Bayelsa and Delta States of the Niger Delta, Nigeria. It examined the level of adoption of aquaculture technologies by Fadama Ⅲ beneficiaries and assessed the differences in adoption levels on sate basis. Five fish farmers were randomly selected on multiple stage bases from 18 Fadama Users＇ Groups （FUGs） amounting to 90 farmers as the sample size for this study （n=90）. Structured questionnaire was used to elicit information from respondents. Data collected were measured using descriptive and adoption Sigma method analysis. Results obtained revealed that of the 12 selected aquaculture based technologies recommended by Fadama Ⅲ, the ratio of adoption skills ranged from 1 high： 7 medium： 5 low. The adoption levels followed a sequence of earthen ponds preparation being the highest, and stocking density techniques being the lowest. The overall adoption level was 4.20 which implied that the aquaculture farmers were categorized as medium adopters using the Sigma method scale. It was recommended that farmers with adoption levels at medium and low ranges should be focused upon with more teaching sessions by community facilitators and that other extension workers should emulate the strategies used by Fadama Ⅲ in developing farmers.
文摘Nigeria is a country endowed with alluvial aquifers that occur along major river valleys, in low lying areas which are frequent to flooding during the rainy season. They are scattered across the ecological zones of Guinea savannah, Sudan savannah and the Sahel Savannah and are the thickest along the river Niger and river Benue. The irrigated flood plains (Fadama) are formed by the deposition of transported weathered exogenic terrigenous materials derived from the surrounding basement rocks. These shallow aquifers are mostly unconfined and are recharged through flash flooding events which make them hold great groundwater resources for dry season farming. The fertility of the soils with their residual moisture content makes them attractive for dry season farming. The potential and importance of Fadama agriculture for food production and economic development are crucial, given the recent rising food prices, climatic changes, environmental risks associated with “modern” agriculture, modelled farming systems and population growth. Fadama areas are therefore of critical importance to the survival and economic development of millions of rural dwellers. This paper reviews the groundwater potential of the Floodplains of Fadama for dry farming systems in semi-arid northern Nigeria.
