Soil Physico-Chemical Characteristics and Level of Selenium In Soil and Staple Crops From Areas of Contrasting Human Selenium Status in the Amhara Region, Ethiopia
| dc.contributor.advisor | Gashu, Dawd (PhD) | |
| dc.contributor.author | Ali, Sahar | |
| dc.date.accessioned | 2019-08-31T02:51:36Z | |
| dc.date.accessioned | 2023-11-09T15:32:30Z | |
| dc.date.available | 2019-08-31T02:51:36Z | |
| dc.date.available | 2023-11-09T15:32:30Z | |
| dc.date.issued | 2018-11-05 | |
| dc.description.abstract | Back ground: Selenium (Se) is an important micronutrient for humans and livestock. It is an integral part of more than 25 seleno-proteins. It plays significant biological role through seleno-cystein compounds such as protection against free radical damage and thyroid hormone metabolism. More than half of the populations in the Amhara region (North and North-West Ethiopia) have Se inadequacy. However, the human Se distribution had spatial variation such that no children in east Amhara had Se inadequacy while majority (up to 90%) of the children from the west Amhara had Se inadequacy. Selenium concentration in the soil determines human Se nutrition particularly in those dependent on local food sources. Method: In the present study, Se in crop and soil samples from areas of contrasting human Se concentration, in the Amhara region, Ethiopia were collected. Selenium in staple crops and soil samples was determined using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). In addition, soil physic-chemical characteristics (moisture, texture, organic matter content, pH, and minerals) were analyzed. Results: There was wide variation in Se concentration within and among staple crops (median=47.7μg/kg for maize to 9653.5μg/kg for finger millet). In general, maize and finger millet had the least and highest Se concentration, respectively. About, 12% of crop samples (majority maize) had low or marginal Se concentration. Teff (median=0.43 vs 0.13; p=0.0003) and maize (0.27±0.1 vs 0.04±0.01; p=0.002) samples collected from east Amhara had significantly higher Se concentration than the corresponding samples from west Amhara. Clay (55%) was the dominant textures in the present study soil samples. In addition, soil samples had diverse pH value (4.5-8.4). About 10% of soil samples had low or marginal Se concentration. In addition, 24.4% had low phosphate extractable Se. Phosphate extractable Se was correlated with soil organic matter (r=0.47; p<0.001), soil pH(r=0.54; p<0.001), and total Se (r=0.56; p<0.01). Soil samples from east Amhara had significantly lower concentration of total Se (0.4±0.1 vs 0.2±0.2 mg/kg; p=0.03), phosphate extractable Se (4.1±2.2 vs 6.7±3.4μg/kg; p<0.001), and organic matter than soil samples from west Amhara. On the other hand, soil samples from the western Amhara had significantly lower pH than soil samples from the east Amhara. Selenium concentration in teff was significantly correlated with soil pH (r=0.45; p<0.01). In addition, there was significant correlation between maize Se concentration with soil aluminum (r= -0.64, p<0.01) and wheat Se concentration with soil calcium (r=0.7; p<0.01). Conclusion: The crop samples in the present study exhibit distinct spatial Se concentration similar to the human Se distribution pattern reported previously. In contrast, total and phosphateextractable Se concentration in soil samples had opposite pattern to human Se. Soil total organic matter content and soil pH were the important factors responsible for the variation in Se concentration. | en_US |
| dc.identifier.uri | http://10.90.10.223:4000/handle/123456789/18926 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Selenium | en_US |
| dc.subject | Soil | en_US |
| dc.subject | Staple Crops | en_US |
| dc.subject | Amhara | en_US |
| dc.subject | Ethiopia | en_US |
| dc.title | Soil Physico-Chemical Characteristics and Level of Selenium In Soil and Staple Crops From Areas of Contrasting Human Selenium Status in the Amhara Region, Ethiopia | en_US |
| dc.type | Thesis | en_US |