A study was conducted in 2007/2008 at Absela locality, Banja Shikudad District of the Amhara National Regional State, Ethiopia to evaluate the effects of soil bunds stabilized with vetiver grass （IT. zizanioides） an...A study was conducted in 2007/2008 at Absela locality, Banja Shikudad District of the Amhara National Regional State, Ethiopia to evaluate the effects of soil bunds stabilized with vetiver grass （IT. zizanioides） and tree lucerne （C. palmensis） on soil physical and chemical properties, bund height, inter-terrace slope and barley （Hordeum vulgare L.） yield. Data were analyzed using one-way analysis of variance （ANOVA） and mean values for the treatments were separated using Duncan＇s Multiple Range Test. Results indicated that the non-conserved fields had significantly （p 〈 0.05） lower organic carbon and was found to contain 66% less OM from the average of the conserved treatment. 9-year old sole soil bund, the 9-year old soil bund stabilized with tree lucerne, the 9-year old soil bund stabilized with vetiver, and the 6-year old soil bund stabilized with tree lucerne had 71.20, 68.56, 52.30, and 36.12%, respectively higher percent OM than the control treatment. The trend was similar for total nitrogen. The non-conserved treatment had a higher bulk density when compared to the conserved fields. Fields with soil bunds stabilized with vetiver grass had the highest bund height and the lowest inter-terrace slope than fields treated with the rest of remaining conservation measures. Barley grain yields were significantly （P 〈 0.05） greater in both the soil accumulation and loss zones of the conserved fields than the non-conserved （control） treatment. Practicing soil conservation measures and curtailing causes of land degradation could improve the soil physical and chemical properties thereby increase land productivity of the conserved land.展开更多
The Merguellil catchment （central Tunisia） has undergone rapid hydrological changes over the last decades. The most visible signs are a marked decrease in surface runoff in the upstream catchment and a complete chan...The Merguellil catchment （central Tunisia） has undergone rapid hydrological changes over the last decades. The most visible signs are a marked decrease in surface runoff in the upstream catchment and a complete change in the recharge processes of the Kairouan aquifer downstream. Fluctuations in rainfall have had a real but limited hydrological impact. Much more important are the consequences of human activities such as soil and water conservation works, small and large dams, pumping for irrigation. Several independent approaches were implemented： hydrodynamics, thermal surveys, geochemistry including isotopes. They helped to identify the different terms of the regional water balance and to characterize their changes over time.展开更多
文摘A study was conducted in 2007/2008 at Absela locality, Banja Shikudad District of the Amhara National Regional State, Ethiopia to evaluate the effects of soil bunds stabilized with vetiver grass （IT. zizanioides） and tree lucerne （C. palmensis） on soil physical and chemical properties, bund height, inter-terrace slope and barley （Hordeum vulgare L.） yield. Data were analyzed using one-way analysis of variance （ANOVA） and mean values for the treatments were separated using Duncan＇s Multiple Range Test. Results indicated that the non-conserved fields had significantly （p 〈 0.05） lower organic carbon and was found to contain 66% less OM from the average of the conserved treatment. 9-year old sole soil bund, the 9-year old soil bund stabilized with tree lucerne, the 9-year old soil bund stabilized with vetiver, and the 6-year old soil bund stabilized with tree lucerne had 71.20, 68.56, 52.30, and 36.12%, respectively higher percent OM than the control treatment. The trend was similar for total nitrogen. The non-conserved treatment had a higher bulk density when compared to the conserved fields. Fields with soil bunds stabilized with vetiver grass had the highest bund height and the lowest inter-terrace slope than fields treated with the rest of remaining conservation measures. Barley grain yields were significantly （P 〈 0.05） greater in both the soil accumulation and loss zones of the conserved fields than the non-conserved （control） treatment. Practicing soil conservation measures and curtailing causes of land degradation could improve the soil physical and chemical properties thereby increase land productivity of the conserved land.
文摘The Merguellil catchment （central Tunisia） has undergone rapid hydrological changes over the last decades. The most visible signs are a marked decrease in surface runoff in the upstream catchment and a complete change in the recharge processes of the Kairouan aquifer downstream. Fluctuations in rainfall have had a real but limited hydrological impact. Much more important are the consequences of human activities such as soil and water conservation works, small and large dams, pumping for irrigation. Several independent approaches were implemented： hydrodynamics, thermal surveys, geochemistry including isotopes. They helped to identify the different terms of the regional water balance and to characterize their changes over time.
