The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Jan Nyssen - One of the best experts on this subject based on the ideXlab platform.
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effects of drainage ditches and stone Bunds on topographical thresholds for gully head development in north ethiopia
Geomorphology, 2015Co-Authors: Jean Poesen, Jozef Deckers, Elise Monsieurs, Mekete Dessie, Enyew Adgo, Niko E C Verhoest, Jan NyssenAbstract:Abstract Gully erosion is an extreme process of land degradation operating in different regions of the world. A common way to quantify the susceptibility of land to gully incision is the use of topographical thresholds for different land use types. However, the impact of various management practices in cropland on these thresholds has not been studied to date, although land management may significantly affect runoff production, erosion processes and rates. Here, the impact of different land management practices on gully head development in cropland is studied based on a standardized procedure for topographical threshold analysis: s > kA− b, where s represents the slope gradient of the soil surface, A the drainage area at the gully head, b an exponent and k a coefficient reflecting the resistance of the land to gully head development. A case study area was chosen around Wanzaye, North Ethiopia, where three different cropland management practices were studied in 75 catchments: (i) the catchment-wide use of stone Bunds on the contour, (ii) the use of slightly sloping drainage ditches (feses), and (iii) the combined use of stone Bunds and feses. The lowest k-values (0.078–0.090) are found for catchments treated with feses, the highest k-values (0.198–0.205) are observed for stone bund catchments, and medium k-values (0.092–0.099) are found for mixed catchments. This finding implies that catchments with the exclusive use of drainage ditches are the most vulnerable to gully head development compared with mixed catchments and stone bund catchments. However, on-site sheet and rill erosion rates are reduced by feses as they lower the gradient of the overland flow lines. Three trends in cropland management around Wanzaye and the wider region are observed: (i) feses are exclusively made on rather steep slopes where small drainage areas lead to the rapid development of gully heads; (ii) stone Bunds are constructed on both steeper and gentle sloping cropland; and (iii) larger and gently sloping catchments seem to be most suitable for the combined use of drainage ditches and stone Bunds.
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interdisciplinary on site evaluation of stone Bunds to control soil erosion on cropland in northern ethiopia
Soil & Tillage Research, 2007Co-Authors: Jan Nyssen, Desta Gebremichael, Jean Poesen, Gerard Govers, J Moeyersons, Karen Vancampenhout, Margo Daes, Gebremedhin Yihdego, Herwig Leirs, J NaudtsAbstract:Since two decades, stone Bunds have been installed in large areas of the Tigray Highlands, Northern Ethiopia, to control soil erosion by water. Field studies were conducted to quantify the effectiveness, efficiency, side effects and acceptance of stone Bunds. Based on measurements on 202 field parcels, average sediment accumulation rate behind 3–21 year old stone Bunds is 58 t ha � 1 year � 1 .The Universal Soil Loss Equation’s P-factor for stone Bunds was estimated at 0.32. Sediment accumulation rates increase with slope gradient and bund spacing, but decrease with bund age. Truncation of the soil profile at the lower side of the bund does not lead to an important soil fertility decrease, mainly because the dominant soil types in the study area (Regosols, Vertisols and Vertic Cambisols) do not have pronounced vertical fertility gradients. Excessive removal of small rock fragments from the soil surface during stone bund building may lead to a three-fold increase in sheet and rill erosion rates. Negative effects of runoff concentration or crop burial by sediment deposition due to Bunds were only found over 60 m along 4 km of studied Bunds. As the rodent problem is widespread and generally not specific to stone Bunds, it calls for distinct interventions. On plots with stone Bunds of different ages (between 3 and 21 years old), there is an average increase in grain yield of 53% in the lower part of the plot, as compared to the central and upper parts. Taking into account the space occupied by the Bunds, stone Bunds led in 2002 to a mean crop yield increase from 0.58 to 0.65 t ha � 1 . The cost of stone bund building averages s13.6 ha � 1 year � 1 , which is nearly the same as the value of the induced crop yield increase in 2002 (s13.2 ha � 1 year � 1 ). Besides positive off-site effects such as runoff and flood regulation, the enhanced moisture storage in deep soil horizons on both sides of the Bunds indicates that the stone bund areas can be made more productive through tree planting. We conclude that from the technical, ecological and economical point of view, the extensive use of stone Bunds, involving people’s participation, is a positive operation. Overall, 75% of the farmers are in favour of
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stone Bunds for soil conservation in the northern ethiopian highlands impacts on soil fertility and crop yield
Soil & Tillage Research, 2006Co-Authors: Karen Vancampenhout, Desta Gebremichael, Jan Nyssen, Jean Poesen, Jozef Deckers, Mitiku Haile, J MoeyersonsAbstract:Abstract In the Ethiopian highlands, large-scale stone bund building programs are implemented to curb severe soil erosion. Development of soil fertility gradients is often mentioned as the major drawback of stone bund implementation, as it would result in a dramatic lowering of crop yield. Therefore, the objectives of this study are to assess soil fertility gradients on progressive terraces and their influence on crop yield, in order to evaluate the long-term sustainability of stone Bunds in the Ethiopian Highlands. The study was performed near Hagere Selam, Tigray and comprises (i) measurement of P av , N tot and C org along the slope on 20 representative plots and (ii) crop response measurement on 143 plots. Results indicate that levels of P av , N tot and C org in the plough layer are highly variable between plots and mainly determined by small-scale soil and environmental features, plot history and management. After correcting for this “plot effect” a significant relationship ( p av and N tot , which are higher near the lower stone bund, especially on limestone parent material. For C org and on basalt-derived soils in general no significant relationship was found. Although soil fertility gradients are present, they are not problematic and can be compensated by adapted soil management. Only in areas where a Calcaric or Calcic horizon is present at shallow depth, care should be taken. Crop Yields increased by 7% compared to the situation without stone Bunds, if a land occupation of 8% by the structures is accounted for. Yield increased from 632 to 683 kg ha −1 for cereals, from 501 to 556 kg ha −1 (11%) for Eragrostis tef and from 335 to 351 kg ha −1 for Cicer arietinum . No negative effects reducing stone-bund sustainability were found in this study. Soil erosion on the other hand, poses a major threat to agricultural productivity. Stone bund implementation therefore is of vital importance in fighting desertification and establishing sustainable agriculture in the Ethiopian highlands.
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effectiveness of stone Bunds in controlling soil erosion on cropland in the tigray highlands northern ethiopia
Soil Use and Management, 2005Co-Authors: Desta Gebremichael, Jan Nyssen, Jean Poesen, Jozef Deckers, Mitiku Haile, Gerard Govers, J MoeyersonsAbstract:Use of stone Bunds to enhance soil and water conservation was first introduced to Tigray, northern Ethiopia in 1981. This studs was designed to examine the factors that control the effectiveness of Bunds installed on cropland. Qualitative and quantitative assessments of soil loss and sediment accumulation were conducted on 202 plots at 12 representative sites in Dogu'a Tembien district. Mean annual soil loss from the foot of the Bunds due to tillage erosion was estimated at 39kgm - 1 yr - 1 or 20tha - 1 yr - 1 a a rate which decreased with increasing age of bund. The assessed mean annual soil loss rate by sheet and rill erosion in the absence of stone Bunds is 57t ha - 1 yr - 1 . The mean measured annual rate of sediment accumulation behind the stone bonds is 119 kg m - 1 yr - 1 or 59t ha - 1 yr - 1 . The measurements show that the introduction of stone Bunds to the region has led to a 68% reduction in annual soil loss due to water erosion. This reduction is due to the accumulation of sediment behind the stone Bunds, which occurs faster in the early years after construction and decreases as the depression behind the Bunds becomes filled with sediment. New stone Bunds are particularly effective in trapping sediment in transport, but regular maintenance and increase in height of the Bunds is necessary to maintain their effectiveness. The average USLE P factor for stone Bunds in the study area is estimated to be 0.32.
J Moeyersons - One of the best experts on this subject based on the ideXlab platform.
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interdisciplinary on site evaluation of stone Bunds to control soil erosion on cropland in northern ethiopia
Soil & Tillage Research, 2007Co-Authors: Jan Nyssen, Desta Gebremichael, Jean Poesen, Gerard Govers, J Moeyersons, Karen Vancampenhout, Margo Daes, Gebremedhin Yihdego, Herwig Leirs, J NaudtsAbstract:Since two decades, stone Bunds have been installed in large areas of the Tigray Highlands, Northern Ethiopia, to control soil erosion by water. Field studies were conducted to quantify the effectiveness, efficiency, side effects and acceptance of stone Bunds. Based on measurements on 202 field parcels, average sediment accumulation rate behind 3–21 year old stone Bunds is 58 t ha � 1 year � 1 .The Universal Soil Loss Equation’s P-factor for stone Bunds was estimated at 0.32. Sediment accumulation rates increase with slope gradient and bund spacing, but decrease with bund age. Truncation of the soil profile at the lower side of the bund does not lead to an important soil fertility decrease, mainly because the dominant soil types in the study area (Regosols, Vertisols and Vertic Cambisols) do not have pronounced vertical fertility gradients. Excessive removal of small rock fragments from the soil surface during stone bund building may lead to a three-fold increase in sheet and rill erosion rates. Negative effects of runoff concentration or crop burial by sediment deposition due to Bunds were only found over 60 m along 4 km of studied Bunds. As the rodent problem is widespread and generally not specific to stone Bunds, it calls for distinct interventions. On plots with stone Bunds of different ages (between 3 and 21 years old), there is an average increase in grain yield of 53% in the lower part of the plot, as compared to the central and upper parts. Taking into account the space occupied by the Bunds, stone Bunds led in 2002 to a mean crop yield increase from 0.58 to 0.65 t ha � 1 . The cost of stone bund building averages s13.6 ha � 1 year � 1 , which is nearly the same as the value of the induced crop yield increase in 2002 (s13.2 ha � 1 year � 1 ). Besides positive off-site effects such as runoff and flood regulation, the enhanced moisture storage in deep soil horizons on both sides of the Bunds indicates that the stone bund areas can be made more productive through tree planting. We conclude that from the technical, ecological and economical point of view, the extensive use of stone Bunds, involving people’s participation, is a positive operation. Overall, 75% of the farmers are in favour of
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stone Bunds for soil conservation in the northern ethiopian highlands impacts on soil fertility and crop yield
Soil & Tillage Research, 2006Co-Authors: Karen Vancampenhout, Desta Gebremichael, Jan Nyssen, Jean Poesen, Jozef Deckers, Mitiku Haile, J MoeyersonsAbstract:Abstract In the Ethiopian highlands, large-scale stone bund building programs are implemented to curb severe soil erosion. Development of soil fertility gradients is often mentioned as the major drawback of stone bund implementation, as it would result in a dramatic lowering of crop yield. Therefore, the objectives of this study are to assess soil fertility gradients on progressive terraces and their influence on crop yield, in order to evaluate the long-term sustainability of stone Bunds in the Ethiopian Highlands. The study was performed near Hagere Selam, Tigray and comprises (i) measurement of P av , N tot and C org along the slope on 20 representative plots and (ii) crop response measurement on 143 plots. Results indicate that levels of P av , N tot and C org in the plough layer are highly variable between plots and mainly determined by small-scale soil and environmental features, plot history and management. After correcting for this “plot effect” a significant relationship ( p av and N tot , which are higher near the lower stone bund, especially on limestone parent material. For C org and on basalt-derived soils in general no significant relationship was found. Although soil fertility gradients are present, they are not problematic and can be compensated by adapted soil management. Only in areas where a Calcaric or Calcic horizon is present at shallow depth, care should be taken. Crop Yields increased by 7% compared to the situation without stone Bunds, if a land occupation of 8% by the structures is accounted for. Yield increased from 632 to 683 kg ha −1 for cereals, from 501 to 556 kg ha −1 (11%) for Eragrostis tef and from 335 to 351 kg ha −1 for Cicer arietinum . No negative effects reducing stone-bund sustainability were found in this study. Soil erosion on the other hand, poses a major threat to agricultural productivity. Stone bund implementation therefore is of vital importance in fighting desertification and establishing sustainable agriculture in the Ethiopian highlands.
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effectiveness of stone Bunds in controlling soil erosion on cropland in the tigray highlands northern ethiopia
Soil Use and Management, 2005Co-Authors: Desta Gebremichael, Jan Nyssen, Jean Poesen, Jozef Deckers, Mitiku Haile, Gerard Govers, J MoeyersonsAbstract:Use of stone Bunds to enhance soil and water conservation was first introduced to Tigray, northern Ethiopia in 1981. This studs was designed to examine the factors that control the effectiveness of Bunds installed on cropland. Qualitative and quantitative assessments of soil loss and sediment accumulation were conducted on 202 plots at 12 representative sites in Dogu'a Tembien district. Mean annual soil loss from the foot of the Bunds due to tillage erosion was estimated at 39kgm - 1 yr - 1 or 20tha - 1 yr - 1 a a rate which decreased with increasing age of bund. The assessed mean annual soil loss rate by sheet and rill erosion in the absence of stone Bunds is 57t ha - 1 yr - 1 . The mean measured annual rate of sediment accumulation behind the stone bonds is 119 kg m - 1 yr - 1 or 59t ha - 1 yr - 1 . The measurements show that the introduction of stone Bunds to the region has led to a 68% reduction in annual soil loss due to water erosion. This reduction is due to the accumulation of sediment behind the stone Bunds, which occurs faster in the early years after construction and decreases as the depression behind the Bunds becomes filled with sediment. New stone Bunds are particularly effective in trapping sediment in transport, but regular maintenance and increase in height of the Bunds is necessary to maintain their effectiveness. The average USLE P factor for stone Bunds in the study area is estimated to be 0.32.
Jean Poesen - One of the best experts on this subject based on the ideXlab platform.
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effects of drainage ditches and stone Bunds on topographical thresholds for gully head development in north ethiopia
Geomorphology, 2015Co-Authors: Jean Poesen, Jozef Deckers, Elise Monsieurs, Mekete Dessie, Enyew Adgo, Niko E C Verhoest, Jan NyssenAbstract:Abstract Gully erosion is an extreme process of land degradation operating in different regions of the world. A common way to quantify the susceptibility of land to gully incision is the use of topographical thresholds for different land use types. However, the impact of various management practices in cropland on these thresholds has not been studied to date, although land management may significantly affect runoff production, erosion processes and rates. Here, the impact of different land management practices on gully head development in cropland is studied based on a standardized procedure for topographical threshold analysis: s > kA− b, where s represents the slope gradient of the soil surface, A the drainage area at the gully head, b an exponent and k a coefficient reflecting the resistance of the land to gully head development. A case study area was chosen around Wanzaye, North Ethiopia, where three different cropland management practices were studied in 75 catchments: (i) the catchment-wide use of stone Bunds on the contour, (ii) the use of slightly sloping drainage ditches (feses), and (iii) the combined use of stone Bunds and feses. The lowest k-values (0.078–0.090) are found for catchments treated with feses, the highest k-values (0.198–0.205) are observed for stone bund catchments, and medium k-values (0.092–0.099) are found for mixed catchments. This finding implies that catchments with the exclusive use of drainage ditches are the most vulnerable to gully head development compared with mixed catchments and stone bund catchments. However, on-site sheet and rill erosion rates are reduced by feses as they lower the gradient of the overland flow lines. Three trends in cropland management around Wanzaye and the wider region are observed: (i) feses are exclusively made on rather steep slopes where small drainage areas lead to the rapid development of gully heads; (ii) stone Bunds are constructed on both steeper and gentle sloping cropland; and (iii) larger and gently sloping catchments seem to be most suitable for the combined use of drainage ditches and stone Bunds.
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interdisciplinary on site evaluation of stone Bunds to control soil erosion on cropland in northern ethiopia
Soil & Tillage Research, 2007Co-Authors: Jan Nyssen, Desta Gebremichael, Jean Poesen, Gerard Govers, J Moeyersons, Karen Vancampenhout, Margo Daes, Gebremedhin Yihdego, Herwig Leirs, J NaudtsAbstract:Since two decades, stone Bunds have been installed in large areas of the Tigray Highlands, Northern Ethiopia, to control soil erosion by water. Field studies were conducted to quantify the effectiveness, efficiency, side effects and acceptance of stone Bunds. Based on measurements on 202 field parcels, average sediment accumulation rate behind 3–21 year old stone Bunds is 58 t ha � 1 year � 1 .The Universal Soil Loss Equation’s P-factor for stone Bunds was estimated at 0.32. Sediment accumulation rates increase with slope gradient and bund spacing, but decrease with bund age. Truncation of the soil profile at the lower side of the bund does not lead to an important soil fertility decrease, mainly because the dominant soil types in the study area (Regosols, Vertisols and Vertic Cambisols) do not have pronounced vertical fertility gradients. Excessive removal of small rock fragments from the soil surface during stone bund building may lead to a three-fold increase in sheet and rill erosion rates. Negative effects of runoff concentration or crop burial by sediment deposition due to Bunds were only found over 60 m along 4 km of studied Bunds. As the rodent problem is widespread and generally not specific to stone Bunds, it calls for distinct interventions. On plots with stone Bunds of different ages (between 3 and 21 years old), there is an average increase in grain yield of 53% in the lower part of the plot, as compared to the central and upper parts. Taking into account the space occupied by the Bunds, stone Bunds led in 2002 to a mean crop yield increase from 0.58 to 0.65 t ha � 1 . The cost of stone bund building averages s13.6 ha � 1 year � 1 , which is nearly the same as the value of the induced crop yield increase in 2002 (s13.2 ha � 1 year � 1 ). Besides positive off-site effects such as runoff and flood regulation, the enhanced moisture storage in deep soil horizons on both sides of the Bunds indicates that the stone bund areas can be made more productive through tree planting. We conclude that from the technical, ecological and economical point of view, the extensive use of stone Bunds, involving people’s participation, is a positive operation. Overall, 75% of the farmers are in favour of
-
stone Bunds for soil conservation in the northern ethiopian highlands impacts on soil fertility and crop yield
Soil & Tillage Research, 2006Co-Authors: Karen Vancampenhout, Desta Gebremichael, Jan Nyssen, Jean Poesen, Jozef Deckers, Mitiku Haile, J MoeyersonsAbstract:Abstract In the Ethiopian highlands, large-scale stone bund building programs are implemented to curb severe soil erosion. Development of soil fertility gradients is often mentioned as the major drawback of stone bund implementation, as it would result in a dramatic lowering of crop yield. Therefore, the objectives of this study are to assess soil fertility gradients on progressive terraces and their influence on crop yield, in order to evaluate the long-term sustainability of stone Bunds in the Ethiopian Highlands. The study was performed near Hagere Selam, Tigray and comprises (i) measurement of P av , N tot and C org along the slope on 20 representative plots and (ii) crop response measurement on 143 plots. Results indicate that levels of P av , N tot and C org in the plough layer are highly variable between plots and mainly determined by small-scale soil and environmental features, plot history and management. After correcting for this “plot effect” a significant relationship ( p av and N tot , which are higher near the lower stone bund, especially on limestone parent material. For C org and on basalt-derived soils in general no significant relationship was found. Although soil fertility gradients are present, they are not problematic and can be compensated by adapted soil management. Only in areas where a Calcaric or Calcic horizon is present at shallow depth, care should be taken. Crop Yields increased by 7% compared to the situation without stone Bunds, if a land occupation of 8% by the structures is accounted for. Yield increased from 632 to 683 kg ha −1 for cereals, from 501 to 556 kg ha −1 (11%) for Eragrostis tef and from 335 to 351 kg ha −1 for Cicer arietinum . No negative effects reducing stone-bund sustainability were found in this study. Soil erosion on the other hand, poses a major threat to agricultural productivity. Stone bund implementation therefore is of vital importance in fighting desertification and establishing sustainable agriculture in the Ethiopian highlands.
-
effectiveness of stone Bunds in controlling soil erosion on cropland in the tigray highlands northern ethiopia
Soil Use and Management, 2005Co-Authors: Desta Gebremichael, Jan Nyssen, Jean Poesen, Jozef Deckers, Mitiku Haile, Gerard Govers, J MoeyersonsAbstract:Use of stone Bunds to enhance soil and water conservation was first introduced to Tigray, northern Ethiopia in 1981. This studs was designed to examine the factors that control the effectiveness of Bunds installed on cropland. Qualitative and quantitative assessments of soil loss and sediment accumulation were conducted on 202 plots at 12 representative sites in Dogu'a Tembien district. Mean annual soil loss from the foot of the Bunds due to tillage erosion was estimated at 39kgm - 1 yr - 1 or 20tha - 1 yr - 1 a a rate which decreased with increasing age of bund. The assessed mean annual soil loss rate by sheet and rill erosion in the absence of stone Bunds is 57t ha - 1 yr - 1 . The mean measured annual rate of sediment accumulation behind the stone bonds is 119 kg m - 1 yr - 1 or 59t ha - 1 yr - 1 . The measurements show that the introduction of stone Bunds to the region has led to a 68% reduction in annual soil loss due to water erosion. This reduction is due to the accumulation of sediment behind the stone Bunds, which occurs faster in the early years after construction and decreases as the depression behind the Bunds becomes filled with sediment. New stone Bunds are particularly effective in trapping sediment in transport, but regular maintenance and increase in height of the Bunds is necessary to maintain their effectiveness. The average USLE P factor for stone Bunds in the study area is estimated to be 0.32.
Karen Vancampenhout - One of the best experts on this subject based on the ideXlab platform.
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interdisciplinary on site evaluation of stone Bunds to control soil erosion on cropland in northern ethiopia
Soil & Tillage Research, 2007Co-Authors: Jan Nyssen, Desta Gebremichael, Jean Poesen, Gerard Govers, J Moeyersons, Karen Vancampenhout, Margo Daes, Gebremedhin Yihdego, Herwig Leirs, J NaudtsAbstract:Since two decades, stone Bunds have been installed in large areas of the Tigray Highlands, Northern Ethiopia, to control soil erosion by water. Field studies were conducted to quantify the effectiveness, efficiency, side effects and acceptance of stone Bunds. Based on measurements on 202 field parcels, average sediment accumulation rate behind 3–21 year old stone Bunds is 58 t ha � 1 year � 1 .The Universal Soil Loss Equation’s P-factor for stone Bunds was estimated at 0.32. Sediment accumulation rates increase with slope gradient and bund spacing, but decrease with bund age. Truncation of the soil profile at the lower side of the bund does not lead to an important soil fertility decrease, mainly because the dominant soil types in the study area (Regosols, Vertisols and Vertic Cambisols) do not have pronounced vertical fertility gradients. Excessive removal of small rock fragments from the soil surface during stone bund building may lead to a three-fold increase in sheet and rill erosion rates. Negative effects of runoff concentration or crop burial by sediment deposition due to Bunds were only found over 60 m along 4 km of studied Bunds. As the rodent problem is widespread and generally not specific to stone Bunds, it calls for distinct interventions. On plots with stone Bunds of different ages (between 3 and 21 years old), there is an average increase in grain yield of 53% in the lower part of the plot, as compared to the central and upper parts. Taking into account the space occupied by the Bunds, stone Bunds led in 2002 to a mean crop yield increase from 0.58 to 0.65 t ha � 1 . The cost of stone bund building averages s13.6 ha � 1 year � 1 , which is nearly the same as the value of the induced crop yield increase in 2002 (s13.2 ha � 1 year � 1 ). Besides positive off-site effects such as runoff and flood regulation, the enhanced moisture storage in deep soil horizons on both sides of the Bunds indicates that the stone bund areas can be made more productive through tree planting. We conclude that from the technical, ecological and economical point of view, the extensive use of stone Bunds, involving people’s participation, is a positive operation. Overall, 75% of the farmers are in favour of
-
stone Bunds for soil conservation in the northern ethiopian highlands impacts on soil fertility and crop yield
Soil & Tillage Research, 2006Co-Authors: Karen Vancampenhout, Desta Gebremichael, Jan Nyssen, Jean Poesen, Jozef Deckers, Mitiku Haile, J MoeyersonsAbstract:Abstract In the Ethiopian highlands, large-scale stone bund building programs are implemented to curb severe soil erosion. Development of soil fertility gradients is often mentioned as the major drawback of stone bund implementation, as it would result in a dramatic lowering of crop yield. Therefore, the objectives of this study are to assess soil fertility gradients on progressive terraces and their influence on crop yield, in order to evaluate the long-term sustainability of stone Bunds in the Ethiopian Highlands. The study was performed near Hagere Selam, Tigray and comprises (i) measurement of P av , N tot and C org along the slope on 20 representative plots and (ii) crop response measurement on 143 plots. Results indicate that levels of P av , N tot and C org in the plough layer are highly variable between plots and mainly determined by small-scale soil and environmental features, plot history and management. After correcting for this “plot effect” a significant relationship ( p av and N tot , which are higher near the lower stone bund, especially on limestone parent material. For C org and on basalt-derived soils in general no significant relationship was found. Although soil fertility gradients are present, they are not problematic and can be compensated by adapted soil management. Only in areas where a Calcaric or Calcic horizon is present at shallow depth, care should be taken. Crop Yields increased by 7% compared to the situation without stone Bunds, if a land occupation of 8% by the structures is accounted for. Yield increased from 632 to 683 kg ha −1 for cereals, from 501 to 556 kg ha −1 (11%) for Eragrostis tef and from 335 to 351 kg ha −1 for Cicer arietinum . No negative effects reducing stone-bund sustainability were found in this study. Soil erosion on the other hand, poses a major threat to agricultural productivity. Stone bund implementation therefore is of vital importance in fighting desertification and establishing sustainable agriculture in the Ethiopian highlands.
J Naudts - One of the best experts on this subject based on the ideXlab platform.
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interdisciplinary on site evaluation of stone Bunds to control soil erosion on cropland in northern ethiopia
Soil & Tillage Research, 2007Co-Authors: Jan Nyssen, Desta Gebremichael, Jean Poesen, Gerard Govers, J Moeyersons, Karen Vancampenhout, Margo Daes, Gebremedhin Yihdego, Herwig Leirs, J NaudtsAbstract:Since two decades, stone Bunds have been installed in large areas of the Tigray Highlands, Northern Ethiopia, to control soil erosion by water. Field studies were conducted to quantify the effectiveness, efficiency, side effects and acceptance of stone Bunds. Based on measurements on 202 field parcels, average sediment accumulation rate behind 3–21 year old stone Bunds is 58 t ha � 1 year � 1 .The Universal Soil Loss Equation’s P-factor for stone Bunds was estimated at 0.32. Sediment accumulation rates increase with slope gradient and bund spacing, but decrease with bund age. Truncation of the soil profile at the lower side of the bund does not lead to an important soil fertility decrease, mainly because the dominant soil types in the study area (Regosols, Vertisols and Vertic Cambisols) do not have pronounced vertical fertility gradients. Excessive removal of small rock fragments from the soil surface during stone bund building may lead to a three-fold increase in sheet and rill erosion rates. Negative effects of runoff concentration or crop burial by sediment deposition due to Bunds were only found over 60 m along 4 km of studied Bunds. As the rodent problem is widespread and generally not specific to stone Bunds, it calls for distinct interventions. On plots with stone Bunds of different ages (between 3 and 21 years old), there is an average increase in grain yield of 53% in the lower part of the plot, as compared to the central and upper parts. Taking into account the space occupied by the Bunds, stone Bunds led in 2002 to a mean crop yield increase from 0.58 to 0.65 t ha � 1 . The cost of stone bund building averages s13.6 ha � 1 year � 1 , which is nearly the same as the value of the induced crop yield increase in 2002 (s13.2 ha � 1 year � 1 ). Besides positive off-site effects such as runoff and flood regulation, the enhanced moisture storage in deep soil horizons on both sides of the Bunds indicates that the stone bund areas can be made more productive through tree planting. We conclude that from the technical, ecological and economical point of view, the extensive use of stone Bunds, involving people’s participation, is a positive operation. Overall, 75% of the farmers are in favour of
