scholarly journals Impacts of conservation tillage on the hydrological and agronomic performance of <i>Fanya juus</i> in the upper Blue Nile (Abbay) river basin

2012 ◽  
Vol 16 (12) ◽  
pp. 4725-4735 ◽  
Author(s):  
M. Temesgen ◽  
S. Uhlenbrook ◽  
B. Simane ◽  
P. van der Zaag ◽  
Y. Mohamed ◽  
...  

Abstract. Adoption of soil conservation structures (SCS) has been low in high rainfall areas of Ethiopia mainly due to crop yield reduction, increased soil erosion following breaching of SCS, incompatibility with the tradition of cross plowing and water-logging behind SCS. A new type of conservation tillage (CT) involving contour plowing and the construction of invisible subsoil barriers using a modified Maresha winged "subsoiler" is suggested as a means to tackle these problems as an integral part of the SCS. We investigated the effect of integrating the CT with SCS on the surface runoff, water-logging, soil loss, crop yield and plowing convenience. The new approach of conservation tillage has been compared with traditional tillage (TT) on 5 farmers' fields in a high rainfall area in the upper Blue Nile (Abbay) river basin. Test crops were wheat [triticum vulgare] and tef [eragrostis tef]. Farmers found CT convenient to apply between SCS. Surface runoff appeared to be reduced under CT by 48 and 15%, for wheat and tef, respectively. As a result, CT reduced sediment yield by 51 and 9.5%, for wheat and tef, respectively. Significantly reduced water-logging was observed behind SCS in CT compared to TT. Grain yields of wheat and tef increased by 35 and 10%, respectively, although the differences were not statistically significant apparently due to high fertility variations among fields of participating farmers. Farmers who tested CT indicated that they will continue this practice in the future.

2012 ◽  
Vol 9 (1) ◽  
pp. 1085-1114 ◽  
Author(s):  
M. Temesgen ◽  
S. Uhlenbrook ◽  
B. Simane ◽  
P. van der Zaag ◽  
Y. Mohamed ◽  
...  

Abstract. Adoption of soil conservation structures (SCS) has been low in high rainfall areas of Ethiopia mainly due to crop yield reduction, increased soil erosion following breaching of SCS, incompatibility with the tradition of cross plowing and water-logging behind SCS. A new type of conservation tillage (CT) involving contour plowing and the construction of invisible subsoil barriers using a modified Maresha winged "subsoiler" is suggested as a means to tackle these problems as an integral part of the SCS. We investigated the effect of integrating the CT with SCS on the surface runoff, water-logging, soil loss, crop yield and plowing convenience. The new approach of conservation tillage has been compared with traditional tillage (TT) on 5 farmers' fields in a high rainfall area in the upper Blue Nile (Abbay) river basin. Test crops were wheat [triticum vulgare] and tef [eragrostis tef]. Farmers found CT convenient to apply between SCS. Surface runoff appeared to be reduced under CT by 48 and 15%, for wheat and tef, respectively. As a result, CT reduced sediment yield by 51 and 9.5%, for wheat and tef, respectively. Significantly reduced water-logging was observed behind SCS in CT compared to TT. Grain yields of wheat and tef increased by 35 and 10%, respectively, although the differences were not statistically significant apparently due to high fertility variations among fields of participating farmers. Farmers who tested CT indicated that they will continue this practice in the future.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7093
Author(s):  
Solmaz Rasoulzadeh Gharibdousti ◽  
Gehendra Kharel ◽  
Arthur Stoecker

Best management practices (BMPs) are commonly used to reduce sediment loadings. In this study, we modeled the Fort Cobb Reservoir watershed located in southwestern Oklahoma, USA using the Soil and Water Assessment Tool (SWAT) and evaluated the impacts of five agricultural BMP scenarios on surface runoff, sediment yield, and crop yield. The hydrological model, with 43 sub-basins and 15,217 hydrological response units, was calibrated (1991–2000) and validated (2001–2010) against the monthly observations of streamflow, sediment grab samples, and crop-yields. The coefficient of determination (R2), Nash-Sutcliffe efficiency (NS) and percentage bias (PB) were used to determine model performance with satisfactory values of R2 (0.64 and 0.79) and NS (0.61 and 0.62) in the calibration and validation period respectively for streamflow. We found that contouring practice reduced surface runoff by more than 18% in both conservation tillage and no-till practices for all crops used in this modeling study. In addition, contour farming with either conservation tillage or no-till practice reduced sediment yield by almost half. Compared to the conservation tillage practice, no-till practice decreased sediment yield by 25.3% and 9.0% for cotton and grain sorghum, respectively. Using wheat as cover crop for grain sorghum generated the lowest runoff followed by its rotation with canola and cotton regardless of contouring. Converting all the crops in the watershed into Bermuda grass resulted in significant reduction in sediment yield (72.5–96.3%) and surface runoff (6.8–38.5%). The model can be used to provide useful information for stakeholders to prioritize ecologically sound and feasible BMPs at fields that are capable of reducing sediment yield while increasing crop yield.


Author(s):  
B. Prabhu Dass Batvari ◽  
K. Nagamani

Precipitation is the primary source of fresh water in the world. Surface runoff will happen when the amount of rainfall is greater than the soil’s infiltration capacity. In most water resource applications, runoff is the most important hydrological variable. Aside from these rainfall characteristics, there are a number of catchment-specific elements that have a direct impact on runoff amount and volume. This research focuses on estimating surface runoff over the lower Vellar basin, a river basin in the southern part of India, by integrating Soil Conservation Service-Curve Number (SCS-CN) method with GIS. This technique is one of the most common methods used by hydrologists for estimating surface runoff. Curve Number (CN) is an index established by the Natural Resource Conservation Service (NRCS) to denote the potential for stormwater runoff. The nature of the watershed is explored first by creating land use and land cover pattern followed by the preparation of slope, drainage, and location maps. The area taken for this study is the lower Vellar basin situated in the Cuddalore District of Tamil Nadu, India. The curve number is analyzed using the rainfall data of 15 years (2001-2015) and the runoff is being calculated. The watershed pattern of the study area is also explored being analyzed and executed. Preservation of the runoff water is also discussed.


Solid Earth ◽  
2015 ◽  
Vol 6 (2) ◽  
pp. 765-774 ◽  
Author(s):  
T. Erkossa ◽  
A. Wudneh ◽  
B. Desalegn ◽  
G. Taye

Abstract. The study was conducted in three watersheds (Dapo, Meja and Mizewa) in the Ethiopian part of the Blue Nile Basin to estimate the on-site cost of soil erosion using the productivity change approach, in which crop yield reduction due to plant nutrients lost with the sediment and runoff has been analysed. For this purpose, runoff measurement and sampling was conducted during the main rainy season of 2011 at the outlet of two to three sub-watersheds in each watershed. The sediment concentration of the runoff, and N and P contents in runoff and sediment were determined. Crop response functions were developed for the two plant nutrients based on data obtained from the nearest Agricultural Research Centres. The response functions were used to estimate crop yield reduction as a result of the lost N and P assuming there is no compensation through fertilization. The results show a significant yield reduction and resultant financial loss to the farmers. Considering only grain yield of maize (Zea mays), farmers at Dapo annually lose about USD 220 ha−1 and 150 ha−1 due to the loss of N and P, respectively. In view of the importance of the crop residues, including as feed, the loss can be even greater. The study demonstrated that in addition to the long-term deterioration of land quality, the annual financial loss suffered by farmers is substantial. Therefore, on farm soil and water conservation measures that are suitable in biophysical and socio-economic terms in the landscapes and beyond need to be encouraged.


2018 ◽  
Author(s):  
Solmaz Rasoulzadeh Gharibdousti ◽  
Gehendra Kharel ◽  
Arthur Stoecker

Best management practices (BMPs) are commonly used to control sediment yields. In this study, we modeled the Fort Cobb Reservoir watershed located in southwestern Oklahoma, USA using the Soil and Water Assessment Tool (SWAT) and evaluated the impacts of agricultural five different BMP scenarios on surface runoff, sediment load, and crop yield. The hydrological model with 43 sub-basins and 15,217 hydrological response units was calibrated (1991 ̶ 2000) and validated (2001 ̶ 2010) against the monthly observations of streamflow, sediment grab samples, and crop-yields. The coefficient of determination (R2), Nash-Sutcliffe efficiency (NS) and percentage bias (PB) were used to determine model performance with satisfactory values of R2 (0.64) and NS (0.61) in the calibration period and a good model performance (R2 = 0.79; NS = 0.62) in the validation period for streamflow. We found that contouring practice reduced surface runoff by more than 18% in both conservation tillage and no-till practices for all crops. In addition, contour farming with either conservation tillage or no-till practice reduced sediment yield by almost half. Compared to the conservation tillage practice, no-till system decreased sediment yield by 25.3% and 9.0% for cotton and grain sorghum, respectively. Using wheat as cover crop for grain sorghum generated the lowest runoff followed by its rotation with canola and cotton regardless of contouring. Converting all the crops in the watershed into Bermuda grass resulted significant reduction in sediment yield (72.5-96.3%) and surface runoff (6.8-38.5%). The model was capable of providing precise information for stakeholders to prioritize ecologically sound feasible BMPs at fields that are capable of reducing overland soil erosion and sediment delivery to channels while increasing crop yield.


2018 ◽  
Author(s):  
Solmaz Rasoulzadeh Gharibdousti ◽  
Gehendra Kharel ◽  
Arthur Stoecker

Best management practices (BMPs) are commonly used to control sediment yields. In this study, we modeled the Fort Cobb Reservoir watershed located in southwestern Oklahoma, USA using the Soil and Water Assessment Tool (SWAT) and evaluated the impacts of agricultural five different BMP scenarios on surface runoff, sediment load, and crop yield. The hydrological model with 43 sub-basins and 15,217 hydrological response units was calibrated (1991 ̶ 2000) and validated (2001 ̶ 2010) against the monthly observations of streamflow, sediment grab samples, and crop-yields. The coefficient of determination (R2), Nash-Sutcliffe efficiency (NS) and percentage bias (PB) were used to determine model performance with satisfactory values of R2 (0.64) and NS (0.61) in the calibration period and a good model performance (R2 = 0.79; NS = 0.62) in the validation period for streamflow. We found that contouring practice reduced surface runoff by more than 18% in both conservation tillage and no-till practices for all crops. In addition, contour farming with either conservation tillage or no-till practice reduced sediment yield by almost half. Compared to the conservation tillage practice, no-till system decreased sediment yield by 25.3% and 9.0% for cotton and grain sorghum, respectively. Using wheat as cover crop for grain sorghum generated the lowest runoff followed by its rotation with canola and cotton regardless of contouring. Converting all the crops in the watershed into Bermuda grass resulted significant reduction in sediment yield (72.5-96.3%) and surface runoff (6.8-38.5%). The model was capable of providing precise information for stakeholders to prioritize ecologically sound feasible BMPs at fields that are capable of reducing overland soil erosion and sediment delivery to channels while increasing crop yield.


2015 ◽  
Vol 7 (1) ◽  
pp. 565-594 ◽  
Author(s):  
T. Erkossa ◽  
A. Wudneh ◽  
B. Desalegn ◽  
G. Taye

Abstract. The study was conducted in three watersheds (Dapo, Meja and Mizewa) in the Ethiopian part of the Blue Nile Basin to estimate the onsite cost of soil erosion using the productivity change approach, in which crop yield reduction due to plant nutrients lost with the sediment and runoff has been analyzed. For this purpose, runoff measurement and sampling was conducted during the main rainy season of 2011 at the outlet of two to three sub watersheds in each watershed. The sediment concentration of the runoff, and nitrogen and phosphorus content of the runoff and sediment were determined. Crop response functions were developed for the two plant nutrients based on data obtained from the nearest Agricultural Research Centers. The response functions were used to estimate crop yield reduction as a result of the lost N and P assuming there is no compensation through fertilization. The results show a significant yield reduction and resultant financial loss to the farmers. Considering only grain yield of maize (Zea mays), farmers at Dapo annually lose about 220 and USD 150 ha-1 due to the loss of nitrogen and phosphorus, respectively. In view of the importance of the crop residues including as feed, the loss can be even greater. The study demonstrated that in addition to the long-term deterioration of land quality, the annual financial loss suffered by farmers is substantial. Therefore, on farm soil and water conservation measures that are suitable in biophysical and socio-economic terms in the landscapes and beyond need to be encouraged.


1987 ◽  
Vol 19 (8) ◽  
pp. 75-86 ◽  
Author(s):  
S. P. Amaral

The technology of treatment through landfarming for oily wastes has been more and more often utilized in Brazil, always successfully. The definition, the processes which occur, as well as the factors which affect its performance are herein presented. Design parameters, such as location, ground characterization, dimensioning of the area of application, groundwater protection, drainage, treatment of surface runoff water and percolated liquid, among others, are presented. Operational procedures and quality monitoring of effluents and environment are also described. PETROBRÁS is already operating two landfarming systems and has several others in the design stage. We present data from these projects and report that oily waste degradation has been achieved in around six months. Finally, we expect to be contributing to the affirmation and development of this technology in our Country.


1992 ◽  
Vol 26 (7-8) ◽  
pp. 1851-1856 ◽  
Author(s):  
J. L. Lai ◽  
K. S. L. Lo

A mixing-based model for describing solute transfer to overland flow was developed. This model included a time-dependent mixing depth of the top layer and a complete-mixed surface runoff zone. In a series of laboratory experiments, runoff was passed at various velocities and depths over a medium bed. The media were saturated with uniform concentration of potassium chloride solution. Runoff water was sampled at the beginning and end of the flume and the potassium chloride concentration analyzed. Using this model, dimensionless ultimate mixing depth and dimensionless change rate of mixing depth from experimental data were investigated and implemented. The results showed that the Reynolds number and relative roughness are two important factors.


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