Evaluation of three simple hydrosalinity models applied to citrus orchards in the Lower Coerney River irrigation area, Eastern Cape, South Africa
- Authors: Cobban, Dale Anne
- Date: 1992
- Subjects: Irrigation -- Management , Irrigation -- Research -- South Africa -- Eastern Cape , Water in agriculture , Citrus -- Irrigation -- South Africa , Soils, Salts in
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4829 , http://hdl.handle.net/10962/d1005504 , Irrigation -- Management , Irrigation -- Research -- South Africa -- Eastern Cape , Water in agriculture , Citrus -- Irrigation -- South Africa , Soils, Salts in
- Description: Three hydrosalinity models of different complexity were evaluated against data from selected citrus orchards in the Lower Coerney River irrigation area. These models were statistically compared with field data, and found to vary in accuracy of output predictions. The simplest model, the LEACHING REQUIREMENT (LR) model, has the lowest data input requirements and produces output predictions that correlate with up to 93% of the variance in measured data. SODICS, which is theoretically more detailed and requires a greater level of detail in input, produces predictions of an accuracy equivalent to the LR model. The PEAK model was assessed in two parts, the PEAKM module simulating soil moisture and soil moisture movement was able to predict variations in moisture up to 99% of the time. The PEAKD module, which predicts solute concentrations was less effective in replicating real world conditions
- Full Text:
- Authors: Cobban, Dale Anne
- Date: 1992
- Subjects: Irrigation -- Management , Irrigation -- Research -- South Africa -- Eastern Cape , Water in agriculture , Citrus -- Irrigation -- South Africa , Soils, Salts in
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4829 , http://hdl.handle.net/10962/d1005504 , Irrigation -- Management , Irrigation -- Research -- South Africa -- Eastern Cape , Water in agriculture , Citrus -- Irrigation -- South Africa , Soils, Salts in
- Description: Three hydrosalinity models of different complexity were evaluated against data from selected citrus orchards in the Lower Coerney River irrigation area. These models were statistically compared with field data, and found to vary in accuracy of output predictions. The simplest model, the LEACHING REQUIREMENT (LR) model, has the lowest data input requirements and produces output predictions that correlate with up to 93% of the variance in measured data. SODICS, which is theoretically more detailed and requires a greater level of detail in input, produces predictions of an accuracy equivalent to the LR model. The PEAK model was assessed in two parts, the PEAKM module simulating soil moisture and soil moisture movement was able to predict variations in moisture up to 99% of the time. The PEAKD module, which predicts solute concentrations was less effective in replicating real world conditions
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The effect of pineapple cultivation on factors influencing soil erodibility in the Eastern Cape, South Africa
- Authors: Boucher, Kim Gillian
- Date: 1992
- Subjects: Soil erosion -- South Africa Pineapple industry -- South Africa -- Eastern Cape Agriculture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4827 , http://hdl.handle.net/10962/d1005502
- Description: The study examines the effect of ridged pineapple cultivation on factors influencing the soil erodibility of Glenrosa and Oakleaf soil forms in the Bathurst district of South Africa. A number of physical and chemical variables influencing soil erodibility are investigated, namely soil moisture, bulk density, porosity, infiltration rate, aggregate stability, shear strength, soil texture, soil structure, penetrability, organic carbon, pH and cation exchange capacity. These soil characteristics are examined in undisturbed soils under natural vegetation and compared to those on adjacent traffic areas, pineapple ridges and pineapple furrows. The results of the analyses between the four sample sites indicate that ridged cultivation of pineapples has a negative effect on factors influencing soil erodibility on the areas studied. The results of the analysis within each of the sample sites do not illustrate any clear relationships and thus depict the complexity and multiplicity of the soil erodibility phenomenon. A further study, augmenting the soil erodibility data with actual soil loss data, is recommended
- Full Text:
- Authors: Boucher, Kim Gillian
- Date: 1992
- Subjects: Soil erosion -- South Africa Pineapple industry -- South Africa -- Eastern Cape Agriculture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4827 , http://hdl.handle.net/10962/d1005502
- Description: The study examines the effect of ridged pineapple cultivation on factors influencing the soil erodibility of Glenrosa and Oakleaf soil forms in the Bathurst district of South Africa. A number of physical and chemical variables influencing soil erodibility are investigated, namely soil moisture, bulk density, porosity, infiltration rate, aggregate stability, shear strength, soil texture, soil structure, penetrability, organic carbon, pH and cation exchange capacity. These soil characteristics are examined in undisturbed soils under natural vegetation and compared to those on adjacent traffic areas, pineapple ridges and pineapple furrows. The results of the analyses between the four sample sites indicate that ridged cultivation of pineapples has a negative effect on factors influencing soil erodibility on the areas studied. The results of the analysis within each of the sample sites do not illustrate any clear relationships and thus depict the complexity and multiplicity of the soil erodibility phenomenon. A further study, augmenting the soil erodibility data with actual soil loss data, is recommended
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