Gravimetric field capacity and permanent wilting point for South African soils.¶
Source¶
Myeni, L., Mdlambuzi, T., Paterson, D. G., De Nysschen, G., & Moeletsi, M. E. (2021). Development and evaluation of pedotransfer functions to estimate soil moisture content at field capacity and permanent wilting point for South African soils. Water, 13(19), 2639. https://doi.org/10.3390/w13192639
Scope¶
Territory: South Africa.
Dataset: ARC national soil database: 6307 soil horizons retained after quality control, with 3171 development horizons and 3136 validation horizons. Horizons were grouped regardless of depth, soil type, textural class, geographic location and climate, then randomly split per granulometric range (Sections 2.1-2.2; Tables 2-3).
Functions¶
calc_ptf_myeni2021_fc¶
Estimate gravimetric field capacity from clay, silt and soil organic carbon.
Status: implemented
Prediction target: Gravimetric soil moisture content at field capacity (-33 kPa).
Inputs¶
| Name | Type | Unit | Domain | Description |
|---|---|---|---|---|
clay | number | % | Development dataset range: 1.00-83.00% (Table 3). | Clay content by weight, particle diameter below 0.002 mm. |
silt | number | % | Development dataset range: 1.00-64.00% (Table 3). | Silt content by weight, particle diameter 0.002-0.05 mm. |
soc | number | % | Development dataset range: 0.01-9.36% (Table 3). | Soil organic carbon content by weight, measured by the Walkley-Black method. |
Outputs¶
| Name | Unit | Domain | Description |
|---|---|---|---|
fc | kg kg⁻¹ | Observed development dataset range: 0.01-0.50 kg/kg (Table 3). | Gravimetric soil moisture content at field capacity (-33 kPa). |
Note
Table 5 gives the stepwise multiple linear regression for FC.
Note
Inputs are weight percentages; output is gravimetric water content.
Warning
Apply with caution outside South Africa, even under similar soil and climatic conditions.
Warning
Disturbed samples were used; soil structure is not explicitly represented.
calc_ptf_myeni2021_pwp¶
Estimate gravimetric permanent wilting point from clay, silt and soil organic carbon.
Status: implemented
Prediction target: Gravimetric soil moisture content at permanent wilting point (-1500 kPa).
Inputs¶
| Name | Type | Unit | Domain | Description |
|---|---|---|---|---|
clay | number | % | Development dataset range: 1.00-83.00% (Table 3). | Clay content by weight, particle diameter below 0.002 mm. |
silt | number | % | Development dataset range: 1.00-64.00% (Table 3). | Silt content by weight, particle diameter 0.002-0.05 mm. |
soc | number | % | Development dataset range: 0.01-9.36% (Table 3). | Soil organic carbon content by weight, measured by the Walkley-Black method. |
Outputs¶
| Name | Unit | Domain | Description |
|---|---|---|---|
pwp | kg kg⁻¹ | Observed development dataset range: 0.00-0.31 kg/kg (Table 3). | Gravimetric soil moisture content at permanent wilting point (-1500 kPa). |
Note
Table 5 gives the stepwise multiple linear regression for PWP without an additive constant.
Note
Inputs are weight percentages; output is gravimetric water content.
Warning
Apply with caution outside South Africa, even under similar soil and climatic conditions.
Warning
Disturbed samples were used; soil structure is not explicitly represented.