Africa Soil Information for taking agronomy to scale

Transcription

1 Africa Soil Information for taking agronomy to scale results Johan Leenaars (September 23 rd, 2015)

2 ISRIC brief (e.g. AfSIS) (e.g. GYGA)

3 Africa Soil Information Need for Complete, coherent, detailed, properties, uncertainty cm cm cm cm cm cm

4 Africa Soil Information From points to grids

5 Soil data processing Global Soil Information Facilities + Soil collections World Soil Profiles Soil profile data Soil information (maps) Derived response maps Use soil information

6 Soil data processing Global Soil Information Facilities + Soil collections World Soil Profiles Soil profile data Validate & update (new soil data) Soil information (maps) Derived response maps Use soil information

7 Africa Soil Profiles database 2770

8 Africa Soil Profiles database 7300

9 Africa Soil Profiles database AfSP version

10 Africa Soil Profiles database AfSP version 1.0 B d B c B a H b H a

11 Africa Soil Information 1km Africa (AfSIS) Soil organic carbon ISRIC,

12 Africa Soil Information 1km Africa (AfSIS) Uncertainty Soil organic carbon ISRIC, 2013

13 Africa Soil Information 1km Africa (AfSIS) Sand Silt Clay OC BD CEC ph H2O Soil organic carbon ISRIC, 2013

14 Africa Soil Information AfSP PTF Sand Silt Clay OC BD CEC ph H2O Africa (AfSIS) Soil water retention Wösten et al., 2013

15 Globally integrated Africa Soil Information Upscaling World SoilGrids1 km Sand Silt Clay OC BD CEC ph H2O ph Hengl et al., Globally integrated

16 Africa Soil Information updating AfSoilGrids250m Hengl et al., 2015

17 Africa Soil Information updating cm 5 15 cm cm AfSP version cm cm cm

18 Africa Soil Information updating Sentinel sites soil data

19 Africa Soil Information updating AfSoilGrids1km Soil organic carbon ISRIC, 2013 AfSoilGrids250m Soil organic carbon Hengl et al.,

20 Africa Soil Information Soil property Unit updating Sample size RMSE % variance explained Coarse fragments v% 39, Sand w% 55, Silt w% 54, Clay w% 54, Bulk density t m ph (H2O) - 68, Exch. Calcium cmol+/kg 65, Exch. Magnesium cmol+/kg 63, Exch. Sodium cmol+/kg 42, Exch. Potassium cmol+/kg 64, Exch. Acidity cmol+/kg 24, CEC cmol+/kg 47, Organic carbon g kg -1 64, Total nitrogen g kg -1 50, Extr. Aluminium mg kg -1 18, AfSoilGrids250m Hengl et al., Globally integrated

21 Total Available Water Capacity = - Volumetric soil water retention - pf-curve fine earth (AWC) - Soil volume - Gravel - Rootable soil depth Africa Soil Information AfSIS services and products

22 Relevance of soil data Saria Total Available Water Capacity = - Volumetric soil water retention - pf-curve fine earth (AWC) - Soil volume - Gravel - Rootable soil depth Response increases with - Increasing soil TAWC - Increasing soil fertility JGB Leenaars

23 Grain yield (kg/ha) Relevance of soil data Saria Fertilised (org & min) Fertilised (mineral) Year After Pichot et al.

24 Water content (m3 / m3) Africa Soil Information AfSP FC PWP Africa Soil water retention AfSP average clayey AfSP average loamy AfSP average sandy AfSP stdev clayey AfSP stdev loamy AfSP stdev sandy n = 14,500 n = 13,500 n = 15, Water potential (pf)

25 fine earth at cm Africa Soil Grids for GYGA Soil Water Content (v%) at PWP (pf4.2)

26 fine earth at cm Africa Soil Grids for GYGA Available Soil Water Capacity (v%)

27 whole earth at cm Africa Soil Grids for GYGA Coarse fragments content

28 Africa Soil Grids for GYGA Rootable soil depth: rules and thresholds Shallowest depth of: Maximum rooting depth of maize Depth of soil Depth of aerated soil Depth to a layer with root restricting soil factor

29 Africa Soil Grids for GYGA Rootable soil depth: rules and thresholds Shallowest depth of: Maximum rooting depth of maize (150 cm) Depth of soil (depth to bedrock or iron pan) Depth of aerated soil (as determined by drainage class Depth to a layer with root restricting soil factor

30 Africa Soil Grids for GYGA Rootable soil depth: rules and thresholds Depth to a layer with root restricting soil factor Volume of soil (coarse fragments) Porosity (bulk density) Porosity (TetaSat) Texture Abrupt textural change Acidity (ph-h2o) Alkalinity (ph-h2o) Salinity (EC) Sodicity (Exch Na) Toxicity (Exch Al)

31 Africa Soil Grids for GYGA Rootable soil depth: rules and thresholds

32 Africa Soil Grids for GYGA Rootable soil depth: rules and thresholds Level Soil quality Soil property Unit Trend a b X Y Threshold score Threshold value Voxels Foothold CfPC v% > 88 Voxels Porosity TetaS (PTF-Wosten) v% < 32 Voxels Porosity BlkDens (1.6-(0.0035*Clay)) kg/dm3 < > > 0.28 Voxels Texture Sand w% > 99 Voxels Texture change Clay n - clay n-1 w% > 56 Voxels Texture change Sand n - sand n-1 w% > 56 Voxels Acidity phh2o low < 4 Voxels Alkalinity phh2o high > 8.8 Voxels Salinity EC ds/m > > 5.7 Voxels Sodicity ExNa*100/CECsoil % > 22 Voxels Sodicity ExNa cmolc/kg > > 4.2 Voxels Toxicity ExAcid*100/eCEC % > 75 Voxels Toxicity ExAcid cmolc/kg > > 5.7 Voxels Assess most limiting score (%) LRI, plus associated factor LRF Level Soil quality Soil property Unit Pixels LRD Assessed from LRI cm Pixels Foothold Rock Depth cm Pixels Aeration Drain (classes) cm Pixels Max (maize) 150 cm Pixels Assess shallowest depth (cm) = ERZD, plus associated factor

33 Africa Soil Grids for GYGA Rootable soil depth: rules and thresholds Level Soil quality Soil property Unit Trend a b X Y Threshold score Threshold value Voxels Foothold CfPC v% > 88 Voxels Porosity TetaS (PTF) v% < 32 Voxels Porosity f.blkdens kg/dm3 < > > 0.28 Voxels Texture Sand w% > 99 Voxels Texture change Clay n - clay n-1 w% > 56 Voxels Texture change Sand n - sand n-1 w% > 56 Voxels Acidity phh2o low < 4 Voxels Alkalinity phh2o high > 8.8 Voxels Salinity EC ds/m > > 5.7 Voxels Sodicity ExNa*100/CECsoil % > 22 Voxels Sodicity ExNa cmolc/kg > > 4.2 Voxels Toxicity ExAcid*100/eCEC % > 75 Voxels Toxicity ExAcid cmolc/kg > > 5.7 Voxels Assess most limiting score (%) LRI, plus associated factor LRF Level Soil quality Soil property Unit Pixels LRD Assessed from LRI cm Pixels Foothold Rock Depth cm Pixels Aeration Drain (classes) cm Pixels Max (maize) 150 cm Pixels Assess shallowest depth (cm) = ERZD, plus associated factor

34 Africa Soil Grids for GYGA Rootable soil depth: rules and thresholds Level Soil quality Soil property Unit Trend a b X Y Threshold score Threshold value Voxels Foothold CfPC v% > 88 Voxels Porosity TetaS (PTF) v% < 32 Voxels Porosity f.blkdens kg/dm3 < > > 0.28 Voxels Texture Sand w% > 99 Voxels Texture change Clay n - clay n-1 w% > 56 Voxels Texture change Sand n - sand n-1 w% > 56 Voxels Acidity phh2o low < 4 Voxels Alkalinity phh2o high > 8.8 Voxels Salinity EC ds/m > > 5.7 Voxels Sodicity ExNa*100/CECsoil % > 22 Voxels Sodicity ExNa cmolc/kg > > 4.2 Voxels Toxicity ExAcid*100/eCEC % > 75 Voxels Toxicity ExAcid cmolc/kg > > 5.7 Voxels Assess most limiting score (%) LRI, plus associated factor LRF Level Soil quality Soil property Unit Pixels LRD Assessed from LRI cm Pixels Foothold Rock Depth cm Pixels Aeration Drain (classes) cm Pixels Max (maize) 150 cm Pixels Assess shallowest depth (cm) = ERZD, plus associated factor

35 whole soil Africa Soil Grids for GYGA Most limiting factor to rootability Maize

36 Africa Soil Grids for GYGA Rootable soil depth (cm) RZD Maize

37 Africa Soil Grids for GYGA Total AWC (mm) of the rootable whole soil, 1 st draft TAWC Maize

38 Africa Soil Grids for GYGA Total AWC (mm) of the rootable whole soil, 1 st draft Soil factor Soil variable RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC mm mean sd km² km² km² km² km² km² km² km² km² mm mm Foothold (soil volume) CfPc Porosity TetaS Porosity f.bd Texture adequacy Sand Texture adequacy f.clay Texture adequacy f.sand Induration (cement.) CaCO Induration (cement.) CaSO Acidity ph-h2o Alkalinity ph-h2o Salinity EC Sodicity f.exna Sodicity ExNa Toxicity f.exacid Toxicity ExAcid Depth of aerated soil f.drain Depth of soil RockDpth Maize max root depth 150 cm Total (km²)

39 Africa Soil Grids for GYGA Total AWC (mm) of the rootable whole soil, 1 st draft Soil factor Soil variable RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC RZPAWHC mm mean sd km² km² km² km² km² km² km² km² km² mm mm Foothold (soil volume) CfPc Porosity TetaS Porosity f.bd Texture adequacy Sand Texture adequacy f.clay Texture adequacy f.sand Induration (cement.) CaCO Induration (cement.) CaSO Acidity ph-h2o Alkalinity ph-h2o Salinity EC Sodicity f.exna Sodicity ExNa Toxicity f.exacid Toxicity ExAcid Depth of aerated soil f.drain Depth of soil RockDpth Maize max root depth 150 cm Total (km²)

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41 Africa Soil Information Taking Agronomy to Scale World Soil Profiles Validate & update Derived response maps Use soil information

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