Teelba. Soil summary sheets. Locality and site notes. Site Details

Transcription

1 Teelba Soil summary sheets Locality and site notes The Teelba sites characterise soil and regolith properties in the belah/brigalow and poplar box landscapes on sandstone. Soil properties along two transects across the landscape were investigated. Deep sampling was conducted in three locations along one of the transects. " Meandarra " Tara!. 8D 8D2!.!. 8E!.!.!.!.!.!.!. Teelba Ck " Flinton Moonie R iver QLD 8A 8A2!.!. "Roma Miles " " Goondiwindi!. 8B St George Goondiwindi " Upper Moonie Catchment " NSW 4 8 Kilometres 3 6 Kilometers!. 8C Site Details Site Soil type Vegetation Land use Surface fertility Profile analysis Regolith profile Property 8A Brown Dermosol Belah Treeline Canmaroo 69 8A2 Brown Vertosol Belah (cleared) Cropping Canmaroo 77 8B Red Sodosol Poplar box (treeline) Grazing Canmaroo 7 8B2 Red Sodosol Poplar box (cleared) Grazing 8C Brown Dermosol Poplar box (cleared) Grazing Canmaroo 7 8D Brown Dermosol Brigalow/belah (cleared) Grazing Billenbah 6 8D2 Brown Vertosol Brigalow/belah (cleared) Grazing Billenbah 5 8E Brown Vertosol Brigalow/belah Grazing Billenbah 7 Site ID* * internal NRW site identification for the QMDSC project LOCALITY 8 in the Compendium of Site Information from: Harms BP, Hughes KE and Payne JE (28) Soil reference sites for improved land management report for the Queensland Murray Darling Committee. Department of Natural Resources and Water, Brisbane.

2 Teelba (Belah, upper slope) Site 8A characterises the belah/brigalow soils on sandstone. It consists of: Treeline site (Site 8A) soil description, surface soil fertility, profile chemistry, bulk density. regolith description, ph and chloride chemistry to 7. m. Cropping site (Site 8A2) surface soil fertility, profile chemistry. Site 8A Landscape description Landform Geology General soil qualities Infiltration Permeability Nutrient availability ph Salinity Sodicity Bulk density (8A2) Physical root limitations Toxicities Available water store Undulating rises upper slope position Cretaceous sandstone Vegetation Belah (Casuarina cristata) open forest. Scattered brigalow (Acacia harpophylla) nearby. Slope 3% Runoff moderately rapid Drainage moderately well drained Moderate when soil is dry. Moderate to low in deep subsoil.. Soil and landscape correlation Land resource area Land system Soil Name Source Brigalow uplands ATR Brigalow rises (5a) MWD Bungunya north (rises) WLM 2 unresistant weathered sediments; lowlands; ZBA belah/brigalow Wondolin* ATR Ulimaroa* MWD Wynhari/Arden WLM * noncracking variants The surface fertility is moderate to high. Moderate cation exchange capacity, which means this soil has a reasonable capacity to supply cation nutrients. Slightly acid at the surface, grading to strongly alkaline (26 cm), and then very strongly acid below about m. Site 8A (treeline) high salinity below about 2 cm. Site 8A2 (cropping) salinity below about 6 cm. This indicates there has been considerable leaching of chloride down the profile. Strongly sodic below 2 cm. Measured bulk density of >.5 g/cm 3 below 5 cm indicates a very compact clay soil, with a consequent reduction in porosity. The high sodicity may lead to dense, intractable subsoil clay. However, the chloride profile for the cultivated site indicates that there is no major restriction to drainage in the profile. Potential toxicities (e.g. aluminium) due to very strong acidity below 8 cm particularly in the cultivated paddock. High chloride concentration at 3 cm in treeline site, and at 8 cm in the cropped site. PAWC estimated to be moderate for cropping and high for pastures (effective rooting depth limited to approximately 8 cm due to high salinity). Soil pit, Site 8A 2

3 Site 8A Belah upper slope Teelba A A2 B2 General information Site 8A Location coordinates me mn Zone 55 Location ID. QMDSC 69 Obs. Brief soil description Moderately deep noncracking clay soil Surface condition Firm, hard setting Surface coarse fragments 2% ferricrete pebbles (26mm), <2% ferricrete cobbles (62mm) Classification Australian Soil Classification Brown Dermosol Great Soil Group Solonised soil Principal Profile Form Uf6.3 Soil morphology Horizon Depth Colour Mottles Texture Structure Coarse Fragments Grade Type Size Segregations Boundary B3 A.. dark (7.5YR33) light clay strong subangular blocky 5mm 2% subrounded ironstone pebbles (62 mm) clear A2..3 (7.5YR44) clay strong angular blocky 2mm <2% subrounded ironstone pebbles (26mm) gradual C B2.3.7 strong (7.5YR45) moderate prismatic 25mm 2% subrounded ironstone pebbles (26mm) strong angular blocky 2mm <2% calcareous soft segregations (62mm) gradual B3.7. C..5 strong (7.5YR46) yellow (2.5Y86) 25% 55mm distinct yellow clay weak gradual clay massive 3

4 Teelba (Belah, upper slope) Site 8A Surface soil fertility (bulked sample. m) Site 8A Site ph EC Cl NO 3 N Org.C Total N C:N :5 soil/water solution ratio Avail. P (bicarb) Extr. K SO 4 S DTPA extractable trace elements (mg/kg) (ds/m) (mg/kg) (mg/kg) (%) (%) (mg/kg) (meq/g) (mg/kg) Cu Zn Mn Fe 8A A Soil profile analysis Site 8A (treeline) Depth ph EC Cl NO3 :5 soil/water solution Particle size % Exchangeable cations * m.eq/g (m) (ds/m) (mg/kg) (mg/kg) CS FS SIL CLA Ca Mg Na K CEC (%) (%) R * extracted using alcoholic ammonium chloride at ph 8.5 Soil profile analysis Site 8A2 (cropping) Depth ph EC Cl NO3 :5 soil/water solution Particle size % Exchangeable cations * m.eq/g (m) (ds/m) (mg/kg) (mg/kg) CS FS SIL CLA Ca Mg Na K CEC (%) (%) R.. B * extraction using alcoholic ammonium chloride at ph 8.5 ESP ESP Moist WP Moist WP Disp. ratio Disp. ratio Bulk density Site 8A Depth Bulk density (m) (g/cm 3 ) Soil Bulk Density (g/cm 3 )

5 Teelba (Belah, upper slope) Graphs of soil characteristics treeline (Site 8A) and cropping (Site 8A2). Site 8A Soil ph ph Soil Sodicity ESP (%) Site 8A Treeline Site 8A2 Cropping Site 8A Treeline Site 8A2 Cropping Soil Chloride Cl (mg/kg) Electrical Conductivity Soil EC (ds/m) Site 8A Treeline Site 8A2 Cropping Site 8A Treeline Site 8A2 Cropping The cropping site is located 2 m away from the treeline site. The ph profile is very similar between the two sites and the sodicity profiles are marginally different. Moderate levels of salinity occur below 6 cm in the cropped paddock. However the EC and chloride graphs show that in the cropped paddock considerable leaching of salts down the profile has occurred 5

6 Teelba (Belah, upper slope) Site 8A Regolith profile summary (Site 8A) Weathered sandstone is first encountered at.95 m, but is mixed with clay soil to a depth of.9 m. Below that, the regolith profile consist of layers of weathering Cretaceous sandstone. The layers delineated correspond to variable degrees of weathering and varying proportions: mineral particles of clay, quartz, feldspars and iron oxides (which show up as mottles). The regolith profile is extremely acid throughout with ph hovering around 4.5. Horizons.m A A2 structured clay Regolith ph ph B2 red structured clay B3.9 m 2. m.m B32 alternatings layer of clay with weak structure (highly weathered sandstone) and massive structure (less weathered sandstone) 3. m 3.2 m m C 3.4 m 3.6 m 4 5 C2 6 C3 4.3 m 4.5 m 7 3.m C4 8 Regolith chloride C m 5.5 m Cl (mg/kg) m C6 C7 C8 weathered sandstone consisting of feldspars, clay minerals, quartz, and iron oxides 5.2 m 5.4 m 2 5.m C9 C C 6. m 6.3 m C2 6.7 m 6.9 m 6 6.m C3 7 C4 6.9 m 7. m 8 7.m 7.m C5 C6 Salinity is very high throughout, as indicated by both EC and chloride. Since atmospheric accessions of salt are unlikely to have penetrated deep into the weathering substrate, the source of the salt is almost certainly the bedrock itself. 6

7 Teelba (Poplar box, mid slope) Site 8B Site 8B characterises the red poplar box soils on sandstone. It consists of: Treeline site 8B soil description, surface soil fertility, profile chemistry. regolith description, ph and chloride chemistry. Pasture site 8B2 surface soil fertility, profile chemistry (ph and salinity only). Landscape description Landform Geology Vegetation Slope 2% Runoff Drainage Gently sloping plain Cretaceous sandstone Poplar box (Eucalyptus populnea) open forest moderately rapid moderately well drained Soil and landscape correlation Name Land resource area Brigalow uplands Brigalow rises (5b) Bungunya north western brigalow/belah landscapes; lowlands Land system 2 unresistant weathered sediments; lowlands; belah/brigalow Soil Wondolin Arubial / Weengallon* Jindabyne * no direct soil match with MWD Source ATR MWD WLM ZBA ATR MWD WLM General soil qualities Infiltration Permeability Nutrient availability ph Salinity Sodicity Physical root limitations Toxicities Available water store Moderate when soil is dry; limited by shallow depth of surface loam. Moderate to low in subsoil. Surface fertility is low (deficiencies in phosphorus, sulfur and zinc). Organic carbon has declined significantly in the pasture site compared to the treeline. Calcium is well supplied throughout the profile, but there are probable deficiencies of potassium at <.3 meq/g below 3 cm. Slightly acid at the surface, otherwise strongly alkaline. High salinity below about 3 cm. Strongly sodic (ESP > 5%) below 3 cm. High sodicity below about 3 cm has contributed to a very dense, intractable subsoil clay, with low porosity. High chloride levels below 3 cm. Low for cropping, moderate for pastures. Limitations to plant rooting depth reduce the available water store. Soil pit, Site 8B 7

8 Site 8B Poplar box midslope Teelba A A2j B2 General information Site 8B Location coordinates me mn Zone 55 Location ID QMDSC 7, Obs. Brief soil description Red texturecontrast soil profile, with a thin loamy surface soil overlying a subsoil. Surface condition Hard setting Surface coarse fragments <2% Ironstone pebbles (62mm) Soil morphology Soil classification Australian Soil Classification Red Sodosol Great Soil Group Solodic soil Principal Profile Form Dr2.33 B22 B23k B24k Horizon Depth Colour Mottles Texture Structure Coarse Fragments Grade Type Size A.. A2j..5 B B B23k.5.9 B24k.9.4 dark (7.5YR34) pinkish grey (7.5YR62) moist (7.5YR54) dry dark reddish grey (5YR42) dark reddish grey (5YR42) (7.5YR54) reddish (5YR54) clay loam fine sandy clay loam fine sandy clay Segregations Boundary massive clear massive sharp strong prismatic 25mm clear strong lenticular 2mm moderate lenticular 25mm moderate prismatic 25mm moderate prismatic 2mm <2% subrounded ironstone pebbles <2% manganiferous concretions (2mm) <2% calcareous nodules (26mm) <2% manganiferous concretions (2mm) 2% calcareous soft segregations (26mm) 2% calcareous soft segregations (26mm) <2% manganiferous concretions (2mm) gradual gradual gradual B25 B strong (7.5YR56) <2% 55mm faint orange 2% 55mm faint yellow clay weak 8

9 Teelba (Poplar box, mid slope) Site 8B Surface soil fertility Site 8B (bulked sample. m) Site ph EC Cl NO 3 N Org.C Total N Avail. P :5 soil/water solution (bicarb) Extr. K SO 4 S DTPA extractable trace elements (mg/kg) Soil profile analysis Site 8B (treeline) Depth (ds/m) (mg/kg) (mg/kg) (%) (%) (mg/kg) (meq/g) (mg/kg) Cu Zn Mn Fe 8B B < ph EC Cl NO3 :5 soil/water solution Particle size % Exchangeable cations * m.eq/g (m) (ds/m) (mg/kg) (mg/kg) CS FS SIL CLA Ca Mg Na K CEC (%) (%) R < < < < * extraction using alcoholic ammonium chloride at ph 8.5 ESP Moist WP Disp. ratio Soil ph ph Soil Sodicity ESP (%) Site 8B Treeline Site 8B2 Pasture Site 8A Treeline Soil Chloride Cl (mg/kg) Electrical Conductivity Soil EC (ds/m) Site 8B Treeline Site 8B2 Pasture.6 Site 8B Treeline Site 8B2 Pasture 9

10 Teelba (Poplar box, mid slope) Regolith profile summary (Site 8B) Horizons.m A A2j B2.m B22 B23 unstructured clay loam structured clay red structured clay structured clay Site 8B The layers of clay observed to a depth of 4.5 m are differentiated by changes in colour and degree of mottling. Below 4.5 m, the layers of weathering Cretaceous sandstone are delineated by degree of mottling and variation in mineral composition. The regolith profile is very strongly acid until a depth of approx. 7.5 m where the ph suddenly jumps up to neutral/mildly alkaline. This corresponds to carbonate segregations in the profile, which could indicate a groundwater influence. Chloride is at a moderate to high level throughout. The oscillations of salinity can be correlated to regolith properties and the degree of weathering that has taken place. The dips correspond to zones where quartz is dominant, while the high points correspond to zones with a greater proportion of clay mineral (and hence reduced porosity). 2.m B24 B25 B26 structured clay red structured clay.8 m 2. m Regolith ph B27 structured clay with grey mottle 2 2. m 2.3 m 3.m B28 structured clay 3 B29 structured clay with grey mottle 2.8 m 3. m 4 5 B2 structured clay 6 4.m B2 grey structured clay with orange mottle 3.65 m 3.85 m m C 2C 4.3 m 4.5 m 4.9 m 5. m 9 Regolith chloride Cl (mg/kg) m 3C 4C 5C weathered sandstone consisting of feldspars, quartz and clay minerals 5.4 m 5.6 m m 6C 5.8 m 6. m m 7C 8C 9C C C 2C carbonate segregations carbonate segregations 6.9 m 7. m 7.45 m 7.65 m m 3C m 8.35 m

11 Teelba (Poplar box lower slope) Site 8C Site 8C is a poplar box soil on a lower slope position. It consists of: soil description, surface soil fertility. regolith description, ph and chloride chemistry. Landscape description Landform Geology Vegetation Slope.5% Runoff Drainage Level plain Local alluvium Poplar box (Eucalyptus populnea) open forest (cleared) slow imperfectly drained Soil and landscape correlation Land resource area Land system Soil Name Balonne a clay alluvial plains 3 alluvial plains, poplar box woodland No match Source ATR MWD ZBA This land unit (local alluvium) is not delineated at the scale of land system mapping General soil qualities Infiltration Permeability Nutrient availability ph Salinity Sodicity Physical root limitations Toxicities Available water store Slow. Moderate to low in subsoil. Surface fertility is low to moderate (deficiencies in phosphorus, sulfur is marginal). Slightly acid at the surface, otherwise strongly alkaline. High salinity below about 3 cm. Not tested. Wetness, poor drainage (indicated by mottling and manganese segregations). High chloride concentration at 3 cm. Limitations to plant rooting depth reduce the available water store low for cropping, moderate for pastures. Surface soil fertility Site 8C (bulked sample. m) ph EC Cl NO 3 N Org.C Total N :5 soil/water solution C/N ratio Avail. P (bicarb) Extr. K SO 4 S DTPA extractable trace elements (mg/kg) (ds/m) (mg/kg) (mg/kg) (%) (%) (mg/kg) (meq/g) (mg/kg) Cu Zn Mn Fe

12 Site 8C Poplar box lower slope Teelba A A2 B2k Soil morphology General information Site 8C Location coordinates me mn Zone 55 Location ID. QMDSC 7 Obs. Brief soil description Very deep, noncracking clay soil Surface condition Firm, hard setting Surface coarse fragments None Permeability Moderately permeable Classification Australian Soil Classification Brown Dermosol Great Soil Group Solonised soil Principal Profile Form Uf6.3 B22 Horizon Depth Colour Mottles Texture Structure Coarse Fragments Grade Type Size A.. A2..3 (7.5YR53) (7.5YR42) light clay Segregations Boundary moderate subangular blocky 5mm gradual clay moderate subangular blocky 25mm <2% manganiferous concretions (2mm) gradual B2k.3.6 (7.5YR43) moderate subangular blocky 25mm <2% subrounded ironstone pebbles weak subangular blocky 2mm (26mm) 2% calcareous soft segregations (62mm) gradual B23 B B reddish (5YR54) (YR53) 2% 55mm faint yellow 2% 55mm faint orange strong prismatic 25mm moderate subangular blocky 2mm clay strong polyhedral 5mm <2% calcareous soft segregations (26mm) <2% calcareous nodules (26mm) 2% manganiferous soft segregations (62mm) <2% manganiferous concretions (26mm) clear 2

13 Teelba (Poplar box lower slope) Horizons.m A.m Regolith profile summary (Site 8C) A2 B B2 B22 B23 structured clay grey structured clay structured clay structured clay with grey mottle Site 8C Grey and clay soil horizons continue to a depth of approx. 4.5 m. Below this depth, the regolith profile is composed of unconsolidated sedimentary strata that have large amounts of sedimentary detritus, fragments of ironstone and manganese segregations. The upper part of the regolith profile is neutral (below the top.5 m of soil ). Alkaline conditions (at approx. 4 m and >6.75 m) correspond to the occurrence of carbonate segregations in the profile, which are almost certainly groundwater depositions. Salinity is at moderate levels throughout, until a depth of 6.3 m where it suddenly increases to a high level. Elevated salinity corresponds to the zone of increased ph, which may be due to the influence of ground water. B24 Regolith ph 2.m B25 structured clay with grey and orange mottle.8 m 2. m ph B26 structured clay with grey mottle 3. m 3.3 m 2 3.m 4.m B27 B28 B29 B2 grey structured clay with orange mottle structured clay with grey mottle carbonate segregations 3.4 m 3.6 m 4.3 m 4.5 m B2 B3 4.5 m 4.7 m m m 5. m Regolith chloride Cl (mg/kg) m D horizons layers of grey and clay (variously mottled) and varying amounts of sedimentary detritus, ironstone fragments and manganese segregations 5. m 5.3 m 5.9 m 6. m m 7. m 7.2 m 4 5 carbonate segregations common below 6.5 m 6 8.m 7.7 m 7.9 m m 8.2 m 8.45 m 3

14 Teelba (Brigalow slope) Site 8D Site 8D characterises the brigalow soils on sandstone rises. It comprises two sites on a hillslope. Both sites have been used for cropping in the past, but have now been converted to grazing. Site 8A consists of: Upper slope (Site 8D) soil description, surface soil fertility, profile chemistry. Lower slope (Site 8D2) soil description, surface soil fertility, profile chemistry. Upper slope Site 8D Landscape description Landform Gently undulating rises upper slope position. Geology Cretaceous sandstone. Vegetation Scattered belah (Casuarine cristata) and brigalow (Acacia harpophylla) cleared. Slope 5% Runoff Moderately rapid Drainage Moderately well drained Soil and landscape correlation Land resource area* Land system Soil Name Brigalow uplands Brigalow rises (5a/5b) Bungunya north (rises) 2 unresistant weathered sediments; lowlands; belah/ brigalow Wondolin** Ulimaroa** Arden/Tandawanna Source ATR MWD WLM ZBA ATR MWD WLM * this site is incorrectly mapped as Unit 9 (scarps, rolling terrain) (ZBA) and Yuleba (ATR). ** noncracking soil variants ` General soil qualities Infiltration Permeability Nutrient availability ph Salinity Sodicity Physical root limitations Toxicities Available water store Moderate when soil is dry. Moderate. The surface fertility is moderate (phosphorus is low for cropping). Below 3 cm a Ca:Mg ratio of <.5 indicates a potential nutrient imbalance, and a higher risk of clay dispersion. Potassium is potentially deficient at <3 meq/g below 3 cm. Slightly acid at the surface, then strongly alkaline changing to very strongly acid in the deep subsoil. High salinity (as indicated by soil EC and chloride) below at about 6 cm. Strongly sodic (ESP > 2%) below about 5 cm. Restricted aeration in wet periods (high sodicity). Chloride levels reach a high level at about 6 cm, which will affect a range of sensitive plant species. May be high levels of manganese and/or aluminium in the very strongly acid subsoil. Estimated to be low for cropping and moderate for pastures (effective rooting depth of 6 cm). 4

15 Site 8D Brigalow upper slope Teelba A A2 B General information Site 8D Location coordinates me mn Zone 55 Location ID QMDSC 6 Obs. Brief soil description Moderately deep, noncracking clay soil overlying sandstone at approximately m. Surface condition Firm Surface coarse fragments 2% ironstone pebbles (62 mm) Soil classification Australian Soil Classification Red Dermosol Great Soil Group Solonised soil Principal Profile Form Ug 5.32 B2k B22 Soil morphology Horizon Depth Colour Mottles Texture Structure Coarse Fragments Grade Type Size A..3 A2.3.2 dark (7.5YR33) very dark (7.5YR2.5/3) Segregations Boundary light clay weak subangular blocky 5mm sharp moderate subangular blocky 2mm clear B23 C B.2.22 B2k B B C..5 (7.5YR44) dark reddish (5YR33) reddish (5YR44) 7.5YR44) olive yellow (2.5Y68) <2% subangular moderate subangular blocky 25mm ironstone pebbles (26mm) moderate lenticular 25mm moderate polyhedral 25mm <2% angular ironstone pebbles (62 mm) <2% angular ferricrete pebbles (62 mm) 2% angular moderate subangular blocky 25mm ferricrete pebbles (62 mm) clay moderate polyhedral 2mm 2% angular ferricrete pebbles (26 mm) 25% angular ferricrete pebbles (62 mm) clear 2% calcareous soft segregations (26mm) 2% calcareous soft segregations (62mm) massive clear sharp clear 5

16 Teelba (Brigalow slope) Site 8D Lower slope Site 8D 2 Landscape description Landform Gently undulating rises lower slope position Geology Cretaceous sandstone Vegetation Scattered belah (Casuarine cristate) and brigalow (Acacia harpophylla) (cleared) Slope 2.5% Runoff Moderately slow Drainage Moderately well drained Soil and landscape correlation Name Land resource area Brigalow uplands Brigalow rises (5a/5b) Bungunya north (rises) Land system 2 unresistant weathered sediments; lowlands; belah/ brigalow Soil Wondolin Ulimaroa Arden * this site is incorrectly mapped as unit 9 (scarps, rolling terrain) (ZBA) and Yuleba (ATR). Source ATR MWD WLM ZBA ATR MWD WLM ` General soil qualities Infiltration Permeability Nutrient availability ph Salinity Sodicity Physical root limitations Toxicities Available water store Moderate when soil is dry. Moderate. The surface fertility is moderate (phosphorous is low for cropping, sulfur is low for cropping and pasture). CEC is high, indicating a generally strong capacity of this soil to supply cation nutrients. Organic carbon is lower than desirable. Moderately alkaline at the surface and then strongly alkaline throughout except for zone that contains gypsum (68 cm). Moderate salinity below about 6 cm. The high electrical conductivity (EC) recorded is probably due to the presence of gypsum, which does not have a strong effect on soilplant relationships as it exists as crystals, which are sparingly soluble under field conditions. Strongly sodic (ESP > 5%) below about 4 cm. The weathered sandstone at approx. 9 cm may restrict root growth, but is unlikely to be a complete barrier due to its relatively soft consistence. Chloride levels reach a moderate level at about 6 cm and may affect sensitive plants. Estimated to be moderate for cropping and high for pastures (effective rooting depth of 9 cm above the weathered substrate). 6

17 Site 8D2 Brigalow lower slope Teelba Ap A2 B2 General information Site 8D2 Location coordinates 7349 me mn Zone 55 Location ID. QMDSC 5 Obs. Brief soil description Moderately deep, cracking clay soil overlying sandstone at approximately 8 cm. Surface condition Periodic cracking, selfmulching Surface coarse fragments 2% ferricrete and ironstone pebbles (62 mm) Classification Australian Soil Classification Brown Vertosol Great Soil Group Grey and clays Principal Profile Form Ug5.34 Soil morphology Horizon Depth Colour Mottles Texture Structure Grade Type Size Coarse Fragments Segregations Boundary B22 Ap..8 (7.5YR42) moderate subangular blocky 2mm abrupt A2.8.2 dark greyish (YR42) strong polyhedral 2mm <2% calcareous nodules (2mm) clear C B2.2.5 dark (YR33) strong lenticular 2mm strong subangular blocky 2mm 2% calcareous nodules (2mm) gradual B (7.5YR43) moderate polyhedral 2mm <2% subangular ironstone pebbles (26mm) <2% calcareous nodules (26mm) clear C2 C.85. yellowish (YR56) sandy loam 2% calcareous soft segregations (26mm) gradual C2..5 yellowish (YR56) 7

18 Teelba (Brigalow slope) Site 8D Surface soil fertility (bulked sample. m) Site 8D & 8D2 site ph EC Cl NO 3 N Avail. P Org.C Total N :5 soil/water solution (bicarb) Extr. K SO 4 S Exchangeable cations* (m.eq/g) ESP DTPA extractable trace elements (mg/kg) (ds/m) (mg/kg)(mg/kg) (%) (%) (mg/kg) (meq/g) (mg/kg) Ca Mg Na K CEC (%) Cu Zn Mn Fe 8D D < * extraction using alcoholic ammonium chloride at ph 8.5 Soil profile analysis Site 8D upper slope Depth ph EC Cl NO3 :5 soil/water solution Particle size % Exchangeable cations * m.eq/g (m) (ds/m) (mg/kg) (mg/kg) CS FS SIL CLA Ca Mg Na K CEC (%) (%) R < < < *..m extracted using alcoholic ammonium chloride at ph m extracted using aqueous ammonium chloride at ph 7.. ESP Moist WP Disp ratio Soil profile analysis Site 8D2 lower slope Depth ph EC Cl NO3 :5 soil/water solution Particle size % Exchangeable cations * m.eq/g (m) (ds/m) (mg/kg) (mg/kg) CS FS SIL CLA Ca Mg Na K CEC (%) (%) R ** ** ** * extraction using alcoholic ammonium chloride at ph 8.5 ** results for exch. K not reported because they appear to be incorrect. ESP Moist WP Disp ratio 8

19 Teelba (Brigalow slope) Graphs of soil characteristics Upper slope (Site 8D) and lower slope (Site 8D2). Site 8D Soil ph ph Soil Sodicity ESP (%) Site 8D upper slope Site 8D2 low er slope Site 8D upper slope Site 8D2 low er slope Soil Chloride Cl (mg/kg) Electrical Conductivity Soil EC (ds/m) Site 8D upper slope Site 8D2 low er slope.6 Site 8D upper slope Site 8D2 low er slope These graphs indicate that there is a considerable difference in soil properties between the upper slope (8D) and the lower slope (8D2) sites. There are also differences not illustrated by the graphs. As a cropping soil, the soil in the lower slope position is considerably superior because: it does not have the strongly acid subsoil found in the upper slope position. it has only moderate salinity compared to high salinity in the upper slope position (as indicated by the chloride profiles). it has a higher cation exchange capacity (CEC) and therefore a higher capacity to supply cation nutrients. the balance of cations is more favourable (especially the higher Ca:Mg ratio). The lower chloride levels in the lower slope site are most likely due to the increased drainage through the profile in this landscape position. The jumpup located above the upper slope site is the likely source of salt and as such would have the greatest influence on the salinity levels of the upper slope site. The bulge in EC between 6 and 8 cm (lower slope position only) is probably due to naturally occurring gypsum that does not have a significant impact on soilplant relationships. 9

20 Teelba (Brigalow flat) Site 8E Site 8E characterises a brigalow belah soil on sandstone in a lower slope position. It consists of: soil description, surface soil fertility, profile chemistry. Landscape description Landform Geology Vegetation Slope 5% Runoff Drainage Undulating rises lower slope position Cretaceous sandstone Scattered brigalow (Acacia harpophylla) and belah (Casuarina cristata) (cleared) moderately rapid moderately well drained Soil and landscape correlation Land resource area Land system Soil Name Brigalow uplands Brigalow rises (5a) Billa Billa (rises) 2 unresistant weathered sediments; lowlands; belah/ brigalow Wondolin Ulimaroa Wynhari Source ATR MWD WLM ZBA ATR MWD WLM ` General soil qualities Site 8E Infiltration Permeability Nutrient availability ph Salinity Sodicity Physical root limitations Toxicities Available water store Moderate when soil is dry. Moderate to low in the deep subsoil. Surface fertility is moderate (phosphorus is low for cropping, potential deficiencies of sulfur and zinc in the surface soil). Moderately alkaline at the surface and then strongly alkaline throughout except for zone that contains gypsum (68 cm). Moderate to high salinity (as measured by chloride) below about 4 cm. The very high electrical conductivity recorded is due to the presence of gypsum, but this does not have a strong effect on soilplant relationships as it exists mainly in crystal form. Strongly sodic (ESP > 5%) below about 4 cm. However the presence of gypsum in the subsoil may offset some of the potential problems caused by sodicity. Restricted aeration in wet periods (high sodicity). High chloride levels below 8 cm will affect sensitive crops. Effective rooting depth determines total volume of water available to plants. The chloride profile indicates that plant growth is extracting limited moisture below about 8 cm, Therefore PAWC is likely to be moderate for cropping. 2

21 Site 8E Brigalow Teelba A B B2 General information Site 8E Location coordinates me mn Zone 55 Location ID QMDSC 7, Obs. Brief soil description Deep, cracking clay soil Surface condition Periodic cracking, selfmulching Surface coarse fragments <2% ferricrete pebbles (62 mm); <2% ironstone pebbles (62 mm) Soil classification Australian Soil Classification Brown Vertosol Great Soil Group Grey, and red clays Principal Profile Form Ug5.34 Soil morphology Horizon Depth Colour Mottles Texture Structure Coarse Fragments Grade Type Size Segregations Boundary B22y A.. (YR43) greyish (YR52) light clay moderate subangular blocky 5mm clear B..2 dark (YR33) clay moderate polyhedral 2mm clear B23 B2.2.6 dark (YR33) moderate lenticular 25mm <2% subangular ironstone pebbles moderate subangular blocky 2mm (62 mm) <2% calcareous nodules (<2mm) 2% calcareous soft segregations (62mm) clear B22y.6.9 (YR53) clay strong lenticular 2mm moderate polyhedral 2mm 2% gypseous crystals (26mm) gradual B red (2.5Y56) clay 2

22 Teelba (Brigalow flat) Surface soil fertility (bulked sample. m) Site 8E Site 8E ph EC Cl NO 3 N C/N Org.C Total N :5 soil/water solution ratio Avail. P (bicarb) Extr. K SO 4 S Exchangeable cations* (m.eq/g) ESP DTPA extractable trace elements (mg/kg) Soil profile analysis Site 8E Depth ph EC Cl NO3 :5 soil/water solution Particle size % Exchangeable cations * m.eq/g (m) (ds/m) (mg/kg) (mg/kg) CS FS SIL CLA Ca Mg Na K CEC (%) (%) R (ds/m) (mg/kg)(mg/kg) (%) (%) (mg/kg) (meq/g) (mg/kg) Ca Mg Na K CEC (%) Cu Zn Mn Fe < * extraction using alcoholic ammonium chloride at ph < * extraction using alcoholic ammonium chloride at ph 8.5 ESP Moist WP Disp ratio Soil ph Soil Sodicity (ESP %) Soil Chloride (mg/kg) 5 5 Soil EC (ds/m) The chloride levels within the soil profile are similar to those at site 8D (upper slope in the adjacent paddock). The bulge in EC is due to the presence of gypsum in the soil profile, which does not contribute significantly to salinity. 22