Surface soil acidity and fertility in the central-western wheatbelt of New South Wales

2007 ◽  
Vol 47 (2) ◽  
pp. 184 ◽  
Author(s):  
C. M. Evans ◽  
B. J. Scott
Keyword(s):  
Organic Carbon ◽  
Soil Acidity ◽  
Surface Soil ◽  
Soil Depth ◽  
New South ◽  
New South Wales ◽  
Sodic Soils ◽  
Surface Soils ◽  
Pasture Production ◽  
South Wales

Documentation of the chemical fertility status of the soils is sparse for the western and central-western wheatbelt of New South Wales, Australia. We examined properties of the surface soils (0–10 cm) from central-western NSW by collating two published and nine unpublished datasets of soil analyses representing about 2800 soil samples. The emphasis was on the red soils used extensively for cropping. The surface soils of central-western NSW have low phosphorus (47% of soils) and sulfur (70% of soils <5 mg S/kg using KCl-40 analysis) status and commonly have organic carbon contents of about 1%. Surface soil acidity was a substantial problem with 56% of soils (0–10 cm) having a pHCa <5.0. Sodic and dispersive soils are also of concern in this area and these soils have received little attention or research. Approximately 5% of surface (0–10 cm) soils had an exchangeable sodium percentage of ≥6% (sodic). Salinity of surface soils was of minor significance compared with other soil problems in the area, although isolated areas occur. These results indicated that lime applications in this area are likely to benefit crop and pasture production. Additional use of phosphorus and sulfur fertilisers and agricultural practices which increase or maintain organic carbon will also need to be adopted to improve pasture and crop production. The use of gypsum and/or lime on sodic soils may also need to be addressed. As a priority, we suggest that the benefits of lime application to crop yield be examined. The application of lime to the 0–10 cm soil depth should ultimately arrest acidification of the subsurface soil (10–20 cm depth) through downward movement of the lime effect. Further examination of gypsum applications to dispersive sodic soils and the evaluation of sulfur deficiency in the field for pastures and canola are also priority areas of likely agricultural relevance.

Land-use and historical management effects on soil organic carbon in grazing systems on the Northern Tablelands of New South Wales

Soil Research ◽  
2013 ◽  
Vol 51 (8) ◽  
pp. 668 ◽  
Author(s):  
Brian R. Wilson ◽  
Vanessa E. Lonergan
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Surface Soil ◽  
Soil Depth ◽  
New South ◽  
New South Wales ◽  
Soil Layers ◽  
South Wales ◽  
Native Pasture ◽  
Historical Management

We examined soil organic carbon (SOC) concentration (mg g–1) and total organic carbon (TOC) stock (Mg ha–1 to 30 cm soil depth) in three pasture systems in northern New South Wales: improved pasture, native pasture, and lightly wooded pasture, at two sampling times (2009 and 2011). No significant difference was found in SOC or TOC between sample times, suggesting that under the conditions we examined, neither 2 years nor an intervening significant rainfall event was sufficient to change the quantity or our capacity to detect SOC, and neither represented a barrier to soil carbon accounting. Low fertility, lightly wooded pastures had a slightly but significantly lower SOC concentration, particularly in the surface soil layers. However, no significant differences in TOC were detected between the three pasture systems studied, and from a carbon estimation perspective, they represent one, single dataset. A wide range in TOC values existed within the dataset that could not be explained by environmental factors. The TOC was weakly but significantly correlated with soil nitrogen and phosphorus, but a more significant pattern seemed to be the association of high TOC with proportionally larger subsoil (0.1–0.3 m) organic carbon storage. This we attribute to historical, long-term rather than contemporary management. Of the SOC fractions, particulate organic carbon (POC) dominated in the surface layers but diminished with depth, whereas the proportion of humic carbon (HUM) and resistant organic carbon (ROC) increased with soil depth. The POC did not differ between the pasture systems but native pasture had larger quantities of HUM and ROC, particularly in the surface soil layers, suggesting that this pasture system tends to accumulate organic carbon in more resistant forms, presumably because of litter input quality and historical management.

The fate of nitrogen fertilisers added to red gradational soils at Batlow, New South Wales, and its implications with respect to soil acidity

Soil Research ◽  
1997 ◽  
Vol 35 (4) ◽  
pp. 863 ◽  
Author(s):  
I. P. Little
Keyword(s):  
Ammonium Sulfate ◽  
Soil Acidity ◽  
Surface Soil ◽  
Soil Analysis ◽  
New South ◽  
New South Wales ◽  
Soil Profiles ◽  
Eucalypt Forest ◽  
South Wales ◽  
Exchangeable Ca

Red gradational soils at Batlow, in New South Wales, which are used for apple growing, have acid subsoils with exchangeable aluminium (Al) frequently in excess of exchangeable calcium (Ca). There is often inadequate Ca in the fruit cortex of post-harvest apples to maintain good fruit quality and this can lead to losses in cool-store. It is possible that Al in these acid subsoils has interfered with Ca uptake by the trees. The excessive use of nitrogenous fertilisers leads to soil acidity, and it was thought likely that this was exacerbating the subsoil acidity common in the district. In October 1992, soil analysis detected considerable ammonium in the surface 0·3 m at orchard sites at Batlow monitored for mineral nitrogen (N). This probably came from heavy spring dressings of fertiliser. One site examined in detail showed that about half of the ammonium had disappeared by January 1993, but a large nitrate envelope appeared with a peak at 0·6 m which in turn disappeared by April that year. This establishes that heavy applications of ammonium are nitrified, leached into the subsoil, and lost. Under such a high N regime, orchard soil profiles should be more acid than adjacent forest soils. However, it was found that the acidity of the surface soil was less, and the exchangeable Ca greater in the orchard soils, compared with soil profiles in the adjacent eucalypt forest, although amelioration of the subsoils had not occurred. Samples taken from representative sites at Batlow, at the 0–0·1, 0·1–0·2, and 0·3–0·4 m depths, were dosed with ammonium sulfate and leached with water in the laboratory for 23 days in a free-draining environment. Nitrate and ammonium were determined in the leachates. At the end of the experiment, the pH and exchangeable Ca, Mg, and Mn were determined in the leached samples. Only the neutral surface soils were able to nitrify ammonium effectively and nitrification was positively correlated with pH, and with exchangeable Ca and Mg. From this it is argued that the acidity produced by the addition of ammonium sulfate or urea will be nitrified in the surface but the acidity produced will be neutralised, provided it is accompanied by an adequate dressing of lime. Ammonium tends to remain in the surface soil, but if leached, it will not be nitrified in the subsoil. Nitrate leached into the subsoil will not be acid-forming but, if denitrified, may help to reduce acidity. For this work, the soil pH was measured in 1 KCl. So that readers can refer this to the pH in 0·01 CaCl2, a relationship was established between the two measures.

Scattered paddock trees, litter chemistry, and surface soil properties in pastures of the New England Tablelands, New South Wales

Soil Research ◽  
2004 ◽  
Vol 42 (8) ◽  
pp. 905 ◽  
Author(s):  
S. Graham ◽  
B. R. Wilson ◽  
N. Reid ◽  
H. Jones
Keyword(s):  
Soil Properties ◽  
Soil Acidity ◽  
Surface Soil ◽  
New South ◽  
New South Wales ◽  
Soil Conditions ◽  
Ash Alkalinity ◽  
South Wales ◽  
Surface Soil Properties ◽  
Tree Stem

Scattered paddock trees are widespread throughout rural Australia but their effect on soil conditions has received only limited research attention. This study investigated the influence of 3 Eucalyptus species on surface soil properties on different parent materials at both stocked and unstocked sites on the Northern Tablelands of New South Wales. Mineral soil samples to a depth of 5 cm were collected at intervals up to twice the canopy radius away from tree trunks and litter samples were collected at corresponding points. Mineral soils were analysed for pH (CaCl2), organic carbon (C), and extractable phosphorus (P) concentration, while for the litter samples, P, sulfur, cations, and ash alkalinity were determined. Stocking with sheep and cattle increased surface soil acidity and C and P concentrations at each location. However, soils under E. melliodora and E. viminalis showed higher pH and increased C and P concentrations close to the tree stem irrespective of grazing. Soils under E. caliginosa, while having similar patterns of C and P, showed variable acidity patterns with instances of lower pH close to the tree stem. Spatial patterns in soil acidity were associated with the ash alkalinity of litter, indicating litter as a source of alkalinity addition to the soil surface, although different patterns of soil pH could not be fully explained by litter ash alkalinity alone. The close correlation of litter Ca content with ash alkalinity suggests that this element might be a suitable indicator of the acid amelioration capacity of different tree species.

Driving factors of soil organic carbon fractions over New South Wales, Australia

Geoderma ◽  
2019 ◽  
Vol 353 ◽  
pp. 213-226 ◽  
Author(s):  
Jonathan Gray ◽  
Senani Karunaratne ◽  
Thomas Bishop ◽  
Brian Wilson ◽  
Manoharan Veeragathipillai
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
New South ◽  
New South Wales ◽  
Driving Factors ◽  
Carbon Fractions ◽  
South Wales ◽  
Organic Carbon Fractions ◽  
Soil Organic Carbon Fractions

Characteristics of soil and productivity of Pinus radiata (D Don) in New South Wales .II. Pedogenesis on a range of parent materials

Soil Research ◽  
1986 ◽  
Vol 24 (1) ◽  
pp. 103 ◽  
Author(s):  
PJ Ryan
Keyword(s):  
Pinus Radiata ◽  
Soil Depth ◽  
New South ◽  
New South Wales ◽  
Morphological Properties ◽  
Slope Position ◽  
Site Classification ◽  
Physical Factors ◽  
Parent Materials ◽  
South Wales

Soil profile descriptions were made at a series of 11-year-old unfertilized Pinus radiata stands in the Lithgow district of New South Wales. Catenas within three soil parent materials were selected to compare variation in soil physical and morphological properties with growth of P. radiata. These parent materials were a Silurian siltstone, a Permian conglomerate and a Silurian-Devonian rhyolite. Basal area growth of the P. radiata stands increased down catenas on the Silurian siltstone as soil depth to a root impeding layer increased. Plateau soils on the Permian conglomerate had hardsetting surfaces and high gravel contents, and were associated with very poor pine growth. By way of contrast, lower slope, colluvial gradational earths were deep, fine-textured soils and supported more productive pine stands. The Silurian-Devonian rhyolite parent material produced highly leached soils, commonly with conspicuously bleached A2 horizons and poor sandy textures of surface soil. Both physical and chemical features of the rhyolite interacted with pedological processes to affect adversely soil physical conditions and trace element availability, in particular boron. The poorer P. radiata growth on lower or concave slope in comparison with upper slope position was a result of increased soil leaching and horizon differentiation. This pattern contrasted with improved pine growth on the deeper soils on lower slopes on the two sedimentary parent materials. These case studies emphasize the importance of geology and pedological processes when evaluating the applicability of specific soil physical factors to site classification for P. radiata plantations.

Spatial variation in soil organic carbon and nitrogen at two field sites under crop and pasture rotations in southern New South Wales, Australia

Soil Research ◽  
2018 ◽  
Vol 56 (8) ◽  
pp. 780 ◽  
Author(s):  
Mark Conyers ◽  
Beverley Orchard ◽  
Susan Orgill ◽  
Albert Oates ◽  
Graeme Poile ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Spatial Variation ◽  
New South ◽  
New South Wales ◽  
Wagga Wagga ◽  
Soil Cores ◽  
South Wales ◽  
Sampling Protocols ◽  
The Mean

Estimating the likely variance in soil organic carbon (OC) at the scale of farm fields or smaller monitoring areas is necessary for developing sampling protocols that allow temporal change to be detected. Given the relatively low anticipated soil OC sequestration rates (&lt;0.5 Mg/ha.0.30 m/year) for dryland agriculture it is important that sampling strategies are designed to reduce any cumulative errors associated with measuring soil OC. The first purpose of this study was to evaluate the spatial variation in soil OC and nitrogen (N), in soil layers to 1.50 m depth at two monitoring sites (Wagga Wagga and Yerong Creek, 0.5 ha each) in southern New South Wales, Australia, where crop and pasture rotations are practiced. Four variogram models were tested (linear, spherical, Gaussian and exponential); however, no single model dominated across sites or depths for OC or N. At both sites, the range was smallest in surface soil, and on a scale suggesting that sowing rows (stubble) may dominate the pattern of spatial dependence, whereas the longer ranges appeared to be associated with horizon boundaries. The second purpose of the study was to obtain an estimate of the population mean with 1%, 5% and 10% levels of precision using the calculated variance. The number of soil cores required for a 1% precision in estimation of the mean soil OC or N was impractical at most depths (&gt;500 per ha). About 30 soil cores per composite sample to 1.50 m depth, each core being at least 10 m apart, would ensure at least an average of 10% precision in the estimation of the mean soil OC at these two sites, which represent the agriculture of the region.

scholarly journals Mathematical Functions to Model the Depth Distribution of Soil Organic Carbon in a Range of Soils from New South Wales, Australia under Different Land Uses

Soil Systems ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 46 ◽  
Author(s):  
Brian W. Murphy ◽  
Brian R. Wilson ◽  
Terry Koen
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Exponential Function ◽  
Depth Distribution ◽  
Soil Depth ◽  
New South ◽  
Exponential Functions ◽  
Two Phase ◽  
Mathematical Functions ◽  
South Wales

The nature of depth distribution of soil organic carbon (SOC) was examined in 85 soils across New South Wales with the working hypothesis that the depth distribution of SOC is controlled by processes that vary with depth in the profile. Mathematical functions were fitted to 85 profiles of SOC with SOC values at depth intervals typically of 0–5, 5–10, 10–20, 20–30, 30–40, 40–50, 50–60, 60–70, 70–80, 80–90 and 90–100 cm. The functions fitted included exponential functions of the form SOC = A exp (Bz); SOC = A + B exp (Cz) as well as two phase exponential functions of the form SOC = A + B exp (Cz) + D exp (Ez). Other functions fitted included functions where the depth was a power exponent or an inverse term in a function. The universally best-fitting function was the exponential function SOC = A + B exp (Cz). When fitted, the most successful function was the two-phase exponential, but in several cases this function could not be fitted because of the large number of terms in the function. Semi-log plots of log values of the SOC against soil depth were also fitted to detect changes in the mathematical relationships between SOC and soil depth. These were hypothesized to represent changes in dominant soil processes at various depths. The success of the exponential function with an added constant, the two-phase exponential functions, and the demonstration of different phases within the semi-log plots confirmed our hypothesis that different processes were operating at different depths to control the depth distributions of SOC, there being a surface component, and deeper soil component. Several SOC profiles demonstrated specific features that are potentially important for the management of SOC profiles in soils. Woodland and to lesser extent pasture soils had a definite near surface zone within the SOC profile, indicating the addition of surface materials and high rates of fine root turnover. This zone was much less evident under cropping.

A review of organic carbon accumulation in soils within the agricultural context of southern New South Wales, Australia

2015 ◽  
Vol 184 ◽  
pp. 177-182 ◽  
Author(s):  
Mark Conyers ◽  
De Li Liu ◽  
John Kirkegaard ◽  
Susan Orgill ◽  
Albert Oates ◽  
...  
Keyword(s):  
Organic Carbon ◽  
New South ◽  
New South Wales ◽  
Carbon Accumulation ◽  
South Wales

Should we manage soil organic carbon in Vertosols in the northern grains region of Australia?

2003 ◽  
Vol 43 (3) ◽  
pp. 261 ◽  
Author(s):  
R. J. Farquharson ◽  
G. D. Schwenke ◽  
J. D. Mullen
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
New South ◽  
New South Wales ◽  
Soil Health ◽  
Organic Carbon Content ◽  
Continuous Cropping ◽  
South Wales ◽  
On Farm ◽  
Carbon Concentrations

Two issues prompted this paper. The first was the measured soil organic carbon decline in fertile northern Australian soils under continual cropping using traditional management practices. We wanted to see whether it was theoretically possible to maintain or improve soil organic carbon concentrations with modern management recommendations. The second was the debate about use of sustainability indicators for on-farm management, so we looked at soil organic carbon as a potential indicator of soil health and investigated whether it was useful in making on-farm crop decisions. The analytical results indicated first that theoretically the observed decline in soil organic carbon concentrations in some northern cracking clay soils can be halted and reversed under continuous cropping sequences by using best practice management. Second, the results and associated discussion give some support to the use of soil organic carbon as a sustainability indicator for soil health. There was a consistent correlation between crop input decisions (fertilisation, stubble management, tillage), outputs (yield and profits) and outcomes (change in soil organic carbon content) in the short and longer term. And this relationship depended to some extent on whether the existing soil organic carbon status was low, medium or high. A stock dynamics relationship is one where the change in a stock (such as soil organic carbon) through time is related not only to the management decisions made and other random influences (such as climatic effects), but also to the concentration or level of the stock itself in a previous time period. Against such a requirement, soil organic carbon was found to be a reasonable measure. However, the inaccuracy in measuring soil organic carbon in the paddock mitigates the potential benefit shown in this analysis of using soil organic carbon as a sustainability indicator.These results are based on a simulation model (APSIM) calibrated for a cracking clay (Vertosol) soil typical of much of the intensively-cropped slopes and plains region of northern New South Wales and southern Queensland, and need to be interpreted in this light. There are large areas of such soils in north-western New South Wales; however, many of these experience lower rainfalls and plant-available soil water capacities than in this case, and the importance of these characteristics must also be considered.

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