Surface soil acidity and fertility in the eastern Riverina and Western Slopes of southern New South Wales

2007 ◽  
Vol 47 (8) ◽  
pp. 949 ◽  
Author(s):  
B. J. Scott ◽  
I. G. Fenton ◽  
A. G. Fanning ◽  
W. G. Schumann ◽  
L. J. C. Castleman
Keyword(s):  
Surface Soil ◽  
New South ◽  
Annual Rainfall ◽  
Acidic Soils ◽  
The West ◽  
Surface Soils ◽  
South Wales ◽  
Subsurface Soil ◽  
Average Annual Rainfall

This study, in southern New South Wales (NSW), examined the chemical properties of ~4700 surface soils in agricultural paddocks and recorded lime and gypsum inputs. The area was bounded approximately by Cootamundra in the north, the NSW/Victorian border in the south, extending to Tumbarumba in the east and to near Berrigan in the west. The long-term average annual rainfall ranged from ~420 mm in the west to a maximum of 1175 mm in the east. The data, collected between 1997 and 2003, were for the surface 20 cm of soil, in two 10-cm layers. The data were generated from a soil testing program conducted with farmers in the region. We grouped the soils into three zones based on a GPS location taken at the time of sampling. These zones were 1 (lower rainfall mixed farming), 2 (higher rainfall mixed farming) and 3 (long-term pasture). Acidic soils occurred across all three zones; however, the soils in zone 1 appeared to be less acidic than soils in the other two zones. We found that surface soils (0–10 cm) with soil pH in 1 : 5 soil : 0.01 mol/L calcium chloride (pHCa) ≤4.5 represented 27%, 57% and 54% for zones 1, 2 and 3, respectively. In addition, zone 1 had 74% of surface soils with a pHCa ≤ 5.0, and this was more acidic than previously reported. However, the surface soils in zone 1 had relatively low exchangeable aluminium (Alex) and had less acidic subsurface soils (10–20 cm), so that responses to lime application by pastures and crops may be less frequent or smaller than the surface soil pHCa alone may indicate. There was a higher frequency of acidic soils (pHCa ≤ 4.5) in the subsurface soils than in the surface soils in zones 2 (62 cf. 57%) and 3 (64 cf. 54%), suggesting that the acidity problem at this depth was a major problem. Low pHCa in the subsurface soil is known to be a constraint on crop yield. We found no evidence of the amendment of this soil depth when lime was applied and incorporated into the 0–10 cm depth, and economic amendment of acidity in the 10–20 cm depth remains unresolved. Increased adoption of liming occurred in the late 1990s, and by 1997 the percentage of paddocks limed was 14.3%, 21.3% and 13.6% in zones 1 to 3, respectively. Soil pH buffering and long-term pHCa decline after liming were similar to rates reported in field experiments. The total quantities of lime applied were insufficient for soil amendment and maintenance of soil pHCa, particularly in the long-term pasture areas. The rate of soil acidification in the 0–20 cm depth in the average annual rainfall range of 525–625 mm was estimated to be 1.52 kmol H+/ha.year. This would require 76 kg lime/ha.year to neutralise. Sodic and saline soils occurred mainly in the lower rainfall cropping areas, and were more frequent in an area around the township of Lockhart. Half the gypsum applications were at low rates (≤0.5 t/ha), and were probably for sulfur application to canola. Some of the sodic soils were acidic (34% ≤ pHCa 4.5) so that the application of lime/gypsum mixes could be appropriate in the amendment of these soils. Soils in the pasture system had mean organic carbon content (OC%) of 2.42, compared to the cropping zones at 1.65 and 1.75%. OC% was related to annual average rainfall; the increase in OC% was 0.19% and 0.08% for each 100 mm of average annual rainfall for the surface and subsurface soil, respectively. A group of soils in the cropping areas had surface OC% ≤ 1.25% OC (zone 1, 12%; zone 2, 20%) and this could be the result of intensive cropping. Most soils (55–63%) were of moderate P status (P(Colwell), 21–60 µg/g). However, there was still a substantial group of soils (31–43%) of low P status (P ≤ 20 µg/g). Most surface soils in all zones (72–80%) were low to marginal in sulfur status (KCl 40, ≤10 mg S/kg). Sulfur deficiency has been identified in canola, and current practice in the cropping areas is for inputs of gypsum at low rates.

Trends in Kangaroo Numbers in Western New South Wales and their relation to Rainfall

1984 ◽  
Vol 11 (3) ◽  
pp. 415 ◽  
Author(s):  
J Caughley ◽  
P Bayliss ◽  
J Giles
Keyword(s):  
Maximum Rate ◽  
New South ◽  
Time Lag ◽  
New South Wales ◽  
Annual Rainfall ◽  
The West ◽  
Annual Average ◽  
South Wales ◽  
Rate Of Increase ◽  
Average Annual Rainfall

Annual aerial counts of kangaroos within randomly selected blocks of the western plains of New South Wales showed that the numbers of kangaroos doubled between 1975-76 and 1982, and that the widespread drought of 1982 reduced the populations on average by 43%. Localized reductions of similar magnitude occurred after regional droughts in 1977 and 1980 within parts of the monitored area. The observed trends in kangaroo numbers, with eastern and western blocks treated separately, were correlated with annual rainfall with a time lag of 6 months in the response. The relationships show that kangaroos reach their maximum rate of increase following rainfall 100 mm above the annual average in the east and approximately 50 mm above the annual average in the west. At average annual rainfall kangaroos increase at 25% (greys) and 35% (reds) per annum in the east and at 25% (greys) and 30% (reds) per annum in the west. Rate of increase is zero when rainfall is 100 mm below average in the east and approximately 60 mm below average in the west. When rainfall is below these values, kangaroo numbers decline.

The relationship between average annual rainfall and exchangeable aluminium in soils of south-eastern New South Wales

1986 ◽  
Vol 26 (5) ◽  
pp. 587 ◽  
Author(s):  
M Conyers
Keyword(s):  
Surface Soil ◽  
New South ◽  
New South Wales ◽  
Aluminium Toxicity ◽  
Annual Rainfall ◽  
Neutral Salt ◽  
South Eastern ◽  
South Wales ◽  
Average Annual Rainfall ◽  
The Relationship

Surface soil samples (0-10 cm) from a range of soil types were collected in south-eastern New South Wales. Linear regression and analysis of variance were used to establish that, at a given pH (0.01M CaCl2), the amount of neutral salt exchangeable aluminium in surface soils tends to increase with increasing average annual rainfall. Where aluminium toxicity is a factor limiting plant growth, soils in higher rainfall areas will generally require higher pH for the removal of aluminium from the cation exchange complex.

Long-term benefits of limestone applications to soil properties and to cereal crop yields in southern and central New South Wales

2003 ◽  
Vol 43 (1) ◽  
pp. 71 ◽  
Author(s):  
M. K. Conyers ◽  
C. L. Mullen ◽  
B. J. Scott ◽  
G. J. Poile ◽  
B. D. Braysher
Keyword(s):  
Grain Yield ◽  
New South ◽  
New South Wales ◽  
Commercial Application ◽  
South Wales ◽  
Cereal Grain ◽  
Subsurface Soil ◽  
Acid Tolerant ◽  
The Cost

The cost of buying, carting and spreading limestone, relative to the value of broadacre crops, makes investment in liming a questionable proposition for many farmers. The longer the beneficial effects of limestone persist, however, the more the investment in liming becomes economically favourable. We re-established previous lime trials with the aim of measuring the long-term effects of limestone on surface acidity (pH run-down), subsurface acidity (lime movement) and grain yield. The study made use of experiments where there was adequate early data on soil chemical properties and cereal yields. We report data from 6 trials located at 4 sites between Dubbo and Albury in New South Wales. The rate of surface soil (0–10 cm) pH decline after liming was proportional to the pH attained 1 year after liming. That is, the higher the pH achieved, the more rapid the rate of subsequent pH decline. Since yields (product removal) and nitrification (also acid producing) may both vary with pH, the post-liming pH acts as a surrogate for the productivity and acid-generating rate of the soil–plant system. The apparent lime loss rate of the surface soils ranged from the equivalent of nearly 500 kg limestone/ha.year at pH approaching 7, to almost zero at pH approaching 4. At commercial application rates of 2–2.5 t/ha, the movement of alkali below the layer of application was restricted. However, significant calcium (Ca) movement sometimes occurred to below 20 cm depth. At rates of limestone application exceeding the typical commercial rate of 2.5 t/ha, or at surface pH greater than about 5.5, alkali and Ca movement into acidic subsurface soil was clearly observed. It is therefore technically feasible to ameliorate subsurface soil acidity by applying heavy rates of limestone to the soil surface. However, the cost and risks of this option should be weighed against the use of acid-tolerant cultivars in combination with more moderate limestone rates worked into the surface soil.There was a positive residual benefit of limestone on cereal grain yield (either barley, wheat, triticale, or oats) at all sites in both the 1992 and 1993 seasons. While acid-tolerant cultivars were less lime responsive than acid-sensitive ones, the best yields were generally obtained using a combination of liming and acid-tolerant cultivars.The long-term residual benefits of limestone were shown to extend for beyond 8–12 years and indicate that liming should be profitable in the long term.

Influence of moist - dry cycles on pH changes in surface soils

Soil Research ◽  
1999 ◽  
Vol 37 (6) ◽  
pp. 1057 ◽  
Author(s):  
K. I. Paul ◽  
M. K. Conyers ◽  
A. S. Black
Keyword(s):  
Soil Moisture ◽  
New South ◽  
N Mineralisation ◽  
Moist Soil ◽  
Water Acidification ◽  
Acidic Soils ◽  
Surface Soils ◽  
Soil Layers ◽  
South Wales ◽  
Dry Soil

It is well established that in the moderately acidic soils of southern Australia, the 0–2 cm layer commonly has a higher pH than soil layers between 2 and 10 cm depth. The surface 2 cm of soil is also exposed to much greater fluctuations of moisture content than deeper soil layers. There are contradictory or speculative reports in the literature on how soil moisture fluctuation affects pH and processes which influence pH. Therefore, the aim of this study was to determine the effect of moist–dry cycles on pH, and on processes involving H+ transformations, in 3 surface soils (0–2 cm) sampled from southern New South Wales. Following a pre-incubation, the 3 surface soils were incubated for 28 days at 30°C and were: (i) maintained continuously dry, (ii) subjected to short (2 days dry, 5 days moist) or long (7 days dry, 7 days moist) moist–dry cycles, or (iii) maintained continuously moist. During the incubation, the pH of continuously dry soil slightly increased by 0.03–0.10 units, while the pH of continuously moist soil decreased by 0.16–0.39 units. In soils subject to both short and long moist–dry cycles, the pH decreased by 0.06–0.34 units. However, relative to soils maintained moist, exposure to moist–dry cycles suppressed acidification by 0.05–0.26 pH units. In dry soils the pH increased, since some of the NH4+-N produced by net N mineralisation was not subsequently nitrified, and there was a net reduction of Mn. In soils which received water, acidification was predominately attributed to nitrification. Relative to soils maintained moist, acidification was suppressed by 1.6–6.5 mmol H+/kg due to the 11–35% decrease of nitrification on exposure to moist–dry cycles. In acidic surface soils (pH <5.5), acidification rates were further suppressed by 0.1–1.0 mmol H+/kg due to the 1.06–2.06 times greater net Mn reduction in moist–dry soils than in continuously moist soils.

Comparison of Wheel Point and Point Frame Methods for Plant Cover Measurement of Semiarid and Arid Rangeland Vegetation of New South Wales.

1994 ◽  
Vol 16 (1) ◽  
pp. 94
Author(s):  
H Arzani ◽  
GW King
Keyword(s):  
New South ◽  
Plant Cover ◽  
New South Wales ◽  
Annual Rainfall ◽  
Biomass Estimation ◽  
Tall Grass ◽  
South Wales ◽  
Significant Difference ◽  
Drought Conditions ◽  
Average Annual Rainfall

Ground cover is frequently estimated in rangeland monitoring and it is an important intermediate measurement between biomass estimation and satellite imagery. As a preliminary phase in a longer term program, wheel point and point frame methods were used to measure vegetation cover on four permanent Soil Conservation Service transects at each of four land systems in western New South Wales, at Nyngan (410 mm average annual rainfall), at Cobar (364 mm average annual rainfall) and two at Fowlers Gap (200 mm average annual rainfall) north of Broken Hill. The majority of this work used 400 wheel point hits per transect and 100 point quadrats sub sampled 9 - 13 times along each of four transects. There was no statistically significant difference between these techniques for total foliage cover over a combined analysis of all sites under pre-drought conditions, and for pre-drought and post-drought at Cobar. However, there was a 10% difference estimated between the techniques for total foliage cover at Nyngan when it was analysed in isolation. There were no consistent differences in technique for cover estimation for more than 40 plant species including annual grasses and herbs, perennial grasses and saltbushes. Significant differences between techniques were found for Medicago sp. and Thyridolepis mitchelliana on one occasion. We believe that these differences were due to the problems of finding small plants in tall grass and identifying heavily grazed grasses during drought conditions at Cobar and, in the latter case, this was also associated with a significantly greater estimate of mean cover for all grasses and thus total foliage cover. Although there was generally no statistical difference between techniques our observations suggest that the point frame tends to give lower estimates of cover than the wheel point in the situations measured. This may be associated with the circumference of the marker pins on the wheel point or perhaps observer error but as this effect appeared to be more noticeable with grasses we suspect that the former is most likely. The wheel point is less time consuming, more convenient and simpler to use than the point frame, and will readily accommodate most temporal and spatial variation in sampling requirements in similar land forms in western New South Wales.

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.

Farmer experience with perennial pastures in the mixed farming areas of southern New South Wales: on-farm participatory research investigating pasture establishment with cover-cropping

2014 ◽  
Vol 65 (10) ◽  
pp. 973 ◽  
Author(s):  
A. D. Swan ◽  
M. B. Peoples ◽  
R. C. Hayes ◽  
G. D. Li ◽  
G. R. Casburn ◽  
...  
Keyword(s):  
Cover Crop ◽  
New South ◽  
New South Wales ◽  
Annual Rainfall ◽  
Individual Species ◽  
Cover Cropping ◽  
Mixed Farming ◽  
South Wales ◽  
Average Annual Rainfall ◽  
On Farm

In 2009, 95 farmers in the mixed farming zone of southern New South Wales (NSW), average annual rainfall 450–700 mm, were surveyed about their use of perennial pasture species. Survey responses indicated that, on average, 52% of land was under crop, 29% contained perennial pasture and 19% annual pastures. The proportion of land sown to perennial pastures and the species used differed with rainfall. Farmers identified concerns about the cost of establishment and poor survival of perennial pasture species as constraints to wider adoption. The survey also revealed that cover-cropping (sowing pasture species under the final grain crop in a cropping phase) was the dominant method of pasture establishment. Large-scale, on-farm participatory experiments were sown with the farm machinery, three at Ariah Park and one at Brocklesby in southern NSW in 2009 (annual rainfall 100 mm less than long-term average), and a further two experiments (one at each location) commenced in 2010 (annual rainfall >200 mm above average). These experiments compared the effect of cereal cover-crop sowing rate (standard rates used by the collaborating farmer and half of the standard rate) on the establishment of the perennials lucerne (Medicago sativa), phalaris (Phalaris aquatica), cocksfoot (Dactylis glomerata), and chicory (Cichorium intybus) sown in different mixes and rates with various annual legume species. The persistence and productivity of individual species were monitored for 2 years after sowing. Results indicated little or no effect of the presence of a cover-crop on the initial establishment of any of the perennials, but pasture species survival were severely affected by cover-crop sowing rates as low as half of the farmer practice (10 kg barley or 12 kg wheat ha–1) in 2009. Despite higher than average annual rainfall in 2010 and 2011, the residual effect of establishing pastures under a cover-crop in 2009 was poorer persistence and lower productivity by lucerne at the standard cover-cropping rate, and by phalaris, cocksfoot and chicory at all cover-crop rates, and an increased incidence of weeds. Similar responses to cover-cropping occurred between 2010 and 2012, even with the wetter establishment conditions in 2010, for phalaris, chicory and weeds, despite demonstration at Ariah Park that higher populations of individual perennial species could be achieved by doubling the sowing rate of pasture seed in 2010. Lucerne compensated for lower plant numbers by increasing herbage growth in response to rainfall, but phalaris could not and total pasture productivity over the first 2 years after establishment was greatly reduced by the use of cover-crops in both 2009 and 2010. Cover-cropping also reduced annual legume seedset, which could have implications for future pasture performance. Lucerne was the most consistently productive perennial pasture species evaluated regardless of establishment technique or climatic conditions.

Relationship between environmental and land-use variables on soil carbon levels at the regional scale in central New South Wales, Australia

Soil Research ◽  
2013 ◽  
Vol 51 (8) ◽  
pp. 645 ◽  
Author(s):  
Warwick B. Badgery ◽  
Aaron T. Simmons ◽  
Brian M. Murphy ◽  
Andrew Rawson ◽  
Karl O. Andersson ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Carbon ◽  
Land Management ◽  
Environmental Variables ◽  
New South ◽  
Annual Rainfall ◽  
Permanent Pasture ◽  
South Wales ◽  
Average Annual Rainfall ◽  
Soc Stock

The potential to change agricultural land use to increase soil carbon stocks has been proposed as a mechanism to offset greenhouse gas emissions. To estimate the potential carbon storage in the soil from regional surveys it is important to understand the influence of environmental variables (climate, soil type, and landscape) before land management can be assessed. A survey was done of 354 sites to determine soil organic carbon stock (SOC stock; Mg C/ha) across the Lachlan and Macquarie catchments of New South Wales, Australia. The influences of climate, soil physical and chemical properties, landscape position, and 10 years of land management information were assessed. The environmental variables described most of the regional variation compared with management. The strongest influence on SOC stock at 0–10 cm was from climatic variables, particularly 30-year average annual rainfall. At a soil depth of 20–30 cm, the proportion of silica (SiO2) determined by mid-infrared spectra (SiMIR) had a negative relationship with SOC stock, and sand and clay measured by particle size analysis also showed strong relationships at sites where measured. Of the difference in SOC stock explained by land use, cropping had lower soil carbon than pasture in rotation or permanent pasture at 0–10 cm. This relationship was consistent across a rainfall gradient, but once soil carbon was standardised per mm of average annual rainfall, there was a greater difference between cropping and permanent pasture with increasing SiMIR in soils. Land use is also regulated by climate, topography, and soil type, and the effect on SOC stock is better assessed in smaller land-management units to remove some variability due to climate and soil.

Goat and Sheep Grazing in Shrub-Infested Semi-arid Woodlands of New South Wales.

1986 ◽  
Vol 8 (2) ◽  
pp. 140 ◽  
Author(s):  
BH Downing
Keyword(s):  
Animal Species ◽  
New South ◽  
Economic Implications ◽  
Dietary Preferences ◽  
South Wales ◽  
Continuous Grazing ◽  
Local Observation ◽  
Grazing Systems ◽  
Western Division

Examination of data on dietary preferences of sheep, goats and cattle suggests that different grazing systems are desirable for each of the three major woodland types (belah-rosewood, mulga, poplar box) examined. Competition for herbs, frequently palatable to all animal species, indicates that goats and sheep are unsuitable for joint use either in heavily wooded country or where annual herbaceous production is less than 200 kg-ha. Supplementary feeding, fire and judicious stocking are proposed as a strategy for inducing goats to eat a proportion of unpalatable shrubs. The literature provides little helpful information on how rangelands in the Western Division should be managed. No reports are given on comparisons of grazing systems, such as rotational grazing, rotational resting, and continuous grazing. No guidance is given on grazing after burning of the rangeland. Recommendations are generally against the use of goats for control of woody plants, whereas local observation shows this to be an apparently effective practice. The recommendations are mostly based on experimental procedures which, although suitable for detecting animal dietary preferences in the short term, are less appropriate for investigation of the effects of grazing on range condition in the long term. Some suggestions are made towards a different approach for: investigating the effects of grazing by sheep and goats on rangeland condition, and the economic implications of this in terms of animal production.

Outflow ignimbrite sheets from Late Carboniferous calderas, Currabubula Formation, New South Wales, Australia

1983 ◽  
Vol 120 (5) ◽  
pp. 487-503 ◽  
Author(s):  
J. McPhie
Keyword(s):  
New South ◽  
Sedimentary Facies ◽  
Late Carboniferous ◽  
The West ◽  
Pyroclastic Deposits ◽  
Flow Units ◽  
South Wales ◽  
Accretionary Lapilli ◽  
North Eastern ◽  
Thickness Variations

SummaryRegionally mappable, silicic, outflow ignimbrite sheets are interbedded with fluvial volcanogenic conglomerates and sandstones of the Late Carboniferous Currabubula Formation of north-eastern N.S.W. Four of the most widespread of these ignimbrites are described and defined as members. The oldest member is comprised of many thin, originally non-welded flow units. Interbedded accretionary lapilli horizons may indicate phreatomagmatic activity at vent during the eruption in addition to local rain-flushing of co-ignimbrite ash clouds. Of the three other members, two are multiple flow-unit sheets, 160–180 m in aggregate thickness. Substantial portions of these sheets were originally welded. The remaining member is a simple welded ignimbrite characterized by abundant spherulites and lithophysae. Irregular pre-eruption topography and contemporaneous erosion were responsible for thickness variations of the ignimbrite sheets. Some palaeovalleys, now delineated by the ignimbrites, persisted in spite of repeated pyroclastic influxes. Relic pumice, shards and crystal fragments are ubiquitous components of the sedimentary facies of the Currabubula Formation, and were probably derived from originally poorly consolidated pyroclastic deposits such as airfall ash layers and non-welded ignimbrites. No surface trace of the sources of these ignimbrites exists. However, internal facies, thickness variations and volumes of the ignimbrites indicate that they periodically emanated from a multiple-caldera terrain which was continuously active during the Late Carboniferous, and located several kilometres to the west of present exposures.

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