bluuebunny/crossref_metadata_2025 huggingface dataset:
Is pedology dead and buried?
Authors: Basher L. R.
Published: August 2004

Pedology, the field study of soils as natural landscape bodies, has suffered
serious cutbacks in stang and funding in many developed countries. Soil
survey, a strong focus for pedology, has been most affected by this recession.
The cutbacks to pedology reflect the reduction in funding for general purpose
soil resource inventories and a decline in central government planning and
land development, as well as changing needs for soil information and perceived
failure of soil survey to respond by delivering relevant, timely information
at affordable cost.
A refocusing of research effort in pedology is required to contribute to
research into environmental issues of sustainable land management, and global
change processes and impacts. The adoption of modern, ecient approaches to
collecting, analysing, interpreting and presenting field soil data will
improve the fund-raising capability of pedology and enhance its institutional
stature. The general purpose paper soil map and soil survey report has largely
been superseded as a medium for presenting soil information. Increasingly, it
will be replaced by computer-generated, special purpose, interpretive soil
maps that are based on soil–landscape models and include more objective,
statistically estimated information on soil variability. There is a continuing
role for pedology to define the extent, distribution, properties, suitability,
and vulnerability of soils as a basis for sustainable land management. There
is a need for increasing focus on temporal changes in soil properties, greater
attention to soil properties that determine soil functioning and influence
soil use, and interpretation of the environmental record contained in soils
and regolith.
Solute movement through undisturbed soil columns under pasture during unsaturated flow
Authors: Vogeler I. , Scotter D. R. , Green S. R. , Clothier B. E.
Published: August 2004

Previous studies of solute movement concerning the influence of initial soil
water content have led to apparently contradictory results. Here we describe
some experiments which aimed to determine the effect of both pasture and
initial water content on solute movement. Solid SrCl2,
CaCl2, and
Ca(NO3)2 were surface-applied to
undisturbed columns of a fine sandy loam under short pasture. The soil columns
were 300 mm in both diameter and length. A rotating rainfall simulator
delivered steady-state rainfall at about 10 mm/h. The leachate at the base
was collected under suction and analysed, and one column was analysed for
resident concentrations of strontium. Solute transport could be accurately
described by coupling Richards’ equation with the convection dispersion
equation, when ion exclusion or exchange were taken into account. The
dispersivity was about 70 mm, only slightly higher than found previously for
the same soil without vegetation. There was no significant difference in
intrinsic behaviour when solute was applied to either an initially wet or a
dry topsoil. The contrasting results from earlier published studies were
probably due to incipient ponding and macropore flow. This will not usually
occur in New Zealand pasture soils under typical rainfall intensities, but
might under irrigation or when the soil structure is degraded. It is suggested
that soil cores need to have dimensions at least as large as the dispersivity
if they are to encompass most of the local variation in solute concentration.
On kaolinitic and mixed mineralogy classes of shrink - swell soils
Authors: Bhattacharyya T. , Pal D. K. , Deshpande S. B.
Published: August 2004

Spatially associated red (Typic Hapludalf) and black (Vertic Eutropept) soils
developed on the Deccan plateau in the Western Ghats of India were analysed
for clay mineralogy and also physical properties relating to
shrink–swell. This was done in order to examine a possible correlation
between shrink–swell phenomena and the content of expansible clay
minerals, and to reconcile the apparent incompatibility between such a
correlation and the classification of some Vertisols into kaolinitic, illitic,
and mixed mineralogy classes. The fine clay mineralogy of the red soil was
dominated by interstratified smectite/kaolinite with a little amount of
smectite, but it had low cation exchange capacities and other associated
non-vertic physical properties. Some of the smectite was interlayered with
chlorite. This red soil is grouped into the kaolinitic mineralogy class. The
fine clay mineralogy of the black soil was dominated by a highly smectitic
interstratified smectite/kaolinite and also some smectite, which also
shows some interlayering with chlorite. This soil has vertic physical
properties but has a mixed mineralogy classification. The results suggest that
there is an incompatibility between marked shrink–swell characteristics
and mineralogical classification of soils in Soil Taxonomy, in view of the
fact that it is smectite content which governs the vertic character of soils.
Physical rehabilitation of degraded krasnozems using ley pastures
Authors: Bell M. J. , Bridge B. J. , Harch G. R. , Orange D. N.
Published: August 2004

The physical fertility of krasnozems and euchrozems (Red Ferrosols) in
Australia has declined substantially as a result of continuous cropping. Much
of this decline is associated with reduced levels of soil organic carbon and
soil compaction due to vehicle trac when soils are too wet. We examined the
impact of kikuyu (Pennisetum clandestinum) and Rhodes
grass (Chloris gayana) pasture leys with various
management inputs on the regeneration of physical fertility of continuously
cropped krasnozems from 2 locations in the South Burnett region of southern
Queensland.
Pasture leys significantly improved the physical fertility of continuously
cropped soils within 2–4 years. The most significant effects were on the
creation of improved surface and subsurface macroporosity, and in a reduction
in surface crust formation under high energy rain due to improved aggregate
stability. Final steady state infiltration rates under well-managed leys
increased 4-fold compared with those in continuously cropped soil.
Pastures were unable to ameliorate compacted layers below approx. 15 cm,
although significant improvements in hydraulic conductivity through these
layers (and to depths of at least 70 cm) were made, presumably by creating of
continuous biopores. Introduced earthworms improved pasture effectiveness in
ameliorating this layer, but only to depths of 20 cm, while deep ripping
during the ley phase was the most effective treatment.
Kikuyu was the more effective pasture species in overcoming soil physical
infertility, particularly in terms of improving aggregate stability under
rain. In addition, the ability of kikuyu to resist the compacting influence of
cattle trampling during wet weather meant that rainfall infiltration eciency
was maintained during the ley phase and management options on returning to
cropping were more flexible (e.g. direct drill strategies can be used).
However, if pastures were ungrazed, the advantages of kikuyu in soil physical
restoration were evident in only 2 years.
Hydrology models DRAINMOD and SWIM applied to large soil lysimeters with artificial drainage
Authors: Barkle G. F. , Brown T. N. , Painter D. J. , Singleton P. L.
Published: August 2004

Two hydrological models, which used different methods to determine the soil
water distribution in a soil profile, were evaluated against 4 years of data
from large soil lysimeters. SWIM determines soil water distribution from a
finite difference implementation of the Richards" equation. DRAINMOD uses
a soil-specific relationship between the air volume in a profile and the
watertable height to locate the depth to the saturated zone. An
‘equilibrium’ relationship between soil water tension and depth is
then assumed to distribute the soil water in the unsaturated zone. Predicted
values and measured values for drainage and watertable heights were compared
for 3 drainage treatments. The drainage in the lysimeters was achieved by
installing an outlet tube on the slowly permeable layer at 0·75 m from
the soil surface. The conventional drainage treatment allowed gravity drainage
to occur directly from this drainage outlet tube. The other 2 drainage
treatments employed controlled drainage, where a step (or weir) is installed
in the outlet tube. No drainage can occur from the lysimeters until the water
table within the lysimeters reaches the step height. Two different step
heights provided 2 controlled drainage treatments.
Independently determined model parameters were used without additional
calibration for the analysis. Both models performed well. DRAINMOD
over-predicted the 4-year cumulative drainage for all treatments, with the
largest error being 7%. SWIM conversely under-predicted cumulative
drainage, with a maximum error of 16%. The standard error of estimation
for the watertable height over the full 4-year data period was lower for SWIM,
ranging from 0 ·06 to 0·12 m. DRAINMOD’s standard error
over the same period for the watertable height ranged from 0·09 to
0·21 m. Generally, error values from this work were smaller than
comparable values from other studies. The hydrology of the lysimeters where
there was no lateral inflow, surface runoff, or deep seepage losses, coupled
to an essentially 1-dimensional flow domain, probably contributed to the lower
errors. Furthermore, limitation of the maximum watertable heights by the
controlled drainage regime in the lysimeters also reduces the maximum possible
magnitude of the standard error term.
Nitrogen fluxes in surface soils of 1 - 2-year-old eucalypt plantations in Tasmania
Authors: Wang X. J. , Smethurst P. J. , Holz G. K.
Published: August 2004

To improve our understanding of nitrogen (N) supply in eucalypt plantations in
Tasmania, N fluxes were determined in surface soils (0–10 cm) at 4 sites
supporting 1–2-year-old plantations of E. nitens.
Net N mineralisation, nitrification, leaching, and uptake were measured by an
in situ soil-core technique. Soils were derived from
basalt (3 sites) or mudstone (1 site). Average rates of net N mineralisation
ranged from 18 to 91 kg N/ha·year, and most mineralised N was
nitrified and leached. There were significant linear relationships among net N
mineralisation, nitrification, and leaching (r =
0·61–0·83). Annual rates of net N mineralisation varied as
much within sites as between them, and rates in individual plots were
significantly correlated with anaerobically mineralisable N
(r = 0·82) or total N
(r = 0·66), but were not correlated or
only weakly correlated with C: N ratio, loss-on-ignition, organic C, water
content, or temperature. Leaching was weakly correlated with effective
rainfall (rainfall minus evaporation, r =
0·39). Soil contained most mineral N during February–April (i.e.
late summer–early autumn) and least during October–November (i.e.
late spring). We concluded that available N at these sites was highly variable
spatially and temporally, and at a plot scale was closely related to
concentrations of mineralisable substrate and not to soil water or
temperature.
A survey of the impact of cropping on soil physical and chemical properties in north-western New South Wales
Authors: Whitbread A. M. , Lefroy Rod D. B. , Blair Graeme J.
Published: August 2004

The soil survey was conducted on cropped and uncropped Red Earths (Alfisols),
Grey Clays, and Black Earths (Vertisols) in northern New South Wales. The
degradation of soil physical properties between the cropped and uncropped
reference sites was reflected in declines of 29–86% in hydraulic
conductivity (K) and 33–71% in aggregation.
Generally there was a substantial loss of carbon with cropping, and the loss
of labile carbon (CL) was usually greater than the loss
of total carbon (CT). A Grey Clay which had been cropped
for >40 years had lost 63% and 51% of its
CL and CT, respectively. An
adjacent Grey Clay which had been cleared and cropped for only 2 years had
lost 43% and 26% of its CL and
CT, respectively, resulting in a C management index
(CMI) of 55, indicating that a large proportion of soil C was lost soon after
the commencement of cropping. Where well-managed legume leys had recently been
grown, the loss of C was reduced, resulting in a higher CMI. A loss of total
and available nutrients after cropping was also found, with the magnitude of
the losses modified by fertiliser history. A highly significant correlation
was found between CT or CL and the
proportion of water-stable aggregates >250 µm for the Red Earth and
Grey Clay soils, but this correlation was poor for the Black Earth. The
importance of organic matter in maintaining aggregation in low clay soils such
as the Red Earth was highlighted.
Changes in extractable and microbial C, N, and P in a Western Australian wheatbelt soil following simulated summer rainfall
Authors: McNeill A. M. , Sparling G. P. , Murphy D. V. , Braunberger P. , Fillery I. R. P.
Published: August 2004

The effects of simulated rainfall events during the summer fallow period on
extractable and microbial carbon (C), nitrogen (N), and phosphorus (P) in
soils under either continuous wheat or the second-year pasture phase of a
2-pasture-1-wheat rotation in the Western Australian wheatbelt were
investigated. A ‘single wetting’ treatment (45 mm rainfall on Day
0) was compared with a 55 mm ‘multiple wetting’ treatment (45 mm
at Day 0, 5 mm at Day 3, and 5 mm at Day 8). Soil samples from 0{10 cm
depth were taken prior to, and at regular intervals up to 14 days following,
the inital wetting event. Soil extracts were assayed for total soluble N
(TSN), total oxidisable C (TOC), Olsen-P, and ninhydrin-positive compounds
(NPC). Prior to the simulated rainfall events, extractable TSN and TOC in the
air-dry fallow soils were significantly higher (P <
0·01), and Olsen-P significantly lower, for the pasture land use
compared with the continuous wheat. However, subsequent to wetting there were
no significant differences between the 2 land uses, or single and multiple
wetting treatments, for extractable TSN, TOC, Olsen P, or NPC. Extractable
soluble organic N (SON), calculated by subtracting measured inorganic N from
TSN, decreased within 48 h of each wetting event to a minimal value but, after
the first 2 wetting events, subsequently increased to at least the prewet
value. Microbial C, N, and P were estimated from the difference in TOC, TSN,
and Olsen-P of extracts from fumigated and unfumigated soils (microbial
‘flush’) and microbial C and N were also estimated from the NPC
‘flush’. There was generally good agreement between the 2
estimates of microbial N (NPC and TSN,
R2 = 0·50), but less
so for the 2 estimates of microbial C (NPC and TOC,
R2 = 0 ·31). There
was no significant difference in microbial C, N, or P between the 2 land uses,
but there was a highly significant response of the microbial biomass to
wetting events and also significant differences in temporal patterns between
the single and multiple wetting treatments. Microbial C and N increased in the
period following initial wetting, more rapidly in the wheat than the pasture,
reaching a peak at Day 2 for wheat and Day 3 for pasture. Subsequently, for
the single wet treatment, there was a steady linear decline in microbial C and
N until Day 10, whereas over the same period (Days 4-10) in the multiple wet
treatment there were 2 highly significant quadratic responses to time,
manifest as a linear increase in microbial C and N following each re-wetting
event, to a peak value 24 h after the event, and a subsequent decline to the
pre-wet value after a further 24 h.
Desorption of native and added zinc from a range of New Zealand soils in relation to soil properties
Authors: Singh D. , McLaren R. G. , Cameron K. C.
Published: August 2004

Compared with zinc (Zn) sorption, there is very little information on the
effect of soil properties on Zn desorption from soils. In this study,
desorption of native and added Zn from 7 Canterbury (NZ) soils was determined
using a technique involving repeated equilibration of soil in 0·01 M
Ca(NO3)2. The concentrations and
patterns of desorption of both native and added Zn varied between the
different soils. Greater concentrations of native Zn were desorbed from
surface soils than from subsoils, and greater concentrations of added Zn were
desorbed from subsoils than from their corresponding surface horizons.
Correlation analysis showed that cation exchange capacity (CEC) and organic
carbon (C) were the dominant soil variables contributing towards sorption or
desorption of Zn. However, simple linear regressions involving CEC or organic
C explained only 48–62% of the total variation in Zn sorption or
desorption from the different soils.
Multiple regression analysis indicated that cumulative native Zn desorption
(expressed as percentage of DTPA-extractable Zn) was strongly related to CEC
and the content of Mn oxides, which in combination explained 80% of the
variability between soils. Regression analysis also showed that CEC plus Mn
oxides and pH explained 91% of the variability in Zn sorption between
the soils; whereas for added Zn desorbed (%), CEC plus pH and
crystalline Al oxides explained 93% of variability in added Zn
desorption.
Mineralogical properties of sandy podzols on the Swan Coastal Plain, south-west Australia, and the effects of drying on their phosphate sorption characteristics
Authors: He J. Z. , Gilkes R. J. , Dimmock G. M.
Published: August 2004

Very sandy and sometimes seasonally inundated humus podzols of the Bassendean
soil association in southwest Australia experience severe leaching of
fertiliser P with consequent eutrophication of waterways. P sorption by these
soils is mostly minimal and is primarily due to the podzol Bh horizon. The
consequence of seasonal drying of profiles under the prevailing Mediterranean
climate on the P sorption capacity of these B horizon materials is not known.
The effects of air-drying on P sorption were studied for 3 sandy podzols
using samples from entire soil profiles collected in winter (wet) and summer
(dry). Results confirm that the surface and near surface horizons (i.e. A and
E horizons) of these soils have very low P sorption capacities. Only some B
horizon materials exhibit substantial P sorption and this is mostly due to
allophane, with minor contributions from extractable Fe forms, organic carbon,
and clay. Air-drying during summer and in the laboratory increased P sorption
of B horizon materials by up to 120% compared with field-moist samples.
The difference in P sorption between air-dried samples and the field-moist
samples decreased for long reaction times.
The distribution and relative losses of soil organic carbon fractions in aggregate size fractions from cracking clay soils (Vertisols) under cotton production
Authors: Conteh A. , Blair G. J.
Published: August 2004

The distribution and losses of organic carbon fractions in various aggregate
sizes from cracking clay soils were studied to understand some factors
associated with losses of soil organic carbon under cultivation. Five pairs of
samples from cropped and adjacent uncropped (reference) soils were collected
from 5 of the main cotton-growing regions of Australia. Five aggregate sizes
were separated from each of these soils (<50 µm, 50-150 µm,
150-250 µm, 250-450 µm, and 450-500 µm). On each of these
aggregate fractions, measurements were made for total carbon
(CT), labile carbon by ease of oxidation
(CL), d 13 C, total light fraction
(LF), carbon content of light fraction (C%-LF), and the proportion of
soil carbon in the light fraction (LF-C) calculated. CT and CL were found to
increase with a decrease in aggregate size, whereas LF was found to decrease
with a decrease in aggregate size. Losses of both CT and
CL as a result of cultivation were higher in larger
aggregates than in smaller aggregates. The δ13C of
both the whole soil and the LF was higher in the cropped soil than in the
reference soil. It was concluded that most of the organic matter present in
the cracking clay soils used for cotton production is highly decomposed, and
most of it is concentrated in the microaggregates of the soil.
Sorption and desorption of cadmium from some New Zealand soils: effect of pH and contact time
Authors: Gray C. W. , McLaren R. G. , Roberts A. H. C. , Condron L. M.
Published: August 2004

The effects of soil pH on the desorption of native soil cadmium (Cd), and on
the sorption and desorption of added Cd at low concentrations, have been
examined for 6 New Zealand soils ranging from pH 4·9 to 6·2. The
effect of contact time with added Cd on subsequent desorption from soil has
also been studied. Cadmium desorption was determined by repeated
equilibrations in 0·01 М
Ca(NO3)2 solution. Cadmium
sorption ranged between 38% and 96% from an initial addition of
2 µg Cd/g soil. The effect of increasing soil pH was to increase
substantially the amount of Cd sorbed. Sorption isotherms were all linear,
with a negative intercept on the y-axis. Sorption data
also fitted a linearised Freundlich sorption equation. Cadmium desorption was
also very sensitive to pH, with a dramatic reduction in the amount of native
Cd desorbed from the soil as pH increased, as was observed for samples where
Cd was added. The cumulative amounts of native Cd desorbed represented only a
relatively small proportion (0–22%) of total soil Cd
concentrations. Added Cd desorption ranged between 22% and 99%
of the Cd initially sorbed on the soil at varying pH. Organic matter appeared
to be the most important soil component controlling both sorption and
desorption in the soils studied. In the contact period experiment, the
proportion of Cd desorbed was decreased by increasing initial contact time to
70 days before desorption for all 4 soils studied. Contact time had the
greatest effect on Cd desorption in soils with the highest amounts of soil
oxide components. Implications of the study are that, for the soils studied,
soil pH, Cd contact time, and soil organic matter content are controlling
factors on Cd desorption into soil solution, and are therefore likely to play
an important role in Cd phytoavailability.
Soil structure assessment and 3-dimensional visualisation of a Vertosol under controlled traffic
Authors: Bakker D. M. , Barker T. M.
Published: August 2004

There is evidence that controlled traffic can be detrimental to crop growth
due to soil structural degradation in the wheel tracks. An experiment was
conducted in which the effects of 2 different types of wheel tracks (raised
and recessed) on soil structure were assessed. Large monoliths were taken and
impregnated with epoxy resin. A special jig was employed to create and expose
smooth level surfaces in which the crack pattern was highlighted with UV
light. Images from the patterns were used to describe soil structure with 4
different attributes. Special image analysis software was used to combine
multiple images to reconstruct the structure of the soil blocks. From the
images and the 4 attributes, it was concluded that after 2 years the raised
wheel track had a more massive soil structure than the recessed wheel track.
The reconstructed soil structure revealed an intricate network of cracks and a
large variability over a short distance, as well as dominant features of
continuous cracks parallel to the plant row. From this work it is proposed
that, in these soils, the well-documented benefit of controlled traffic in the
Australian cotton industry is primarily related to minimising structural
decline caused by cultivation rather than by traffic.
Relating phosphorus quantity, intensity, and buffer capacity to phosphorus uptake
Authors: Probert M.E. , Moody P. W.
Published: August 2004

The short-term (25 days) phosphorus (P) uptake by maize has been reported to
be most strongly correlated with measurements of P intensity in soil.
Correlations of P uptake with bicarbonate-extractable P (a measure of the
quantity factor) were improved when indices of P buffer capacity were
included, but not to the extent obtained with the direct measure of P
intensity. Thus, one might infer that measurements of the quantity factor and
P buffer capacity were less satisfactory for describing P availability. It is
now shown that this conclusion results entirely from the model fitted to the
data. By using a multiplicative rather than additive model, it is shown that
bicarbonate-extractable P in combination with measures of P buffer capacity
can describe the P uptake data equally as well as a direct measurement of P
intensity.
Proteoid root mats bind surface materials in Hawkesbury Sandstone biomantles
Authors: Gould Susan F.
Published: August 2004

Sediment yield following bushfire on Hawkesbury Sandstone hillslopes is highly
variable and catastrophic stripping of soils often does not occur as
anticipated. Proteoid root mats were examined as a potential mechanism for
limiting catastrophic stripping of Hawkesbury Sandstone biomantles. It was
found that surface and subsurface proteoid root mats were widespread and
concentrated in the uppermost portion of the soil profile. The proteoid roots
bound mineral soil from the size of clay to gravel. The roots were observed
growing up into the leaf litter and bound leaf litter to the mineral soil
surface. It is concluded that proteoid root mats bind surface materials in
Hawkesbury Sandstone biomantles and are sufficiently widespread to account for
the stability of soil materials that appear to be unprotected following
bushfire.
Chemical losses off dairy catchments located on a texture-contrast soil: carbon, phosphorus, sulfur, and other chemicals
Authors: Fleming N. K. , Cox J. W.
Published: August 2004

Runoff (overland flow and A/B horizon interflow) from 2 grazed dairy
pastures at Flaxley, South Australia, accounted for <15% of
April{October rainfall in 1996; 88{96% of runoff was overland
flow.
A range of chemicals, including carbon (C), phosphorus (P), and sulfur (S),
was measured in runoff As much as 2·3 kg P/ha, 10·7
kg/ha of total dissolved C, and 1·8 kg S/ha was lost from the
catchments in that year. Loads of other chemicals ranged from 0·6
g/ha (boron) to 39·8 kg/ha (aluminium). Over 92% of P,
76% of total dissolved C, and 93% of S was lost in overland
flow. Between 50% and 60% of P, and 60% and 85% of
S, was in the dissolved form; 64-96% of total dissolved C was dissolved
organic C. Other chemicals varied from 0% (aluminium) to 97%
(sodium) as the dissolved form.
Relatively high losses of P and dissolved organic C are important to a dairy
industry which is under increasing pressure to demonstrate minimal
environmental impact from farming practices.
Effects of humic and fulvic acids on the rhizotoxicity of lanthanum and aluminium to corn
Authors: Diatloff E. , Harper S. M. , Asher C. J. , Smith F. W.
Published: August 2004

Effects of varying lanthanum (La) or aluminium (Al) concentrations (0-30
µM) on corn (Zea mays L.)
root elongation were examined in the presence and absence of
(i) humic acid (HA) at 35 mg carbon (C)/L, or
(ii) fulvic acid (FA) at 15 mg C/L, using dilute
nutrient solutions. The organic acids were extracted from a mixture of
decomposed grass (Sorghum halepense) and lucerne
(Medicago sativa) hay. In the absence of added HA or FA,
the addition of La at ≥5 µM and Al at 30
µM was toxic to the root growth of corn. The
rhizotoxic effects of La at 5 and 10 µM were
negated by HA. The ability of FA to overcome La rhizotoxicity was much less,
significantly ameliorating the toxic effects of 5
µM La but not those of 10 or 30
µM La. HA and FA did not precipitate La from
solution. Both organic acids ameliorated Al toxicity by complexing Al and
reducing monomeric Al in solution.
It is concluded that concentrations of HA and FA, commonly present in soil
solutions, are capable of forming non-rhizotoxic complexes with La, hence
plant tolerance to La in the soil solution may be appreciably higher than
would be indicated by results of solution culture experiments in which these
ligands are not present.
The role of active fractions of soil organic matter in physical and chemical fertility of Ferrosols
Authors: Bell M. J. , Moody P. W. , Connolly R. D. , Bridge B. J.
Published: August 2004

The relationships between fractions of soil organic carbon (C) oxidised by
varying strengths of potassium permanganate (KMnO4) and
important soil physical and chemical properties were investigated for
Queensland Ferrosols. These soils spanned a wide range of clay contents
(31-83%), pH values (4·4-7·9; 1 : 5 water), and total C
contents (12· 1-111 g/kg). Carbon fractions were derived by
oxidation with 33 mM (C1), 167 mM (C2), and 333 mM (C3)
KMnO4, while organic C and total C were determined by
Heanes wet oxidation and combustion, respectively. Aggregate stability was
determined by wet sieving soil from the surface crust after 30 min of high
intensity (100 mm/h), simulated rainfall on disturbed samples in the
laboratory. The proportion of aggregates <0·125 mm (P125) was used
as the stability indicator because of the high correlation between this size
class and the final rainfall infiltration rate
(r2 = 0qa86,
n = 42). The soil organic C fraction most closely
correlated with P125 was C1 (r2
= 0·79, n = 42). This fraction was
also highly correlated with final, steady-state infiltration rates in field
situations where there were no subsurface constraints to infiltration
(r2 = 0·74,
n = 30). Multiple linear regression techniques
were used to identify the soil properties determining effective cation
exchange capacity (ECEC, n = 89). Most variation
in ECEC (R2 = 0 ·72)
was accounted for by a combination of C1 (P <
0·0001) and pH (P < 0·0001). These
results confirm the very important role played by the most labile (easily
oxidised) fraction of soil organic matter (C1) in key components of the
chemical and physical fertility of Ferrosols. Management practices which
maintain adequate C1 concentrations are essential for sustainable cropping on
these soils.
Effects of spent mushroom substrate on soil physical conditions and plant growth in an intensive horticultural system
Authors: Stewart D. P. C. , Cameron K. C. , Cornforth I. S. , Sedcole J. R.
Published: August 2004

A 2-year field trial determined the influence of applying spent mushroom
substrate (SMS) on soil physical properties and the growth of 4 consecutive
vegetable crops (sweetcorn, cabbage, potato, cabbage). Treatments comprised 0,
20, 40, and 80 t/ha of moist SMS, both with and without inorganic
fertiliser, applied to each crop, giving a range of SMS rates up to 320
t/ha.
SMS improved the environment for plant root growth by decreasing soil bulk
density (by 0· 05-0·25 g/cm 3 at 100 mm depth), increasing
aggregate stability (by 13-16%), reducing clod and surface crust
formation (by 16-31 and 18-94%, respectively), increasing the
infiltration rate (by 130-207 mm/h), increasing the water content of the
soil (by 0-7% w/w), and reducing diurnal temperature changes. Some
of these changes were not evident until repeated applications of 80 t/ha
SMS had been made.
Soil physical properties were related to crop yield, and soil physical
properties’ principal components were related to crop principal
components using regression analysis
(r2 of 0·20-0·60 and
0·16-0·54, respectively). The soil physical properties that had
the most influence on plant growth were specific to each crop and included
bulk density, water content, surface crust cover, infiltration rate, and
aggregate size distribution. Soil physical properties had a large influence on
the potato yield irrespective of fertiliser use and on both cabbage crop
yields when fertiliser was not used, but not on the sweetcorn yield (the first
crop to be grown). The effect of changing soil physical properties on plant
growth was most apparent when fertiliser was not used. This was because the
improved physical properties increased plant yield (at least in part) because
of increased plant nutrient uptake.
Enhancement of soil nutrients around nest entrances of the funnel ant Aphaenogaster barbigula (Myrmicinae) in semi-arid eastern Australia
Authors: Eldridge D. J. , Myers C. A.
Published: August 2004

The distribution of soil nutrients around nest entrances of the ant
Aphaenogaster barbigula was studied in a semi-arid
woodland in eastern Australia. The ants re-excavate their nest chambers after
rainfall, trapping any litter which falls near the entrance, and blocking the
passage of litter moving downslope by processes of overland flow. The
entrapment of organic matter around nest entrances resulted in significantly
higher levels of nitrogen, organic matter, and some cations compared with
nest-free surfaces. Significant depth nest interactions suggest that these
nutrients are being concentrated close to the surface.
Effects of time and temperature on the sorption of cadmium, zinc, cobalt, and nickel by a soil
Authors: Barrow N. J.
Published: August 2004

Several levels of cadmium (Cd), zinc (Zn), nickel (Ni), or cobalt (Co) were
added to samples of a soil as solutions of nitrate salts. The samples were
incubated at about field capacity for up to 30 days at differing temperatures
and the concentration of the metal ions in the soil solution was estimated at
4 times for each temperature. The effects of level of addition, time, and
temperature on solution concentration were well described using a mechanistic
model. The model suggests that the metals react with a differing range of soil
components and that the pathways for diffusion into the particles also differ.
The change in solution concentration was slowest for Cd and fastest for Co and
Ni but these were not significantly faster than Zn. These results suggest that
the toxic effects of Cd added to soils will not decrease greatly with time
whereas the effectiveness of fertilisers (Zn and Co), and potential
fertilisers (Ni), will decrease.
Studies on the Hygrophoraceae (Fungi, Homobasidiomycetes, Agaricales) of Australia
Authors: Young A. M. , Wood A. E.
Published: August 2004

The species of the Australian Hygrophoraceae are considered and three genera
recognised: Hygrophorus Fr.;
Hygrocybe (Fr.) Kummer; and
Camarophyllopsis Herink. Fifty-seven taxa are described,
of which 35 are new species, two are new varieties and six are new
combinations; the position of Hygrocybe flammans (Berk.)
A.M.Young remains uncertain. The taxa described are believed to represent less
than 30% of the Australian family flora. Keys, descriptions and line
drawings are provided to facilitate identification and a possible systematic
structure is proposed. A brief review of Australian literature relevant to the
family is provided.
Contributions Towards a Revision of Daviesia (Fabaceae: Mirbelieae). IV.* D. ulicifolia sens. lat.
Authors: Chandler Gregory T. , Crisp Michael D.
Published: August 2004

Following a morphometric and cladistic analysis of the
Daviesia ulicifolia Andrews group (Chandler and Crisp
1997), a new species, D. sejugata, is described. It
occurs disjunctly in eastern Tasmania and southern Yorke Peninsula, South
Australia, and is closely related to D. arthropoda
F.Muell., differing in a generally more robust habit, thicker fleshy
phyllodes, and larger flowers. Even with this species removed from
D. ulicifolia, the latter varies considerably over a
wide geographic, edaphic and altitudinal range.
Daviesia ulicifolia is divided into six subspecies based
on distinct phenetic and phylogenetic groups delimited in the earlier study.
These are subsp. aridicola (glaucous plants in arid
regions), subsp. incarnata (reddish-flowered plants in
the Mt Lofty Range, South Australia), subsp. ruscifolia
(plants with ovate-acuminate leaves and orange flowers in Victoria and
southern New South Wales (NSW), often at high altitude), subsp.
stenophylla (a narrow-leaved form in northern NSW and
Queensland), subsp. pilligensis (ovate-leaved plants on
sandy soil in western NSW), and subsp. ulicifolia (a
paraphyletic residual from south-eastern states).
Xyris L. Section Pomatoxyris Endl. (Xyridaceae) in Australia
Authors: Conn Barry J. , Doust Andrew N. L.
Published: August 2004

A systematic study of the endemic Australian sectionPomatoxyris Endl. of the genusXyris is presented. Eighteen species are recognised, ofwhich Xyris atrovirida, X. exilisand X. maxima A.N.Doust & B.J.Conn are described forthe first time. Xyris bracteata R.Br. is reinstated forthe taxon more recently known as Xyris gracilis R.Br.subsp. laxa O.D.Evans.Xyris gracilis R.Br. subsp.tasmanica D.I.Morris is here raised to specific statusas X. tasmanica (D.I.Morris) A.N.Doust & B.J.Conn.All recognised taxa are provided with descriptions, distribution information(including maps), habitat descriptions, nomenclatural and other relevantnotes. Where appropriate, lectotypes are here designated for all previouslydescribed species of section Pomatoxyris Endl. which areaccepted by us. All species are illustrated.
Contributions Towards a Revision of Daviesia (Fabaceae: Mirbelieae). V. D. cardiophylla sens. lat.
Authors: Crisp Michael D. , Chandler Gregory T.
Published: August 2004

Three new species, Daviesia cunderdin,
D. euryloba and D. umbonata, are
described from south-western Western Australia. The first is a recently
discovered rare and endangered species from near the town after which it is
named. The latter two are segregated from the widespread and variable species
D. cardiophylla F.Muell. Full descriptions,
illustrations, a distribution map and a key to all four species are presented.
Variation in Callistemon viminalis (Myrtaceae): New evidence from leaf essential oils
Authors: Brophy Joseph J. , Forster Paul I. , Goldsack Robert J. , Hibbert D. Brynn , Punruckvong Acharaporn
Published: August 2004

Analysis of leaf essential oils in Callistemon viminalis
(Sol. ex Gaertner) G.Don ex Loudon was used to determine the validity of
infraspecific taxa recognised in the taxon. The leaf essential oils obtained,
in 0.08–0.63% yield, have been found to be qualitatively similar
over the wide geographic distribution of the species (from 12°28′S
to 29°43′S) but to differ quantitatively over this range. All oils
contained α-pinene, β-pinene, myrcene and 1,8-cineole as their major
compounds and traces of the β-triketones, leptospermone and flavesone.
Overall the essential oils that contained the most 1,8-cineole
(60–82%) came from the more southern latitudes (29°14′S
to 20°16′S) while those oils with less 1,8-cineole
(0.5–47%) came from the more northerly latitudes
(12°53′S to 25°18′S). There was overlap in the region
25° S to 22° S, although the majority of samples from this region
contained high 1,8-cineole values. Partial least squares analysis allowed the
latitude to be calibrated by the leaf oil concentrations. These data would
lend only equivocal support for the establishment of two intraspecific taxa of
C. viminalis.
A catalogue of Phaeophyta (brown algae) from Queensland, Australia
Authors: Phillips J . A. , Price I. R.
Published: August 2004

A catalogue of 126 species of benthic marine brown macroalgae (Phaeophyta) hasbeen compiled for the coastline of tropical–subtropical Queensland,Australia. This number represents a significant decrease compared to the 139brown macroalgal species previously recorded for the State (Lewis 1985).Cutleria mollis Allender & Kraft,Padina gymnospora (KÜtzing) Sonder, andTaonia australasica J.Agardh are newly recorded forQueensland. With the exception of the genus Sargassum, ataxonomically difficult genus in urgent need of revision, misidentificationshave been corrected and erroneous records excluded from the flora. Species ofthe Fucales (59 species), particularly the genusSargassum (51 species), and the Dictyotales (31 species)comprise approximately three quarters of the total number of species recordedand often are ecologically important as dominant species in lower intertidaland subtidal communities. The flora is composed of predominantly tropicalspecies, but also includes temperate species which range into subtropicalsouthern Queensland. However, the geographical ranges of most species remainpoorly documented and little is known of their patterns of abundance orhabitat specificity. Consequently, it is not currently possible to determinethe conservation status of many Queensland brown algal species.
The circumscription and systematic position of Carpodetaceae
Authors: Gustafsson Mats H. G. , Bremer Kåre
Published: August 2004

The genus Carpodetus from New Zealand, New Guinea, and
the Solomon Islands, traditionally has been included in the extremely
heterogeneous Saxifragaceae sensu lato, but on account
of morphological peculiarities it has sometimes been classified in its own
family. On palynological grounds it has been suggested to belong near the
Ericales. Parsimony analyses of matrices comprising rbcL
sequences of 80 taxa sampled from the entire Asteridae and Rosidae provide
support for a sister group relationship between
Carpodetus and a clade comprising the closely related
Australian genera Abrophyllum and
Cuttsia, also formerly placed in Saxifragaceae
sensu lato, but recently shown to belong within the
order Asterales sensu lato. A morphological comparison
between the three interrelated genera is provided. They have in common an
indumentum of thick-walled unicellular hairs with warty cuticle, and are also
uniform in wood anatomy as well as fruit and seed structure. It is proposed
that the family Carpodetaceae be expanded to encompass
Abrophyllum and Cuttsia.
A revision of the genus Diplaspis (Mulinae–Hydrocotyloideae–Apiaceae)
Authors: Borre A. Van den , Henwood M. J.
Published: August 2004

For the last 150 years considerable confusion has surrounded the
circumscription of the taxa within Diplaspis Hook. f.
The nomenclatural and taxonomic history of the genus is reviewed, and the
current species limits are assessed.
Diplaspis hydrocotyle Hook. f. and
D. cordifolia Hook. f. are considered to be restricted
to Tasmania, and D. nivis, a new species from the alpine
region of the Australian mainland, is described.
Algal systematics in Australia
Authors: Entwisle Timothy J. , Huisman John
Published: August 2004

Documentation of the algal flora of Australia had its beginnings in the
seventeenth century and has progressed sporadically but with increasing vigour
ever since. Earlier studies dealing with Australian algae were undertaken by
overseas phycologists working with specimens collected during scientific
voyages or short visits. Recent floristic studies have concentrated on
specific regions, isolated localities, or particular taxonomic or ecological
groupings. The algal flora of Australia is unevenly documented: northern
Australia remains largely uncollected for seaweeds and marine phytoplankton,
freshwater algal sampling sites are eclectically scattered across Australia,
and collecting of terrestrial algae has been almost completely neglected. At
present, numbers and names of species reported from Australia can only be
provisional, and an immense amount of floristic and revisionary work is needed
before we can match our current knowledge of the vascular plant flora. Until
recently, documentation of records was poor and voucher material seldom
adequate. We recommend extensive collecting, thorough taxonomic revisions, and
regular contribution to Floras and guidebooks. A critical corollary is the
training and employment of systematic phycologists in Australian herbaria and
universities. Only then can we follow the path that leads ‘beyond the
Floras’.
Gene sequences, collaboration and analysis of large data sets
Authors: Chase Mark W. , Cox Antony V.
Published: August 2004

DNA sequences are well suited to international collaboration due to the
universality of their simple nature, making them easy to be exchanged and
understood. In addition, the output of modern automated sequencers is
electronic, making the raw data themselves easy to exchange electronically.
Software programs have also been significantly improved, and researchers are
tending to focus on standardised ones, which contributes to increased ease of
communication. The major problem confronting modern systematics is that large
analyses, made possible by all the technological improvements in DNA
sequencing and the ability of widely separated researchers to pool data, have
been viewed as untenable, simply due to their size. We present evidence here
that such large analyses are not as impractical as has been thought,
particularly those that are combined analyses of multiple genes. When there is
increased signal, as there is in many combined analyses, starting trees
generally are much closer to the ultimate shortest trees than any of the
individual analyses. Combined with increased ease of analysis, the large
angiosperm matrices are providing congruent ideas about relationships, and
this makes possible the initiation of the re-classification process, which
should also utilise the capacity for rapid information transfer by electronic
media. The first truly synthetic and phylogenetic angiosperm classification is
in reach, and it should ideally involve all interested systematists in its
production, making it also the first broadly collaborative taxonomic system.
Tertiary palynology: Beaupreaidites and new Conospermeae (Proteoideae) affiliates
Authors: Milne Lynne A.
Published: August 2004

Late Eocene proteaceous pollen assemblages of southern Australia containnumerous specimens of Conospermeae affiliation. As many of these aremorphologically confusing or nondescript, they have often been overlooked orgrouped within other fossil pollen species. In the western Eucla and MurrayBasins these fossil pollen types fall into two major categories: small speciesconventionally referred to unrelated New Zealand fossil taxa, and thoseincluded in Beaupreaidites elegansiformis Cookson 1950or Beaupreaidites spp. Integrated microscopy of singlefossil grains and a thorough investigation of extant Conospermeae pollen typesaided an investigation of the morphology and affiliations of these problematicgroups. Beaupreaidites elegansiformis was originallyillustrated by three dissimilar specimens, each from a different locality. Ofthese, two can be aligned with Beauprea Brongn. & Gris., and the other, the former lectotype, is an extinct form unrelated toBeauprea. The diagnosis ofBeaupreaidites Cookson emend. Martin is amplified;B. elegansiformis is emended and its lectotypesuperseded; B. orbiculatus Dettmann & Jarzen 1988 istransferred to Proteacidites; and five new species aredescribed (Beaupreaidites diversiformis,Proteacidites bireticulatus,P. carobelindiae, P. cirritulus,and P. marginatus).Proteacidites cirritulus can be positively aligned withpollen of the sclerophyllous genus Petrophile R.Br., inparticular with species now endemic to eastern Australia. The remainingProteacidites species, previously assigned toBeaupreaidites, were likely to have been shed by extinctproteaceous taxa closely allied to Petrophile. Therelative abundance of Petrophile-like pollen in thepalynofloras of the western Eucla and Murray Basins implies the presence ofsclerophyll communities akin to heath, woodland, and/or dry sclerophyllforests in coastal southern Australia during the Late Eocene. Fossilproteaceous genera are reviewed. The species referred here toProteacidites cannot be accommodated within any singlegenus as described in a recent revision of fossil proteaceous genera. Therehas long been quiet dissent among Australian Tertiary palynologists withrespect to revisions of fossil proteaceous genera and their subsequentinterpretation. Consensus, rather than individual determination and conflict,is overdue.