bluuebunny/crossref_metadata_2025 huggingface dataset:
Capacitation-like changes in equine spermatoza throughout the cryopreservation process
Authors: Schembri M. A. , Major D. A. , Maxwell W. M. C. , Suttie J. J. , Evans G.
Published: September 2002

Chlortetracycline (CTC) fluorescence staining analysis was used to investigate cryopreservation- induced capacitation-like changes in equine spermatozoa. Freshly ejaculated spermatozoa were found to display a high proportion of F pattern cells (uncapacitated; 93.6%) and a lower proportion of B pattern (capacitated; 5.4%) and AR pattern (acrosome-reacted; 1%) cells. Following cryopreservation in modified Kenney's medium, capacitation-like changes were observed. There was a significant increase in the proportion of spermatozoa displaying the B pattern (64.8%; P<0.001) and AR pattern (32.8%; P<0.001), with a corresponding decrease in the proportion of spermatozoa displaying the F staining pattern (2.5%; P<0.001). Further analysis of CTC fluorescence staining patterns showed that there was a major decrease in the proportion of F pattern spermatozoa corresponding to an increase in B pattern spermatozoa following removal of seminal plasma after centrifugation and resuspension in freezing medium. There was a further decline in the proportion of F pattern spermatozoa, corresponding to increases in B and AR pattern spermatozoa, after the freezing and thawing steps. Resuspension of centrifuged spermatozoa in homologous seminal plasma did not induce capacitation-like changes. These data indicate that the process of freezing and thawing stallion semen induces capacitation-like changes in spermatozoa and that most of the change is brought about by removal of seminal plasma, with further changes induced by the actual freezing and thawing step.
Comparative studies on limb morphogenesis in mice and bats: a functional genetic approach towards a molecular understanding of diversity in organ formation
Authors: Cretekos Chris J. , Rasweiler IV John J. , Behringer Richard R.
Published: September 2002

The basis of species-specific morphogenesis has been a topic of fascination
and speculation for centuries. In 1828, Karl Ernst von Baer noted that at the
pharyngula stage of development all vertebrate embryos are morphologically
very similar. Most subsequent hypotheses have proposed that the vertebrate
body plan develops by a conserved mechanism, and that divergent forms develop
by differential elaboration on this basic plan. Gene cloning and expression
studies have largely confirmed that the genetic pathways of embryonic
patterning are highly conserved. The finding that the proteins encoded by
paralogous and orthologous genes within and between species can functionally
replace each another is no longer novel; in most cases this is the expected
result. How, then, does divergent morphology arise between species? One
hypothesis that fits well with comparative data is that divergent
morphogenesis arises from genetic differences in the timing, level and pattern
of orthologous gene expression during development. This idea is being tested
using a functional genetic approach comparing limb morphogenesis between the
mouse and bat.
Damaging effects of polychlorinated biphenyls on chicken primordial germ cells
Authors: Fang Changge , Zhang Caiqiao , Xia Guoliang , Yang Wei
Published: September 2002

This work describes the effects of a commercial polychlorinated biphenyl (PCB) mixture, Aroclor 1254, as well as 17β-oestradiol (E2) and testosterone on numbers and histomorphological changes of primordial germ cells (PGCs) in gonadal regions of Day 5 Hyline chicken embryos. The oestrogen receptor antagonist, clomiphen, alone or with PCBs was used in an attempt to protect the developing gonad from oestrogen-like effects of chemical PCBs. The results were as follows: (i) PCBs delayed embryonic development independently of dose (1�µg/eggP<0.05; 10 µg/eggP<0.01; 100 µg/eggP<0.001 v. the control) and caused a dose-independent increase in mortality compared with the control group (10 µg/egg P<0.01; 100 µg/eggP<0.05); maximal mortality was observed in the 1 µg/eggP<0.001); (ii) PCBs decreased PGC numbers dose dependently (P<0.001) and caused a swollen nucleus with hyperchromatism (pyknosis) or cytoplasm vacuolation as signs of gonadal PGC degeneration in all PCB groups, or even complete disappearance in the 100 µg/eggiii) after PCB treatment, the index of gonadal lesion increased significantly with the decrease of gonadal PGC number (1, 10 and 100 µg/eggP<0.001); (iv) there were no observed effects of E2, testosterone and clomiphen on PGCs in the experiments; and (v) clomiphen failed to block the damaging effects of PCBs. These results suggest that the adverse effects of PCBs on chicken gonadal and germ cell development were initiated during the early stages of incubation through direct toxic effects, rather than through oestrogen-mimicking actions. As PGC numbers in the gonads decrease and the index of gonadal lesion increases, one may expect reproductive function to be compromised.
Folliculogenesis in buffalo (Bubalus bubalis): a review
Authors: Manik R. S. , Palta P. , Singla S. K. , Sharma V.
Published: September 2002

The urgent need for improving the reproductive performance of buffalo necessitates a better understanding of the mechanisms controlling ovarian follicular growth and development. Attention needs to be focused on improving superovulation responses and conception rates, and reducing the variability in ovulation rate and embryo loss. Application of ultrasonic imaging has revealed that follicular turnover during an unstimulated oestrous cycle occurs in waves, with each wave involving synchronous development of a group of follicles, one dominant and several subordinate follicles. There is a predominance of two waves with the first wave beginning around Day 0 (day of ovulation) and the second wave around Day 9 or 10. Primary reasons for a lower superovulation response in buffalo compared with that in cattle is a lower number of primordial and antral follicles, a slower shift from small to large follicles during superovulation, a higher incidence of deep atresia and inability of several large follicles to ovulate, especially when superovulation is induced by equine chorionic gonadotrophin treatment. There is near complete lack of information in Bubalus bubalis on the factors controlling the selection of the dominant follicle, the period of functional dominance and the effects of environmental factors, such as climate and nutrition, on follicular dynamics.
Revison of of some Australasian taxa of Perenniporia (Basidiomycetes, Aphyllophorales)
Authors: Decock Cony , Buchanan Peter K. , Ryvarden Leif
Published: September 2002

The type specimens of Perenniporia clelandii (Lloyd)Ryvarden, Perenniporia subcretacea (Lloyd) Ryvarden,Perenniporia subaurantiaca (Rodw. & Clel.)P.K.Buchanan & Ryvarden, Perenniporia oviformisG.Cunn. ex P.K.Buchanan & Ryvarden, andPerenniporia podocarpi P.K.Buchanan & Hood, alloriginally described from Australasia, as well as ofPerenniporia clelandii (Lloyd) Ryvarden var.subrosea Corner andPerenniporia oviformis (G.Cunn.) Corner var.borneensis Corner, both described from South-east Asia,were re-examined. Perenniporia clelandii,P. subaurantiaca and P. oviformisare accepted in Perenniporia. Corner’s concept ofP. clelandii was confused and his reports of thisspecies are based on a different taxon. Separation of the varietyP. oviformis var. borneensis isrejected. Perenniporia podocarpi is maintained inPerenniporia although with doubts. Its taxonomicposition is discussed, in comparison withPhaeotrametes decipiens (Berk.) Wright.Perenniporia cunninghamii is described as new.Perenniporia subcretacea is excluded fromPerenniporia, and transferred toSpongipellis.Perenniporia clelandii,P. subaurantiaca, P. oviformis,P. podocarpi andSpongipellis subcretaceus are redescribed andillustrated.
Phylogenetic analyses of New Caledonian Metrosideros and Carpolepis (Myrtaceae) from nrDNA (ITS) sequences
Authors: Wright Shane D. , Keeling D. Jeannette , Ashton Fern G. , Dawson John W. , Gardner Richard C.
Published: September 2002

We have analysed the phylogenetic relationships of all known species in the
genera Metrosideros and Carpolepis
(Myrtaceae) from New Caledonia. Variation in nucleotide characters from the
internally transcribed spacers of nuclear ribosomal DNA was used to construct
parsimony and neighbour-joining phylogenies. These show that there is a large
measure of congruence between the existing morphological taxonomy for those
species and the relationships inferred from analyses of sequence variation.
However, the DNA analyses suggest that Carpolepis may
have only equal ranking to the infrageneric Metrosideros
clades. The DNA analyses also nest M. tetrasticha among
the species of subg. Metrosideros, as opposed to its
present classification as a monotypic section
(Neocaledonica) within subg.
Mearnsia. On the basis of these findings, and of the
observed differentiation shown in the analyses between the sectional clades
Calyptropetala and Mearnsia of
subg. Mearnsia, equivalent rankings may be appropriate
for four infrageneric clades in Metrosideros. These four
are currently classified as the genus Carpolepis (three
species), and subg. Metrosideros (seven species), subg.
Mearnsia sect. Mearnsia (five
species) and subg. Mearnsia sect.
Calyptropetala (five species) within
Metrosideros.
Variation in the Dendrobium speciosum (Orchidaceae) complex: a numerical approach to the species problem
Authors: Burke Jacinta M. , Adams Peter B.
Published: September 2002

The Dendrobium speciosum Sm.
(Dendrobium sect. Dendrocoryne:
Orchidaceae) complex is a taxonomic problem because of intrapopulational and
interpopulational heterogeneity. The pattern of morphological variation
exhibited is partly associated with geographical regions in eastern Australia,
from the base of Cape York Peninsula to eastern Victoria. Variation within the
species was investigated by multivariate and univariate analyses of data
obtained from living specimens. The analyses that differentiate section
Dendrocoryne species do not form discrete groups for
previously recognised regional or any other variants of
Dendrobium speciosum, providing no support for
recognising subgroups of Dendrobium speciosum at species
level. Dendrobium speciosum is regarded as a variable
species forming a complex continuum. In some designated areas, the varieties
speciosum, hillii,
grandiflorum, curvicaule,
pedunculatum and capricornicum can
be retained. It is strongly recommended that all individuals be specified by
their geographical origin since this is the only system that provides
unambiguous identification.
Australasian sequestrate (truffle-like) fungi. XII. Amarrendia gen. nov.: an astipitate, sequestrate relative of Torrendia and Amanita (Amanitaceae) from Australia
Authors: Bougher Neale L. , Lebel Teresa
Published: September 2002

Five species of Amarrendia gen. nov. (Amanitaceae) are presented, three new species A. oleosa, A.�nemoribus and A. peridiocrystalia and two new combinations A. grandispora and A. lignicolor formerly placed in Alpova. It is proposed that Amarrendia occupies a systematic position within a complex of related taxa that also incorporates Torrendia and Amanita. Basidiomes of Amarrendia resemble those of the genus Torrendia, except for the absence of a stipe. Characteristics of Amarrendia that closely resemble those of Torrendia include (i) white or cream peridium and the similarly coloured, loculate gleba which may be empty or filled with a rapidly drying clear liquid, (ii) fragile consistency of the basidiome flesh in some species, (iii) glistening, minutely granular surface of the basidiomes (because of inflated cells exposed at the surface), (iv) broad ellipsoid, smooth, thin-walled, hyaline, non-amyloid, non-dextrinoid spores with a large oil droplet and a broad tapering apiculus and (v) context trama composed of inflated and hyphal elements intermixed. Amarrendia is currently known only in temperate Australia where it occurs in natural ecosystems and plantations in association with ectomycorrhizal plants such as Eucalyptus, Allocasuarina and Gastrolobium.
Ceramium juliae (Ceramiaceae, Ceramiales), a new red algal species with distinctive spines from eastern Australia
Authors: Millar Alan J. K.
Published: September 2002

Ceramium juliae sp. nov. (Ceramiaceae, Ceramiales, Rhodophyta) is described from subtidal habitats on the southeast coast of Australia. Plants are prostrate on the basal parts of the brown algae Cladostephus spongiosus and Halopteris platycena and the red alga Chondria succulenta and reach lengths of no more than 8 mm. Individual axes grow to widths of 160 �m, are dichotomously to alternately branched and have markedly involute apices. Each axial cell produces six periaxial cells, each of which produces a distinctive spine. The first-formed spine becomes multiseriate, as does the second-formed which lies on the opposite side of the filament. Four uniseriate spines are then formed, two on each side of the axis, to make a total of six spines per cortical node. Tetrasporangia are cut off from the periaxial cells and occur one per cortical segment. Comparisons are made with other spined Ceramium species as are the generic characteristics of the genus Ceramium with relation to Centroceras, Ardreanema, Campylaephora, Corallophila and Reinboldiella.
Taxonomic revision of the Salwoods: Acacia aulacocarpa Cunn. ex Benth. and its allies (Leguminosae: Mimosoideae: section Juliflorae)
Authors: McDonald M. W. , Maslin B. R.
Published: September 2002

A taxonomic revision of Acacia aulacocarpa Cunn. exBenth. and its seven close relatives is presented. These species comprise theA. aulacocarpa group in the AcaciaMill. section Juliflorae and occur naturally in eastern and northernAustralia, New Guinea and Wetar, eastern Indonesia. In the past, the nameA. aulacocarpa has been widely misapplied. This speciesis relatively uncommon but has an extensive geographic range extending fromthe Atherton Tableland region in Queensland, south to northern New SouthWales. Acacia aulacocarpa var.fruticosa C.T.White is considered conspecific withA. aulacocarpa. The nameA. lamprocarpa O.Schwarz is reinstated for a northernAustralian taxon that extends from western Queensland through NorthernTerritory to the Kimberley region of Western Australia. Five new taxa aredescribed from A. aulacocarpa sens. lat., namelyA. celsa Tindale (Queensland),A. disparrima subsp. disparrimaM.W.McDonald & Maslin (northern New South Wales and Queensland),A. disparrima subsp. calidestrisM.W.McDonald & Maslin (Queensland), A. midgleyiM.W.McDonald & Maslin (Queensland) andA. peregrina M.W.McDonald & Maslin (New Guinea).A full description is provided for A. crassicarpa Cunn.ex Benth. Mainly on the basis of their mode of pod dehiscence, two subgroupswithin the A. aulacocarpa group are defined:A. aulacocarpa, A. celsa andA. disparrima comprise theA. aulacocarpa subgroup and have pods that dehisce alongthe dorsal suture; and A. crassicarpa,A. lamprocarpa, A. midgleyi,A. peregrina and A. wetarensiscomprise the A. crassicarpa subgroup and have pods thatdehisce along the ventral suture. All species in the group, including theIndonesian species A. wetarensis, are illustrated and akey to the taxa is provided. Acacia celsa,A. crassicarpa, A. peregrina andA. midgleyi have considerable potential for wood production in tropical plantation forestry.
Rhytismatales of Australia: the genus Coccomyces
Authors: Johnston Peter R.
Published: September 2002

Thirteen species of Coccomyces are reported for
Australia; a further species is recognised but not described because of
insufficient material. Six of the species are described as new. Most of the
Australian species are C. leptosporus-like in
morphology, a characteristic of most Coccomyces spp.
from tropical and Southern Hemisphere regions. One of the new species,
C. cunninghamii, found on
Nothofagus cunninghamii, is morphologically similar to
Lophodermium medium, a species occurring on
N. menziesiiin New Zealand. The seven previously
described species also occur in New Zealand, and three of them are widespread
in tropical Asia and tropical America. All species are described and
illustrated, and a key to the Australian Coccomyces
species is provided.
Systematics of the Australian species of Dictyopteris (Dictyotales, Phaeophyceae)
Authors: Phillips J. A.
Published: September 2002

Eleven species of Dictyopteris are recognised for Australia. The tropical
species D. australis (Sonder) Askenasy,
D. deliculata Lamouroux,
D. plagiogramma (Montagne) Vickers,
D. repens (Okamura) Børgesen,
D. serrata (Areschoug) Hoyt and
D. woodwardia (R.Brown ex Turner) C.Agardh are recorded
for warmer coasts, although isolated populations of
D. australis occur in the Gulfs region of South
Australia. Dictyopteris acrostichoides (J.Agardh) Bornet
and D. crassinervia (Zanardini) Schmidt are endemic to
eastern Australia, with D. acrostichoides also extending
to the eastern end of the southern coast.
Dictyopteris gracilis Womersley and
D. muelleri (Sonder) Reinbold occur on temperate
southwestern and southern coasts. The west coast species
Dictyopteris secundispiralis J.A.Phillips sp. nov. is
described, and D. nigricans Womersley is reduced to a
taxonomic synonym ofD. muelleri. Detailed comparative
studies undertaken on these species have identified several new
taxonomically-informative characters useful for generic circumscription and
species discrimination. Thallus branches which have a cortical layer composed
of large cuboidal cells and reproductive organs scattered in fertile zones are
additional characters which characterise the genus. Australian species of
Dictyopteris are now well defined by differences in
several distinctive vegetative and reproductive characters such as thallus
morphology, blade cell layer number, structure of the thallus apex, presence
of marginal teeth and lateral veins, distribution and structure of hair
bundles, sporangia, oogonia and antheridial sori.
Morphological and taxonomic studies of selected genera from the tribe Amansieae (Rhodomelaceae, Rhodophyta)
Authors: Wilson S. M. , Kraft G. T.
Published: September 2002

The morphology and taxonomy of seven poorly understood species from five
genera of the Amansieae are documented. The basic characters by which genera
of the tribe are currently distinguished include: (1) the number of
pericentral cells; (2) the degree of thallus flattening and lateral wing
development; (3) the type of endogenous branching; (4) branch and/or spine
features of blade margins; and (5) the position of reproductive axes. Two
Australian species of Enantiocladia Falkenberg,
E. robinsonii (J.Agardh) Falkenberg and
E. axillaris Falkenberg, do not conform to the defining
features of Enantiocladia as exhibited by specimens of
the type species examined in this study, and the two new genera
Plectrophora and Nanopera are
proposed to accommodate them. The genusKuetzingia Sonder
has previously included four species, the three Australian endemics
K. canaliculata (Greville) Sonder,
K. angusta (Harvey) and
K. pectinella (Harvey) Falkenberg, and the South African
K. natalensis J.Agardh. Phoographs in AD of the holotype
specimen of Kuetzingia pectinella indicate that it is an
earlier taxonomic synonym of Enantiocladia robinsonii
and is thus the type species of the genus Plectrophora
Wilson et Kraft. Kuetzingia natalensis is also
transferred to Plectrophora, leaving
Kuetzingia as an Australian-endemic genus of two
species. A rare tropical-Atlantic species previously credited to
Protokuetzingia, P. schottii
Taylor, is provisionally transferred to Enantiocladia
because the number of its pericentral cells and the position of its procarps
conform to that of the Caribbean type species of
Enantiocladia, E. duperreyi
(C.Agardh) Falkenberg. This transfer leaves
Protokuetzingia monotypic and also an Australian-endemic
genus. A review of the genera of the Amansieae is given and conclusions are
drawn as to the generic criteria most likely to be important within the tribe.
Libardi's method refinement for soil hydraulic conductivity measurement
Authors: Libardi P. L. , Libardi P. L. , Reichardt K. , Reichardt K.
Published: September 2002

The method of Libardi to estimate soil hydraulic conductivity in the field,
during the redistribution of soil water, is discussed and improved. It is
shown that if the saturated soil water content is measured at the soil
surface, values at any other depth can be calculated from the database used to
compute hydraulic conductivity. Since the saturated soil water content is
difficult to measure and critical to the establishment of the hydraulic
conductivity functions, this is an important refinement of the method. It is
also shown that the unit hydraulic gradient assumption, which is part of the
methodology, does not introduce significant errors in the estimation of soil
hydraulic conductivity.
Rotation crops for irrigated cotton in a medium-fine, self-mulching, grey Vertosol
Authors: Hulugalle N. R. , Entwistle P. C. , Scott F. , Kahl J.
Published: September 2002

Many cotton growers sow rotation crops after irrigated cotton
(Gossypium hirsutum L.), assuming that they will improve
soil quality and maintain profitability of cotton. Wheat
(Triticum aestivum L.) is the most common rotation crop,
although more recently, legumes such as faba bean
(Vicia Faba L.) and chickpea
(Cicer arietinum L.) have come into favour. This paper
reports data on soil quality (organic C, nitrate-N, soil structure), yield
(cotton lint and rotation crop grain yield, fibre quality), economic returns
(gross margins/ha, gross margins/ML irrigation water), and management
constraints from an experiment conducted from 1993 to 1998 near Wee Waa,
north-western New South Wales, Australia. The soil is a medium-fine,
self-mulching, grey Vertosol. The cropping sequences used were cotton followed
by N-fertilised wheat (urea at 140 kg N/ha in 1993; 120 kg N/ha
thereafter), unfertilised wheat, and unfertilised grain legumes (chickpea in
1993; faba bean thereafter), which were either harvested or the grain
incorporated during land preparation. Soil organic C in the 0—0.6 m
depth was not affected by the rotation crop, although variations occurred
between times of sampling. Regression analysis indicated that there had been
no net gain or loss of organic C between June 1993 and October 1998. Sowing
leguminous rotation crops increased nitrate-N values. A net increase in
root-zone nitrate-N reserves occurred with time (from June 1993 to October
1998) with all rotation crops. Soil compaction (measured as specific volume of
oven-dried soil) was lower with wheat by October 1998. A net decrease in soil
compaction occurred in the surface 0.15 m with all rotation crops between 1993
and 1998, whereas it increased in the 0.15–0.60 m depth. Cotton lint
yield and quality, and gross margins/ha and gross margins/ML, were
always higher where wheat was sown, with highest gross margins occurring when
N fertiliser was applied. Applying N fertiliser to wheat did not significantly
increase cotton lint yield and fibre quality, but increased gross margins of
the cotton–wheat sequence due to higher wheat yield and protein
percentage. Lint yield and fibre quality were decreased by sowing leguminous
rotation crops. Management constraints such as lack of effective herbicides,
insect damage, harvesting damage, and availability of suitable marketing
options were greater with legumes than with wheat. Overall, wheat was a better
rotation crop than grain legumes for irrigated cotton.
A multi-purpose rainfall simulator for field infiltration and erosion studies
Authors: Loch R. J. , Robotham B. G. , Zeller L. , Masterman N. , Orange D. N. , Bridge B. J. , Sheridan G. , Bourke J. J.
Published: September 2002

This paper describes a rainfall simulator developed for field and laboratory
studies that gives great flexibility in plot size covered, that is highly
portable and able to be used on steep slopes, and that is economical in its
water use.
The simulator uses Veejet 80100 nozzles mounted on a manifold, with the
nozzles controlled to sweep to and from across a plot width of 1.5 m.
Effective rainfall intensity is controlled by the frequency with which the
nozzles sweep. Spatial uniformity of rainfall on the plots is high, with
coefficients of variation (CV) on the body of the plot being
8–10%. Use of the simulator for erosion and infiltration
measurements is discussed.
Management of salinity and sodicity in a land FILTER system, for treating saline wastewater on a saline-sodic soil
Authors: Jayawardane N. S. , Biswas T. K. , Blackwell J. , Cook F. J.
Published: September 2002

The FILTER (Filtration and Irrigated cropping for Land Treatment and Effluent
Reuse) technique was developed to provide a sustainable system for treatment
of saline sewage effluent on naturally occurring saline and/or sodic
soils. Potentially, it can also be used to ameliorate soils that are salinised
by inappropriate application of saline effluent on soils with impeded
drainage. The FILTER technique involves using the nutrient-rich effluent for
irrigated cropping combined with removal of excess water from the rootzone
through a subsurface drainage system, during wet weather and winter periods
when evapotranspiration demand is low.
This paper describes the changes in salinity and sodicity in FILTER plots used
for land application of saline sewage effluent on a heavy clay soil with
restricted drainage, at the Griffith City Council sewage works site. The field
experiments consist of trials conducted on four 1-ha plots, over an 18-month
period. The pre-FILTER soil chemical characteristics and their changes with
FILTER operations were measured. In addition, the volumes and the chemical
properties of the effluent applied and subsurface drainage water passing
through the soil were monitored. These data are used to explain the salinity
and sodicity changes within the FILTER soils, and their potential effects on
soil stability. Management options to minimise salinity and sodicity to
provide a sustainable system are suggested.
Comparing simple methods for measuring phosphate sorption by soils
Authors: Allen D. G. , Barrow N. J. , Bolland M. D. A.
Published: September 2002

Phosphate sorption curves were measured for 103 Western Australian soils
sampled from farmers’ fields. A measure of phosphate buffering obtained
from a fitted curve was compared with indexes obtained from single-point
measurements of phosphate sorption. The single-point indexes were adjusted for
the phosphate present in the sampled soils by adding the phosphate extracted
by the bicarbonate reagent to the measured sorption. Iron and aluminium
extracted by an oxalate solution were measured as indirect indexes.
The single-point indexes were closely correlated with the values obtained from
the sorption curve. Their correlation was much larger than that of indirect
measures.
Leaching of bacterial indicators of faecal contamination through four New Zealand soils
Authors: Aislabie J. , Smith J. J. , Fraser R. , McLeod M.
Published: September 2002

Land application of animal waste can result in bacterial contamination of
shallow groundwater and/or waterways. Using 500-mm-diameter barrel
lysimeters, we investigated the potential for bacterial indicators to leach
through 4 New Zealand soils treated with dairy shed effluent (DSE). DSE was
applied to soil lysimeters containing poorly drained Gley Soils (Te Kowhai and
Netherton) and well-drained Allophanic (Waihou) and Pumice Soils (Atiamuri) at
50 mm/h, a typical field application rate used by farmers. Simulated
rainfall was applied continuously at a rate of 5–10 mm/h, and
leachate collected at a depth of 700 or 750 mm was analysed for faecal
coliforms, Escherichia coli, and faecal enterococci.
Bacterial indicators of faecal contamination readily moved through the Te
Kowhai and Netherton soils, but not the Waihou and Atiamuri soils.
Differential microbial movement was attributed to differences in soil
structure. The poorly drained soils have coarse subsoil structures with
macropores, favouring bypass flow. In contrast, the welldrained soils have a
finer, more uniformly porous soil structure that minimised bypass flow and
allowed matrix flow.
Mineralisation of organic matter in intact versus sieved/refilled soil cores
Authors: Stenger R. , Barkle G. F. , Burgess C. P.
Published: September 2002

In a 6-month laboratory incubation study, we compared the net C and N
mineralisation of the soil organic matter (SOM) of 3 pasture soils and the
mineralisation of glucose-C in intact versus sieved/refilled soil cores.
The main questions were whether the net C and N mineralisation differed
between intact and sieved/refilled soil cores after a conditioning period
of 4 weeks, and how much the C and N mineralisation of SOM differed among the
similarly managed pasture soils.
Apart from the net nitrogen mineralisation in one soil, there were no
significant differences in cumulated mineralisation of C or N from SOM between
the core types. In a fine-textured soil, net mineralisation of glucose-C
differed significantly between core types, which was attributed to the
different distribution of the amended glucose in intact and
sieved/refilled cores. Net C and N mineralisation of SOM were closely
correlated in the sieved/refilled cores, whereas no significant
correlation was found in the intact cores. Expressing net C and N
mineralisation as percentages of total soil C and N showed a more than 2-fold
maximum difference between the soils in spite of similar long-term organic
matter input. Subsequent studies should be done using more replicates and
wider diameter, better controllable cores on ceramic plates.
CO2, net nitrogen mineralisation (NNM), soil microbial biomass.
Effects of agricultural management on tenosols in northern Tasmania
Authors: Cotching W. E. , Cooper J. , Sparrow L. A. , McCorkell B. E. , Rowley W.
Published: September 2002

Attributes of 15 Tasmanian sandy tenosols were assessed using field and
laboratory techniques to determine differences under 3 typical forms of
agricultural management: long-term pasture, cropping with shallow tillage
using discs and tines, and cropping (including potatoes) with more rigorous
and deeper tillage including deep ripping and powered implements. Soil organic
carbon in the surface 75 mm was 2.6% under long-term pasture compared
with 1.1% in rigorously tilled cropping paddocks. Readily oxidisable
carbon concentrations were 2.3 mg/g and 1.0 mg/g, respectively. These
differences were negatively correlated with the number of years cropped, which
we viewed with concern. Infiltration rate was greater and shear strength less
in cropped paddocks compared with long-term pasture. Dry bulk density was
greater and total porosity and macroporosity were less in rigorously tilled
paddocks. Subsoil compaction was apparent in paddocks which had grown
potatoes. Cropping was not clearly associated with smaller or less stable
aggregates. A survey of farmers' perceptions found that they identified
more healthy than unhealthy soil attributes under all management histories.
Significant negative correlations were found between the number of unhealthy
attributes identified in a farmer survey and laboratory-determined
water-stable aggregates and mean weight diameter of dry soil aggregates. The
effects of cropping are not associated with a broad range of degraded soil
attributes on these Tasmanian tenosols.
tenosols, sandy soils, organic carbon, soil strength, aggregate stability,
land management, cropping.
Crop yields and soil properties on eroded slopes of red ferrosols in north-west Tasmania
Authors: Cotching W. E. , Hawkins K. , Sparrow L. A. , McCorkell B. E. , Rowley W.
Published: September 2002

The differences in soil properties and crop yield on slopes of varying steepness in intensively cropped paddocks with red ferrosols (Humic Eutrodox), which had evidence of erosion over many years, were determined at 5 sites in north-west Tasmania. We found that soils on the steeper slopes, which have had greater soil loss, had significantly lower topsoil carbon concentrations than soils on flatter slopes. We found that significant redistribution of soil had occurred on the sites in this study. Areas with concave slope positions had over-thickened topsoils. However, the effect of erosion on the topsoil thickness of eroded slope positions was masked by the uniform depth of cultivation across paddocks. Penetration resistance increased gradually with depth on all transects, indicating no compacted layers or plough pans on these intensively cropped sites. Soil physical properties did not significantly change from non-eroded, level areas to steep, eroded parts of the paddocks, even although considerable soil loss had occurred from the steep slopes. We attribute this to the gradational nature of these red ferrosols, which characteristically have strongly structured subsoils. Crop yield was significantly correlated with slope but was not significantly different on land up to 18% slope. We anticipate that continued erosion at current rates on this less steep land will inevitably reduce crop yields. We found a significant correlation between organic carbon, total exchangeable bases, extractable K, and crop yield, but no correlation between available water content and crop yield. We conclude that soil organic matter contributes to productivity through its effect on nutrient concentrations. Total exchangeable bases appeared to provide the best and simplest explanatory model to predict crop yield. We propose a set of 4 tests for future assessment of soil condition on these red ferrosols.
Hydrofluoric acid pre-treatment for improving 13C CPMAS NMR spectral quality of forest soils in south-east Queensland, Australia
Authors: Mathers Nicole J. , Xu Zhihong , Berners-Price Susan J. , Senake Perera M. C. , Saffigna Paul G.
Published: September 2002

Hydrofluoric acid (HF) was used to pre-treat forest soils of south-east Queensland for assessing the effectiveness of iron (Fe) removal, carbon (C) composition using 13C cross-polarisation (CP) with magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) before and after the HF pre-treatment, and the improvement of 13C CPMAS NMR spectra. Soil samples were collected from 4 experimental sites of different soil types, harvest residue management or prescribed burning, and tree species. More than 86% of Fe was in all soil types removed by the HF treatment. The 13C NMR spectral quality was improved with increased resolution, especially in the alkyl C and O-alkyl C regions, and reduced NMR run-time (1-5�h per sample compared with >20�h per sample without the pre-treatment). The C composition appeared to alter slightly after the pre-treatment, but this might be largely due to improved spectrometer conditions and increased resolution leading to more accurate NMR spectral integration. Organic C recovery after HF pre-treatment varied with soil types and forest management, and soluble soil organic matter (SOM) could be lost during the pre-treatment. The Fourier Transform-Infrared (FT-IR) spectra of HF extracts indicated the preferential removal of carboxylic C groups during the pre-treatment, but this could also be due to adsorbed water on the mineral matter. The NMR spectra revealed some changes in C composition and quality due to residue management and decomposition. Overall, the HF treatment was a useful pre-treatment for obtaining semi-quantitative 13C CPMAS NMR spectra of subtropical Australian forest soils.
Measuring atrazine degradation and PRZM-2 testing
Authors: Noshadi M. , Amin S. , Maleki N.
Published: September 2002

This study investigated spatial and temporal variation of atrazine concentration and its transportation in the Daneshkadeh soil series (fine, mixed, mesic, Calcixerollic Xerochrepts) at the experimental fields of the Agricultural College, Shiraz University, Iran. It also assessed the risk of soil and water contamination due to applying atrazine, and evaluated the PRZM-2 model for the simulation of atrazine concentration. The experiment had 3 plots of size 209 m2 (19 by 11 m). Irrigation water was applied according to corn evapotranspiration by a solid-set sprinkler system. Seven weeks after planting of maize (Zea mays L.) in early summer, atrazine (2-chloro-4-ethylamino-6-isopropylamins-s-triazine) was applied at a rate of 3.5 kg a.i./ha to each plot. During the growing season, soil samples were collected from each plot 7 times to 1 m soil depth at 0.10-m increments. The PRZM-2 model was applied using our field data for atrazine transport simulation. The observed data showed temporal reduction of atrazine concentrations in the soil profile. The maximum depth of atrazine traced was about 0.5 m below the soil surface. Statistical parameters ME, RMSE, EF (model efficiency), and CRM (coefficient of residual mass) were obtained to compare predicted and observed soil residue concentrations, and were 2.78 (mg/kg soil), 12.73, 0.49, and 0.25, respectively. The simulation results were in close agreements with the observed data, especially 1 month after application due to the small effect of ambient and soil temperature on atrazine transformation.
pesticides, transport
Charge properties of red Argentine soils as an indicator of iron oxide/clay associations
Authors: Torres Sánchez R. M. , Okumura M. , Mercader R. C.
Published: September 2002

The order of the relative degree of iron oxide coating of 4 samples of red
soils from north-eastern Argentina was established using the point of zero
charge (PZC), yielded by potentiometric titration, and the isoelectric point
(IEP), obtained from the diffusion potential. When PZC is different from IEP,
the relative fraction of apparent surface coverage could be assessed from the
IEP. The results obtained by the application of X-ray diffraction, scanning
electron microscopy, electron probe microanalysis, X-ray photoelectron
spectroscopy, Mössbauer spectroscopy, and specif ic surface area,
although essential to characterise the samples, did not allow us to determine
the degree of iron oxide coating. Our findings show that the order of this
degree is opposite to the order of the ratio of the amount of free iron oxides
to that of clay in iron oxides/clay mixtures.
Medium-term erosion simulation of an abandoned mine site using the SIBERIA landscape evolution model
Authors: Hancock G. R. , Evans K. G. , Willgoose G. R. , Moliere D. R. , Saynor M. J. , Loch R. J.
Published: September 2002

This study forms part of a collaborative project designed to validate the
long-term erosion predictions of the SIBERIA landform evolution model on
rehabilitated mine sites. The SIBERIA catchment evolution model can simulate
the evolution of landforms resulting from runoff and erosion over many years.
SIBERIA needs to be calibrated before evaluating whether it correctly models
the observed evolution of rehabilitated mine landforms. A field study to
collect data to calibrate SIBERIA was conducted at the abandoned Scinto 6
uranium mine located in the Kakadu Region, Northern Territory, Australia. The
data were used to fit parameter values to a sediment loss model and a
rainfall–runoff model. The derived runoff and erosion model parameter
values were used in SIBERIA to simulate 50 years of erosion by concentrated
flow on the batters of the abandoned site. The SIBERIA runs correctly
simulated the geomorphic development of the gullies on the man-made batters of
the waste rock dump. The observed gully position, depth, volume, and
morphology on the waste rock dump were quantitatively compared with the
SIBERIA simulations. The close similarities between the observed and simulated
gully features indicate that SIBERIA can accurately predict the rate of gully
development on a man-made post-mining landscape over periods of up to 50
years. SIBERIA is an appropriate model for assessment of erosional stability
of rehabilitated mine sites over time spans of around 50 years.
Litter cover as an index of nitrogen availability in rehabilitated mine sites
Authors: Todd M. C. L. , Grierson P. F. , Adams M. A.
Published: September 2002

The spatial heterogeneity of litter cover and bioavailability of nitrogen
within a 9-year-old rehabilitated bauxite mine in south Western Australia was
examined. Three replicate plots (6 m by 6 m) were each divided into 100
quadrats. Litter cover, vegetation distribution, and projected foliage cover
were mapped, and litter (overstorey leaves, understorey leaves, and other
assorted fractions) and soil (depth: 0–5, 5–10, and 10–30
cm) were sampled from within each quadrat. Litter distribution reflected
projected foliage cover, and accumulated within microtopographic depressions.
Distribution of soil nitrate (NO3–) reflected the
distribution of litter. The 15N natural abundance
(d15N) values of soil (0–5 cm) and the understorey
litter fraction were significantly correlated
(R2 = 0.529,
P < 0.05), whereas carbon isotope composition
(d13C) of soil (0–5 cm) was significantly
correlated with the distribution of the assorted litter fraction
(R2 = 0.296,
P < 0.05). It is concluded that site preparation
practices that effect microtopography, such as contour ripping and
revegetation along contours, will have a significant impact on nitrogen (N)
distribution and bioavailability within rehabilitated mine sites.
Soil development of an artificial soil mix: nutrient dynamics, plant growth, and initial physical changes
Authors: Cox J. A. , Whelan R. J.
Published: September 2002

An artificial soil mix made out of industry wastes and sewage sludge has been
created for the revegetation of an industrial site. Physico-chemical
properties were measured over time to examine soil formation in a
chronosequence of 11 gardens aged 3–11 years, and in a 3-year
longitudinal study of 8 replicate experimental plots. In the field plots,
available nutrient content was initially high but declined quickly in 3
months. Particle weathering occurred, with an increase in the finer soil
fractions after 1 year. pH was initially 7.62 and declined to 6.85 by 3 years.
Native tree growth was exceptionally good over the 2 years monitored, with
average trunk diameter increases of 144 mm for
Corymbia maculata, 94 mm for
Acacia floribunda, and 39 mm for
Callistemon salignus. In the chronosequence study, there
was a build- up of nutrients (C, N, and P) in the soil mix over 6–10
years, with a slight decrease by 11 years. This study has shown that soil
development has occurred in the short and longer terms, with rapid changes
seen in the first 12 months. High levels of N and P remaining after 11 years,
and abundant organic C for microbial decomposition, indicate the potential for
nutrient cycling
Recent advances in the application of 13C and 15N NMR spectroscopy to soil organic matter studies
Authors: Mathers N. J. , Mao X. A. , Saffigna P. G. , Xu Z. H. , Berners-Price S. J. , Perera M. C. S.
Published: September 2002

Nuclear magnetic resonance (NMR) spectroscopy has been applied to many studies
in soil science, geochemistry, and environmental science. In recent years, the
study of soil organic matter (SOM) using NMR techniques has progressed
rapidly. NMR spectroscopy has been used to study chemical changes of SOM
during decomposition, and also of soil extract fractions such as humic acid
and fulvic acid. NMR spectroscopy of soils has improved rapidly in recent
years with the introduction of pre-treatment and particle-size fractionation.
In addition to routine liquid- and solid-state 13C NMR
applications, 15N NMR spectra of natural abundant
samples have been reported, but 15N-enriched material is
more convenient to use due to the low natural abundance of
15N. Some newly developed NMR techniques have also been
utilised, such as 2-dimensional NMR spectroscopy and improved
1H NMR techniques. These are reviewed and commented on
in this paper.
An aeolian component in Pleistocene and Holocene valley aggradation: evidence from Dicks Creek catchment, Yass, New South Wales
Authors: Melis M. I. , Acworth R. I.
Published: September 2002

Four late Quaternary depositional units are identified overlying
sub-vertically dipping Ordovician bedrock in the upper reaches of the Dicks
Creek catchment, near Yass in the Southern Highlands of New South Wales. The
units are spatially discontinuous and separated from each other by erosional
unconformities. They are found only on the lower slopes and in the valley
floors, often exposed by recent gully erosion. The oldest unit (Unit 4) is a
competent consolidated well-sorted fine to medium silt that unconformably
overlies bedrock. It often forms the base to erosion gullies. Unit 3 is
strongly dispersible and frequently has the characteristics of a debris flow.
Unit 3 is particularly prone to sheet erosion and exhibits a high risk of
dryland salinity development. Unit 2 is light to dark grey, poorly sorted, and
often contains irregularly dispersed charcoal. Unit 2 is unconformably
overlain by a predominantly pale yellow sand (Unit 1) that shows clear
evidence of very recent deposition.
Physical and chemical characteristics of Units 2, 3, and 4 suggest an aeolian
component. The silt size (4–8 on phi scale) fraction of Unit 4 is often
>70% of the total mass, with grain sizes consistent with an origin
as aeolian dust. Unit 3 is yellow brown in colour and often has the
characteristics of a diamict with a major grain size component similar in size
to Unit 4. Unit 2 is typically uniform in appearance and contains a
predominantly kaolinite and illite clay mineralogy that contrasts strongly
with a predominance of quartz in the underlying bedrock. A simple sediment
budget indicates that the volume of Unit 2 could be accounted for by a
combination of sheet and rill erosion within the catchment and additional
aeolian deposition in the order of 4–8 t/km 2
year.
Radiocarbon dates for charcoal recovered from Unit 2 indicate that some
deposition was associated with cooler, drier conditions of the late Holocene
‘Little Ice Age’, approximately 200–600 years ago.
Nutrient concentrations in soil solution of some Brazilian Oxisols under conventional and no-tillage systems in the early part of the rainy season
Authors: Lilienfein Juliane , Wilcke Wolfgang , Lima Samuel do Carmo , Vilela Lourival , Thomas Richard , Zech Wolfgang
Published: September 2002

In the South American savanna, no-tillage (NT) is implemented to improve the
sustainability of cropping systems. At the beginning of the rainy season,
however, more plant nutrients may be leached under NT than under conventional
tillage (CT) because of more pronounced organic matter mineralisation and
increased pore continuity. To test this hypothesis, we analysed the chemical
composition of the soil solution under conventional (CT) and no-tillage (NT)
soybean (Glycine max (L.) Merr.) fields in the Brazilian
savanna (Cerrados).
We collected the soil solution at 0.15, 0.3, 0.8, 1.2, and 2 m depth and the
precipitation in 1- to 3-day intervals from 28 October to 23 December 1998 on
plots under CT and NT, replicated 3 times. We determined pH, electrical
conductivity (EC), Ca, K, Mg, Na,
NO3– ,
NH4+,
Cl–, and total organic carbon (TOC) concentrations
in soil solution and precipitation.
Soil solution pH under NT was 0.3–0.8 units lower than under CT and was
inversely related to TOC concentrations (average under NT, 1.02; CT, 0.70 mmol
C/L) at all depths. Average Cl– , Ca, and Mg
concentrations at 0.15–0.3 m depth were significantly higher under CT
(1.09, 1.1, and 0.25 mmol/L) than under NT (0.50, 0.83, and 0.17
mmol/L), respectively. No difference was observed in average Na (0.09
mmol/L) and NO3–
concentrations (2.2 mmol/L) between CT and NT. At 0.8–2 m, average
NO3– (0.30 mmol/L),
Cl– (0.18 mmol/L), Ca (0.19 mmol/L), Mg
(0.05 mmol/L), and Na (0.04 mmol/L) concentrations under CT were
significantly lower than under NT
(NO3– , 0.38;
Cl– , 0.40; Ca, 0.23; Mg, 0.09; Na, 0.06
mmol/L). In the monitored period, the Cl–
which had accumulated during the dry season and which was applied with KCl
fertiliser on 29 October reached a depth of 0.3 m under CT and of 1.2m under
NT.
The results suggest higher mineralisation rates and faster leaching in the NT
than in the CT systems, being the combined result of different plowing
practices and different cropping sequences.