Maireana Brevifolia Research Articles

Evaluation of rainwater harvesting and shrub establishment methods for sustainable watershed management in northern Afghanistan

Watershed rangelands in Northern Afghanistan provide various ecosystem services that support the local people’s livelihoods, but they are now highly degraded essentially due to the continuous high grazing pressure and recurrent droughts. Effects of shrub establishment method enhanced by water harvesting techniques to rehabilitate degraded rangelands have not been well addressed. The main goal of this study was to evaluate the impact of direct seeding and transplanting of seedlings in combination with semi-circular bunds on growth, yield, and survival rate of four shrub species (Atriplex halimus, Atriplex nummularia, Atriplex lentiformis, and Maireana brevifolia) under semi- arid conditions of Sayyad village, Khulm watershed. Survival rate (%), plant height, width, and plant length (cm) and plant cover (%) were measured for each plant over five occasions. A non-destructive reference unit was used to estimate biomass production. The results showed that growth attributes and biomass production of shrubs were consistently greater in the transplanting compared to direct seeding. On average, the plant length, width, height, volume, cover, and biomass production of transplanted shrubs were greater than direct-seeded shrubs by 24.3%, 8.6%, 8.7%, 121.5%, 13.8% and 34.1%, respectively. Biomass production of transplanted seedlings was the highest for A. nummularia (1313.5 g DM/plant) and A. halimus (800 g DM/plant). There was a strong correlation between plant biomass production and plant volume (R2Plant volume = 0.88) for the shrub A. nummularia, indicating that plant volume is a key variable for assessing biomass production for this species. Additionally, the survival rate of M. brevifolia was 100% in both planting methods, suggesting that based on better survival this halophytic plant has great potential when restoring degraded rangelands. Collectively, on the basis of better growth rates, yield, and survival, transplanting A. nummularia and A. halimus may enhance shrub establishment and contribute to the rehabilitation of sloping semi-arid degraded areas of Northern Afghanistan.

Toward an Updated Taxonomy of the South American Chenopodiaceae I: Subfamilies Betoideae, Camphorosmoideae, and Salsoloideae

This paper is the first in a projected series of publications treating the Chenopodiaceae in South America. We present here a taxonomic revision of subfamilies Betoideae, Camphorosmoideae, and Salsoloideae in South America, where all representatives of these subfamilies are introduced. Our research is based on the study of herbarium material, type specimens, digital images, original publications, and field observations. The South American Chenopodiaceae flora includes only Beta vulgaris L. from Betoideae, Bassia hyssopifolia (Pall.) Kuntze, Bassia scoparia (L.) A. J. Scott, and Maireana brevifolia (R. Br.) P. G. Wilson from Camphorosmoideae, and Salsola kali L., Salsola tragus L., and Soda inermis Fourr. from Salsoloideae. Lectotypes for Echinopsilon reuterianus Boiss., Kochia alata Bates, K. parodii Aellen, K. parodii var. elongata Aellen, K. parodii var. densa Aellen, K. parodii var. glabrescens Aellen, and Suaeda sieversiana Pall. are designated here, as well as a second-step lectotype for K. brevifolia R. Br. The distribution of all species is updated based on the revision and proper identification of many herbarium specimens and field observations. The distribution of M. brevifolia in Chile is here expanded. New synonyms for Bassia scoparia are proposed. A preliminary key to the genera of Chenopodiaceae in South America is also presented.

Native plant Maireana brevifolia drives prokaryotic microbial community development in alkaline Fe ore tailings under semi-arid climatic conditions

Native pioneer plants of high environmental tolerance may be exploited as early colonisers in alkaline Fe-ore tailings to drive the development of functional prokaryotic microbial communities, which is one of the critical pedogenic processes leading to in situ soil formation in the tailings. The present study deployed high throughput Illumina Miseq sequencing, to characterise the diversity and potential functionality of prokaryotic microbial communities in the aged Fe-ore tailings and topsoils colonised by native plant species Maireana brevifolia at an Fe ore mine in Western Australia, in comparison with those in the tailings/topsoils without plants. The composition of prokaryotic microbial communities differed between the aged tailings (AT) and topsoil sites (TS). Aged tailings (AT1-AT3) contained more bacteria tolerant of alkaline/saline conditions (e.g., Alkalilimnicola sp.) and those related to Fe biogeochemical cycling (e.g., Acidiferrobacter sp., Aciditerrimonas sp.). In comparison, the prokaryotic microbial communities in the topsoil (TS) contained abundant bacteria related to N cycling (e.g., Rhizobium sp., Frankia sp.). The presence of M. brevifolia plants significantly increased the diversity of prokaryotic microbial communities in tailings and topsoil, particularly favouring the development of bacteria related to N cycling and OM degradations (e.g., Mesorhizobium sp. Paracoccus sp., Oxalicibacterium horti, and Microbacterium sp.). The variation of microbial community were mainly explained by pH, amorphous Fe, and total N, which were regulated by M. brevifolia colonisation. The beneficial roles of pioneer plants M. brevifolia in the development of prokaryotic microbial community in the alkaline Fe ore tailings may be integrated as a key factor when designing and scaling up the process of eco-engineering Fe-ore tailings into soil under semi-arid climatic conditions.

Halophytic shrubs accumulate minerals associated with antioxidant pathways

AbstractHalophytic shrubs from the Chenopodiaceae family are planted by farmers in Mediterranean climate and semi‐arid farming systems because they produce year‐round feed for livestock and grow on poor‐quality soils that are unfit for cereal or traditional pasture production. Halophytes have evolved in environments that exert a high oxidative stress and through this have a high antioxidant capacity. The higher antioxidant capacity of halophytes means that they could have elevated concentrations of the minerals and vitamins associated with antioxidant defence and, as a consequence, may be a good source of antioxidant minerals and vitamins for sheep, cattle and goats. It was hypothesized that a range of halophytic shrub species and accessions within species will contain copper (Cu), manganese (Mn), selenium (Se), zinc (Zn) and sulphur (S) concentrations that will exceed the requirements of grazing ruminants. Concentrations of these minerals were measured across nineteen shrub accessions representing seven widely distributed Australian chenopod species: Atriplex amnicola, Atriplex nummularia, Atriplex rhagodioides, Chenopodium nitrariaceum, Enchylaena tomentosa, Maireana brevifolia and Rhagodia preissii, as well as Eremophila glabra from the Scrophulariaceae family. Measurements were made at one location in spring and winter and at another location in winter only. Concentrations of the elements analysed almost always exceeded requirements and ranged up to 610%, 952%, 1840%, 590% and 250% of the requirement for grazing sheep for Cu, Mn, Se, Zn and S respectively. These results indicate some shrubs have significant potential for use as an antioxidant mineral supplement for ruminants.

Geochemical and mineralogical constraints in iron ore tailings limit soil formation for direct phytostabilization

The present study aimed to characterize key physico-chemical and mineralogical attributes of magnetite iron (Fe) ore tailings to identify potential constraints limiting in situ soil formation and direct phytostabilization. Tailings of different age, together with undisturbed local native soils, were sampled from a magnetite mine in Western Australia. Tailings were extremely alkaline (pH > 9.0), with a lack of water stable aggregate and organic matter, and contained abundant primary minerals including mica (e.g., biotite), with low specific surface area (N2-BET around 1.2 m2 g−1). These conditions remained relatively unchanged after four years' aging under field conditions. Chemical extraction and spectroscopic analysis [e.g., X-ray diffraction (XRD) and synchrotron-based Fe K edge X-ray absorption fine structure spectroscopy (XAFS) analysis] revealed that the aging process decreased biotite-like minerals, but increased hematite and magnetite in the tailings. However, the aged tailings lacked goethite, a compound abundant in natural soils. Examination using backscattered-scanning electron microscope - energy dispersive X-ray spectrometry (BSE-SEM-EDS) revealed that aged tailings contained discrete sharp edged Fe-bearing minerals that did not physically integrate with other minerals (e.g., Si/Al bearing minerals). In contrast, Fe minerals in native soils appeared randomly distributed and closely amassed with Si/Al rich phyllosilicates, with highly eroded edges. The lack of labile organic matter and the persistence of alkaline-saline conditions may have significantly hindered the bioweathering of Fe-minerals and the biogenic formation of secondary Fe-minerals in tailings. However, there is signature that a native pioneer plant, Maireana brevifolia can facilitate the bioweathering of Fe-bearing minerals in tailings. We propose that eco-engineering inputs like organic carbon accumulation, together with the introduction of functional microbes and pioneer plants, should be adopted to accelerate bioweathering of Fe-bearing minerals as a priority for initiating in situ soil formation in the Fe ore tailings.

Two new species of Dactylasioptera (Diptera: Cecidomyiidae) inducing stem galls on Maireana (Chenopodiaceae)

AbstractTwo new species of gall midges of the genus Dactylasioptera Kolesik & Veenstra‐Quah, (Lasiopteridi: Lasiopterini) are described from hairy stem tip galls on Maireana (Chenopodiaceae) in southern Australia. Dactylasioptera lebelae sp. nov. Veenstra & Kolesik, 2018 causes galls on Maireana pyramidata ranging from filamentous to spheroid. Dactylasioptera milnae sp. nov. Veenstra & Kolesik, 2018 causes rosette shaped, leafy galls on Maireana brevifolia. Descriptions of larvae, pupae, male and female adults, as well as geographical distributions of the new gall midges are given. The two species differ from each other in the larval, pupal and adult morphology as well as in mtDNA sequence data (COI). Galls of both species contained fungal mycelium and inquiline wasps Megastigmus sp. (Hymenoptera: Torymidae) and Aprostocetus sp. (Hymenoptera: Eulophidae: Tetrastichinae). The new species are the first confirmed gall makers from the Australian genus Dactylasioptera that contained previously two described species: Dactylasioptera adentata Kolesik & Veenstra‐Quah, and Dactylasioptera dentata Kolesik & Veenstra‐Quah, 2018, both of which are likely inquilines reared from galls induced by Asphondylia spp. (Diptera: Cecidomyiidae) on chenopod host plants. A matrix of morphological characters of Dactylasioptera species is given.

Survival and growth of perennial halophytes on saltland in a Mediterranean environment is affected by depth to watertable in summer as well as subsoil salinity

Farmers need methods for assessing the capability of saltland for productive use based on characteristics that are readily measurable at the paddock scale. We conducted experiments on saltland transects with gradients of salinity and depth to watertable at three sites in south-western Australia. Each was planted with five perennial species with at least some salt tolerance: samphire (Tecticornia mellaria K.A.Sheph.), river saltbush (Atriplex amnicola Paul G.Wilson), small leaf bluebush (Maireana brevifolia (R.Br.) Paul G.Wilson), saltwater couch (Paspalum vaginatum Sw.), and Rhodes grass (Chloris gayana Kunth). Survival and growth of species was related to depth to watertable in summer and average subsoil (0.25–0.50 m depth) electrical conductivity of the saturation extract (ECe). It has been hypothesised that plant zonation on land affected by dryland salinity is affected by the level of salinity and waterlogging on sites. While plant survival ≥60% could be associated with particular ranges of depth to watertable and soil salinity, our data suggest that the most important factor affecting survival and growth was the presence of shallow groundwater in summer. The range of depths to watertable in summer associated with ‘good survival’ (≥60%) was 0.7–1.0 m with samphire, 0.7–1.6 m with saltwater couch, 0.8–1.5 m with Rhodes grass, 0.7–2.4 m with river saltbush, and 0.9–2.4 m with small leaf bluebush. The subsoil ECe (95% confidence interval) associated with ‘good survival’ was 5–14 dS/m for Rhodes grass, 6–11 dS/m for small leaf bluebush, 7–11 dS/m for river saltbush, 6–16 dS/m for saltwater couch, and 27–65 dS/m for samphire. Growth of the perennial grasses was strongly affected by the presence of a shallow watertable in summer; the size of saltwater couch and Rhodes grass increased many-fold as watertable depths decreased from ~1.3 to 0.9 m from the soil surface.

<i>Maireana brevifolia</i> (Chenopodiaceae: Camphorosmeae), a new naturalized alien plant species in South Africa

We describe and discuss the distribution of a new, naturalized alien species, Maireana brevifolia (R.Br.) Paul G.Wilson (Chenopodiaceae), a native of Australia, in the western regions of South Africa. First discovered near Worcester, Western Cape in 1976, the species is now established in disturbed karoo shrubby rangelands, along dirt roads and on saline alluvia, from northern Namaqualand to the western Little Karoo. In the South African flora, M. brevifolia is most easily confused with the indigenous Bassia salsoloides (Fenzl) A.J.Scott, from which it is distinguished by the flat to cup-shaped and almost glabrous perianth with woolly-ciliate lobes, and the hardened and winged fruiting perianth.

Comparison of in vivo organic matter digestion of native Australian shrubs by sheep to in vitro and in sacco predictions

There is increasing interest in selection of genotypes of Australian perennial shrubs such as saltbush ( Atriplex nummularia, Atriplex amnicola and Atriplex semibaccata), orange wattle ( Acacia saligna), small-leaved bluebush ( Maireana brevifolia) and rhagodia ( Rhagodia preissii) for extensive grazing systems with sheep or cattle. A major limitation to cultivar development is that determining the in vivo organic matter digestibility of forage is expensive, time consuming and requires substantial amounts of biomass. A number of in vitro and in sacco techniques are available to predict in vivo digestibility of grasses and legumes however none of these prediction methods have been calibrated to in vivo data for Australian native shrubs. The aim of this study was to determine the in vivo digestibility of native shrub forage and compare these data to predictions using in vitro and in sacco methodologies. The hypothesis tested was that there is a linear relationship between in vivo organic matter digestibility (OMD) of Australian perennial shrub forage and a number of commonly used prediction methods. Of all the methods used, in vitro gas production from microbial fermentation showed the best relationship with in vivo OMD ( r 2 = 0.904). This method appears to be suitable for broad screening and ranking of genotypes. The in vitro pepsin-cellulase technique did not provide a good first estimate of in vivo OMD across all plant species but may be suitable to rank genotypes if data are calibrated with internal standards to manage intrinsic assay variation (step 1) followed by a correction to account for the high salt content of some plants (step 2) and a final linear correction to account for systematic overestimation of OMD of native shrubs (step 3). Further testing and refining of this third calibration step is required. The prediction of in vivo OMD using a 72 h in sacco digestion was adequate for the saltbush species but not for the orange wattle and small-leaved bluebush accessions. Prediction of in vivo OMD using the Daisy II rumen fluid digestion system was not satisfactory and there was not a statistically significant relationship between the acid detergent fibre, neutral detergent fibre or the acid detergent lignin content of the shrubs and in vivo OMD. The differences between the various laboratory-based methods to predict in vivo OMD are discussed and we hypothesise that the presence of plant secondary compounds may interfere with rumen microbial fermentation.

Salsola tragus or S. australis (Chenopodiaceae) in Australia—untangling taxonomic confusion through molecular and cytological analyses

Salsola tragus sensu lato (Chenopodiaceae) is found throughout Western Australia and is considered to be a weed in both natural and agricultural ecosystems, although the current taxonomic status of this species is not clear. The taxonomic literature reports morphological variation within Australian populations of the weed, indicating that there may be genetically distinct ecotypes or unidentified subspecies present within the species. A genetic and cytological approach was used to detect variation between 22 populations of S. tragus sensu lato in the south-west of Western Australia. Out-groups used in this study included a population of S. tragus L. from the USA and Maireana brevifolia (R.Br.) Paul G.Wilson (Chenopodiaceae) from Lake Grace. Four genetically distinct groups were identified, which were not closely related to the S. tragus out-group (~60% similarity). Further, these groups and a S. australis R.Br. sample from the USA were all diploid (2n = 18), unlike the tetraploid (2n = 36) S. tragus. The predominant wheatbelt weed, group A, which was previously classified as S. tragus ssp. tragus L., was identified as S. australis. This species is probably native to Australia, given its arrival predated European invasion. Further research is required to clarify the taxonomic status of the other three possible taxa and determine their status in relation to S. australis.

The impact of shade on establishment of shrubs adapted to the high light irradiation of semi-arid environments

Light may be an important limiting resource that influences community structure of chenopod shrublands. As part of a larger study that aimed to determine the factors that influence chenopod community structure, the focus of this study was the influence of plant canopy on the growth and establishment of smaller plants. We therefore measured the height and cover of three chenopods ( Enchylaena tomentosa, Maireana brevifolia and Maireana georgei) when growing within and outside of the canopy of Atriplex bunburyana under field conditions. All three chenopods had lower cover and E. tomentosa was taller when growing within the canopy of A. bunburyana in comparison to those growing outside of the canopy. The chenopods were then grown under three artificial shade regimes. Plant height, cover, biomass, relative leaf area and photosynthetic surface area measurements showed that each species responded differently to shade. E. tomentosa biomass was facilitated by shade. This was inferred by an increase in total plant biomass. M. brevifolia, in contrast, tolerated shade by increasing above-ground biomass allocation. M. georgei was adversely affected by the shade regimes: root biomass decreased in response to shade. Competition for light is, therefore, likely to influence chenopod community structure of semi-arid and arid environments.

Implications of Plant Density on the Resulting Community Structure of Mine Site Land

Abstract The relative abundances of Chenopodiaceae shrubs are different from the seed composition in the original seed mix when sown on mine waste material in semiarid regions of Western Australia. Experiments were therefore undertaken to determine what species interactions are responsible for shifts in relative abundance after seeding. The growth parameters of five members of the Chenopodiaceae were used to determine intra‐ and interspecific density‐dependent interactions. Dominant and subordinant species were paired and grown in pots at differing densities. The growth parameters measured were height, root, and shoot biomass. Of the five species chosen for this study, Maireana georgei (golden bluebush) and Enchylaena tomentosa (ruby saltbush) do not establish well on mine site areas. These were sensitive to density in monoculture, as well as in the presence of both Atriplex bunburyana (silver saltbush) and Atriplex codonocarpa (flat‐topped saltbush). Although Maireana brevifolia (small leaf bluebush) does establish successfully on mine sites when sown, it showed the same negative reaction when grown in monoculture and in a two‐species mixture. Atriplex bunburyana and A. codonocarpa, in contrast, are dominant species and reacted differently when grown with increasing numbers of the target species (M. georgei, M. brevifolia, and E. tomentosa). Atriplex bunburyana did not exhibit any decreases in growth when grown in competition with up to four plants of the target species. However, A. codonocarpa did react adversely to the presence of the target species. It is thought that the resulting plant community organization reflects the original seed mixture, which is usually sown at a high density. Yet, this study has shown that the differing intra‐ and interspecific density responses of these chenopod species provide an indication of the resulting community organization. To maximize diversity and to prevent dominance by highly competitive species, such as A. bunburyana, it is important to take density‐dependent effects into account during the restoration planning stage.

Establishment of Perennial Shrub and Tree Species in Degraded Eucalyptus salmonophloia (Salmon Gum) Remnant Woodlands: Effects of Restoration Treatments

AbstractWoodlands dominated by Eucalyptus salmonophloia (salmon gum) occur throughout the fragmented landscape of the southwestern Australian wheatbelt. These remnants are often degraded by livestock grazing and weed invasion and in many cases there is little or no understorey remaining and little or no regeneration of the dominant tree E. salmonophloia. There is a growing interest in developing techniques for restoring remnant woodlands. This study describes techniques for establishing seedlings of the dominant tree and perennial understorey species in E. salmonophloia (salmon gum) woodlands degraded by livestock grazing. The study tests the hypothesis that, in addition to the exclusion of livestock, management of weeds and reintroduction of plant species, restoration of plant species diversity will require techniques which mimic large‐scale disturbances, reduce soil compaction, and restore soil water infiltration to suitable rates. Five‐month‐old seedlings of the dominant tree E. salmonophloia and four commonly associated woody shrubs (Acacia hemiteles, Atriplex semibaccata, Maireana brevifolia, and Melaleuca pauperiflora) were planted into areas that differed with respect to grazing (–rabbit/ −livestock and +rabbit/–livestock), tree canopy disturbance (+/–competition with tree canopy) and amelioration of soil compaction (+/–deep ripping). Following three growing seasons and two summers, the exclusion of rabbits had no significant effect on the survival and growth of planted species. As a consequence grazing treatments are pooled for the purposes of presenting the impacts of removing competition with adult trees and soil deep ripping. The removal of competition with adult E. salmonophloia trees significantly improved the survival of E. salmonophloia seedlings but did not improve survival of understorey species. Deep ripping the soil significantly improved the survival of both E. salmonophloia and the shrub A. hemiteles but did not improve the survival of other understorey species. In contrast to seedling survival, the removal of adult E. salmonophloia trees and deep ripping soil significantly increased the growth of all species. The results indicate that increasing levels of intervention will increase the chances of successfully restoring tree and understorey species diversity in degraded E. salmonophloia woodlands.

Tailings revegetation - on non-ameliorated substrate

ABSTRACT The Westonia open pit gold mine, 320 km east of Perth, Western Australia (31°18'S, 118°42'E) was decommissioned in July 1991. Normandy Mining Pty Ltd seeded in May-June I993, the entire surface of the tailings storage facility. The rehabilitation objective was to stabilise the tailings structure. Tailings slurry had been pumped into three Cells at different periods throughout mining operations. The near surface layer of tailings is most significant from a rehabilitation perspective, as it is where plants are growing. Vegetated areas have lower salinity than areas lacking vegetation (8.23 compared with 47,39 dS m−1 ECe). Revegetation density averages 1.734 stems m−2 in October 1999 and foliage cover is 30%. Nine chenopods were recorded in October 1999 with Maireana brevifolia, Atriplex undulata and A. leniiformis more prevalent. Grasses continue to show accelerated establishment. A cryptogamic cover prevalent over the upper surfaces of ‘raw’ tailings appears to be enhanced under established vegetation where moisture levels and the soil nutrient status are inherently higher. The tailings profile in the centre of the third cell (vegetation absent) showed similar changes in salinity to previous samplings. The surface sample in April 1999 (102 dS m−1) was less saline than the April 1998 sampling (225 dS m−1). The layer between 0.1 m and 0.4 m remains extremely saline, i.e. range 83-150 dS m−1 ECe. Around the perimeter of his cell the tailings is coarser, and sampling of the profile to 0.3 m depth gave salinities from 5 to 20 dS m−1 ECe.

Self-sustainable reclamation: Shrub and tree establishment on saline mine wastes

ABSTRACT Mining ceased in 1991 at the Westonia open-cut goldmine, 320 km east of Perth, Western Australia. The early May 1990 seeding of 40 ha of dump surfaces used a suite of species local to the area, and additional selected salt tolerant varieties. No fertiliser was applied. Subsequently stratified random sampling assessed the revegetation at twice yearly intervals. In 1995 two different sampling strategies were required. The chosen samplings were repeatable and accurate, and cost, labour and time effective. Seeding success was evaluated. Eucalypts and tall shrubs were prevalent and chenopods provided ground cover. Densities of eucalypts approximated 625 per hectare, with individuals to 4 m not uncommon. Acacias (wattles) and other woody perennial shrubs and trees were present. Saltbushes were prevalent. An extensive chenopod ground cover included Atriplex semibaccata, Enchylaena tomentosa and Maireana brevifolia. With this appropriate data base prediction of longer term ecosystem development can be made.

Placing and infrastructure of reservations in the arid zone of the USSR (in Russian): A. F. Kovshar & A. L. Zatoka, Problemy Osvoeniya Pustyn' — Akademiya Nauk Turkmenskoi SSR, 3–4, 1991, pp 155–161

Ten species of shrubs namely: Atriplex lentiformis, A. undulata, A. canescens, A. semi-baccata, A. nummularia, A. halimus, A. paludosa, A. amnicola, Salsola rigida and Maireana brevifolia were transplanted into a two-block experiment at Dalmaj Station 200 km south-east of Baghdad, in 1982. The site is highly saline with an ECe value for the top 10 cm soil layer of 62 dS m−1. The experiment was conducted under conditions with an annual rainfall average of 80 mm and a mean annual evaporation rate of 3212 mm for the period of study 1982–1986. Measurements and observations on plant survival, growth rate, flowering and production of seeds and volunteer seedlings and total production were made. Atriplex lentiformis had the greatest survival rate with M. brevifolia the least. Best growth was given by A. lentiformis. All species except A. amnicola produced seeds, and volunteer seedlings were observed from A. semi-baccata, A. leentiformis, A. halimus, A. nummularia and A. undulata. Dry matter production ranged from 17 800 kg ha−1 in A. lentiformis to 360 kg ha−1 in S. rigida over the four years.

Survival and productivity of chenopods in salt-affected lands of Iraq

Ten species of shrubs namely: Atriplex lentiformis, A. undulata, A. canescens, A. semi-baccata, A. nummularia, A. halimus, A. paludosa, A. amnicola, Salsola rigida and Maireana brevifolia were transplanted into a two-block experiment at Dalmaj Station 200 km south-east of Baghdad, in 1982. The site is highly saline with an EC e value for the top 10 cm soil layer of 62 dS m −1. The experiment was conducted under conditions with an annual rainfall average of 80 mm and a mean annual evaporation rate of 3212 mm for the period of study 1982–1986. Measurements and observations on plant survival, growth rate, flowering and production of seeds and volunteer seedlings and total production were made. Atriplex lentiformis had the greatest survival rate with M. brevifolia the least. Best growth was given by A. lentiformis. All species except A. amnicola produced seeds, and volunteer seedlings were observed from A. semi-baccata, A. leentiformis, A. halimus, A. nummularia and A. undulata. Dry matter production ranged from 17 800 kg ha −1 in A. lentiformis to 360 kg ha −1 in S. rigida over the four years.

Soil mulches and sprayed coatings and seed washing to aid Chenopod establishment on saline soil.

Three field experiments were conducted on saline sites to compare vermiculite and 'Compeat' mulches and sprayed latex or bituminous coatings as coverings for seed placed on soil in a 'V' shaped niche. Chenopod fruits were washed in water to remove germination inhibitors before planting. The effectiveness of the treatments were assessed by counting seedling emergence and survival. Black pigmented latex and bituminous emulsion coatings gave significant improvements in emergence and survival on Atriplex spp. and Maireana brevifolia seedlings over 10 months. Bituminous emulsion stabilized the soil in the niche better than lattices, especially at high dilutions. Seed washing doubled emergence of Atriplex amnicola (river saltbush) if used in combination with a mulch. Vermiculite gave a marked increase in emergence and survival of seedlings of river saltbush and was significantly better than 'Compeat'. Low temperatures and high soil salinities were postulated as possible causes of reduced emergence on saline sites.

Black paint soil amendment and mulch effects on chenopod establishment in a saline soil

A niche-seeding technique has been developed for establishing salt-tolerant forage shrubs on salt-affected soils under natural rainfall. The technique involves niche formation and spot treatment in the niche. The establishment response of Maireana brevifolia (small leaved hluebush), Atriplex undulata (wavy leaf saltbush) and A. rhagodioides (river saltbush) to treatments including soil amendments, seed coverings and spraying with black latex paint was studied in the field. Gypsum, ‘Lima’ and covering the seed with soil or chaff all failed to give as good a result either with or without black latex paint as did paint alone. Black latex paint was shown to raise the temperature of the top 1 to 2 mm of soil by about 5 °C on a clear still mid-winter day. Temperature requirements of two of the species indicate that the response to black paint is at least partly a temperature effect.