960 resultados para Alkali lands
Resumo:
Recently, second-generation (non-vegetable oil) feedstocks for biodiesel production are receiving significant attention due to the cost and social effects connected with utilising food products for the production of energy products. The Beauty leaf tree (Calophyllum inophyllum) is a potential source of non-edible oil for producing second-generation biodiesel because of its suitability for production in an extensive variety of atmospheric condition, easy cultivation, high fruit production rate, and the high oil content in the seed. In this study, oil was extracted from Beauty leaf tree seeds through three different oil extraction methods. The important physical and chemical properties of these extracted Beauty leaf oils were experimentally analysed and compared with other commercially available vegetable oils. Biodiesel was produced using a two-stage esterification process combining of an acid catalysed pre-esterification process and an alkali catalysed transesterification process. Fatty acid methyl ester (FAME) profiles and important physicochemical properties were experimentally measured and estimated using equations based on the FAME analysis. The quality of Beauty leaf biodiesels was assessed and compared with commercially available biodiesels through multivariate data analysis using PROMETHEE-GAIA software. The results show that mechanical extraction using a screw press produces oil at a low cost, however, results in low oil yields compared with chemical oil extraction. High pressure and temperature in the extraction process increase oil extraction performance. On the contrary, this process increases the free fatty acid content in the oil. A clear difference was found in the physical properties of Beauty leaf oils, which eventually affected the oil to biodiesel conversion process. However, Beauty leaf oils methyl esters (biodiesel) were very consistent physicochemical properties and able to meet almost all indicators of biodiesel standards. Overall this study found that Beauty leaf is a suitable feedstock for producing second-generation biodiesel in commercial scale. Therefore, the findings of this study are expected to serve as the basis for further development of Beauty leaf as a feedstock for industrial scale second-generation biodiesel production.
Resumo:
High resolution electron microscopic (HREM) investigation of potassiumbeta-alumina and the related gallate and ferrite has revealed that whereas the aluminate and gallate are highly disordered, consisting of random sequence ofbeta andbetaPrime units, the ferrite is more ordered. The aluminate and gallate are sensitive to electron beam irradiation exhibiting beam-induced damage similar to sodiumbetaPrime-alumina. Significantly, the ferrite is beamstable, the difference in behaviour amongst these related oxides arising from the different mechanisms by which alkali metal nonstoichiometry is accommodated. Barium hexaaluminate and hexaferrite are both highly ordered; specimens prepared by the barium borate flux method exhibit a new radic3a×radic3a superstructure of the hexagonal magnetoplumbite cell.
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35S incorporation studies showed that Candida tropicalis tRNA contained two thionucleosides, one of which was identified as 5-methyl-2-thiouridine. The other thionucleoside was alkali labile, and it appeared to be an ester. Pulse-chase experiments suggested that the two thionucleosides were structurally related. 5-Methyl-2-thiouridine was present in one of the lysine tRNAs. This is the first report of the presence of this nucleoside in a yeast tRNA.
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The project objective is to undertake paddock modelling across the Great Barrier Reef catchments to determine magnitude of sediment and particulate nutrient reductions from agricultural lands to GBR lagoon achieved over 5 years. Discussions, development and design of a plan (including a monitoring, evaluation, reporting and improvement plan) for GRASP paddock modelling will be undertaken to determine changes in water quality as a result of land management practices adopted by pastoralists. Biophysical outputs will be derived from range of land types, starting conditions and grazing management strategies. GRASP derived outputs will then be incorporated into water models to determine sediment and nutrient estimates for the catchments.
Resumo:
The Wambiana grazing trial started in 1997 to test and develop sustainable and profitable grazing strategies to manage for rainfall variability. It is important that this trial continue as the results are still relatively short-term relative to rainfall cycles and significant treatment changes are still occurring. This new proposal will maintain baseline treatments but will modify others based on trial learning’s to date. It builds on treatment differences and evidence collected over the last 12 years to deliver evidence-based guidelines and principles for sustainable and productive management. The trial also links to other projects modelling water quality, climate change, methane emissions and soil C sequestration on grazing lands.
Resumo:
The potential for fertiliser use in Lockyer Valleys intensive vegetable production to impact on the Moreton Bay Waterways (MBW) is not well defined. Notwithstanding nutrient runoff through soil erosion of agricultural lands has been identified as a process that significantly contributes artificial fertiliser to the MBW (SEQ Healthy Waterways Draft Strategy 2006). In order to better understand this issue the present study undertakes a nutrient mass balance to evaluate nitrogen use efficiency in the intensive horticultural industry of the Lockyer Valley.
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Service provision project to be undertaken by staff from the Department of Employment, Economic Development and Innovation (DEEDI) to the Flower Association of Queensland Inc. (FAQI) to fulfil FAQI's requirements under the South East Queensland - Irrigation Futures project.
Resumo:
This project aims to develop integrated irrigation and nutrition management strategies under limited water for irrigators currently investing in overhead irrigation systems (CPLM) to minimize the learning lag in their use and optimize crop and economic performance.
Resumo:
Austral bracken, Pteridium esculentum, occurs widely in Australian grazing lands and contains both the known carcinogen ptaquiloside and its hydroxy analogue, ptesculentoside, with untested carcinogenic potential. Calves were fed a diet containing 19% P. esculentum that delivered 1.8 mg of ptaquiloside and 4.0 mg of ptesculentoside per kilogram of body weight (bw) per day to explore the carcass residue potential of these compounds. Concentrations of ptaquiloside and ptesculentoside in the liver, kidney, skeletal muscle, heart, and blood of these calves were determined as their respective elimination products, pterosin B and pterosin G, by HPLC-UV analysis. Plasma concentrations of up to 0.97 mu g/mL ptaquiloside and 1.30 mu g/mL ptesculentoside were found, but were shown to deplete to <10% of these values within 24 h of bracken consumption. Both glycosides were also detected in all tissues assayed, with ptesculentoside appearing to be more residual than ptaquiloside. Up to 0.42 and 0.32 mu g/g ptesculentoside was present in skeletal muscle and liver, respectively, 15 days after bracken consumption ended. This detection of residual glycosides in tissues of cattle feeding on Austral bracken raises health concerns for consumers and warrants further investigation.
Resumo:
a,a-Trehalose induced a rapid blackening of the terminal 2.5-centimete region of excised Cuscuta relexa Roxb. vine. The incorporation of radioactivite from [I'C]glucose into alkali-insoluble fraction of shoot tip was markedly inhibited by 12 hours of trehalose feeding to an excised vine. This inhibition was confied to the apical segment of the vine in which cell elongation occurred. The rate of blackening of shoot tip explants was hastened by the addition of gibberellic acid A3, which promoted elongationgrowth of isolated Cuscuta shoot tips. The symptom of trehalose toxicity was duplicated by 2-deoxygucose, which has been shown to ba potent inhibitor of ceD wall synthesis in yeast. The observations suggest that trehalose interferes with the synthesis of ceDl wail polysaccharides, the chief component of which was presumed to be cellulose.
Resumo:
This paper describes the employment of two experienced graziers as consultants to apply and evaluate a model for calculating 'safe' long-term grazing capacities of individual properties. The model was based on ecological principles and entailed estimates of average annual forage grown (kglha) on the different land systems on each property and the calculation of the number of livestock (dry sheep equivalents, DSE) required to 'safely' utilise this forage. The grazier consultants applied and evaluated the 'safe' grazing capacity model on 20 properties of their choosing. For evaluation, model results were compared with; (a) the Department of Lands rated carrying capacities for those properties and (b) the grazing capacity assessed independently by the owners of those properties. For the 20 properties, the average 'safe' grazing capacity calculated by the model (21.0 DSE/kmZ) was 8% lighter than the average of the owner assessed capacities (22.7 DSE/kmZ), which in tum was 37% lighter than the average of the pre-1989 Department of Lands rated carrying capacity (31.0 DSE/kmZ). The grazing land management and administrative implications of these results and the role graziers played as consultants are discussed.
Resumo:
The impact of excessive sediment loads entering into the Great Barrier Reef lagoon has led to increased awareness of land condition in grazing lands. Improved ground cover and land condition have been identified as two important factors in reducing sediment loads. This paper reports the economics of land regeneration using case studies for two different land types in the Fitzroy Basin. The results suggest that for sediment reduction to be achieved from land regeneration of more fertile land types (brigalow blackbutt) the most efficient method of allocating funds would be through extension and education. However for less productive country (narrow leaved ironbark woodlands) incentives will be required. The analysis also highlights the need for further scientific data to undertake similar financial assessments of land regeneration for other locations in Queensland.
Resumo:
The issue of the usefulness of different prosopis species versus their status as weeds is a matter of hot debate around the world. The tree Prosopis juliflora had until 2000 been proclaimed weedy in its native range in South America and elsewhere in the dry tropics. P. juliflora or mesquite has a 90-year history in Sudan. During the early 1990s a popular opinion in central Sudan and the Sudanese Government had begun to consider prosopis a noxious weed and a problematic tree species due to its aggressive ability to invade farmlands and pastures, especially in and around irrigated agricultural lands. As a consequence prosopis was officially declared an invasive alien species also in Sudan, and in 1995 a presidential decree for its eradication was issued. Using a total economic valuation (TEV) approach, this study analysed the impacts of prosopis on the local livelihoods in two contrasting irrigated agricultural schemes. Primarily a problem-based approach was used in which the derivation of non-market values was captured using ecological economic tools. In the New Halfa Irrigation Scheme in Kassala State, four separate household surveys were conducted due to diversity between the respective population groups. The main aim was here to study the magnitude of environmental economic benefits and costs derived from the invasion of prosopis in a large agricultural irrigation scheme on clay soil. Another study site, the Gandato Irrigation Scheme in River Nile State represented impacts from prosopis that an irrigation scheme was confronted with on sandy soil in the arid and semi-arid ecozones along the main River Nile. The two cases showed distinctly different effects of prosopis but both indicated the benefits to exceed the costs. The valuation on clay soil in New Halfa identified a benefit/cost ratio of 2.1, while this indicator equalled 46 on the sandy soils of Gandato. The valuation results were site-specific and based on local market prices. The most important beneficial impacts of prosopis on local livelihoods were derived from free-grazing forage for livestock, environmental conservation of the native vegetation, wood and non-wood forest products, as well as shelterbelt effects. The main social costs from prosopis were derived from weeding and clearing it from farm lands and from canalsides, from thorn injuries to humans and livestock, as well as from repair expenses vehicle tyre punctures. Of the population groups, the tenants faced most of the detrimental impacts, while the landless population groups (originating from western and eastern Sudan) as well as the nomads were highly dependent on this tree resource. For the Gandato site the monetized benefit-cost ratio of 46 still excluded several additional beneficial impacts of prosopis in the area that were difficult to quantify and monetize credibly. In River Nile State the beneficial impact could thus be seen as completely outweighing the costs of prosopis. The results can contributed to the formulation of national and local forest and agricultural policies related to prosopis in Sudan and also be used in other countries faced with similar impacts caused by this tree.
Resumo:
The availability and quality of irrigation water has become an issue limiting productivity in many Australian vegetable regions. Production is also under competitive pressure from supply chain forces. Producers look to new technologies, including changing irrigation infrastructure, exploring new water sources, and more complex irrigation management, to survive these stresses. Often there is little objective information investigating which improvements could improve outcomes for vegetable producers, and external communities (e.g. meeting NRM targets). This has led to investment in inappropriate technologies, and costly repetition of errors, as business independently discover the worth of technologies by personal experience. In our project, we investigated technology improvements for vegetable irrigation. Through engagement with industry and other researchers, we identified technologies most applicable to growers, particularly those that addressed priority issues. We developed analytical tools for ‘what if’ scenario testing of technologies. We conducted nine detailed experiments in the Lockyer Valley and Riverina vegetable growing districts, as well as case studies on grower properties in southern Queensland. We investigated root zone monitoring tools (FullStop™ wetting front detectors and Soil Solution Extraction Tubes - SSET), drip system layout, fertigation equipment, and altering planting arrangements. Our project team developed and validated models for broccoli, sweet corn, green beans and lettuce, and spreadsheets for evaluating economic risks associated with new technologies. We presented project outcomes at over 100 extension events, including irrigation showcases, conferences, field days, farm walks and workshops. The FullStops™ were excellent for monitoring root zone conditions (EC, nitrate levels), and managing irrigation with poor quality water. They were easier to interpret than the SSET. The SSET were simpler to install, but required wet soil to be reliable. SSET were an option for monitoring deeper soil zones, unsuitable for FullStop™ installations. Because these root zone tools require expertise, and are labour intensive, we recommend they be used to address specific problems, or as a periodic auditing strategy, not for routine monitoring. In our research, we routinely found high residual N in horticultural soils, with subsequently little crop yield response to additional nitrogen fertiliser. With improved irrigation efficiency (and less leaching), it may be timely to re-examine nitrogen budgets and recommendations for vegetable crops. Where the drip irrigation tube was located close to the crop row (i.e. within 5-8 cm), management of irrigation was easier. It improved nitrogen uptake, water use efficiency, and reduced the risk of poor crop performance through moisture stress, particularly in the early crop establishment phases. Close proximity of the drip tube to the crop row gives the producer more options for managing salty water, and more flexibility in taking risks with forecast rain. In many vegetable crops, proximate drip systems may not be cost-effective. The next best alternative is to push crop rows closer to the drip tube (leading to an asymmetric row structure). The vegetable crop models are good at predicting crop phenology (development stages, time to harvest), input use (water, fertiliser), environmental impacts (nutrient, salt movement) and total yields. The two immediate applications for the models are understanding/predicting/manipulating harvest dates and nitrogen movements in vegetable cropping systems. From the economic tools, the major influences on accumulated profit are price and yield. In doing ‘what if’ analyses, it is very important to be as accurate as possible in ascertaining what the assumed yield and price ranges are. In most vegetable production systems, lowering the required inputs (e.g. irrigation requirement, fertiliser requirement) is unlikely to have a major influence on accumulated profit. However, if a resource is constraining (e.g. available irrigation water), it is usually most profitable to maximise return per unit of that resource.
Resumo:
Sichuanissa Tiibetin ylängön metsäkato on pysähtynyt mutta eroosio-ongelmat jatkuvat Viikin tropiikki-instituutin tutkija Ping ZHOU kartoitti trooppisen metsänhoidon alaan kuuluvassa väitöskirjatyössään maaperän eroosioalttiutta ja sen riippuvuutta metsäkasvillisuudesta Jangtsen tärkeää sivuhaaraa Min-jokea ympäröivällä n. 7400 neliökilometrin suuruisella valuma-alueella Sichuanin Aba-piirikunnassa. Aineistonaan hän käytti muun muassa satelliittikartoitustietoja ja mittaustuloksia yli 600 maastokoealalta. Tutkimuksen nimi suomeksi on "Maaperän eroosion mallinnus ja vuoristoisen valuma-alueen ekologinen ennallistaminen Sichuanissa Kiinassa". Aikaisempien tutkimusten perusteella oli tiedossa että metsien häviäminen tällä alueella pysähtyi jo 1980-luvun alussa. Sen jälkeen on metsien pinta-ala hitaasti kasvanut etupäässä sen vuoksi, että teollinen puunhakkuu luonnonmetsissä kiellettiin kokonaan v. 1998 ja 25 astetta jyrkemmillä rinteillä myös maatalouden harjoittaminen on saatu lopetetuksi viljelijöille tarjottujen taloudellisten houkuttimien avulla. Täten myös pelto- ja laidunmaata on voitu ennallistaa metsäksi. Ping Zhou pystyi jakamaan 5700 metrin korkeuteen saakka kohoavan vuoristoalueen eroosioalttiudeltaan erilaisiin vyöhykkeisiin rinteen kaltevuuden, sademäärän, kasvipeitteen ja maalajin perusteella. Noin 15 prosentilla tutkitun valuma-alueen pinta-alasta, lähinnä Min-joen pääuomaa ympäröivillä jyrkillä rinteillä, eroosioriski oli suuri tai erittäin suuri. Eri tyyppisellä kasvillisuudella oli hyvin erilainen vaikutus eroosioalttiuteen, ja myös alueen sijainti vuoriston eri korkeuksilla vaikutti eroosioon. Säästyneet lähes luonnontilaiset havumetsät, joita on etupäässä vuoriston ylimmissä osissa 2600-4000 metrin korkeudella, edistävät tehokkaasti metsän luontaista uudistumista ja levittäytymistä vaurioituneille alueille. Säilyneiden metsien puulajikoostumus antoi tutkimuksessa mahdollisuuden ennustaa metsien tulevaa kehitystä koko tutkitulla valuma-alueella sen eri korkeusvyöhykkeissä ja eri maaperätyypeillä. Ennallistamisen kannalta ongelmallisimpia olivat alueet joilta metsäpeite oli lähinnä puiden teollisen hakkuun vuoksi kokonaan hävinnyt ja joilla maaperä yleisesti oli eroosion pahoin kuluttama. Näillä alueilla ei ole tehty juuri mitään uudistamis- tai ennallistamistoimenpiteitä. Niillä metsien ennallistaminen vaatii myös puiden tai pensaiden istuttamista. Tähän sopivia ovat erityisesti ilmakehän typpeä sitovat lajit, joista alueella kasvaa luontaisena mm. sama tyrnilaji joka esiintyy myös Suomessa. Työssä tutkittiin yli kahdeksankymmenen paikallisen luontaisen puulajin (joista peräti noin kolmannes on havupuulajeja) ekologisia ominaisuuksia ja soveltuvuutta metsien ennallistamiseen. Avainasemassa työn onnistumisen kannalta ovat nyt paikalliset asukkaat, joiden maankäytön muutokset ovat jo selvästi edistänet luonnonmetsän ennalleen palautumista. Suomen Akatemia rahoitti vuosina 2004-2006 VITRI:n tutkimushanketta, josta Ping Zhou'n väitöskirjatyö muodosti keskeisen osan. Kenttätyö Sichuanissa avasi mahdollisuuden hedelmälliseen monitieteiseen yhteistyöhön ja tutkijavaihtoon Kiinan tiedeakatemian alaisen Chengdun biologiainstituutin (CIB) kanssa; tämä tieteellinen kanssakäyminen jatkuu edelleen.