989 resultados para Soil-Neem relationships


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Previous research showed that daily manifestations of career adaptability fluctuate within individuals over short periods of time, and predict important daily job and career outcomes. Using a quantitative daily diary study design (N = 156 employees; 591 daily entries), the author investigated daily job characteristics (i.e., daily job demands, daily job autonomy, and daily supervisory career mentoring) and daily individual characteristics (i.e., daily Big Five personality characteristics, daily core self-evaluations, and daily temporal focus) as within-person predictors of daily career adaptability and its four dimensions (concern, control, curiosity, and confidence). Results showed that daily job demands, daily job autonomy, daily conscientiousness, daily openness to experience, as well as daily past and future temporal focus positively predicted daily career adaptability. Differential results emerged for the four career adaptability dimensions. Implications for future research on within-person variability in career adaptability are discussed.

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Most research on career adaptability has examined the construct as an individual differences variable and neglected that it may vary within an individual over a short period of time. In two daily diary studies, the author investigated the relationships of career adaptability and its four dimensions (concern, control, curiosity, and confidence) to their daily manifestations as well as daily job and career outcomes. Both Study 1 (N = 53) and Study 2 (N = 234) demonstrated substantial within-person variability in employees' behavioral expressions of career adaptability across five work days. Results further showed that daily career adaptability and daily confidence positively predicted daily task and career performance, as well as daily job and career satisfaction. Daily control positively predicted daily task performance, as well as daily job and career satisfaction. Daily concern positively predicted daily career performance and satisfaction, and daily curiosity positively predicted daily career satisfaction.

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Historical stocking methods of continuous, season-long grazing of pastures with little account of growing conditions have caused some degradation within grazed landscapes in northern Australia. Alternative stocking methods have been implemented to address this degradation and raise the productivity and profitability of the principal livestock, cattle. Because information comparing stocking methods is limited, an evaluation was undertaken to quantify the effects of stocking methods on pastures, soils and grazing capacity. The approach was to monitor existing stocking methods on nine commercial beef properties in north and south Queensland. Environments included native and exotic pastures and eucalypt (lighter soil) and brigalow (heavier soil) land types. Breeding and growing cattle were grazed under each method. The owners/managers, formally trained in pasture and grazing management, made all management decisions affecting the study sites. Three stocking methods were compared: continuous (with rest), extensive rotation and intensive rotation (commonly referred to as 'cell grazing'). There were two or three stocking methods examined on each property: in total 21 methods (seven continuous, six extensive rotations and eight intensive rotations) were monitored over 74 paddocks, between 2006 and 2009. Pasture and soil surface measurements were made in the autumns of 2006, 2007 and 2009, while the paddock grazing was analysed from property records for the period from 2006 to 2009. The first 2 years had drought conditions (rainfall average 3.4 decile) but were followed by 2 years of above-average rainfall. There were no consistent differences between stocking methods across all sites over the 4 years for herbage mass, plant species composition, total and litter cover, or landscape function analysis (LFA) indices. There were large responses to rainfall in the last 2 years with mean herbage mass in the autumn increasing from 1970 kg DM ha(-1) in 2006-07 to 3830 kg DM ha(-1) in 2009. Over the same period, ground and litter cover and LFA indices increased. Across all sites and 4 years, mean grazing capacity was similar for the three stocking methods. There were, however, significant differences in grazing capacity between stocking methods at four sites but these differences were not consistent between stocking methods or sites. Both the continuous and intensive rotation methods supported the highest average annual grazing capacity at different sites. The results suggest that cattle producers can obtain similar ecological responses and carry similar numbers of livestock under any of the three stocking methods.

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Purpose This study investigated how nitrogen (N) nutrition and key physiological processes varied under changed water and nitrogen competition resulting from different weed control and fertilisation treatments in a 2-year-old F1 hybrid (Pinus elliottii Engelm var. elliottii × P. caribaea var. hondurensis Barr. ex Golf.) plantation on a grey podzolic soil type, in Southeast Queensland. Materials and methods The study integrated a range of measures including growth variables (diameter at ground level (DGL), diameter at breast height (DBH) and height (H)), foliar variables (including foliar N concentration, foliar δ13C and δ15N) and physiological variables (including photosynthesis (An), stomatal conductance (gs), transpiration (E), intrinsic water use efficiency (WUEi) (A/gs) and xylem pressure potential (ΨXPP)) to better understand the mechanisms influencing growth under different weed control and fertilisation treatments. Five levels of weed control were applied: standard (routine), luxury, intermediate, mechanical and nil weed control, all with routine fertilisation plus an additional treatment, routine weed control and luxury fertilisation. Relative weed cover was assessed at 0.8, 1.1 and 1.6 years after plantation establishment to monitor the effectiveness of weed control treatments. Soil investigation included soil ammonium (NH4 +-N), nitrate (NO3 −-N), potentially mineralizable N (PMN), gravimetric soil moisture content (MC), hot water extractable organic carbon (HWETC), hot water extractable total N (HWETN), total C, total N, stable C isotope composition (δ13C), stable N isotope composition (δ15N), total P and extractable K. Results and discussion There were significant relationships between foliar N concentrations and relative weed cover and between tree growth and foliar N concentration or foliar δ15N, but initial site preparation practices also increased soil N transformations in the planting rows reducing the observable effects of weed control on foliar δ15N. A positive relationship between foliar N concentration and foliar δ13C or photosynthesis indicated that increased N availability to trees positively influenced non-stomatal limitations to photosynthesis. However, trees with increased foliar N concentrations and photosynthesis were negatively related to xylem pressure potential in the afternoons which enhanced stomatal limitations to photosynthesis and WUEi. Conclusions Luxury and intermediate weed control and luxury fertilisation positively influenced growth at early establishment by reducing the competition for water and N resources. This influenced fundamental key physiological processes such as the relationships between foliar N concentration, A n, E, gs and ΨXPP. Results also confirmed that time from cultivation is an important factor influencing the effectiveness of using foliar δ15N as an indicator of soil N transformations.

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The major banana production areas in Australia are particularly sensitive to environments due to their close proximity to areas of World Heritage rainforest and the Great Barrier Reef catchment. Management of soil quality, nutrients and pesticides are vital to maintaining the integrity of these sensitive areas. Studies on cropping systems have suggested that integrating organic matter into ground cover management would improve the quality of soil under banana cultivation. In this study, an alternative management practice for bananas, which addresses the management of organic matter and fertiliser application, was assessed and compared to the conventional practice currently employed in the banana industry. Several chemical, physical and biological soil parameters were measured including: pH, electrical conductivity, water stable aggregates, bulk density, water filled pore space, porosity, water content, fluorescein diacetate hydrolyis (FDA) and beta-glucosidase activity. The alternative management practice did not have a significant impact of the production and growth of bananas but overall improved the quality of the soil. Although some differences were observed, the chemical and physical soil characteristics did not differ dramatically between the two management systems. The addition of organic matter resulted in the soil under alternative practice having higher FDA and beta-glucosidase levels, indicating higher microbial activity. The integration of organic matter into the management of bananas resulted in positive benefits on soil properties under bananas, however, methods of maintaining organic matter in the soil need to be further researched.

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BACKGROUND: There is growing evidence that regular physical activity (PA) reduces the risk of poor mental health. Less research has focused on the relationship between PA and positive wellbeing. The study aims were to assess the prospective associations between PA and optimism, in both young and mid-aged women. METHODS: 9688 young women (born 1973-1978) completed self-report surveys in 2000 (age 22 to 27), 2003, 2006, and 2009; and 11,226 mid-aged women (born 1946-1951) completed surveys in 2001 (age 50-55) 2004, 2007, and 2010, as part of the Australian Longitudinal Study on Women's Health. Generalized estimating equation models (with 3-year time lag) were used to examine the relationship between PA and optimism in both cohorts. RESULTS: In both cohorts, women reporting higher levels of PA had greater odds of reporting higher optimism over the 9-year period, (young, OR = 5.04, 95% CI: 3.85-6.59; mid-age, OR = 5.77, 95% CI: 4.76-7.00) than women who reported no PA. Odds were attenuated in adjusted models, with depression accounting for a large amount of this attenuation (young, OR = 2.00, 95% CI: 1.57-2.55; mid-age, OR = 1.64 95% CI: 1.38-1.94). CONCLUSIONS: Physical activity can promote optimism in young and mid-aged women over time, even after accounting for the negative effects of other psychosocial indicators such as depression.

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The objective of this study was to investigate patterns of soil water extraction and drought resistance among genotypes of bermudagrass (Cynodon spp.) a perennial C-4 grass. Four wild Australian ecotypes (1-1, 25a1, 40-1, and 81-1) and four cultivars (CT2, Grand Prix, Legend, and Wintergreen) were examined in field experiments with rainfall excluded to monitor soil water extraction at 30-190 cm depths. In the study we defined drought resistance as the ability to maintain green canopy cover under drought. The most drought resistant genotypes (40-1 and 25a1) maintained more green cover (55-85% vs 5-10%) during water deficit and extracted more soil water (120-160 mm vs 77-107 mm) than drought sensitive genotypes, especially at depths from 50 to 110 cm, though all genotypes extracted water to 190 cm. The maintenance of green cover and higher soil water extraction were associated with higher stomatal conductance, photosynthetic rate and relative water content. For all genotypes, the pattern of water use as a percentage of total water use was similar across depth and time We propose the observed genetic variation was related to different root characteristics (root length density, hydraulic conductivity, root activity) although shoot sensitivity to drying soil cannot be ruled out.

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There is a need to develop indicators that relate the dynamics of soil organic carbon (SOC) with changes in land management of horticultural production systems. Soil nematode communities have been shown to be sensitive to land management changes, but often do not include plant-parasites in the calculation of soil nematode community indices. The concept of nematode functional guilds was used to estimate the proportion of carbon entering the soil ecosystem through different channels, such as through decomposition of organic material, the detrital channel, through the roots of plants, the root channel or recycled through the activity of predators, a predation channel. Calculations of the indices were developed and validated using case studies in the north Queensland banana industry. Firstly, a survey of organic and conventional banana farms found a greater proportion of C entering the soil ecosystem through the detrital channel and a reduced proportion of C originating through the root channel at the organic sites relative to conventional sites. Secondly, a field experiment comparing compost amendments, found application of fresh compost significantly increased the proportion of C entering the soil ecosystem through the detrital channel and decreased proportion of C originating from the root channel. Thirdly, a field experiment comparing 'conventional' banana production to an 'alternative' system which incorporated organic matter, found the proportion of C entering the soil ecosystem through the root channel was significantly greater in the conventional systems relative to the alternative system. This research demonstrates that nematode indices can be used to assess horticultural systems, by indicating the origins of SOC.

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Design is ubiquitous to the life of contemporary societies and key to their progress, but for some, it is an elitist concept. This thesis investigates the role of public libraries contribution to the general public's understanding of 'Design'. This study compared participants views in the context of State Libraries in two cities: Brisbane and Curitiba. Findings revealed that exploring four new aspects in the Development and Deliver Stages of a service design framework for public libraries can be an effective tool to enhance people's access and experiences of Design, and ultimately, it can contribute to the democratization of design.

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Design is ubiquitous to the life of contemporary societies and key to their progress, but for some, it is an elitist concept. This thesis investigates the role of public libraries contribution to the general public's understanding of "Design". This study compared participants views in the context of State Libraries in two cities: Brisbane and Curitiba. Findings revealed that exploring four new aspects in the Development and Deliver Stages of a service design framework for public libraries can be an effective tool to enhance people"s access and experiences of Design, and ultimately, it can contribute to the democratisation of design.

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The influence of grazing management on total soil organic carbon (SOC) and soil total nitrogen (TN) in tropical grasslands is an issue of considerable ecological and economic interest. Here we have used linear mixed models to investigate the effect of grazing management on stocks of SOC and TN in the top 0.5 m of the soil profile. The study site was a long-term pasture utilization experiment, 26 years after the experiment was established for sheep grazing on native Mitchell grass (Astrebla spp.) pasture in northern Australia. The pasture utilization rates were between 0% (exclosure) and 80%, assessed visually. We found that a significant amount of TN had been lost from the top 0.1 m of the soil profile as a result of grazing, with 80% pasture utilization resulting in a loss of 84 kg ha−1 over the 26-year period. There was no significant effect of pasture utilization rate on TN when greater soil depths were considered. There was no significant effect of pasture utilization rate on stocks of SOC and soil particulate organic carbon (POC), or the C:N ratio at any depth; however, visual trends in the data suggested some agreement with the literature, whereby increased grazing pressure appeared to: (i) decrease SOC and POC stocks; and, (ii) increase the C:N ratio. Overall, the statistical power of the study was limited, and future research would benefit from a more comprehensive sampling scheme. Previous studies at the site have found that a pasture utilization rate of 30% is sustainable for grazing production on Mitchell grass; however, given our results, we conclude that N inputs (possibly through management of native N2-fixing pasture legumes) should be made for long-term maintenance of soil health, and pasture productivity, within this ecosystem.

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A significantly increased water regime can lead to inundation of rivers, creeks and surrounding floodplains- and thus impact on the temporal dynamics of both the extant vegetation and the dormant, but viable soil-seed bank of riparian corridors. The study documented changes in the soil seed-bank along riparian corridors before and after a major flood event in January 2011 in southeast Queensland, Australia. The study site was a major river (the Mooleyember creek) near Roma, Central Queensland impacted by the extreme flood event and where baseline ecological data on riparian seed-bank populations have previously been collected in 2007, 2008 and 2009. After the major flood event, we collected further soil samples from the same locations in spring/summer (November–December 2011) and in early autumn (March 2012). Thereafter, the soils were exposed to adequate warmth and moisture under glasshouse conditions, and emerged seedlings identified taxonomically. Flooding increased seed-bank abundance but decreased its species richness and diversity. However, flood impact was less than that of yearly effect but greater than that of seasonal variation. Seeds of trees and shrubs were few in the soil, and were negatively affected by the flood; those of herbaceous and graminoids were numerous and proliferate after the flood. Seed-banks of weedy and/or exotic species were no more affected by the flood than those of native and/or non-invasive species. Overall, the studied riparian zone showed evidence of a quick recovery of its seed-bank over time, and can be considered to be resilient to an extreme flood event.

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Cat’s claw creeper vine, Dolichandra unguis-cati (L.) L.G.Lohmann (formerly known as Macfadyena unguis-cati (L.) A.H.Gentry), a Weed of National Significance (WoNS), is a structural woody parasite that is highly invasive along sensitive riparian corridors and native forests of coastal and inland eastern Australia. As part of evaluation of the impact of herbicide and mechanical/physical control techniques on the long-term reduction of biomass of the weed and expected return of native flora, we have set-up permanent vegetation plots in: (a) infested and now chemically/physically treated, (b) infested but untreated and (c) un-infested patches. The treatments were set up in both riparian and non-riparian habitats to document changes that occur in seed bank flora over a two-year post-treatment period. Response to treatment varied spatially and temporally. However, following chemical and physical removal treatments, treated patches exhibited lower seed bank abundance and diversity than infested and patches lacking the weed, but differences were not statistically significant. Thus it will be safe to say that spraying herbicides using the recommended rate does not undermine restoration efforts.

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Vegetable cropping systems are often characterised by high inputs of nitrogen fertiliser. Elevated emissions of nitrous oxide (N2O) can be expected as a consequence. In order to mitigate N2O emissions from fertilised agricultural fields, the use of nitrification inhibitors, in combination with ammonium based fertilisers, has been promoted. However, no data is currently available on the use of nitrification inhibitors in sub-tropical vegetable systems. A field experiment was conducted to investigate the effect of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on N2O emissions and yield from broccoli production in sub-tropical Australia. Soil N2O fluxes were monitored continuously (3 h sampling frequency) with fully automated, pneumatically operated measuring chambers linked to a sampling control system and a gas chromatograph. Cumulative N2O emissions over the 5 month observation period amounted to 298 g-N/ha, 324 g-N/ha, 411 g-N/ha and 463 g-N/ha in the conventional fertiliser (CONV), the DMPP treatment (DMPP), the DMMP treatment with a 10% reduced fertiliser rate (DMPP-red) and the zero fertiliser (0N), respectively. The temporal variation of N2O fluxes showed only low emissions over the broccoli cropping phase, but significantly elevated emissions were observed in all treatments following broccoli residues being incorporated into the soil. Overall 70–90% of the total emissions occurred in this 5 weeks fallow phase. There was a significant inhibition effect of DMPP on N2O emissions and soil mineral N content over the broccoli cropping phase where the application of DMPP reduced N2O emissions by 75% compared to the standard practice. However, there was no statistical difference between the treatments during the fallow phase or when the whole season was considered. This study shows that DMPP has the potential to reduce N2O emissions from intensive vegetable systems, but also highlights the importance of post-harvest emissions from incorporated vegetable residues. N2O mitigation strategies in vegetable systems need to target these post-harvest emissions and a better evaluation of the effect of nitrification inhibitors over the fallow phase is needed.