https://hdl.handle.net/10182/9 2018-01-21T10:33:24Z https://hdl.handle.net/10182/8851 An investigation of relationship quality and supplier performance in New Zealand red meat supply chains Lees, Nicholas Julian Supplier relationships and performance have become increasingly important in agri-food supply chains. This research aimed to investigate buyer-supplier relationships in the New Zealand red meat industry. Specifically, this meant examining how relationship quality, as well as supplier characteristics and relationship attributes affect supplier performance. The analysis improved the conceptualisation of relationship quality by bringing together constructs from the relationship marketing and social capital literature. This established that relationship quality and social capital were closely related constructs. By combining social capital and relationship quality this created a broader measure of the overall strength of the relationship. The findings show that improving supplier performance requires taking into account both supplier characteristics and relationship attributes. Furthermore, relationship quality played a significant mediating role between all the relationship factors and supplier performance. The implications of this research are that there are specific ways buyers can improve supplier performance. This involves identifying and selecting suppliers who have superior ability, motivation and customer focus. They also need to avoid selecting suppliers with high levels of self-direction. Improving supplier performance also involves influencing relationship attributes and improving the quality of relationships with suppliers. In particular, processors need to ensure that suppliers experience positive value from the supply relationship. Furthermore, they need to manage the interaction between specific assets, dependence and use of coercive power. 2017-12-15T00:00:00Z https://hdl.handle.net/10182/8789 Carbonaceous soil amendments to reduce plant uptake of Cd in NZ’s agricultural systems Mamun, Shamim Al Cadmium (Cd) is a non‐essential trace element that accumulates in agricultural soils through the application of Cd-rich phosphate fertiliser and industrial activity. Plants can accumulate Cd to concentrations that sometimes exceed food safety standards presenting a human health risk. Cadmium is readily taken up by plants and can be transferred to grazing animals. In many agricultural systems, Cd concentrations in leafy vegetables and the offal products of grazing animals are at or above food safety standards. There is no practical means of removing Cd from contaminated agricultural soils. Various soil amendments have been used to reduce plant Cd-uptake, but these have mostly focused on heavily contaminated soils and mine tailings. This work aimed to determine whether low cost carbonaceous amendments could effectively reduce Cd uptake by crop plants in agricultural soils with moderate levels of Cd contamination. We used two contrasting market garden soils (a silt loam and a brown granular allophanic soil) for these experiments, where Cd concentrations in selected vegetables were occasionally above food safety standards (0.1 mg/kg fresh weight). Batch sorption experiments were used to determine the ability of the soils and potential soil amendments to bind Cd from a solution of 0.05M Ca(NO3)2. The sorption experiments revealed that composts and lignite bound an order of magnitude more Cd than soils and other potential soil amendments. For all materials, sorption increased with increasing pH of the ambient solution up to a pH of 7.5. Pot trials were used to determine the effect of various composts, lignite and lime on the uptake of Cd by spinach (Spinacia oleracea L.), lettuce (Lactuca sativa L.), onion (Allium cepa L.) and potato (Solanum tuberosum L.). All composts, added at a rate of 2.5% or 5% (w/w) reduced plant Cd uptake by up to 60%. The composts did not induce a deficiency in the uptake of plant nutrients, including essential trace elements such as zinc, and copper. Composts invariably increased plant biomass. An incubation experiment, including treatments with increased temperature and nitrogen as well as regular disturbance, was used to determine the likely longevity of the Cd-immobilising properties of the composts. After one year of incubation, there was no significant release of Cd from the compost-amended soils, despite a significant reduction in soil carbon. A pot trial using incubated soil also revealed that the beneficial effects of compost for reducing plant Cd uptake persisted for at least one year. The results indicated that mechanical disturbance of the soil may have resulted in the dissolution / suspension of iron moieties that subsequently occluded Cd on the surfaces of soil colloids. Lignite generally reduced plant biomass and its effect on plant Cd-uptake was variable. In some cases, lignite caused a significant increase in plant Cd uptake. This was attributed to acidification, probably caused by oxidation of sulphide compounds in the lignite. Potentially, lignite-lime mixtures may be effective, however, the costs of lignite are significantly greater than composts. Using lime to increase the soil pH from 6.0 to 6.5 generally reduced the Cd concentration in soil solution and in vegetables. However, this effect was not consistent, with some treatments causing an increase in plant uptake. Moreover, liming significantly reduced the uptake of essential micronutrients, especially zinc, which offsets its usefulness as a tool to reduce Cd uptake. I conclude that biological wastes, especially composts, are an underutilised resource that can not only reduce plant Cd-uptake but also improve plant production. Future research should include field trials to determine the performance of Cd in field conditions as well as agronomic practicalities. 2017-03-06T00:00:00Z https://hdl.handle.net/10182/8780 Evaluation of drought tolerance in genetically modified Lolium perenne L. and Arabidopsis thaliana Cyriac, Daliya Ubiquitin like proteins (UBLs) are known to have different functions including a potential role in drought tolerance of perennial ryegrass (Lolium perenne L.). UBLs are related in tertiary structure to ubiquitin (UB) and they both serve as regulators of many cellular processes. In previous work over-expression of one UBL, the Lolium perenne L. Ubl5 (LpUbl5) homologue in perennial ryegrass resulted in plants with enhanced drought tolerance. Other studies in the nematode Caenorhabditis elegans have associated Ubl5 with a mitochondrial unfolded protein response (UPRmt), and studies in yeast and human cells suggest a role in alternative splicing for Ubl5. This PhD study aimed to characterize the LpUbl5 gene in the context of its potential role in drought tolerance using LpUbl5-overexpressing perennial ryegrass. The study extended to include Arabidopsis thaliana transformed using LpUbl5 to support the findings. Subsequently subcellular localization of LpUBL5 protein was investigated to identify its potential role in alternative splicing. The study also screened different perennial ryegrass accessions from diverse backgrounds to identify germplasm with potential tolerance under drought stress. The results rejected any role of the LpUbl5 gene in drought tolerance of perennial ryegrass and A. thaliana. A potential seed lethal phenotype was observed in Ubl5 mutants of A. thaliana. The study found co-localization of the LpUBL5 protein into the cytoplasm and nucleus of Nicotiana benthamiana (tobacco) leaves and Allium cepa L. (onion) cells. This supports its potential role in alternative splicing. Importantly, the study also identified a germplasm accession of Lolium perenne L. from Norway with increased drought tolerance in a controlled environment. The results generated from the LpUbl5 overexpressing perennial ryegrass lines emphasize the need to integrate critical evaluation of plant lines in their developmental stages especially in out crossing species. Lack of physiological evidence rejected the potential role of LpUbl5 in drought tolerance. However, the localization of LpUBL5 indicates its functional significance as UBL5 homologues from vertebrates, yeasts and plants and exhibits high levels of protein sequence conservation. It is conceivable that UBL5 homologues possess similar functions across species. The indications of a potential seed-lethal phenotype of mutants is consistent with findings in humans, yeast and C.elegans. Future research is recommended to explore and confirm the potential seed lethal phenotype of Ubl5 mutation in plants using Arabidopsis. This may identify the phenotype characters of Ubl5 in plants. Since cultivar development is an integral part of pasture development, the genetic diversity of Norwegian accession provides a candidate to develop perennial ryegrass plants with enhanced drought tolerance. 2017-07-11T00:00:00Z https://hdl.handle.net/10182/8776 Lessons learned from liquefaction of the Canterbury Earthquake Sequence (2010-2011) to inform paleoliquefaction studies Giona Bucci, Monica Liquefaction affects late Holocene, loose packed and water saturated sediment subjected to cyclical shear stress. Liquefaction features in the geological record are important off-fault markers that inform about the occurrence of moderate to large earthquakes (> 5 Mw). The study of contemporary liquefaction features provides a better understanding of where to find past (paleo) liquefaction features, which, if identified and dated, can provide information on the occurrence, magnitude and timing of past earthquakes. This is particularly important in areas with blind active faults. The extensive liquefaction caused by the 2010-2011 Canterbury Earthquake Sequence (CES) gave the geoscience community the opportunity to study the liquefaction process in different settings (alluvial, coastal and estuarine), investigating different aspects (e.g. geospatial correlation with landforms, thresholds for peak ground acceleration, resilience of infrastructures), and to collect a wealth geospatial dataset in the broad region of the Canterbury Plains. The research presented in this dissertation examines the sedimentary architecture of two environments, the alluvial and coastal settings, affected by liquefaction during the CES. The novel aim of this study is to investigate how landform and subsurface sedimentary architecture influence liquefaction and its surface manifestation, to provide knowledge for locating studies of paleoliquefaction in future. Two study cases documented in the alluvial setting showed that liquefaction features affected a crevasse splay and point bar ridges. However, the liquefaction source layer was linked to paleochannel floor deposits below the crevasse splay in the first case, and to the point bar deposits themselves in the second case. This research documents liquefaction features in the coastal dune system of the Canterbury Plains in detail for the first time. In the coastal dune setting the liquefiable layer is near the surface. The pore water pressure is vented easily because the coastal dune soil profile is entirely composed of non-cohesive, very well sorted sandy sediment that weakly resists disturbance from fluidised sediment under pressure. As a consequence, the liquefied flow does not need to find a specific crack through which the sediment is vented at the surface; instead, the liquefied sand finds many closely spaced conduits to vent its excess of pore water pressure. Therefore, in the coastal dune setting it is rare to observe discrete dikes (as they are defined in the alluvial setting), instead A horizon delamination (splitting) and blistering (near surface sills) are more common. The differences in styles of surface venting lead to contrasts in patterns of ejecta in the two environments. Whereas the alluvial environment is characterised by coalesced sand blows forming lineations, the coastal dune environment hosts apparently randomly distributed isolated sand blows often associated with collapse features. Amongst the techniques tested for the first time to investigate liquefaction features are: 3D GPR, which improved the accuracy of the trenching even six years after the liquefaction events; thin section analysis to investigate sediment fabric, which helped to discriminate liquefied sediment from its host sediment, and modern from paleoliquefaction features; a Random Forest classification based on the CES liquefaction map, which was used to test relationships between surface manifestation of liquefaction and topographic parameters. The results from this research will be used to target new study sites for future paleoliquefaction research and thus will improve the earthquake hazard assessment across New Zealand. 2017-04-13T00:00:00Z