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Temporal variation of river water mean transit times and hydrological pathway contributions in Waikato catchments
No full textBayesian chemistry-assisted hydrograph separation (BACH, Woodward and Stenger, 2018) assumes that river hydrographs can be explained by temporally varying flow contributions by three main pathways connecting the land with the monitoring site (very young near-surface water, young shallow groundwater, and old deep groundwater). Temporal variation in pathway contributions should consequently also result in the mean age of the river water varying with flow. It was the aim of this study to ascertain how dynamic flow contributions and tritium-based mean transit times (MTTs) are in a diverse group of 19 Waikato rivers, and whether the MTT dynamics matches the pathway dynamics
Exploring a plausible future of learning for Ōtautahi, Christchurch through multi-stakeholder perspectives
No full textNineteenth-century education models are inappropriately designed to meet the needs of the twenty-first century due to their traditional approaches, which also have an enduring legacy of colonisation. With the rise of technological innovations, changing societal demographics, and the need to address socio-economic challenges, an opportunity exists to explore an alternative future of edcuation. By focusing on Ōtautahi, Christchurch, this exploratory research assessed the feasibility of integrating cities into collaborative campuses through stakeholder engagement. It sought to investigate the potential for providing learning experiences and fostering interdisciplinary skills vital to contemporary challenges. By creating a map of the education stakeholder ecosystem for Ōtautahi, Christchurch, this research identified the barriers and enablers of change for the future of education
Fast, fresh, healthy and halal: A mobile food app recipe for Muslim millennial loyalty
No full textPurpose: The purpose of this study is to apprise mobile loyalty to halal food purchasing, including food quality, mobile quality, perceived value and satisfaction as its causes, and analyze the halal trust and health risk moderating role on the connections between mobile loyalty and its determinants. Design/methodology/approach: A total of 307 responses from millennial Muslims were collected from the Bandung region of Indonesia via an online survey. Partial least squares modeling was applied to review the proposed mobile loyalty model.
Findings: This research found that the mobile loyalty model integrating halal food quality, mobile service quality, perceived value and satisfaction has satisfactory goodness of fit. The research confirms the function of mobile service quality but not halal food quality as drivers of mobile loyalty. Next, this study suggests that halal trust and health risks do not moderate the association between mobile loyalty and its determinants.
Practical implications: This study recommends that managers devote resources to upgrading the quality of their mobile apps to build loyalty. Offering high-quality halal food is also an important driver of millennial Muslim satisfaction.
Originality/value: To the best of the authors’ knowledge, this research is the first to investigate mobile loyalty in halal food
Determining radon equilibrium concentrations from core samples
No full textRadon (Rn-222) is commonly used as a tracer to identify where rivers gain and lose water to groundwater (Cartwright & Hoffman), 2016; Cook et al., 2006). However, it's utility as a quantitative tracer is limited by the need to know the secular equilibrium value for the associated sediments. For practical reasons, an equilibrium value is often estimated from groundwater samples, and the Rn-222 distribution in the sediments is assumed to be homogenous. The aim of this study was to determine if Rn-222 equilibrium values can be estimated via laboratory-based sediment batch immersions. This study looked at four different methods using a Durridge Rad7 to measure radon equilibrium values from alluvial sediments
Identification of plant soil water and soil aeration corequisites: A management tool
No full textPlant-available soil-water and adequate soil aeration within the root zone are essential corequisites for successful plant growth. Characterization of these two requirements for plant growth is generally done by independent measurements of water and air phase properties and functions in soil, with limited emphasis on their combined effect. This study investigated soil-water characteristic (SWC) measurements in vadose soil profiles (up to 117-cm depth) in six pasture soils to examine the combined behavior of soil-water and diffusion-controlled aeration within the root zone. The soil moisture measurements were made over matric potentials ranging from −1 to −1500 kPa using tension table and pressure plate apparatus. The van Genuchten model was used to parameterize the measured SWC curve, while the Millington–Quick model was used to derive soil-gas diffusivity from measured soil physical properties. Based on two simple indices, derived to represent plant-available soil-water and soil aeration status at a given moisture content, we propose an assessment matrix, which illustrates how a soil satisfies the corequisites for successful plant growth, as it drains to different matric potentials upon irrigation. Results show a pronounced effect of soil texture and, to a lesser extent, soil structure on satisfying these corequisites. With the aid of the assessment matrix, we observed that loam, sandy loam textures exhibited a good overall performance, while sand, clay loam, and clay soils struggled to meet these corequisites during drainag
Effect of river management on regional groundwater levels
No full textThe aim of this work is to determine if long-term trends of declining groundwater levels can be explained by the engineering of braided rivers for flood management. A braided river can be considered as a “river system” consisting of surface channels and an intrinsically linked subsurface gravel reservoir, the “braidplain aquifer” (Wilson et al., 2024). This conceptualisation implies that for settings where the river system is hydraulicallydisconnected to the regional aquifer, groundwater recharge is largely governed by braidplain aquifer width. Additionally, for settings where the river system is hydraulically connected to the regional aquifer, river bed levels will have a large control on recharge rates since they
determine the hydraulic gradient. Consequently, the effect of river management on groundwater recharge will depend on the hydraulic setting of the river syste
A diverse diet increases animal growth performance and carcass yield of grazing lambs
No full textThe current experiments were conducted across two lamb finishing seasons (2019 [experiment 1; Exp1] and 2020 [experiment 2; Exp2]). In both experiments lambs were provided a monotonous (MON) diet (annual ryegrass [Lolium multiflorum L.] during 2019 and perennial ryegrass [L. perenne L.] and white clover [Trifolium repens L.] during 2020) or a diverse (DIV) diet composed of spatially separated strips sown to chicory (Chicorium intybus L.), plantain (Plantago lanceolata L.), perennial ryegrass, lucerne (Medicago sativa L.), and dock (Rumex obtusifolius). During Exp1, the DIV lambs had a stocking rate (SR) of either 80, 95, 100, or 110 m²/lamb/wk, whereas the MON lambs had a 100m²/lamb/wk SR. In Exp2, the SR aimed to allocate the MON lambs with twice the forage allowance (kg DM/lamb/d) as DIV lambs. In Exp1, all lambs provided DIV had a greater (P < 0.01) average daily gain (ADG; + 130%) than MON rams, independent of the SR. Accordingly, DIV had greater (P < 0.05) hot carcass weight (HCW; + 26%) and aged carcass weight (CW; + 27%) compared with MON, across all SR. The 80 m²/lamb/wk SR tended to have a greater (P = 0.10) dressing percentage and had similar (P = 0.29) drip loss percentage to the MON lambs, while the other DIV lamb SR all had greater (P < 0.05; +12%) dressing percentages and lower (P < 0.05) drip loss percentage than MON lambs. In Exp2, DIV lambs had greater (P < 0.01) ADG (+37%), HCW (+15%), and dressing percentage (+6%) compared with MON lambs. This improved animal performance occurred despite being offered 57% less (P = 0.01) dry matter (DM), 56% less (P < 0.01) digestible DM, and 57% less (P = 0.02) metabolizable energy per lamb per day. Ultimately, these experiments demonstrate that providing growing lambs a functionally diverse diet improves animal growth performance and carcass weight compared with a monotonous diet of annual ryegrass or a mixed sward containing perennial ryegrass with white clover. LAY SUMMARY Recent research has demonstrated that offering dietary diversity to growing lambs may improve well-being and growth performance relative to monotonous diets that are traditionally fed. Two experiments were conducted over 2 yr to determine the growth-promoting benefits of offering a diverse diet composed of spatially separated sown strips of perennial ryegrass, plantain, chicory, broad-leaf dock, and alfalfa compared with monotonous diets of Italian ryegrass (experiment 1, Exp1) or perennial ryegrass with white clover (experiment 2, Exp2). In Exp1 the monotonous treatment group were stocked at a rate of 100 m²/lamb/wk, while the diverse fed lambs were stocked at either 80, 95, 100, or 110 m²/lamb/wk. In Exp2, the lambs were stocked at 122.5 m²/lamb/wk in the monotonous treatment, while the diverse lambs were stocked at 74.3 m²/lamb/wk, on average. Lambs offered diverse swards in the 80m²/lamb/wk group in Exp1 and the lambs offered diverse swards in Exp2 were allocated much less area, dry matter, crude protein, and metabolizable energy than the lambs offered monotonous swards, yet still had 34% or greater average daily gain and 13% or greater hot carcass weight. These results suggest that lambs will grow at appreciably faster rates when offered functionally diverse swards, resulting in greater saleable carcass weight compared with lambs offered monotonous swards of Italian ryegrass or Perennial ryegrass with white clover
A review of pasture mixes and management strategies to reduce the impact of facial eczema in New Zealand
No full textIn New Zealand, facial eczema (FE) is a serious health and welfare issue for grazing ruminants caused by ingesting toxic spores of the fungus Pseudopithomyces chartarum. A literature review of research about the effect of pasture plant species, farm management practices and associated environmental factors on FE in New Zealand, was undertaken. An important outcome of this research has been the development of spore count techniques used on-farm to monitor P. chartarum during the summer/autumn risk period. Other research outcomes include: Reduce pasture litter (decaying herbage) by hard spring grazing, with minimal topping, and use pasture species that reduce litter. Avoid hard grazing during the riskiest autumn period. Minimise grazing of perennial ryegrass dominant pastures by increasing legume content or use the less risky species such as tall fescue. Utilise specialist (non-ryegrass) legume and herb-based pastures that provide less litter, are grazed to higher residuals, and provide high-quality feed.Future FE research should focus on the incorporation of ‘high-quality’ FE-safe species, such as tall fescue, legumes and herbs, into existing farming systems. They can enhance feed supply during the summer/autumn FE risk period but require appropriate management guidelines to maximise production and persistence
Soil pore network effects on the fate of nitrous oxide as influenced by soil compaction, depth and water potential
No full textSoil physical properties may determine the fate of nitrous oxide (N₂O) in soil, but little is known about how soil compaction affects specific properties and their interactions. This study aimed to assess the impact of compaction on the soil pore functionality and architecture, and the effects on N₂O diffusion. Intact soil cores were sampled from lysimeters previously subjected to induced topsoil or subsoil compaction, as well as from uncompacted lysimeters. The soil cores were drained, sequentially, to −30, −50, and −100 h Pa to examine gas phase characteristics, each time followed by N₂O diffusion measurements after injecting N₂O at the bottom of the soil cores to simulate hotspots. Pore architecture was determined with X-ray microtomography. Results showed that soil compaction decreased pore volume, gas flow (convection and diffusion), and pore connectivity, and increased water-filled pore space, isolated pore ratios, and solid-to-pore distance, with a concomitant effect on N₂O diffusion. Changes in soil matric water potential did not influence the N₂O diffusion ratio (N₂O in the headspace/N₂O injected into the reservoir). The algorithmic evaluation of interacting effects revealed that pore connectivity was the best predictor for N₂O diffusion. In hierarchical order, the N₂O diffusion ratio could be explained by air permeability, pore connectivity and relative gas diffusivity. Multivariate analysis of functional and architectural pore characteristic parameters provided a comprehensive selection of factors driving N₂O diffusion within the soil layers. This is essential to understand the contribution of N₂Oproduced in agricultural soil to atmospheric emissions under climate change scenario
Using portfolio analysis to assess diverse agricultural landscapes under climate change: A case study in the Marlborough wine region : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
No full textFarmers and growers are increasingly aware of climate change related risks for their operations as they observe a greater frequency in extreme weather events and changes in crop growth cycles. While reactive adaptation by farmers to climatic variability has always occurred, this may not be sufficient in the long term when anticipatory and planned adaptation is required, e.g., changes in cultivar or the development of new markets. Geographical and biological diversification of agricultural production systems has been proposed as a potential climate change adaptation strategy. Understanding how alternative crops, land-uses and management practices will perform under future climates and deliver to stakeholder goals is critical before extensive land-use and practice change occurs. Developing this understanding is difficult due to the high degree of uncertainty of future climatic conditions and the ability of commonly applied economic analysis tools to account for this deep uncertainty. To address these challenges, this PhD developed a stakeholder centred climate change adaptation process that utilises Portfolio Analysis to identify diversified vineyard portfolios and characterised their riskiness across a range of climate change scenarios. In developing this process, the study applied a mixed methods framework, integrating qualitative and quantitative approaches. These included a literature review, stakeholder mapping, focus groups, biophysical assessment and economic modelling, integrated in a case study on Marlborough Sauvignon Blanc.The research found that Portfolio Analysis can be effectively integrated with social and biophysical science to develop diversified vineyard portfolios that are more robust against a range of possible climate futures, helping to inform decision making in the context of deep uncertainty. To accelerate adoption, adaptation needs to be integrated into wider wine business and industry decision making and strategy development. Recognising that adaptation sits alongside existing ambitions and priorities, particularly around environmental sustainability, is also critical