1,720,972 research outputs found
Biophysical, environmental, and economic implications of removing imported supplementary feed from a pasture-based dairy farm system - An upper North Island case study
Get PDFThe biological efficiency and profitability of pasture-based systems is optimised by matching pasture supply with the nutritional demands of the herd across the year. Despite the importance of grazed pasture to the profitability of pasture-based systems, the use of purchased (i.e., non-pasture) feeds (supplementary feeds) has increased considerably over the last two decades within the New Zealand (NZ) dairy industry.
Supplementary feeds may be offered to maintain or increase dry matter intake (DMI) and milk production during periods when pasture supply is insufficient to meet herd demands (i.e., a pasture deficit). However, published results indicate that, despite greater milk production and gross farm revenue (GFR), imported supplementary feed is not associated with an increase in profitability. In addition, the intensification of grazing systems through concurrent increases in stocking rate (SR) have been associated with poorer environmental outcomes, such as reduced water quality and increased greenhouse gas (GHG) emissions.
The primary objective of my Masters project was to investigate the biophysical, economic, and environmental effects of removing imported supplementary feed from a typical pasture-based system in the upper North Island of New Zealand. This was conducted over three years in Northland, New Zealand (35⁰56’39”S 173⁰50’34”E), using a quantitative case-study approach that compared three pasture-based dairy farming treatments differing in SR and the nature of feed supply. As a Control treatment, imported supplementary feed was offered as palm kernel expeller (PKE) during periods of pasture deficit (~ 550kg DM/cow/yr; ~ 10% of the cows’ diet; PKE treatment). This was compared with two alternative systems to remove the need for PKE: 1) reduced SR (Pasture treatment); or, 2) growing potentially high yielding forage crops on the dairy platform and maintaining SR (Cropping treatment). I used the nutrient budgeting software OVERSEER to model treatment effects on nitrogen (N) leaching, phosphorous (P) loss, and GHG emissions. In addition, I conducted a Monte Carlo analysis to investigate economic performance of all three treatments and how it varied over a range of key input prices.
On average, despite no significant difference in milk production, operating profit tended to be lower in the Cropping treatment relative to the PKE treatment. In addition, after accounting for variability in market prices, the Cropping treatment returned a lower operating profit at every probability level relative to the PKE treatment and was, therefore, an inferior system for a profit-focused decision maker.
Milk production and associated GFR were lower in the Pasture treatment compared with the PKE treatment; however, there was no effect of treatment on operating profit at average market prices. When accounting for potential market price variability, the PKE treatment returned a greater operating profit in 70% of scenarios. As a result, the PKE treatment would likely provide a preferable system for a profit-focused decision maker, with low to moderate risk aversion. However, the relative profitability of treatments was highly dependent on the marginal milk production response (MMPR) to supplementary feed. Consistently large MMPRs to supplementary feed were achieved in the current study: 30 to 50% greater than published farm systems experiments. A reduction in the MMPR to supplementary feed by 10% eroded the profit advantage of the PKE treatment. In addition, despite no treatment effect on N leaching, GHG emissions tended to be lower in the Pasture treatment relative to the PKE treatment. As a result, a decision maker, paying or receiving incentives to reduce environmental externalities would likely be indifferent between the PKE and Pasture treatments, even with the large MMPR to supplementary feed achieved in the current study. Depending on the potential response to supplementary feed, profitability may be maintained with the removal of imported supplementary feeds from a pasture based system by decreasing SR
Pro-environmental behaviour change for nature: Empirical and theoretical evidence from a field experiment in Aotearoa New Zealand
Get PDFIndividual behaviour change is a crucial component of our response to current environmental challenges and over recent years, a growing body of literature has focussed on the drivers and levers of pro-environmental behaviours. However, scholars have noted there is a considerable shortage of behavioural science research that focuses on behaviours that directly impact nature and biodiversity. This is concerning, given the enormous value populations place on nature, the fundamental role nature plays in society and because nature is declining rapidly.
In this thesis, we focus on understanding volunteering for nature restoration groups, which we show is an under-researched behaviour in the literature. It also has relatively high potential to deliver positive impacts for biodiversity and nature. We start by developing a simple generalisable theoretical model that suggests three main factors may be inhibiting the uptake of volunteering for nature – uncertainty, inaccuracy and high behavioural adjustment costs. We use this model to inform the design and hypotheses for a large field experiment in Aotearoa New Zealand where we aim to answer the following questions:
How can we increase volunteering for nature restoration groups? What are the effects of volunteering for the first-time on future volunteering behaviour? How does volunteering affect other important outcomes of interest, like environmental identity, locus of control beliefs and wellbeing?
Our field experiment has two stages. In stage one, we randomly assign first-time volunteers (those who are not already engaged in nature volunteering) to treatment groups to assess the impact of a nudge, a supermarket voucher incentive and a nudge and incentive combined on volunteering behaviour. We find that a $50 NZD supermarket incentive increases attendance rates at volunteering events and commitment rates to attend volunteering events. On the other hand, an environmentally and socially motivated nudge in isolation has no effect on volunteering behaviour. However, combining the nudge with the voucher incentive enhances the efficacy of either treatment alone, demonstrating that significant positive synergies exist between nudges and incentives in this context.
In stage two, we show volunteering for the first-time is plausibly randomly assigned, conditional on availability and being offered an incentive. We use this feature to estimate the causal impact of volunteering for the first time on future volunteering behaviour and other outcomes of interest. We find that volunteering for the first time crowds in future volunteering behaviour, generates positive spillovers to other pro-environmental behaviours and strengthens environmental self-identity and locus of control beliefs, which are important pre-cursors to pro-environmental behaviour. Our results show two mechanisms are likely driving these effects. Firstly, volunteering for the first-time provides important information about the benefits of volunteering that are used in future decision-making. Secondly, it strengthens environmental attitudes and identity, which in-turn affect preferences for pro-environmental behaviour. Taken together, our results show that using a financial incentive to help people experiment with volunteering can lead to large positive spillovers and crowding-in effects for future pro-environmental behaviour
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Adoption of in-paddock feeding of methane inhibitors in pasture-based dairy: An application of the ADOPT model and a farm-level cost-effectiveness analysis
Get PDFMethane emissions represent over 40% of New Zealand’s total greenhouse gas emissions. Of these emissions, almost all are biogenic, meaning they come from living organisms such as ruminants. Given that methane has 27-30 times the warming potential of carbon dioxide, reducing methane emissions is an important part of addressing climate change. Many countries are beginning to legislate a reduction of methane emissions in a global effort to reduce the impact of climate change. In New Zealand, where livestock plays a large part in the economy, unique challenges have arisen around reducing biogenic methane emissions. One approach to mitigate methane in the dairy industry is the delivery of methane-inhibiting compounds, which, when added to the diet of ruminants, can reduce their methane emissions significantly. However, these compounds generally require frequent and precise delivery, a characteristic that is difficult to fulfil in New Zealand’s pasture-based sector.
This thesis explores the potential adoption of a novel approach using emergent technology, in-paddock smart-feeders, and how they could deliver methane inhibitor compounds in a New Zealand dairy farming context. The research is conducted in two phases. Firstly, the likely adoption outcomes are assessed, which depends on how in-paddock smart-feeders fit into the range of New Zealand farm systems. In order to evaluate adoption outcomes, the Adoption Diffusion Outcome Prediction Tool (ADOPT) model is utilised in conjunction with a dairy expert consultation and farmer focus groups. After establishing a base case of adoption outcomes, the results are tested with a sensitivity analysis to determine those ADOPT variables impeding increased modelled adoption outcomes. Then, a scenario analysis is conducted to explore different technology performance levels. This chapter finds that the technology is unlikely to become widely adopted unless it is shown to be economically viable. The critical adoption factors are then shown to be trialability, ease and convenience and environmental performance.
The third chapter explores the economic properties of in-paddock smart-feeders by developing a farm-level cost-effectiveness model. This model takes average farm data, introduces the expected costs of the approach and then apportions the associated costs of the quantity of mitigated methane to estimate the breakeven methane price at which the approach becomes viable. The main output of this model is the breakeven methane price, that is, the methane price, where it becomes viable to adopt IPSFs. Similarly to the first chapter, these results hinge on technology performance which is currently relatively uncertain as there is not existing technology to base performance. Therefore the results are explored at length using sensitivity and then scenario analysis. The scenario analysis shows that the breakeven price is most favourable in Northland out of the regions assessed, and the technology was viable only in a best-case scenario.
Ultimately for this novel approach to become economically viable and, therefore, widely adopted by the dairy farmers of New Zealand, the manufacturers of both in-paddock smart-feeders and methane inhibitors will need to make improvements to their products. If these improvements eventuate, a clear path to reducing methane emissions in pasture-based dairy may result
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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