title: Dairy farm system solutions that reduce nitrate leaching and their consequences for profitability: Using plantain, fodder beet and oats on a Canterbury case study farm

authors: Robertson, Charlotte

subjects: nitrate leaching

abstract: Dairy products provide nutrition, energy and income for much of the world. It is currently necessary to continue their supply albeit in a more environmentally sustainable manner. Excess nitrate (NO₃⁻) from dairy cow urine patches can leach from soils with significant consequences for receiving waters. Some potential on-farm management solutions exist, but can be costly to adopt.
The research aim of this thesis was to test prescribed management solutions for reducing NO₃⁻ leaching by 20%, in comparison to an existing farm management baseline for the 2017/2018 dairy season, whilst maintaining profitability. Nitrate leaching and profitability were estimated for a south Canterbury case study dairy farm using the models FARMAX Dairy and OVERSEER® Nutrient Budgets.
Prescribed management practices from the Forages for Reduced Nitrate Leaching (FRNL) programme were modelled to achieve this target. The principles were: (i) reducing nitrogen (N) in cows’ diets through low-N feed (fodder beet), (ii) recapturing N from soils through catch crops (oats) and (iii) diluting urinary N (through ingested plantain). Two crop treatments were applied to the Baseline to address (i) and (ii). Plantain was included in pastures to address (iii). A number of key assumptions were made about plantain’s efficacy for reducing NO₃⁻ leaching. Plantain was not expected to persist in pasture swards without active management and so a persistence curve and maintenance treatments were incorporated. A sensitivity analysis investigated the influence of soil type and poorer persistence of plantain on treatment success.
Most treatments reduced NO₃⁻ leaching, but significant management inputs were required to achieve a 20% reduction from the Baseline. Plantain was identified as the key forage for reducing NO₃⁻ leaching. When plantain was included in pasture swards and undersown every second year to increase its presence, NO₃⁻ leaching could be reduced by 21-24%, however, profitability was reduced by 5-10%. Fodder beet and oats had little impact on NO₃⁻ leaching because the crop area was small in comparison to the rest of the farm (4%). There were no treatments that achieved a 20% reduction in NO₃⁻ leaching and maintained profitability.
The implications of this modelling study for real-life application are that if plantain can be maintained in the pasture sward at high enough levels NO₃⁻ leaching can be substantially reduced, though this would likely result in a loss of profit.

text: Dairy farm system solutions that reduce nitrate leaching and their consequences for profitability: Using plantain, fodder beet and oats on a Canterbury case study farm Dairy products provide nutrition, energy and income for much of the world. It is currently necessary to continue their supply albeit in a more environmentally sustainable manner. Excess nitrate (NO₃⁻) from dairy cow urine patches can leach from soils with significant consequences for receiving waters. Some potential on-farm management solutions exist, but can be costly to adopt.
The research aim of this thesis was to test prescribed management solutions for reducing NO₃⁻ leaching by 20%, in comparison to an existing farm management baseline for the 2017/2018 dairy season, whilst maintaining profitability. Nitrate leaching and profitability were estimated for a south Canterbury case study dairy farm using the models FARMAX Dairy and OVERSEER® Nutrient Budgets.
Prescribed management practices from the Forages for Reduced Nitrate Leaching (FRNL) programme were modelled to achieve this target. The principles were: (i) reducing nitrogen (N) in cows’ diets through low-N feed (fodder beet), (ii) recapturing N from soils through catch crops (oats) and (iii) diluting urinary N (through ingested plantain). Two crop treatments were applied to the Baseline to address (i) and (ii). Plantain was included in pastures to address (iii). A number of key assumptions were made about plantain’s efficacy for reducing NO₃⁻ leaching. Plantain was not expected to persist in pasture swards without active management and so a persistence curve and maintenance treatments were incorporated. A sensitivity analysis investigated the influence of soil type and poorer persistence of plantain on treatment success.
Most treatments reduced NO₃⁻ leaching, but significant management inputs were required to achieve a 20% reduction from the Baseline. Plantain was identified as the key forage for reducing NO₃⁻ leaching. When plantain was included in pasture swards and undersown every second year to increase its presence, NO₃⁻ leaching could be reduced by 21-24%, however, profitability was reduced by 5-10%. Fodder beet and oats had little impact on NO₃⁻ leaching because the crop area was small in comparison to the rest of the farm (4%). There were no treatments that achieved a 20% reduction in NO₃⁻ leaching and maintained profitability.
The implications of this modelling study for real-life application are that if plantain can be maintained in the pasture sward at high enough levels NO₃⁻ leaching can be substantially reduced, though this would likely result in a loss of profit.

year: 2020

title: Ageing, Motion Perception and the Compensation for Eye Movements

authors: Rawley, Kirstyn Michelle

subjects: ageing

abstract: Smooth pursuit over a textured background introduces full-field motion to the retinal image in the direction opposing the eye movement. If this motion is not correctly attributed to the eye movement, it can be falsely perceived as motion in the world (Haarmeier, Thier, Repnow & Petersen, 1997). In order to correctly attribute retinal motion, the visual system must compensate for the effects of eye movements on the retinal image in motion perception. Visual motion perception is important for safely navigating the environment and has been linked to difficulties experienced by older adults while driving (Conlon & Herkes, 2008; Raghuram & Lakshminarayanan, 2006) and walking (Cavanaugh, 2002). The experiments reported in this thesis were devised in order to examine the effects of ageing on the perception of illusory motion during eye movements and therefore on the ability to compensate for eye movements in motion perception. The perception of motion during smooth pursuit eye movements was assessed in adults ranging in age from 17 to 79 years. The computer based task required participants to respond to the speed and direction of motion of a large-field random dot pattern while following a moving target dot with the eyes. For this task, a magnitude estimation tool was especially designed based on the direction response method of Bennett, Sekuler and Sekuler (2007). During the experimental session an eye tracker recorded the participant's eye movements. For the purposes of analysis, four groups were defined by age. It was found that the smooth pursuit of adults from ~40 years of age was slower than that of the younger age groups. With stationary eyes, the oldest age group ranging in age from 60 to 79 years tended to overestimate the speed of the dot pattern as compared to younger observers. This tendency decreased at higher background speeds. Eye movements appeared to affect the perception of the dot field's motion more in the group of participants ranging in age from 40 to 54 years than in the younger age groups. This also seemed to be the case for participants aged over 60 when viewing horizontal motion but not vertical motion. The results of this study suggest that older observers may be less able to compensate for the effects of eye movements on the retinal image. This could potentially affect their ability to safely and confidently navigate the environment.

text: Ageing, Motion Perception and the Compensation for Eye Movements Smooth pursuit over a textured background introduces full-field motion to the retinal image in the direction opposing the eye movement. If this motion is not correctly attributed to the eye movement, it can be falsely perceived as motion in the world (Haarmeier, Thier, Repnow & Petersen, 1997). In order to correctly attribute retinal motion, the visual system must compensate for the effects of eye movements on the retinal image in motion perception. Visual motion perception is important for safely navigating the environment and has been linked to difficulties experienced by older adults while driving (Conlon & Herkes, 2008; Raghuram & Lakshminarayanan, 2006) and walking (Cavanaugh, 2002). The experiments reported in this thesis were devised in order to examine the effects of ageing on the perception of illusory motion during eye movements and therefore on the ability to compensate for eye movements in motion perception. The perception of motion during smooth pursuit eye movements was assessed in adults ranging in age from 17 to 79 years. The computer based task required participants to respond to the speed and direction of motion of a large-field random dot pattern while following a moving target dot with the eyes. For this task, a magnitude estimation tool was especially designed based on the direction response method of Bennett, Sekuler and Sekuler (2007). During the experimental session an eye tracker recorded the participant's eye movements. For the purposes of analysis, four groups were defined by age. It was found that the smooth pursuit of adults from ~40 years of age was slower than that of the younger age groups. With stationary eyes, the oldest age group ranging in age from 60 to 79 years tended to overestimate the speed of the dot pattern as compared to younger observers. This tendency decreased at higher background speeds. Eye movements appeared to affect the perception of the dot field's motion more in the group of participants ranging in age from 40 to 54 years than in the younger age groups. This also seemed to be the case for participants aged over 60 when viewing horizontal motion but not vertical motion. The results of this study suggest that older observers may be less able to compensate for the effects of eye movements on the retinal image. This could potentially affect their ability to safely and confidently navigate the environment.

year: 2010

title: Empowerment evaluation of Te Taiwhenua o Heretaunga Family Start: Improving service delivery

authors: Little, Gaylene Robina

subjects: Family Start

abstract: This thesis explores child maltreatment in New Zealand by considering service delivery of the Family Start programme at Te Taiwhenua o Heretaunga through an empowerment evaluation. The purpose of this research is to evaluate the service delivery process of the Family Start programme at this site to inform the organization and other Family Start key agents of possible improvements to service delivery so that the Family Start programme is best able to reduce the risk factors that are known to influence child maltreatment in New Zealand. The best possible service delivery by kaupapa providers supports sustainability and the continuity of service with Māori through continual funding. The two objectives of this research are to look at how well the Family Start programme is implemented at Te Taiwhenua o Heretaunga and to consider the cultural appropriateness of service delivery. Community psychology is the paradigm within which I position myself. I respect the values of community psychology that aim to improve the position of disadvantaged people through their participation in social change and community development. Te Taiwhenua o Heretaunga is a kaupapa Māori provider and I see an empowerment evaluation as a tool for internal evaluation to assist organizations who value self determination in their own practice. Both quantitative and qualitative data were collected and analyzed. There are two objectives to consider service delivery; firstly process aspects of service delivery are looked at and secondly the cultural relevance of service delivery to the population receiving the Family Start programme at this site. These are described as nine points about service delivery. The aim is to provide an empowerment evaluation for Te Taiwhenua o Heretaunga to inform, assist and improve service delivery of the Family Start programme in a culturally appropriate manner. The findings suggest better understanding is needed by Te Taiwhenua o Heretaunga Family Start staff, about the programme intentions, the use of tools such as Born to Learn/Ahuru Mōwai, individual family plans, service delivery levels, maintaining health records and ways to encourage collaboration between agencies. Te Taiwhenua o Heretaunga are shown in this research to be reaching the intended population for the Family Start programme, and service delivery appears to be culturally relevant to the clients on the programme at this time. The findings are limited by the fact that access to some information was restricted by Te Taiwhenua o Heretaunga Family Start management. Consequently, this research looked only at service delivery, and not the benefits of or barriers to the actual programme. The effectiveness of the programme in reducing child maltreatment is important but could not be measured in this research. Reducing child maltreatment is the main aim of the Family Start programme and would be measured through client outcomes. This research considered service delivery to see if the Family Start programme is offered optimally to assist the aim of reducing child maltreatment.

text: Empowerment evaluation of Te Taiwhenua o Heretaunga Family Start: Improving service delivery This thesis explores child maltreatment in New Zealand by considering service delivery of the Family Start programme at Te Taiwhenua o Heretaunga through an empowerment evaluation. The purpose of this research is to evaluate the service delivery process of the Family Start programme at this site to inform the organization and other Family Start key agents of possible improvements to service delivery so that the Family Start programme is best able to reduce the risk factors that are known to influence child maltreatment in New Zealand. The best possible service delivery by kaupapa providers supports sustainability and the continuity of service with Māori through continual funding. The two objectives of this research are to look at how well the Family Start programme is implemented at Te Taiwhenua o Heretaunga and to consider the cultural appropriateness of service delivery. Community psychology is the paradigm within which I position myself. I respect the values of community psychology that aim to improve the position of disadvantaged people through their participation in social change and community development. Te Taiwhenua o Heretaunga is a kaupapa Māori provider and I see an empowerment evaluation as a tool for internal evaluation to assist organizations who value self determination in their own practice. Both quantitative and qualitative data were collected and analyzed. There are two objectives to consider service delivery; firstly process aspects of service delivery are looked at and secondly the cultural relevance of service delivery to the population receiving the Family Start programme at this site. These are described as nine points about service delivery. The aim is to provide an empowerment evaluation for Te Taiwhenua o Heretaunga to inform, assist and improve service delivery of the Family Start programme in a culturally appropriate manner. The findings suggest better understanding is needed by Te Taiwhenua o Heretaunga Family Start staff, about the programme intentions, the use of tools such as Born to Learn/Ahuru Mōwai, individual family plans, service delivery levels, maintaining health records and ways to encourage collaboration between agencies. Te Taiwhenua o Heretaunga are shown in this research to be reaching the intended population for the Family Start programme, and service delivery appears to be culturally relevant to the clients on the programme at this time. The findings are limited by the fact that access to some information was restricted by Te Taiwhenua o Heretaunga Family Start management. Consequently, this research looked only at service delivery, and not the benefits of or barriers to the actual programme. The effectiveness of the programme in reducing child maltreatment is important but could not be measured in this research. Reducing child maltreatment is the main aim of the Family Start programme and would be measured through client outcomes. This research considered service delivery to see if the Family Start programme is offered optimally to assist the aim of reducing child maltreatment.

year: 2010