title: Farmer participation and irrigation performance: A case study of Nam Thach Han irrigation system, Vietnam

authors: Tran, Hanh Loi

subjects: Participation

abstract: This thesis assesses the determinants of farmer participation in irrigation management and the impact of participation on irrigation quality and agricultural production in the Nam Thach Han irrigation system, Vietnam. Many governments have attempted to increase farmer participation in irrigation system management through participatory irrigation management (PIM). This approach aims to reduce government financial burdens, improve the quality of irrigation management, and in turn, enhance agricultural production. However, the results of PIM have been mixed and the factors affecting its success or failure remain a topic of much debate. 
Using survey data from 391 households of 11 agricultural cooperatives (ACs) in the Nam Thach Han irrigation system,  this study examines (i) the factors that influence farmer participation, (ii) the impact of collective action on irrigation quality (sufficiency and timeliness), and (iii) the impact of irrigation quality on rice farming technical efficiency, while controlling for environmental factors. 
Four main findings emerge from this thesis. We find that (i) institutional factors at the AC level such as inclusion in the PIM project, information transparency and democratic decision-making have a positive impact on participation, but sharing second-level canals between ACs reduces participation; (ii) higher participation rates are associated with a higher probability of receiving sufficient and timely irrigation; (iii) plots and households receiving sufficient water are more likely to attain higher levels of technical efficiency and; (iv) use of household-level data can provide approximately unbiased estimates of technical efficiency provided environmental factors are controlled for.
This thesis provides several contributions to the literature. Participative approaches have been widely adopted in Vietnam but this is the first empirical study to use econometric models to examine the determinants of participation and the effect of collective action on irrigation quality. This is achieved using an improved set of participation indices, constructed using principal component analysis. This thesis also provides the first analysis of the effect of sufficient and timely irrigation on rice farming technical efficiency while controlling for plot-specific environmental factors.

text: Farmer participation and irrigation performance: A case study of Nam Thach Han irrigation system, Vietnam This thesis assesses the determinants of farmer participation in irrigation management and the impact of participation on irrigation quality and agricultural production in the Nam Thach Han irrigation system, Vietnam. Many governments have attempted to increase farmer participation in irrigation system management through participatory irrigation management (PIM). This approach aims to reduce government financial burdens, improve the quality of irrigation management, and in turn, enhance agricultural production. However, the results of PIM have been mixed and the factors affecting its success or failure remain a topic of much debate. 
Using survey data from 391 households of 11 agricultural cooperatives (ACs) in the Nam Thach Han irrigation system,  this study examines (i) the factors that influence farmer participation, (ii) the impact of collective action on irrigation quality (sufficiency and timeliness), and (iii) the impact of irrigation quality on rice farming technical efficiency, while controlling for environmental factors. 
Four main findings emerge from this thesis. We find that (i) institutional factors at the AC level such as inclusion in the PIM project, information transparency and democratic decision-making have a positive impact on participation, but sharing second-level canals between ACs reduces participation; (ii) higher participation rates are associated with a higher probability of receiving sufficient and timely irrigation; (iii) plots and households receiving sufficient water are more likely to attain higher levels of technical efficiency and; (iv) use of household-level data can provide approximately unbiased estimates of technical efficiency provided environmental factors are controlled for.
This thesis provides several contributions to the literature. Participative approaches have been widely adopted in Vietnam but this is the first empirical study to use econometric models to examine the determinants of participation and the effect of collective action on irrigation quality. This is achieved using an improved set of participation indices, constructed using principal component analysis. This thesis also provides the first analysis of the effect of sufficient and timely irrigation on rice farming technical efficiency while controlling for plot-specific environmental factors.

year: 2020

title: Automated aerial seed planting using biodegradable polymers

authors: Cozens, Wade

subjects: Biodegradable

abstract: The purpose of the thesis was to undertake a preliminary product design to assess the feasibility of using drone technology to aid reforestation for automated seed planting. This product would be able to increase productivity and reduce labour costs, especially when applied in difficult to reach terrains around New Zealand. Ultimately, the final product would be a weaponised drone or a swarm of drones that can fire plastic seed capsules into soil to a specific depth to prevent predation and ensure optimal germination conditions. The proof of concept hinges on the success of three objectives: Assessing and controlling the capsule’s biodegradability in soil. A method of mass manufacturing projectile seed capsules that can be delivered at high velocity and the ability of it to be fired into soil to a specific depth to ensure safe germination.  

Novatein was blended with poly(butylene adipate terephthalate) (PBAT) to aid sheet extrusion and improve water resistance. Biodegradability was tested by measuring the ability of bacteria and fungi to metabolise the polymer blends into CO2 by enclosing samples in soil at 25 °C. PBAT showed very little biodegradation under these conditions, where approximately 3 % of the theoretical carbon content of the sample was converted to CO2. Novatein reached 20 %, and the blends were intermediate, based on the amount of PBAT present. It was concluded that PBAT can effectively control the rate and extent of biodegradation in blends with Novatein. 

A method for mass manufacturing seed capsules was evaluated by compression moulding spheres to test mouldability and manufacturing lap welded samples to quantify weld strength. Blends of Novatein and PBAT were successfully moulded and welded above the glass transition temperature of the material; optimal parameters were 105 °C with a three minute hold time. Lap welds were tested by varying the compression force and sheet thickness and thereby reducing the weld times to approximately eight seconds. Welded samples were tested for tensile and peel strength, where 0.68 mm thick sheets, welded at 750 N compression force, yielded the highest tensile strength (88 % that of an un-welded samples). Thicker sheets (1.52 mm) welded at 900 N compression force, resulted in the highest peel force. Producing capsules capable of penetrating soil would benefit from thicker sheets using sufficient pressure to prevent peeling at the seam. 

Finally, seed capsule delivery was assessed using empirical modelling in combination with controlled soil conditions. Models created by Young and Lorenz used a dynamic cone penetrometer (DCP) to measure the soil’s penetration resistance to predict the penetration depth of a known projectile. These models were developed for considerably heavier projectiles (> 2.2 kg) and penetration depths much greater than considered here. Considering the DCP measures the soils resistance to penetration at a depth of one meter, a comparison to a 10th scale model was investigated. Contrary to expected, the standard DCP predicted the penetration depth of high velocity projectiles to a reasonably accuracy (~20 %) using two different types of homogenous sand, tested at three moisture contents. The scaled model failed to account for soil types, which was shown to have significant influence during high velocity testing. The work here highlighted the importance of considering realistic forestry soil, despite the accuracy of the prediction in homogenous sand.

Although an integrated product has not been developed, this project has shown that a strategy exists for controlling the rate of biodegradation of Novatein/PBAT. A plausible method for mass manufacturing seed capsules was demonstrated using compression moulding of Novatein blends. Penetration depth was predicted accurately for homogenous soil, this requires further research into applying the model to realistic top soil conditions. The final stage of the larger project is to integrate a firing mechanism with a drone for automated delivery of seed capsules produced from vacuum forming.

text: Automated aerial seed planting using biodegradable polymers The purpose of the thesis was to undertake a preliminary product design to assess the feasibility of using drone technology to aid reforestation for automated seed planting. This product would be able to increase productivity and reduce labour costs, especially when applied in difficult to reach terrains around New Zealand. Ultimately, the final product would be a weaponised drone or a swarm of drones that can fire plastic seed capsules into soil to a specific depth to prevent predation and ensure optimal germination conditions. The proof of concept hinges on the success of three objectives: Assessing and controlling the capsule’s biodegradability in soil. A method of mass manufacturing projectile seed capsules that can be delivered at high velocity and the ability of it to be fired into soil to a specific depth to ensure safe germination.  

Novatein was blended with poly(butylene adipate terephthalate) (PBAT) to aid sheet extrusion and improve water resistance. Biodegradability was tested by measuring the ability of bacteria and fungi to metabolise the polymer blends into CO2 by enclosing samples in soil at 25 °C. PBAT showed very little biodegradation under these conditions, where approximately 3 % of the theoretical carbon content of the sample was converted to CO2. Novatein reached 20 %, and the blends were intermediate, based on the amount of PBAT present. It was concluded that PBAT can effectively control the rate and extent of biodegradation in blends with Novatein. 

A method for mass manufacturing seed capsules was evaluated by compression moulding spheres to test mouldability and manufacturing lap welded samples to quantify weld strength. Blends of Novatein and PBAT were successfully moulded and welded above the glass transition temperature of the material; optimal parameters were 105 °C with a three minute hold time. Lap welds were tested by varying the compression force and sheet thickness and thereby reducing the weld times to approximately eight seconds. Welded samples were tested for tensile and peel strength, where 0.68 mm thick sheets, welded at 750 N compression force, yielded the highest tensile strength (88 % that of an un-welded samples). Thicker sheets (1.52 mm) welded at 900 N compression force, resulted in the highest peel force. Producing capsules capable of penetrating soil would benefit from thicker sheets using sufficient pressure to prevent peeling at the seam. 

Finally, seed capsule delivery was assessed using empirical modelling in combination with controlled soil conditions. Models created by Young and Lorenz used a dynamic cone penetrometer (DCP) to measure the soil’s penetration resistance to predict the penetration depth of a known projectile. These models were developed for considerably heavier projectiles (> 2.2 kg) and penetration depths much greater than considered here. Considering the DCP measures the soils resistance to penetration at a depth of one meter, a comparison to a 10th scale model was investigated. Contrary to expected, the standard DCP predicted the penetration depth of high velocity projectiles to a reasonably accuracy (~20 %) using two different types of homogenous sand, tested at three moisture contents. The scaled model failed to account for soil types, which was shown to have significant influence during high velocity testing. The work here highlighted the importance of considering realistic forestry soil, despite the accuracy of the prediction in homogenous sand.

Although an integrated product has not been developed, this project has shown that a strategy exists for controlling the rate of biodegradation of Novatein/PBAT. A plausible method for mass manufacturing seed capsules was demonstrated using compression moulding of Novatein blends. Penetration depth was predicted accurately for homogenous soil, this requires further research into applying the model to realistic top soil conditions. The final stage of the larger project is to integrate a firing mechanism with a drone for automated delivery of seed capsules produced from vacuum forming.

year: 2019

title: 'Making its own history': New Zealand historical fiction for children,1862-2008

authors: Clark, Louise Henriette

subjects: children's literature

abstract: This thesis considers historical fiction for children and young people dealing with New Zealand history from the arrival of the first Polynesian settlers to the end of the nineteenth century.  It provides both a comprehensive survey of historical novels published between 1862 and the end of 2008, and an analysis of the way the same historical events and periods have been depicted in historical novels written at different times.  Individual chapters discuss books set during specific historical periods or dealing with particular events - the pre-European period, early contact, nineteenth century immigration, the New Zealand Wars, the gold rushes, and the colonial period - in chronological order of publication.  Since children's literature is particularly adept at reflecting and promoting the dominant ideas of the society in which it is produced, the chronological consideration of these texts reveals contemporary attitudes to such issues as race relations, gender roles, class, war and conflict, and concepts of national identity, as well as the way historical fiction has responded to societal changes since the 1860s.  

The predominant themes of historical fiction set prior to 1900 are: the arrival of settlers in New Zealand; encounters with the country's indigenous inhabitants; the taming of the often hostile landscape; the assertion of the settlers' claims to 'belong' in their new land; and the establishment of New Zealand as a nation with distinctive characteristics.  There are perceptible nuances and differences in the way these themes are discussed depending on the historical moment in which individual authors are writing.  Novels of the Victorian period and early twentieth century reflect the imperialistic and evangelistic ethos of the time, and present the British settlers' right to colonize the land and the ensuing dispossession of Māori as largely unproblematic.  Subsequent historical novels, particularly those written since the 1960s, offer a more inclusive version of New Zealand history, although the lack of historical fiction for children by Māori writers means that Eurocentric views of history continue to dominate, and that all representations of Māori and their history are mediated through Pakeha writers.

Shifts in social attitudes have resulted in changes in the treatment of Māori in historical novels for children, and similar changes have occurred in the portrayal of gender, class, and ethnicity.  The passage of time has seen increased agency and a wider variety of roles allocated to Māori, female and working class characters, as well as greater ethnic diversity.  Developments in New Zealand historiography are also reflected in fiction, although at times historical fiction prefigures written histories, or provides alternative views by depicting the experience of women, children and Māori, who often did not feature in conventional histories.  While many historical novels for children, especially the earlier texts, are adventure stories set in the past and are not necessarily concerned with historical verisimilitude, an increasing number attempt to present authentic recreations of historical periods, including accounts of actual people and events, based on extensive research, and reinforced with peritextual material in the form of historical notes, bibliographies, maps and photographs.  

The role of New Zealand historical fiction for children and young people has been not only to entertain young readers and inform them about their country's past, but to create and foster a sense of national identity.

text: 'Making its own history': New Zealand historical fiction for children,1862-2008 This thesis considers historical fiction for children and young people dealing with New Zealand history from the arrival of the first Polynesian settlers to the end of the nineteenth century.  It provides both a comprehensive survey of historical novels published between 1862 and the end of 2008, and an analysis of the way the same historical events and periods have been depicted in historical novels written at different times.  Individual chapters discuss books set during specific historical periods or dealing with particular events - the pre-European period, early contact, nineteenth century immigration, the New Zealand Wars, the gold rushes, and the colonial period - in chronological order of publication.  Since children's literature is particularly adept at reflecting and promoting the dominant ideas of the society in which it is produced, the chronological consideration of these texts reveals contemporary attitudes to such issues as race relations, gender roles, class, war and conflict, and concepts of national identity, as well as the way historical fiction has responded to societal changes since the 1860s.  

The predominant themes of historical fiction set prior to 1900 are: the arrival of settlers in New Zealand; encounters with the country's indigenous inhabitants; the taming of the often hostile landscape; the assertion of the settlers' claims to 'belong' in their new land; and the establishment of New Zealand as a nation with distinctive characteristics.  There are perceptible nuances and differences in the way these themes are discussed depending on the historical moment in which individual authors are writing.  Novels of the Victorian period and early twentieth century reflect the imperialistic and evangelistic ethos of the time, and present the British settlers' right to colonize the land and the ensuing dispossession of Māori as largely unproblematic.  Subsequent historical novels, particularly those written since the 1960s, offer a more inclusive version of New Zealand history, although the lack of historical fiction for children by Māori writers means that Eurocentric views of history continue to dominate, and that all representations of Māori and their history are mediated through Pakeha writers.

Shifts in social attitudes have resulted in changes in the treatment of Māori in historical novels for children, and similar changes have occurred in the portrayal of gender, class, and ethnicity.  The passage of time has seen increased agency and a wider variety of roles allocated to Māori, female and working class characters, as well as greater ethnic diversity.  Developments in New Zealand historiography are also reflected in fiction, although at times historical fiction prefigures written histories, or provides alternative views by depicting the experience of women, children and Māori, who often did not feature in conventional histories.  While many historical novels for children, especially the earlier texts, are adventure stories set in the past and are not necessarily concerned with historical verisimilitude, an increasing number attempt to present authentic recreations of historical periods, including accounts of actual people and events, based on extensive research, and reinforced with peritextual material in the form of historical notes, bibliographies, maps and photographs.  

The role of New Zealand historical fiction for children and young people has been not only to entertain young readers and inform them about their country's past, but to create and foster a sense of national identity.

year: 2010