title: Multiple small monthly doses of dicyandiamide (DCD) did not reduce denitrification in Waikato dairy pasture

authors: Watkins, Natalie Lisa

subjects: denitrification

abstract: The effectiveness of multiple small doses of the nitrification inhibitor dicyandiamide (DCD) to decrease denitrification under warm moist conditions was tested in a 1-year field trial on a grazed dairy pasture. DCD was applied approximately every 4 weeks as an aqueous spray onto ten replicate plots 3 days after rotational grazing by dairy cows. Each application was at the rate of 3 kg DCD ha⁻¹, with a total annual application of 33 kg ha⁻¹. Denitrification was assessed 5 days after each DCD application using the acetylene block method. At the end of the trial, the rate of degradation of DCD under summer conditions was measured. DCD significantly decreased the mean annual nitrate concentration by about 17%. Denitrification and denitrification enzyme activity were highly variable and no significant effect of DCD in decreasing denitrification was detected. In the summer month of December, DCD degraded rapidly with an estimated half-life of 5 ± 3 days (mean and standard deviation).

text: Multiple small monthly doses of dicyandiamide (DCD) did not reduce denitrification in Waikato dairy pasture The effectiveness of multiple small doses of the nitrification inhibitor dicyandiamide (DCD) to decrease denitrification under warm moist conditions was tested in a 1-year field trial on a grazed dairy pasture. DCD was applied approximately every 4 weeks as an aqueous spray onto ten replicate plots 3 days after rotational grazing by dairy cows. Each application was at the rate of 3 kg DCD ha⁻¹, with a total annual application of 33 kg ha⁻¹. Denitrification was assessed 5 days after each DCD application using the acetylene block method. At the end of the trial, the rate of degradation of DCD under summer conditions was measured. DCD significantly decreased the mean annual nitrate concentration by about 17%. Denitrification and denitrification enzyme activity were highly variable and no significant effect of DCD in decreasing denitrification was detected. In the summer month of December, DCD degraded rapidly with an estimated half-life of 5 ± 3 days (mean and standard deviation).

year: 2013

title: Drying characteristics of New Zealand Chestnuts

authors: Biju Cletus, Anila

subjects: none

abstract: Chestnut is a relatively new nut crop to New Zealand and they do grow well in New Zealand conditions. Research to date in New Zealand indicated that New Zealand chestnuts present some unique features compared to chestnuts world wide. The two main unique problems with New Zealand chestnuts are the susceptibility to fungal disease Phomopsis (accounting for 40% loss of nuts at the wholesale markets) and the difficulty in the removal of the inner skin called the pellicle. No systematic drying trials had been performed on New Zealand chestnuts and therefore this research investigated the drying characteristics of New Zealand chestnuts to establish optimum drying conditions. The study also investigated the influence of the shell and pellicle on the drying process and the efficacy of shell and pellicle removal of New Zealand chestnuts under a range of moisture contents since the moisture content is a key factor which determines this efficiency.

The drying trials were carried out at a temperature of 30 C because preliminary studies indicated that higher temperatures resulted in extensive surface deterioration. Experimental drying curves are considered the only adequate preliminary step for determination of drying characteristics of a food material and the curves clearly indicated that there are two distinct falling rate periods. It was concluded that the first falling rate period corresponded to the period during which the surface of the nut reaches equilibrium moisture content and the second falling rate period occurred as the moisture movement from interior of the nut to the surface was the rate limiting factor. Hence a diffusion based model was used to estimate the apparent moisture diffusivity in chestnuts. The average apparent moisture diffusivity in chestnuts obtained at 30 C was 6.21x 10-11m2s-1. The study revealed that the pellicle is the most significant barrier to mass transfer; considerably more so than the shell. The shelling and peeling efficiency of New Zealand chestnuts were carried out at various moisture contents using a custom-made mechanical shelling machine. The mechanical shell removal of New Zealand chestnuts was accomplished with an efficiency of 94% at the desired storage moisture content of 40%. However mechanical pellicle removal of New Zealand chestnuts proved practically impossible although American varieties (Carolina and Revival) exhibited 100% peeling efficiency.

text: Drying characteristics of New Zealand Chestnuts Chestnut is a relatively new nut crop to New Zealand and they do grow well in New Zealand conditions. Research to date in New Zealand indicated that New Zealand chestnuts present some unique features compared to chestnuts world wide. The two main unique problems with New Zealand chestnuts are the susceptibility to fungal disease Phomopsis (accounting for 40% loss of nuts at the wholesale markets) and the difficulty in the removal of the inner skin called the pellicle. No systematic drying trials had been performed on New Zealand chestnuts and therefore this research investigated the drying characteristics of New Zealand chestnuts to establish optimum drying conditions. The study also investigated the influence of the shell and pellicle on the drying process and the efficacy of shell and pellicle removal of New Zealand chestnuts under a range of moisture contents since the moisture content is a key factor which determines this efficiency.

The drying trials were carried out at a temperature of 30 C because preliminary studies indicated that higher temperatures resulted in extensive surface deterioration. Experimental drying curves are considered the only adequate preliminary step for determination of drying characteristics of a food material and the curves clearly indicated that there are two distinct falling rate periods. It was concluded that the first falling rate period corresponded to the period during which the surface of the nut reaches equilibrium moisture content and the second falling rate period occurred as the moisture movement from interior of the nut to the surface was the rate limiting factor. Hence a diffusion based model was used to estimate the apparent moisture diffusivity in chestnuts. The average apparent moisture diffusivity in chestnuts obtained at 30 C was 6.21x 10-11m2s-1. The study revealed that the pellicle is the most significant barrier to mass transfer; considerably more so than the shell. The shelling and peeling efficiency of New Zealand chestnuts were carried out at various moisture contents using a custom-made mechanical shelling machine. The mechanical shell removal of New Zealand chestnuts was accomplished with an efficiency of 94% at the desired storage moisture content of 40%. However mechanical pellicle removal of New Zealand chestnuts proved practically impossible although American varieties (Carolina and Revival) exhibited 100% peeling efficiency.

year: 2007

title: Finding synergistic conservation values? Māori tikanga, science, resource management and law

authors: Simon, Katie

subjects: Indigenous knowledge

abstract: In this doctorate, I provide a balanced and collaborative approach to knowledge/value change between the contesting worldviews of indigenous knowledge and western science, termed 'synergistic'. My search for synergy is comparative and reconciliatory. This endeavours to overcome the popular pre-occupation with conflict and opposition. Rather, both difference and similarity are recognised. Through the comparison of such synergy, I argue that Māori development requires for its further advancement a focus not only on difference and conflict, but also on affinity and convergence.

My primary concern is to establish a better understanding of the synergistic, adaptive strategies or indigenous innovation of Māori kaitiaki, environmental stewards. I investigate conflicting and converging Māori and western scientific conservation and use values in Aotearoa/New Zealand  environmental governance and management regimes under the Resource Management Act 1991, with specific regard to indicator development. The balance of values were compared in ecological environmental governance, from five Aotearoa governmental authorities and three Māori river communities, utilising Māori and western social science methods. My focus on indicators pinpoints contesting knowledge/value change between the marginalisation of indigenous knowledge and dominance of western science. This seeks to highlight the potential viability of Māori kaitiakitanga, stewardship in global and national terms of sustainability.  

However, potential synergy is held back by a prevailing viewpoint of the indigenous worldview as backward, past-oriented and non-synergistic. An oppositional dogma predominates, which is a key problem to overcome. It spans world and national literature, resulting in considerable gaps in knowledge on synergy, conceptually, methodologically, empirically and analytically.  


This is addressed by an authoritative Māori synergistic standpoint from my own cultural lens and decolonised theorising, termed 'nuanced problem solving'. I articulate both worldviews in knowledge/value change through comparative, evolutionary, multi-dimensional, cross-cultural and inter-disciplinary research on synergy. My nuanced problem solving encapsulates the two main parts of the doctorate, whereby synergy is correlated between theory and social practice. Part one deals with value comparison in theory utilising high abstracted concepts and methods at the global level of environmental governance. Part two deals with value balance in social practice utilising medium abstracted and concrete empirical and analytical research at global, national, regional, district and cross-tribal levels of environmental governance. Potential synergy cross-cuts each part from high abstracted thought down and from the practical flax roots up. I argue that Māori advancement fluctuates between them. 

Drawing on cultural and theoretical leanings of the Māori synergistic standpoint, both a strong correlation with existing theory and expanded synergistic theorising was found. Due to the expansiveness of the research, these correlated findings only provide an embryonic understanding of potential synergy.

A postscript describes my other work on synergy with five external agencies concerning foreshore, lakeside, wastewater, land disposal and carbon marketing kaitiakitanga.  I argue that additional research on synergy is needed in order to further advance Māori.

text: Finding synergistic conservation values? Māori tikanga, science, resource management and law In this doctorate, I provide a balanced and collaborative approach to knowledge/value change between the contesting worldviews of indigenous knowledge and western science, termed 'synergistic'. My search for synergy is comparative and reconciliatory. This endeavours to overcome the popular pre-occupation with conflict and opposition. Rather, both difference and similarity are recognised. Through the comparison of such synergy, I argue that Māori development requires for its further advancement a focus not only on difference and conflict, but also on affinity and convergence.

My primary concern is to establish a better understanding of the synergistic, adaptive strategies or indigenous innovation of Māori kaitiaki, environmental stewards. I investigate conflicting and converging Māori and western scientific conservation and use values in Aotearoa/New Zealand  environmental governance and management regimes under the Resource Management Act 1991, with specific regard to indicator development. The balance of values were compared in ecological environmental governance, from five Aotearoa governmental authorities and three Māori river communities, utilising Māori and western social science methods. My focus on indicators pinpoints contesting knowledge/value change between the marginalisation of indigenous knowledge and dominance of western science. This seeks to highlight the potential viability of Māori kaitiakitanga, stewardship in global and national terms of sustainability.  

However, potential synergy is held back by a prevailing viewpoint of the indigenous worldview as backward, past-oriented and non-synergistic. An oppositional dogma predominates, which is a key problem to overcome. It spans world and national literature, resulting in considerable gaps in knowledge on synergy, conceptually, methodologically, empirically and analytically.  


This is addressed by an authoritative Māori synergistic standpoint from my own cultural lens and decolonised theorising, termed 'nuanced problem solving'. I articulate both worldviews in knowledge/value change through comparative, evolutionary, multi-dimensional, cross-cultural and inter-disciplinary research on synergy. My nuanced problem solving encapsulates the two main parts of the doctorate, whereby synergy is correlated between theory and social practice. Part one deals with value comparison in theory utilising high abstracted concepts and methods at the global level of environmental governance. Part two deals with value balance in social practice utilising medium abstracted and concrete empirical and analytical research at global, national, regional, district and cross-tribal levels of environmental governance. Potential synergy cross-cuts each part from high abstracted thought down and from the practical flax roots up. I argue that Māori advancement fluctuates between them. 

Drawing on cultural and theoretical leanings of the Māori synergistic standpoint, both a strong correlation with existing theory and expanded synergistic theorising was found. Due to the expansiveness of the research, these correlated findings only provide an embryonic understanding of potential synergy.

A postscript describes my other work on synergy with five external agencies concerning foreshore, lakeside, wastewater, land disposal and carbon marketing kaitiakitanga.  I argue that additional research on synergy is needed in order to further advance Māori.

year: 2007