title: Soil carbon stocks under fencelines and adjacent paddocks to test the importance of dung returns

authors: Hay, Holly

subjects: carbon stocks

abstract: Soils are the largest terrestrial store of carbon (C), but agriculture has depleted around 133 Pg C from the upper 2 m of soil, contributing to increases in atmospheric CO2. Soil C sequestration can help offset these atmospheric increases and is determined by the balance between C inputs and C outputs.
New Zealand’s temperate climate supports year-round grazing on approximately one-third of the country’s land area. The conversion of New Zealand’s native forests to pastures increased soil C stocks, yet the mechanisms behind this increase remain unclear. Grazing animals influence the C cycle through the consumption of C embodied within the feed they eat, with excreta returning C to the soil. Although C balances of New Zealand pastures suggest excreta is an important return of C to the soil, this has been poorly quantified. 
The objectives of this thesis were to determine if soil C stocks (0–0.6m) differed between paddock and fenceline areas, assuming the paddock received more dung input. To test this assumption, the spatial distribution of dung in relation to the fenceline was mapped, and dung loading was estimated. Stocks of particulate organic matter C (POM-C) and mineral-associated organic matter C (MAOM-C) were also determined in the top 0.1 m of soil to understand which forms of C contributed to any measured differences in total C stocks. Differences in Olsen P and pH were also determined. 
Paddock and fenceline sites (38 pairs) distributed across six farms in the Waikato region were sampled to a depth of 0.6 m. On average, soil C and N stocks were 10.3 t C ha−1 (P = .002) and 0.96 t N ha−1 (P = .002) higher in paddock areas when compared to fenceline areas. When excluding one paired site with a very poor match of mineral surface area, the differences decreased to 9.3 t C ha−1 (P = .004) and 0.86 t N ha−1 (P = .003). The greatest differences were observed in the 0–0.1 m depth increment. At the 0–0.1 m depth increment, POM-C was significantly greater in paddock samples and largely accounted for the observed difference in total soil C. This suggested that the observed C stock increase was in a more degradable fraction, implying that decreases in dung returns could result in rapid soil C loss. There was no relationship between the age of the fenceline and C stock differences, indicating that differences may have occurred rapidly to a new steady state.
Mapping of 2000+ dug pats showed that paddocks received more dung, with only one pat being within the fenceline sampling zone. The average dung density was 0.2 pats m−2 and a dung-C loading rate of 1.1 t C ha−1 y−1 was calculated.
The detected differences in C stocks due to varying dung input aligned with other studies on cattle manure’s influence on soil C, POM-C and MAOM-C stocks. Further research is needed to better understand the contribution of dung returns to soil C and its potential vulnerability to loss.

text: Soil carbon stocks under fencelines and adjacent paddocks to test the importance of dung returns Soils are the largest terrestrial store of carbon (C), but agriculture has depleted around 133 Pg C from the upper 2 m of soil, contributing to increases in atmospheric CO2. Soil C sequestration can help offset these atmospheric increases and is determined by the balance between C inputs and C outputs.
New Zealand’s temperate climate supports year-round grazing on approximately one-third of the country’s land area. The conversion of New Zealand’s native forests to pastures increased soil C stocks, yet the mechanisms behind this increase remain unclear. Grazing animals influence the C cycle through the consumption of C embodied within the feed they eat, with excreta returning C to the soil. Although C balances of New Zealand pastures suggest excreta is an important return of C to the soil, this has been poorly quantified. 
The objectives of this thesis were to determine if soil C stocks (0–0.6m) differed between paddock and fenceline areas, assuming the paddock received more dung input. To test this assumption, the spatial distribution of dung in relation to the fenceline was mapped, and dung loading was estimated. Stocks of particulate organic matter C (POM-C) and mineral-associated organic matter C (MAOM-C) were also determined in the top 0.1 m of soil to understand which forms of C contributed to any measured differences in total C stocks. Differences in Olsen P and pH were also determined. 
Paddock and fenceline sites (38 pairs) distributed across six farms in the Waikato region were sampled to a depth of 0.6 m. On average, soil C and N stocks were 10.3 t C ha−1 (P = .002) and 0.96 t N ha−1 (P = .002) higher in paddock areas when compared to fenceline areas. When excluding one paired site with a very poor match of mineral surface area, the differences decreased to 9.3 t C ha−1 (P = .004) and 0.86 t N ha−1 (P = .003). The greatest differences were observed in the 0–0.1 m depth increment. At the 0–0.1 m depth increment, POM-C was significantly greater in paddock samples and largely accounted for the observed difference in total soil C. This suggested that the observed C stock increase was in a more degradable fraction, implying that decreases in dung returns could result in rapid soil C loss. There was no relationship between the age of the fenceline and C stock differences, indicating that differences may have occurred rapidly to a new steady state.
Mapping of 2000+ dug pats showed that paddocks received more dung, with only one pat being within the fenceline sampling zone. The average dung density was 0.2 pats m−2 and a dung-C loading rate of 1.1 t C ha−1 y−1 was calculated.
The detected differences in C stocks due to varying dung input aligned with other studies on cattle manure’s influence on soil C, POM-C and MAOM-C stocks. Further research is needed to better understand the contribution of dung returns to soil C and its potential vulnerability to loss.

year: 2024

title: Subsidies, selectivity and the returns to education in urban Papua New Guinea

authors: Gibson, John

subjects: demand for schooling

abstract: There is debate about whether the rate of return to education in developing countries declines with the level of schooling. This paper reports evidence from urban Papua New Guinea which shows that the average private rate of return to an additional year of education rises with the level of education considered. This pattern is robust to the specification of the extended earnings function and is strengthened when the measure of employee compensation includes fringe benefits. The results are not sensitive to controls for sample selectivity bias and the estimated selectivity effects are more consistent with the principle of comparative advantage than is existing evidence from developing countries. The returns to on-the-job training are also higher than indicated by previous evidence in developing countries.

text: Subsidies, selectivity and the returns to education in urban Papua New Guinea There is debate about whether the rate of return to education in developing countries declines with the level of schooling. This paper reports evidence from urban Papua New Guinea which shows that the average private rate of return to an additional year of education rises with the level of education considered. This pattern is robust to the specification of the extended earnings function and is strengthened when the measure of employee compensation includes fringe benefits. The results are not sensitive to controls for sample selectivity bias and the estimated selectivity effects are more consistent with the principle of comparative advantage than is existing evidence from developing countries. The returns to on-the-job training are also higher than indicated by previous evidence in developing countries.

year: 2006

title: Te Mata Ono-The six faces of Māori broadcasting

authors: Kaire-Melbourne, Kimiora

subjects: Māori broadcasting

abstract: Māori have always been involved in media communication and from a traditional viewpoint karanga, whaikōrero, taonga pūoro, haka, waiata and mōteatea are all mediums used to share messages across a mass audience. Since the arrival of European settlers, we have seen Māori content disseminated through platforms such as newspaper, radio, and more recently via the medium of television. This particular study is concerned with the way that Māori are represented and information is shared via indigenous broadcaster, Māori Television. Using a theoretical model made up of six key components, this thesis asserts that Te Mata Ono could not only help to improve the production of Māori content but also reshape and modify the medium of television itself, to become more culturally appropriate. Ultimately, this model could guide Māori Television, outlining a Māori specific approach to broadcasting. This study is one part of a two-part study. Due to the limitations of a four-paper masters thesis, I will only be examining three elements of Te Mata Ono, which are Mata Māori, Mata ō-tua and Mata Pākehā. Another thesis that was conducted simultaneously by Te Aorere Pewhairangi explores the remaining three elements of the same model, Mata Iwi, Mata Ako and Mata Tikanga. Te Mata Ono could be applied to Māori Television, making a positive contribution to the future development of Māori broadcasting.

text: Te Mata Ono-The six faces of Māori broadcasting Māori have always been involved in media communication and from a traditional viewpoint karanga, whaikōrero, taonga pūoro, haka, waiata and mōteatea are all mediums used to share messages across a mass audience. Since the arrival of European settlers, we have seen Māori content disseminated through platforms such as newspaper, radio, and more recently via the medium of television. This particular study is concerned with the way that Māori are represented and information is shared via indigenous broadcaster, Māori Television. Using a theoretical model made up of six key components, this thesis asserts that Te Mata Ono could not only help to improve the production of Māori content but also reshape and modify the medium of television itself, to become more culturally appropriate. Ultimately, this model could guide Māori Television, outlining a Māori specific approach to broadcasting. This study is one part of a two-part study. Due to the limitations of a four-paper masters thesis, I will only be examining three elements of Te Mata Ono, which are Mata Māori, Mata ō-tua and Mata Pākehā. Another thesis that was conducted simultaneously by Te Aorere Pewhairangi explores the remaining three elements of the same model, Mata Iwi, Mata Ako and Mata Tikanga. Te Mata Ono could be applied to Māori Television, making a positive contribution to the future development of Māori broadcasting.

year: 2019