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Size of the prize: The value of closing pasture yield gaps on heterogeneous soil types in a dairy farm in Canterbury, New Zealand
Get PDFIdentifying opportunities to improve pasture production on irrigated Canterbury dairy farms is complex. This paper focuses on managing soil zones to optimise pasture production. Using electromagnetic induction (EM38) mapping, the area under a single centre pivot irrigator was characterised into soil zones of ‘low’, ‘medium’ and ‘high’, according to moisture and texture. Actual measurements of irrigation and soil characteristics were used in the model APSIM to estimate pasture production in ‘low’ and ‘medium’ soils under constant irrigation, giving an annual difference of 2900 kg DM/ha between the zones. In a typical irrigated Canterbury System 4 dairy farm modelled in FARMAX, with 20% ‘low’ and 80% ‘medium’ soil zones, increasing pasture in the ‘low’ zone to that of the ‘medium’ zone gave an increase of 580 kg DM/ha. This produced 51 kg/ha more milksolids and increased stocking rate by 0.2 cow/ha, giving a profit increase of 75,000 per annum. On a regional scale, increasing productivity of 52,900 ha of ‘low’ zone soils on irrigated farms in Canterbury would contribute $14 M to the economy. Taking a spatial management approach to understand variability in pasture can identify opportunities and potential value
Nitrate effects on N₂ fixation, growth and feed quality of lucerne and perennial lupin
No full textThe effects of NO₃¯ supply (0–500 kg N/ha) on total plant dry weight (DW), shoot N content and nutritional quality, and the proportion of plant N derived from the atmosphere (%Ndfa) were determined for lucerne and perennial lupin using ¹⁵NO₃¯ under glasshouse conditions. Fodder beet was used as a non-legume reference plant. In both the initial and repeat experiments, total plant DW, shoot N% and shoot nutritional quality for lucerne and perennial lupin were not affected by NO₃¯ supply. Total plant DW increased 10-fold and shoot N% tripled for fodder beet with increased N supply. In the initial experiment, the %Ndfa for lucerne decreased from 89 to 37% with increased N supply from 0 to 500 kg N/ha, where comparable values for perennial lupin were 96 to 64%. In the repeat experiment, %Ndfa decreased from 90 to 49% and 93 to 65% for lucerne and perennial lupin, respectively, with increasing NO₃¯ supply from 0 to 500 kg N/ha. Both legumes showed an increased reliance on NO₃¯ with increased soil NO₃¯ level, but even at 500 kg N/ha (similar to amount of N in sheep urine patch), perennial lupin obtained much of its N from N₂ fixation
Sweat equity: Student scholarships in Aotearoa New Zealand's universities
Get PDFThis paper responds to calls from past and present students to increase the value of postgraduate scholarships in Aotearoa New Zealand. Here we provide context for understanding the scholarship landscape in Aotearoa, including how scholarships are understood in relation to dominant neoliberal framings of higher education and persistent inequities within the sector. We present data which provides insight into the current inequities in Summer, Masters and PhD scholarship values. The average value of PhD scholarships has remained stagnant between 2011 and 2019 resulting in the average being $11,238 less than the Living Wage in 2019. We show that the average length of time full-time PhD students take to complete their doctorates exceeds the three-year tenure of scholarships. We argue the status-quo of low scholarships, supplemented by postgraduate ‘sweat’, excludes people from participating in postgraduate education, preventing them and their communities from realising the public benefits that such an education can produce. We suggest that these inadequacies could be addressed through (1) raising Summer, Masters and PhD scholarships to the living wage; (2) extending tenure of PhD scholarships; and (3) reinstating the postgraduate student allowance
Emergent spaces of emergency claims: Possibilities and contestation in a national climate emergency declaration
Get PDFClimate emergency declarations have become a prominent mechanism within the environmental movement to emphasise the urgency of the climate crisis, with this activism prompting numerous declarations from governments. Embedded in these declarations are claims of emergency, which hold representations of how different actors make sense of the present political moment and imagine trajectories of change. We analyse the contested meanings of public emergency claims made by activists and the state in Aotearoa New Zealand’s national climate emergency declaration. Identifying three framings of emergency as an objective truth, an activating property, and a responsibility, our analysis suggests emergency declarations hold ambiguous potential for more radical action on climate change. While opening political space on what emergency means, we argue emergency claims hold risks of depoliticising climate politics and re-embedding the neoliberal status quo. Emergency claims also contain tensions in imaginaries of transformation, suggesting the importance of contestation within climate emergency declarations
Quantifying the risk of non‐native conifer establishment across heterogeneous landscapes
Get PDF1. Pines (genus Pinus) are cultivated extensively for forestry purposes, particularly in regions that are outside the genus' native range. The most common forestry species are also typically those most likely to escape cultivation and spread rapidly, and thus pines constitute a substantial weed problem in many regions. However, there is limited knowledge of the factors underlying the spread of pines from plantations. Assessments across heterogeneous landscapes are required to provide rigorous data to support management tools and policies aiming to protect vulnerable ecosystems from pine invasions.
2. We examined the spread of Pinus radiata from forestry plantations over a ~9,000 km² landscape on Banks Peninsula, New Zealand. We used ground-based surveys from a set of viewpoints to determine tree locations, coupled with geographical information system (GIS) viewsheds to define the area surveyed. We used boosted regression trees to build a habitat model for P. radiata establishment on Banks Peninsula.
3. We surveyed an area approximately 107 km², recording 470 naturally established P. radiata individuals. Our habitat models suggested that proximity to the nearest plantation forest was the most important variable predicting P. radiata establishment, with individuals most likely to establish within 150 m of a plantation. Individuals were also most likely to establish in early successional shrub communities, proximate to roads, and on steeper topography. Highly grazed habitats were least vulnerable to P. radiata establishment.
4. The slope and aspect of the source plantation influenced the distances from the plantation at which P. radiata individuals were recorded, with individuals recorded furthest away likely to have originated from plantations that were south-facing or on steeper slopes, and therefore most exposed to strong winds.
5. Synthesis and applications. Our findings on distances from plantations at which individuals established, vulnerable habitats, and the interactions we detected among our predictor variables, can be extended to aid management of non-native conifer plantings elsewhere in the Southern Hemisphere. These data can be used to contribute to improvements of decision support systems that assess likely spread risk from non-native conifer plantings. Such tools can reduce the likelihood of future pine establishment, potentially preventing biological invasions
The ecological importance of moss ground cover in dry shrubland restoration within an irrigated agricultural landscape matrix
Get PDF1. Kānuka (Kunzea serotina, Myrtaceae) dryland shrubland communities of the lowland plains of South Island (Te Wai Pounamu), New Zealand (Aoteoroa), contain a ground cover largely consisting of mosses, predominantly Hypnum cupressiforme. There has been no previous study of the role of mosses in this threatened habitat which is currently being restored within a contemporary irrigated and intensively farmed landscape that may be incompatible with this component of the ecosystem.
2. The aim of the present study was to investigate the influence of moss ground cover on hydrology, nitrogen (N) availability and vascular plant interactions, and in relation to nutrient spillover from adjacent farmland. Experimental work was a combination of glasshouse experiments and field-based studies.
3. Extremes of soil temperature and moisture were found to be mediated by the moss carpet, which also influenced N speciation; available N declined with moss depth. The moss layer decreased the amount of germination and establishment of vascular plants but, in some cases, enhanced their growth. Spillover of mineral nitrogen and phosphate from farmland enhanced invasion of exotic grasses which may have benefited from conditions provided by the moss carpet.
4. Synthesis: We found the moss layer to be crucial to ecosystem functioning in these dry habitats with low nutrient substrate. However, when the moss layer is accompanied by nutrient spillover, it has the potential to increase exotic weed encroachment. Our results not only emphasize the importance of non-vascular plant inclusion in restoration schemes but also highlights the importance of mitigating for nutrient spillover
Effects of interaction of UV-B radiation and water deficit on phenolic compounds in 'Pinot Noir' fruit
Get PDFEnvironmental issues (high UV-B radiation and water deficit) can challenge 'Pinot Noir' growth in New Zealand. The aim of this work is to determine separated and combined UV-B and water deficit effects on phenolic composition of 'Pinot Noir' fruit. In 2016-2017 vintage, two rows of 'Pinot Noir' grapevines in the West Vineyard at Lincoln University were chosen for the study. In comparison to exposure to natural UV-B in the vineyard, the potted vines were put into a glasshouse for the experiments. When berries were directly exposed to UV-B and water deficit, skin anthocyanin and skin total phenolics accumulated to a greater degree in the berry skins. The combined stresses caused larger increases in contents of skin total phenolics than the water deficit in the vineyard and glasshouse. Skin tannin contents were increased by UV-B and water deficit, but there were no consistent changes in seed tannin contents between treatments during ripening and no statistically significant differences between treatments at harvest. This research reported that canopy management (UV-B exposure) interacting with a moderate water deficit may be a good way for vineyard management to increase the accumulation of anthocyanins and tannins in berry skins
Natural regeneration of woody vegetation in pastoral hill country: A case study of Oashore Station, Banks Peninsula : A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Landscape Architecture at Lincoln University
Get PDFThere is a recognised need to establish more permanent indigenous forest throughout the world to mitigate climate change and enhance declining biodiversity. In New Zealand, the Climate Change Commission He Pou a Rangi has recommended the establishment of 300,000 hectares of new indigenous forest by 2035, with a focus on areas of hill country with marginal productivity for agriculture. A significant barrier to the achievement of this goal is the cost and logistical difficulties of restoration planting and direct seeding in hill country landscapes. Reliance on natural regeneration has the potential to be a more practical and economically viable option, particularly where large areas are involved. However, the rate of natural regeneration and key factors enabling it within pastoral hill country landscapes are not well understood.
Based on aerial imagery, object-based image classification was used to detect changes in woody vegetation over a 16-year period on Oashore Station, a 540ha hill country property on Banks Peninsula, Canterbury. The focus was on identifying areas of the property that had changed from grassland to woody shrubland as the first stage in a successional process of natural regeneration from pasture to indigenous forest. Random forest machine learning and logistic regression were then used to evaluate the influence of different variables on the observed natural regeneration, including the impact of environmental factors and grazing regimes.
The results for this study indicate that only 3.3% of Oashore Station experienced observed natural regeneration of woody vegetation in pasture between 2003 and 2019. The key factor influencing natural regeneration was the proximity of existing woody vegetation, with areas within 2m of existing woody vegetation being significantly more likely to experience natural regeneration. Cattle grazing was also found to have a significant negative impact on regeneration of woody vegetation, with regeneration most likely to occur in areas that had been free of cattle grazing for at least 10 years. Grazing by sheep and other environmental factors were not found to have a significant impact on natural regeneration.
These findings have implications for hill country farmers considering natural regeneration on pastoral land with similar conditions and can help to identify locations where regeneration is most likely to occur. Areas with a higher proportion of existing woody vegetation should be prioritised for natural regeneration, with cattle grazing generally excluded from such areas. However, even in favourable conditions, the establishment of indigenous forest through natural regeneration is likely to be a slow, incremental process. This should be recognised in financial incentive schemes such as the Emissions Trading Scheme and has implications for the achievement of broader goals seeking to increase the amount of permanent indigenous forest on marginal hill country. If significantly faster rates of natural regeneration are desired, additional strategic interventions and support may be necessary
AgYields – a national database for collation of past, present and future pasture and crop yield data
Get PDFThe New Zealand agricultural sector has a rich heritage of measuring yield and growth rates for pastures and crops. These data are expensive to collect, spatially and temporally patchy, and stored in a range of electronic and physical platforms. A challenge for data collection and storage is the different priorities and skill sets of those undertaking the task. Thus, there is a need to provide guidelines for the collection, collation and publication of such data to standardize best practice and maximize the value gained from increasingly scarce resources available for pasture and crop research to support the primary industries. In addition, declining funding for field research, means there is an urgent need to draw together existing and future data into a publicly accessible industry good resource. This paper outlines the development of the AgYields web-based repository for pasture and crop growth rate and yield data. It describes the rationale for the database and the need for standardization of data collection to maximize the value of stored data in common formats. The intent is to provide a resource to enhance livestock and crop production systems throughout New Zealand and provide guidelines for future data collection
International corporate cash holdings and firm‐level exposure to COVID‐19: Do cultural dimensions matter?
Get PDFThis study investigates the impact of COVID‐19 exposure on corporate cash holdings using firm data across sixteen developing and developed economies. The results show that firms reserve more cash when their exposure to COVID‐19 increases. We also find a cash burn effect during the COVID‐19 pandemic, meaning that the cash holdings are drained when firm exposure to the pandemic exceeds a tipping point. The effect is more pronounced in larger firms and firms with less cash reserve. Further analyses reveal that the cash burn effect tends to be stronger in countries with a high level of individualism and weaker in countries with high levels of risk aversion, masculinity, and long‐term orientation. The findings provide fresh insights into the connections among corporate cash holdings, national cultures, and firm‐level exposure to COVID‐19