NZGA: Research and Practice Series最新文献

{"title":"Greener Pastures: priorities for a low-footprint, high-value food producing future","authors":"Marie Casey, D. Chapman, David Stevens, Warren King, Graham Kerr, M. Dodd, W. Catto, J. Caradus","doi":"10.33584/rps.17.2021.3604","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3604","url":null,"abstract":"The key challenges and opportunities facing the pasture1 resource underpinning New Zealand’s pastoral industries outlined in this paper are drawn from the knowledge, analysis and feedback of 240 pan-pastoral industry stakeholders2 who participated in the Resilient Pastures Symposium (RPS) at Karapiro in May 2021. Information on the Symposium is provided in Appendix B.The RPS was convened in response to concerns about the resilience3 of our pasture base to rapidly changing pressures and expectations. The purpose of this paper is to deliver on the objectives of the Symposium, namely to:• synthesise the current state of our pastures as seen through the various perspectives of the delegates, and;• propose priorities for consideration by key stakeholders, including the significant investors already supporting Research, Development & Extension (RD&E), as they address the challenges ahead","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"426 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115930917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resilient pastures","authors":"D. Chapman","doi":"10.33584/rps.17.2021.3522","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3522","url":null,"abstract":"High value animal products from New Zealand’s pasture-based livestock systems have consistently earned $25-$30B in export earnings per year for the country over the past 5 years (Ministry for Primary Industries 2021). Total earnings from dairy and meat of $30.5B in 2020 equate to 35% of New Zealand’s total goods and services export earnings of $86.4B. The importance of this revenue to the national economy has been shown in stark relief recently with the Covid-19 pandemic substantially reducing the earnings generated by other key export sectors such as tourism and international education.\u0000While our pasture-based livestock industries have ridden the coronavirus wave well compared with other sectors of the economy, they are facing change at a scale and pace not seen since the far-reaching reforms to the economic settings for agriculture introduced by the Lange Government in the early 1980s. Locally, the ramping-up of government environmental policies beginning c. 2011 has resulted in stringent regulations controlling the amounts of nitrogen (N), phosphorus (P) and sediment that can be discharged into freshwater from farm systems. The most recent iteration in this policy sequence includes new National Environmental Standards for Freshwater, and the new National Policy Statement for Freshwater Management (NPS-FW), which came into force in September 2020.   \u0000These policies reverse the trends of the past two decades when agricultural productivity grew substantially in the virtual absence of regulation to control the environmental externalities of systems intensification. While the initial impacts on land use and farming practices have been localised (e.g., in the lake districts of Rotorua and Taupo), disruption to the farm systems that have emerged over the past two decades, especially intensive dairy systems, will be widespread in the future. For example, Doole et al. (2021) estimated that the new standards introduced in 2020 will require about 40% of New Zealand’s 11400 dairy farms to reduce nitrate leaching by an average of around 42% relative to requirements in previous iterations of the NPS-FW.\u0000The most significant global force driving change in New Zealand agriculture is climate change, via New Zealand’s commitment to the Paris Agreement to reduce carbon (C) emissions to net zero by 2050, C-neutral strategies being implemented by some of our largest customers (e.g., Nestle 2020), and the physical impacts of climate change on conditions for plant growth (e.g., Keller et al. 2021). Of direct and significant relevance to the livestock industries are the methane emission reduction targets proposed by government, of between 27% and 47% below 2017 levels by 2050. Meanwhile our international competitors have been steadily closing the gap in costs of production with New Zealand, and now have other fields on which to out-compete us (e.g., in C footprint) unless we can keep pace.","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133971649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Persistence of perennial ryegrass, tall fescue and cocksfoot following annual sowings: influence of grass species, ryegrass cultivar and pasture age on yield, composition and density","authors":"T. Maxwell, G. Edwards, K. Tozer, G. Cosgrove","doi":"10.33584/rps.17.2021.3466","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3466","url":null,"abstract":"Persistence is an important component of perennial pasture-grass productivity. Defining traits that affect persistence is essential for improving pasture longevity through plant breeding and for identifying persistence traits that should be included in cultivar ranking indices. Compared with conventional longitudinal studies, where a single sowing is monitored over time, repeated annual sowings allow the effects on persistence of sowing year and the ensuing interactions between environment and age of pasture to be identified. An experiment was commenced in 2015 under sheep grazing in Canterbury and in 2016 under cattle grazing in Waikato, where eight cultivars of perennial ryegrass representing different ploidy, flowering date, and cultivar age (release date), and one cultivar each of tall fescue and cocksfoot were sown in four randomised complete blocks in autumn each year. This paper reports interim data on spring and autumn pasture yield, composition, and density of 3-year-old, 2-year-old and 1-year-old pastures exposed to the same environmental conditions within the same, single year. There were significant effects on yield, botanical composition, basal cover and tiller density due to cultivar, pasture age, and their interaction. When the confounding effect of year-to-year variation was removed by comparing each age cohort in the same year, the underlying differences among grass species and cultivars, and ages of pasture, is starting to reveal the nature of this influence on pasture persistence.","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122111172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Annual yield and botanical composition of four dryland grass species with or without nitrogen over six years","authors":"Marcus Talamini Junior, Shirin Sharifiamina, E. David, A. Mills, D. Moot","doi":"10.33584/rps.17.2021.3444","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3444","url":null,"abstract":"Nitrogen (N) and water availability affect pasture production and persistence. Yield and botanical composition of four monocultures of brome (BR), cocksfoot (CF), perennial ryegrass (RG) and tall fescue (TF) were evaluated with (+N) or without (-N) N at Ashley Dene farm, Canterbury, over six growth seasons from establishment in 2014/15 (Year 1) to 2019/20 (Year 6). Total annual yields ranged from 2.04 (RG-N; Year 1) to 12.7 t DM/ha/yr (CF+N; Year 3). Yields differed among species in Years 1, 3, 4 and 6 when TF pastures had the lowest production. There was no difference in DM production from BR, CF and RG pastures. Additionally, +N pastures produced ~55% more yield than –N pastures in Years 3 and 5 when spring/summer rainfall was adequate to maintain growth. Sown grasses accounted for >89% of total DM yield in Years 1 and 2 but the proportion of total annual DM production from sown species declined from Year 3. By Year 6, sown species accounted for 48±3.3 (TF) to 64±3.3% (BR, CF and RG) of total annual DM production. Generally, TF failed to perform in this dryland environment. In contrast, the production and persistence of the other three species were not different when subjected to water deficits alone.","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131601552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climatic factors influencing New Zealand pasture resilience under scenarios of future climate change","authors":"E. Keller, M. Lieffering, Jing Guo, W. Baisden, A. Ausseil","doi":"10.33584/rps.17.2021.3458","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3458","url":null,"abstract":"New Zealand’s intensively managed pastoral agricultural systems are vulnerable to climate change because of their dependence on grazing livestock and pasture as the primary feed supply. Drawing from recent modelling results, annual pasture yields in New Zealand are projected to be robust to a changing climate due to more favourable growing conditions in winter and early spring and increased plant efficiencies from the CO2 fertilization effect. However, growth is also expected to become more variable and unpredictable, particularly in water-limited regions. A combination of short-term, incremental changes (already part of current practice) and longer-term strategic interventions will be necessary to maintain consistent feed supply under future climate change.","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122216418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attributes of resilient pasture for achieving environmental outcomes at farm scale","authors":"C. D. de Klein, R. Monaghan, Mitchell Donovan, A. Wall, L. Schipper, I. Pinxterhuis","doi":"10.33584/rps.17.2021.3487","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3487","url":null,"abstract":"Pasture resilience commonly refers to a pasture’s ability to withstand or rebound from pressures to maintain production and quality of sown species. We suggest that a broader definition of pasture resilience is needed that also includes environmental responses, thus ensuring that productivity and environmental outcomes are considered together. Key attributes of resilient pastures to minimise soil erosion and nutrient, greenhouse gas and soil carbon losses are summarised based on current understanding of environmental losses from pastoral systems. These attributes include maintaining consistent pasture cover, high energy and/or low nitrogen species and species diversity that provides complementary root morphology and/or growth seasonality; all are likely to have positive benefits for production and productivity. There is a potential tension, however, between productivity and methane emissions, as methane production increases with increased feed intake. Increasing pasture quality is therefore also an important consideration for pasture resilience as it can maintain animal productivity at lower levels of feed intake. From a farm systems perspective, the choice of pasture species should reflect the desired attributes for both productivity and environmental outcomes, and ensure that the sown species persist in the sward. Finally, we note that none of the environmental attributes/benefits are likely to deliver major farm-scale improvements on their own; progress will likely be incremental improvements upon implementing a range of attributes.","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114737954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate change impacts on pest ecology and risks to pasture resilience","authors":"S. Mansfield, C. Ferguson, P. Gerard, David Hodges, J. Kean, Craig Phillips, S. Hardwick, S. Zydenbos","doi":"10.33584/rps.17.2021.3477","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3477","url":null,"abstract":"It is well understood that damage by insect pests can have serious consequences for pasture resilience. However, the impacts of climate change on pastoral systems, the responses of insect pests, and implications for pest impact mitigation are unclear. This paper reviews pest responses to climate change, including direct impacts such as temperature and carbon dioxide levels, geographic range expansion, sleeper pests, and outbreaks resulting from disturbance such as drought and farm system changes. The paper concludes with a plea for transdisciplinary research into pasture resilience under climate change that has insect pests as an integral component – not as an afterthought.","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134123055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct and indirect effects of resilient pastures at farm scale","authors":"M. Jagger","doi":"10.33584/rps.17.2021.3524","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3524","url":null,"abstract":"I farm a 550-ha property at coastal Whangarei Heads, Northland, in partnership with my wife Helen. While some land has been in family ownership since the 1850s, our farm has grown over the years through land and farm acquisitions. The farm consists of a dairy platform of 220 ha and 330 ha of dairy beef and dairy support. The farm is kikuyu dominant and summer dry with rainfall varying between 650 and 1100 mm per annum. Summer cropping, in-shed meal feeding, sowing Italian ryegrass and kikuyu mulching are all practices used with the aim of running a sustainable system. Perennial ryegrass pastures have limited persistence and are no longer a focus as more resilient pasture species and varieties are sown.","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127392742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pasture resilience reflects differences in root and shoot responses to defoliation, and water and nitrogen deficits","authors":"D. Moot, A. Black, E. Lyons, L. Egan, R. Hofmann","doi":"10.33584/rps.17.2021.3472","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3472","url":null,"abstract":"The yield of a pasture is directly proportional to the amount of light plants intercept and allocate to different organs. When plants are carbon (C) limited, due to defoliation, they allocate more C preferentially to shoots to restore leaf area. In contrast, water and nitrogen (N) limitations lead to a greater allocation of C to roots. Changes in the root:shoot ratio therefore reflect changes in C and N partitioning and indicate their relative priority. A major factor that influences plant responses to stress is their ability to store and remobilise reserves to restore leaf area. Species with tap roots, like lucerne, have a large potential C and N storage capacity that is utilised seasonally for storage and remobilisation. This has been used to develop seasonally based grazing management rules. Similarly, recommendations to graze perennial ryegrass at the 2- or 3-leaf stage are based on the balance between maximizing growth rates and the need to replenish water-soluble carbohydrate reserves. However, perennial ryegrass has lower levels of perennial reserves than other grass species. This reduces its resilience to concurrent water deficits or N deficiency. Under these conditions maintaining the recommended 3-leaf grazing intervals and/or leaving higher post-grazing pasture masses are recommended to assist canopy recovery. Other grass species, such as cocksfoot and tall fescue, provide more resilience, particularly in response to water deficits.","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114214472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant diversity with species drilled in the same or alternate rows enhanced pasture yield and quality over 4 years","authors":"A. Black, T. Myint, Arulmageswaran Shampasivam, Shuo Yang","doi":"10.33584/rps.17.2021.3470","DOIUrl":"https://doi.org/10.33584/rps.17.2021.3470","url":null,"abstract":"This paper reports on the effects of plant species diversity and sowing method on pasture yield and quality. Nineteen seed mixtures of perennial ryegrass (PR), plantain (Pl), white clover (WC) and red clover (RC) were sown on 26 March 2015 at Lincoln University. Four mixtures of PR, Pl and WC were repeated with species separated in alternate drill rows. Plots were grazed by sheep and irrigated. After 4 years, a mixture with 25% of each species based on seed count – equivalent to 7.5 kg PR, 5.6 kg Pl, 1.9 kg WC and 4.4 kg RC (19.4 kg total seed)/ha – produced an optimal balance of increased total yield (17.44 t DM/ha/yr), weed suppression (0% of total yield), metabolisable energy (11.4 MJ/kg DM) and crude protein (19% of DM). Sowing method had no effect. Plant diversity enhanced pasture production through positive interactions and identity effects among the legumes (WC and RC) and non-legumes (PR and Pl). The strength of interactions between species depended on the identity and relative abundances of the species involved. The diversity effects occurred alongside shifts in species relative abundances over time. This study demonstrated an experimental basis for the evaluation of multi-species pasture mixtures.","PeriodicalId":407057,"journal":{"name":"NZGA: Research and Practice Series","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124023223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}