Journal of New Zealand Grasslands最新文献

{"title":"Nitrate effects on N2 fixation, growth and feed quality of lucerne and perennial lupin","authors":"Eilish Burrows, A. Mills, D. Dash, D. Jack, M. Andrews, A. Black","doi":"10.33584/jnzg.2021.83.3511","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3511","url":null,"abstract":"The 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 control plant. The experiment was repeated. 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: 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 increased 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 N in sheep urine patch) perennial lupin obtained much of its N from N2 fixation.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44247452","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":"Variable-rate application of fertiliser – a new tool for farm system and environmental performance?","authors":"W. King, P. Pletnyakov, A. Taylor, Chavi Ekanayake, A. Werner","doi":"10.33584/jnzg.2021.83.3515","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3515","url":null,"abstract":"Nitrogenous fertilisers – especially urea – are key inputs into many farming systems. With increasing restrictions on nitrogen fertiliser application, there is an urgent need to ensure that nitrogen is used effectively. One technology that has been developed to contribute to this challenge is variable-rate application (VRA) of fertiliser. The theory is that fertiliser is applied at higher rates where there is sufficient grass cover to utilise the fertiliser, and at lower rates where grass cover is reduced (or absent). This trial looked at the effect of VRA on pasture production on five farms over one season and estimated the impact of those changes on farm system metrics, including environmental performance. Averaged over all five farms, there was no statistically significant difference between VRA and blanket-rate application of fertiliser on pasture production. However, one farm did show a significant difference. Although the absolute difference was small, it suggested that VRA could be a useful tool in addressing the challenge of driving better farm performance with reduced environmental impact.  ","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46523110","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":"Farming with reduced winter cropping in southern New Zealand: the risks and practicalities","authors":"D. Stevens, Matt Canton, S. Harpham","doi":"10.33584/jnzg.2021.83.3500","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3500","url":null,"abstract":"Winter cropping practices to provide feed for livestock are being challenged by new freshwater and animal welfare regulations. Investigations to reduce reliance on winter forage crops in southern New Zealand tested farming resilience and practical on-farm all-grass wintering using 60% of the 13,900 breeding ewes at Mararoa Station in the Te Anau basin. Testing the system robustness over time, using modelling of climatic variation, demonstrated that reducing the area of winter forage crop by 25% increased EBITDA by approximately 6% and had similar variations in net earnings over a 10-year period of pasture and crop yield fluctuations. On-farm testing highlighted the need for long-term planning and active management of both the feed resource and animals. Active engagement and contributions of staff were the key to implementing a Less-crop system. Measuring pastures and animal responses provided data to inform key decision making. The success of this test demonstrated the need for staff engagement and accurate implementation from the management team on the ground.  The team needed to be open minded, well planned and have a willingness to implement new practices and learn on the job, providing a platform for future success. Forward planning using Farmax modelling provided a framework for the implementation of the practical test and provided confidence to test future reductions in winter forage crops. Changes to whole-farm practices need to incorporate activities throughout the year to implement significant reductions in winter forage crop use.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45207794","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":"Improving irrigation management on hillslope pastures","authors":"S. Langer","doi":"10.33584/jnzg.2021.83.3495","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3495","url":null,"abstract":"Improving irrigation management in hillslope catchments to mitigate water and nutrient losses requires a better understanding of soil hydrology. A field trial was set up in a small catchment on a centre-pivot irrigated dairy farm. Runoff was monitored over two irrigation seasons across a hillslope and at the catchment outlet. Seasonal rainfall variability influenced the start, frequency and amount of irrigation applied. Irrigation stared earlier in the second season due to a large soil moisture deficit. Nearly 40% of the runoff events in the second season were directly linked to irrigation. \u0000The APSIM model was used to investigate the effects irrigation management on runoff and pasture production. Simulations suggest that changing irrigation could increase pasture yield by 10%, but lead to potentially greater runoff. Using soil moisture to control irrigation improved performance, although where soil moisture was monitored was important. Using frequent and smaller application depths resulted in yield increase and less runoff. Simulation of variable rate irrigation did not produce further gains. The best approach to reduce overall runoff losses was to maintain a soil moisture deficit after irrigation. The impact of changing irrigation management over the whole farm system and its effect on the environment needs further research.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46871711","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":"Empirical assessment of a genomic breeding strategy in perennial ryegrass","authors":"M. Faville, Jana Schmidt, M. Trolove, P. Moran, Won Hong, Mingshu Cao, S. Ganesh, R. George, B. Barrett","doi":"10.33584/jnzg.2021.83.3490","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3490","url":null,"abstract":"In genomic selection (GS) DNA markers and trait data are integrated in a model that then predicts genomic-estimated breeding values (GEBV’s) for individuals using DNA marker information alone, improving breeding efficiency. We assessed a genomic breeding strategy (APWFGS) for improving dry matter yield (DMY) in perennial ryegrass. In APWFGS the best-performing half-sibling families (HS) are identified using phenotypic data and GS is used to select the best individuals within those HS. Four selections were made from three breeding populations: Base (random sample of plants from all HS), HSP (random sample from the six phenotypically-best HS), APWFGS and APWFGS-L (top or bottom 5% of plants, respectively, selected by GEBV from the six HS).  Selected plants were polycrossed, creating 12 experimental synthetics that were evaluated as sown rows for DMY (n=7 harvests) in field trials at two locations over 18 months.  In each population, mean DMY across locations and harvests showed a trend of APWFGS> HSP>Base.  Averaged across all populations, APWFGS increased DMY by 43% (P<0.05) compared to Base, more than twice the level of improvement achieved with conventional HSP. Our results show the APWFGS breeding approach can substantially improve selection response for a genetically complex trait from a single breeding cycle. ","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49279825","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":"A summary of research results on pasture responses to fertiliser and lime in the South Island hill and high country","authors":"J. Morton","doi":"10.33584/jnzg.2021.83.3492","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3492","url":null,"abstract":"The published results from trials used to determine nutrient and lime requirements of legume-based pastures in South Island hill and high country are summarised. Most of the research in the 1950’s and 1960’s found that sulphur (S) alone was required on the less weathered and leached Semi-arid and Pallic soils but both S and phosphorus (P) were required on the more weathered and leached Brown soils. The severe lack of S necessitated the application of rapidly plant-available S as gypsum. Research in the 1970’s and 1980’s determined the most effective particle size ranges in relation to frequency of application of elemental S to provide adequate S. This work highlighted a need for sufficient S for legume growth before a growth response to P was measured on most soils which has resulted in the manufacture of a range of suitable sulphur fortified superphosphate products. During this 40-year period a limited amount of work showed that nitrogen (N) fertiliser could enhance the growth of resident grasses and legumes and that added S could improve the response. Molybdenum (Mo) has been the only trace element that has been lacking for pasture growth and research has been reported that defines optimal rates, frequency of application and criteria for interpretation. In the last 20 years, the need lime to alleviate soil aluminium (Al) toxicity on these mainly acidic soils has been demonstrated to allow legumes to establish and persist.  \u0000Current gaps in available information indicate potential areas for more research. These gaps include identifying responses to rates of P and S on pasture with varying legume content on different hill slopes, differential application of elemental sulphur and lime on shady aspects of Semi-Arid and Pallic soils, definition of P and S requirements of pure legume swards, the role of fertiliser N to improve legume establishment, fertiliser and management options to break down thatch at the soil surface and improve legume establishment, determination of the soil and landscape factors that affect the spatial variability of soil Al concentrations, further confirmation of the role of lime injection into soil layers with high soil Al toxicity,  the assessment of test strips of applied Mo to assist in the identification of deficiencies in legumes and the combination of information into a decision support system to aid farmers in their selection of legume species and fertiliser and lime requirements for different areas of their farms.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42543256","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":"Greenhouse gas emissions from New Zealand sheep and beef farms","authors":"R. Vibart, G. Rennie, K. Hutchinson, A. Burtt, J. Chrystal, R. Dynes","doi":"10.33584/jnzg.2021.83.3501","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3501","url":null,"abstract":"This project aimed to develop a dataset containing animal policies, production efficiencies, and greenhouse gas (GHG) emissions of a large number of sheep and beef farms, and to examine the relationships between farm management and farm physical constraints, and GHG emissions. We used the farm-scale model Farmax to estimate feed inventories, livestock policies and GHG emissions of 170 New Zealand sheep and beef farms. Emissions were calculated from Farmax outputs using Agricultural Inventory methodology. We used a quantitative approach to cluster farms based on physical constraints and management attributes. Mean annual biological GHG emissions from the modelled farms were 3,662 kg CO2 equivalents (CO2-e) per effective hectare, and ranged from 157 to 7,096 kg CO2-e/effective ha. As stocking rate and animal product (wool + net carcass weight) per effective hectare increased, GHG emissions increased. However, there was considerable variability in the data; farms with GHG emissions of approximately 4,000 kg CO2-e/effective ha had an almost three-fold difference in animal product (range 129 to 360 kg/effective ha). Our work provides a holistic assessment of the farm-scale drivers of GHG emissions and a comprehensive current state of affairs or baseline from which future trends in farm-scale GHG emissions can be established.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47069885","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":"Growth rates and persistence of annual and perennial clovers","authors":"S. Olykan, R. Lucas, S. Hunter, D. Moot","doi":"10.33584/jnzg.2021.83.3494","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3494","url":null,"abstract":"This study quantified the temporal productivity of monocultures of four annual and two perennial clover species in a summer dry environment at Lincoln University, Canterbury, New Zealand. Clovers were ungrazed in the first year to enable natural re-establishment of the annuals, but grazed in the second year. \u0000In 2019 clover cultivar affected (P<0.001) yield in early spring (24th September) with ‘Viper’ balansa (Trifolium michelianum) producing 5.0 t DM/ha compared (P<0.05) with 3.5 t for ‘Arrotas’ arrowleaf (T. vesiculosum), 3.2 t for ‘Antas’ and ‘Woogenellup’ sub clovers (T. subterraneum), 1.6 t for ‘Kopu’ white clover (T. repens) and 1.2 t for ‘Relish’ red clover (T. pratense). ‘Arrotas’ grew 111 kg DM/ha/d from 14th to 28th August, ‘Viper’ grew 123 kg DM/ha/d from 28th August to 24th September and then 183 kg DM/d to 9th October. \u0000After a dry autumn in 2020, ‘Kopu’ white and ‘Relish’ red persisted, but only sub clovers ‘Napier’ and ‘Woogenellup’ successfully re-established. By 17th September, accumulated dry matter yield (t) differed with ‘Woogenellup’ sub (4.3) and ‘Relish’ red (3.7) producing more than ‘Kopu’ white  (2.8) and ‘Napier’ sub (2.2). ‘Woogenellup’ sub clover grew at 72 kg/ha/day from 20th August to 17th September, which was more than twice the rate of the other clovers (~30 kg/ha/day). These four clovers continued to provide grazable herbage through the second year. \u0000In 2020 the re-establishment of arrowleaf, balansa and Persian (T. resupinatum) clovers was poor, and each yielded <0.5 t/ha by 17th September, with their plots dominated by weeds. These results confirm monocultures of top flowering annual clovers are productive in their first year but poor re-establishment may occur in their second year. They may therefore be best suited as one-year specialised crops for grazing or conserved feed. \u0000The earlier growth profiles of the annual compared with perennial clovers suggests there is potential to increase their use in summer dry environments to meet early spring feed requirements of ewes and lambs.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45520482","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":"Progress towards delivering high metabolisable energy ryegrass","authors":"Zac Beechey-Gradwell Beechey-Gradwell","doi":"10.33584/jnzg.2021.83.3493","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3493","url":null,"abstract":"A method developed at AgResearch to increase leaf fatty acids (FA) and plant growth called ‘High metabolizable energy’ (‘HME’) could elevate the nutritional quality and productivity of perennial ryegrass-based pastures. The industry strategy has been to perform HME ryegrass field trials offshore to test whether the herbage FA, gross energy (GE) and yield enhancing traits observed in containment translate into field swards. To complement the field testing programme, we have also characterised the growth and nutritional profile of HME miniswards under simulated grazing in containment. The results from one such trial are presented. The major changes measured in HME miniswards; increased FA (+0.8–1.4 %DW), increased GE (+0.3–0.5 MJ/kgDM), and generally similar herbage DW production, closely mirror data from field trials with hemizygous HME populations in the Midwest USA. Changes in other HME nutritional components were generally minor, although WSC was reduced late in the diurnal cycle. Secondary effects of HME on photosynthesis appear to be diminished in swards, suggesting that HME yield benefits may be limited to specific environment and management scenarios. The primary benefit of HME technology is thus expected to come from increasing the energy density of pasture, and animal feeding trials using homozygous HME material are now required.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42903809","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":"Response of white clover cultivars to sheep and beef cattle grazing management across three pastoral environments in New Zealand.","authors":"Z. Jahufer, A. Heslop, G. Cousins, D. Woodfield, J. Ford","doi":"10.33584/jnzg.2021.83.3491","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3491","url":null,"abstract":"White clover (Trifolium repens L.) is the main legume component in temperate perennial pasture swards in New Zealand. Developing broadly adapted cultivars is an important objective in white clover breeding programs. Field trials across years, seasons, locations and grazing environments, help breeders select superior material, and assess the merit of new cultivars available to farmers. This paper is based on results from analysis of data from field trials across three locations in New Zealand: Kerikeri (cattle grazed), Palmerston North (cattle grazed) and Lincoln (sheep grazed), evaluating 44 experimental varieties and 16 cultivars for seasonal growth and leaf size. We report on performance of the 16 cultivars across the three locations. \u0000Significant genotype-by-environment interactions were estimated for seasonal growth and leaf size.  The importance of conducting multi-location and year evaluation trials under cattle and sheep grazing management methods (rotational/set stocking) was demonstrated. Among the 16 cultivars, Legacy showed above average performance across all 3 locations.  Hilltop when compared among similar leaf size material, showed above average seasonal growth across years under rotational sheep grazing management during the first 4 years of the trial at Lincoln. Hilltop also showed above average seasonal growth under set socking with sheep in years 5 and 6 at Lincoln.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43513242","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}