dc.contributor.advisor | Romera, Alvaro J. | |
dc.contributor.advisor | Schipper, Louis A. | |
dc.contributor.advisor | Doole, Graeme J. | |
dc.contributor.author | Robertson, Charlotte | |
dc.date.accessioned | 2020-03-31T22:25:26Z | |
dc.date.available | 2020-03-31T22:25:26Z | |
dc.date.issued | 2020 | |
dc.identifier.citation | Robertson, C. (2020). Dairy farm system solutions that reduce nitrate leaching and their consequences for profitability: Using plantain, fodder beet and oats on a Canterbury case study farm (Thesis, Master of Science (Research) (MSc(Research))). The University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/13533 | en |
dc.identifier.uri | https://hdl.handle.net/10289/13533 | |
dc.description.abstract | Dairy products provide nutrition, energy and income for much of the world. It is currently necessary to continue their supply albeit in a more environmentally sustainable manner. Excess nitrate (NO₃⁻) from dairy cow urine patches can leach from soils with significant consequences for receiving waters. Some potential on-farm management solutions exist, but can be costly to adopt.
The research aim of this thesis was to test prescribed management solutions for reducing NO₃⁻ leaching by 20%, in comparison to an existing farm management baseline for the 2017/2018 dairy season, whilst maintaining profitability. Nitrate leaching and profitability were estimated for a south Canterbury case study dairy farm using the models FARMAX Dairy and OVERSEER® Nutrient Budgets.
Prescribed management practices from the Forages for Reduced Nitrate Leaching (FRNL) programme were modelled to achieve this target. The principles were: (i) reducing nitrogen (N) in cows’ diets through low-N feed (fodder beet), (ii) recapturing N from soils through catch crops (oats) and (iii) diluting urinary N (through ingested plantain). Two crop treatments were applied to the Baseline to address (i) and (ii). Plantain was included in pastures to address (iii). A number of key assumptions were made about plantain’s efficacy for reducing NO₃⁻ leaching. Plantain was not expected to persist in pasture swards without active management and so a persistence curve and maintenance treatments were incorporated. A sensitivity analysis investigated the influence of soil type and poorer persistence of plantain on treatment success.
Most treatments reduced NO₃⁻ leaching, but significant management inputs were required to achieve a 20% reduction from the Baseline. Plantain was identified as the key forage for reducing NO₃⁻ leaching. When plantain was included in pasture swards and undersown every second year to increase its presence, NO₃⁻ leaching could be reduced by 21-24%, however, profitability was reduced by 5-10%. Fodder beet and oats had little impact on NO₃⁻ leaching because the crop area was small in comparison to the rest of the farm (4%). There were no treatments that achieved a 20% reduction in NO₃⁻ leaching and maintained profitability.
The implications of this modelling study for real-life application are that if plantain can be maintained in the pasture sward at high enough levels NO₃⁻ leaching can be substantially reduced, though this would likely result in a loss of profit. | |
dc.format.mimetype | application/pdf | |
dc.language.iso | en | |
dc.publisher | The University of Waikato | |
dc.rights | All items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated. | |
dc.subject | nitrate leaching | |
dc.subject | fodder beet | |
dc.subject | catch crop | |
dc.subject | oats | |
dc.subject | modelling | |
dc.subject | dairy farm system | |
dc.subject | mixed pasture | |
dc.subject | profitability | |
dc.subject | Canterbury | |
dc.subject | plantain | |
dc.title | Dairy farm system solutions that reduce nitrate leaching and their consequences for profitability: Using plantain, fodder beet and oats on a Canterbury case study farm | |
dc.type | Thesis | |
thesis.degree.grantor | The University of Waikato | |
thesis.degree.level | Masters | |
thesis.degree.name | Master of Science (Research) (MSc(Research)) | |
dc.date.updated | 2020-03-25T23:00:35Z | |
pubs.place-of-publication | Hamilton, New Zealand | en_NZ |