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dc.contributor.authorO'Brien, Kieran
dc.date.accessioned2020-07-20T23:14:29Z
dc.date.available2020-07-20T23:14:29Z
dc.date.issued2010
dc.identifier.urihttps://hdl.handle.net/10182/12202
dc.descriptionPoor quality scan - replace with better version when available
dc.description.abstractThe timing of N application in autumn determines the pasture response. A field experiment was conducted to investigate effects of N fertiliser rate (O (N1) and 100 (N2) kg N/ha) and defoliation height (40 (Hl) and 80 (H2) mm) applied on two dates in autumn (10 March (01) and 7 April (02), 2010) on perennial ryegrass/white clover swards over two regrowth periods at Lincoln University. The total yield response was greater for D1 than D2 (1557 vs 557 kg DM/ha) with the majority of this response occurring in the first regrowth period. N increased the leaf appearance rate (LAR) of ryegrass by about 15-23% but doubled the leaf elongation rate (LER) and daughter tiller appearance rate in the first regrowth period, and increased the LER by 29% and tiller populations by 1200/m² in the second regrowth (These differences would have contributed to a faster rate of canopy development for light interception and photosynthesis. The lower N response for D2 than D1 was associated with a lower LAR, LER and daughter tiller appearance in days (but constant in thermal time), which would have slowed canopy development. Average growth rates of the swards expressed in degree days were slower for D2 than D1 in the first regrowth (2.3 vs 4.4 kg DM/ha/°Cday), possibly due to changes in radiation use efficiency. Yield responses to N were not affected by defoliation height. Therefore time of application was the main factor that influenced the N response because it determines the temperatures that the swards experience.en
dc.format.extentx, 68 pages
dc.language.isoenen
dc.publisherLincoln Universityen
dc.rights.urihttps://researcharchive.lincoln.ac.nz/page/rights
dc.subjectdaughter tillersen
dc.subjectdefoliation heighten
dc.subjectleaf appearance rateen
dc.subjectleaf elongation rateen
dc.subjectphyllochronen
dc.subjecttime of nitrogen applicationen
dc.subjectthermal timeen
dc.titleDry matter yield and tiller development of perennial ryegrass/white clover swards in response to autumn applied nitrogen : A dissertation submitted for partial fulfilment of the requirement for the degree of Bachelor of Agricultural Science with Honoursen
dc.typeDissertationen
thesis.degree.grantorLincoln Universityen
thesis.degree.levelOtheren
thesis.degree.nameBachelor of Agricultural Science (Honours)en
lu.thesis.supervisorBlack, A.
lu.contributor.unitDepartment of Agricultural Sciencesen
dc.rights.accessRightsDigital thesis can be viewed by current staff and students of Lincoln University only.en
dc.subject.anzsrc0703 Crop and Pasture Productionen
dc.subject.anzsrc079902 Fertilisers and Agrochemicals (incl. Application)en


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