Abstract
Abstract Nine cultivars of white clover (Trifolium repens L.) were grown with perennial ryegrass ( Lolium perenne L.) and their productivity was determined over 3 years under nitrogen (N) fertiliser regimes of 0 or 390 kg N/ha per year. The site was grazed by sheep at 3‐ or 6‐week intervals and after each grazing N fertiliser was applied at 0 or 30 kg N/ha. Fertiliser N application increased total annual pasture production by 25–31%, with the largest proportional responses occurring in autumn and winter. White clover production decreased as a result of N application by 8, 17, and 30% in Years 1, 2, and 3 respectively. During the first 2 years this reduction in clover growth occurred only in spring, and in Year 3 it was also most marked in spring. There was no significant cultivar × N interaction for clover or total pasture production on an annual or seasonal basis. Thus, differences between cultivars in relative clover production were similar in the absence or presence of N fertiliser application. Clover cultivars varied greatly in productivity, and in the nil N treatment there was a positive correlation between clover production and total pasture production in Years 1 and 2, when clover content of pastures averaged 45 and 28% respectively. In all years, Aran and Kopu were higher yielding than all other cultivars. During winter, Kopu was 2–5 fold more productive than other cultivars. In all other seasons, Aran and Kopu were the most productive. There was a highly significant negative correlation between clover production and grass production in both N treatments and in all years. Thus, the more competitive erect‐growing, large‐leaved cultivars of Aran and Kopu maintained a lower associated grass component in their swards.
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Claims 8
Claim · model-written summary
Fertiliser N application increased total annual pasture production by 25–31%.
- Taxon
- white clover
Trifolium repenst0 - Treatment
- Fertiliser N applicatione1
- Outcome
- total annual pasture productione1
- Direction
- increasede1
- Value
- 25–31%e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Productivity of white clover cultivars under intensive grazing, as affected by high nitrogen fertiliser application”
e1“Fertiliser N application increased total annual pasture production by 25–31%”
Claim · model-written summary
N application reduced white clover production by 8, 17, and 30% in Years 1, 2, and 3 respectively.
- Taxon
- white cloverTrifolium repenst0
- Treatment
- N applicatione2
- Outcome
- White clover productione2
- Direction
- decreasede2
- Value
- 8, 17, and 30%e2
- Qualifier
- in Years 1, 2, and 3 respectivelye2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Productivity of white clover cultivars under intensive grazing, as affected by high nitrogen fertiliser application”
e2“White clover production decreased as a result of N application by 8, 17, and 30% in Years 1, 2, and 3 respectively”
Claim · model-written summary
In the nil N treatment, clover production and total pasture production were positively correlated in Years 1 and 2.
- Taxon
- white cloverTrifolium repenst0
- Treatment
- nil N treatmente3
- Outcome
- clover production and total pasture productione3
- Direction
- positive correlatione3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Productivity of white clover cultivars under intensive grazing, as affected by high nitrogen fertiliser application”
e3“in the nil N treatment there was a positive correlation between clover production and total pasture production in Years 1 and 2”
Claim · model-written summary
Aran and Kopu were higher yielding than all other white clover cultivars.
- Taxon
- white cloverTrifolium repenst0
- Material
- Aran and Kopue4
- Outcome
- higher yieldinge4
- Direction
- highere4
- Comparator
- all other cultivarse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Productivity of white clover cultivars under intensive grazing, as affected by high nitrogen fertiliser application”
e4“In all years, Aran and Kopu were higher yielding than all other cultivars.”
Claim · model-written summary
During winter, Kopu was 2–5 fold more productive than other white clover cultivars.
- Taxon
- white cloverTrifolium repenst0
- Material
- Kopue7
- Outcome
- more productivee7
- Value
- 2–5 folde7
- Comparator
- other cultivarse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Productivity of white clover cultivars under intensive grazing, as affected by high nitrogen fertiliser application”
e7“During winter, Kopu was 2–5 fold more productive than other cultivars”
Claim · model-written summary
In all other seasons, Aran and Kopu were the most productive white clover cultivars.
- Taxon
- white cloverTrifolium repenst0
- Material
- Aran and Kopue1
- Outcome
- the most productivee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Productivity of white clover cultivars under intensive grazing, as affected by high nitrogen fertiliser application”
e1“In all other seasons, Aran and Kopu were the most productive.”
Claim · model-written summary
Clover production and grass production were negatively correlated in both N treatments and in all years.
- Taxon
- white cloverTrifolium repenst0
- Treatment
- both N treatmentse5
- Outcome
- clover production and grass productione5
- Direction
- negativee5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Productivity of white clover cultivars under intensive grazing, as affected by high nitrogen fertiliser application”
e5“a highly significant negative correlation between clover production and grass production in both N treatments and in all years”
Claim · model-written summary
Aran and Kopu maintained a lower associated grass component in their swards.
- Taxon
- white cloverTrifolium repenst0
- Material
- Aran and Kopue6
- Outcome
- lower associated grass componente6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Productivity of white clover cultivars under intensive grazing, as affected by high nitrogen fertiliser application”
e6“Aran and Kopu maintained a lower associated grass component”
The same questions in other papers
nitrogen · yield · Trifolium repens (white clover)Results differ
10 papers in the same direction as this paper · 11 in the opposite direction · 2 reporting no difference from an alternative
- positive
- negative
- negative
20 papers more in this group
See all 24 papers →fertilization · yield · Trifolium repens (white clover)Positive and negative results
19 papers in the same direction as this paper · 6 in the opposite direction · 1 reporting no difference from an alternative
- negative
- negative
- no effect
23 papers more in this group
See all 27 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.