Abstract
Abstract Mixed pastures of white clover and ryegrass are profitable and widely used. However, loss of clover is common with time due to N fertiliser applications in late winter. The factors that cause this loss have yet to be determined. This work investigated reasons for the competitive disadvantage suffered by white clover relative to ryegrass in autumn and winter. White clover ( Trifolium repens cv. ‘Grasslands Huia’) and ryegrass (Lolium perenne cv. ‘Grasslands Nui’) were sown in March in Canterbury, New Zealand, and grown as single plants in silica sand. Nitrogen (N; 0.5 mol m –3 N); was applied daily simulating an unfertilised soil; solution N concentration was increased to 5.0 mol m –3 N for treatments in autumn (May) or winter (August), simulating fertiliser treatment. Net photosynthesis was measured before each harvest and over a diurnal period at 123 days after sowing. Plants were destructively harvested six times (33–185 days after sowing) and plant dry weight and N concentration (%) measured. White clover had a significantly ( P < 0.05) lower dry weight than ryegrass. Extra N applied from May significantly increased ( P < 0.05) dry weight of ryegrass. No significant changes in shoot N concentration were found. Except at the last harvest, net photosynthesis was significantly lower ( P < 0.05) in white clover than in ryegrass; this was also apparent for diurnal net photosynthetic rates 123 days after sowing. Results indicated that white clover growth was limited by temperature, whereas ryegrass growth was limited by N supply.
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Claims 7
Claim · model-written summary
White clover dry weight was significantly lower than ryegrass.
- Taxon
- White clover
Trifolium repense0 - Outcome
- dry weighte0
- Direction
- lowere0
- Value
- P < 0.05e0
- Comparator
- ryegrasse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“White clover had a significantly ( P < 0.05) lower dry weight than ryegrass.”
Claim · model-written summary
Extra nitrogen from May significantly increased ryegrass dry weight.
LoliumNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Extra N applied from May significantly increased ( P < 0.05) dry weight of ryegrass.”
Claim · model-written summary
Shoot nitrogen concentration did not change significantly.
- Taxon
- white clover (Trifolium repens) and perennial ryegrass (Lolium perenne)Trifolium repens
Lolium perennet0 - Treatment
- nitrogen fertiliser applied in autumn and wintert0
- Outcome
- shoot N concentratione0
- Direction
- No significant changese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No significant changes in shoot N concentration were found.”
t0“white clover (Trifolium repens) and perennial ryegrass (Lolium perenne) to nitrogen fertiliser applied in autumn and winter”
Claim · model-written summary
White clover net photosynthesis was significantly lower than ryegrass except at the last harvest.
- Taxon
- white cloverTrifolium repense0
- Outcome
- net photosynthesise0
- Direction
- lowere0
- Qualifier
- Except at the last harveste0
- Comparator
- ryegrasse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Except at the last harvest, net photosynthesis was significantly lower ( P < 0.05) in white clover than in ryegrass”
Claim · model-written summary
White clover diurnal photosynthesis was lower than ryegrass at 123 days.
- Taxon
- white cloverTrifolium repenst0
- Outcome
- diurnal net photosynthetic ratese0
- Qualifier
- 123 days after sowinge0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this was also apparent for diurnal net photosynthetic rates 123 days after sowing.”
t0“white clover”
Claim · model-written summary
The authors infer temperature limited white clover growth.
- Taxon
- white cloverTrifolium repense0
- Outcome
- growthe0
- Qualifier
- temperaturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“white clover growth was limited by temperature”
Claim · model-written summary
The authors infer nitrogen supply limited ryegrass growth.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ryegrass growth was limited by N supply”
The same questions in other papers
fertilization · nutrient: content · Trifolium repens (white clover)Positive and negative results
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- positive
- positive
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See all 6 papers →fertilization · nutrient: content · Lolium perenne (perennial ryegrass)Positive and negative results
4 papers in the same direction as this paper · 12 in the opposite direction
- positive
- positive
- positive
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See all 17 papers →nitrogen · growth · LoliumPositive and negative results
24 papers in the same direction as this paper · 3 in the opposite direction
- no effect
- negative
- no effect
24 papers more in this group
See all 28 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.