Abstract
(1) Seeds of Poa annua L., P. trivialis L. and Festuca rubra L. were sown into gaps within established Lolium perenne L. (ryegrass) swards, planted in a systematic pattern to give a range of densities. (2) Competition above-ground was controlled by reflective aluminium tubes, and competition below-ground by polythene tubes. The supply of N and of P and K was varied. (3) When seedlings were in root competition with ryegrass, in the absence of N fertilizer, increasing the density of ryegrass from 2.5 to 40 plants m-2 reduced the dry weight of seedlings by about seventyfold. Increasing ryegrass density from 40 to 160 plants m-2 had little further effect. F. rubra was least affected by root competition and P. annua most affected. (4) Application of N fertilizer (400 kg N ha-' y-1) alleviated the effects of root competition, even though it also increased the yield of ryegrass approximately threefold at the highest densities. Applications of P and K fertilizer had little effect on the yield of either ryegrass or intersown seedlings at any density. (5) Shoot competition with ryegrass had little effect on seedlings, regardless of ryegrass density or fertilizer application. (6) These results indicate that established ryegrass plants mainly competed with invading seedlings below-ground, probably for nitrogen. (7) The results are discussed in the context of changes in the composition of sown pastures, and the invasion of gaps in plant communities.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Increasing ryegrass density from 2.5 to 40 plants m-2 reduced seedling dry weight about seventyfold without N fertilizer under root competition.
- Outcome
- dry weight of seedlingse0
- Direction
- reducede0
- Value
- about seventyfolde0
- Qualifier
- in the absence of N fertilizere0
LoliumNot reportedSetting
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Established Ryegrass and Invading Grass Seedlings”
e0“When seedlings were in root competition with ryegrass, in the absence of N fertilizer, increasing the density of ryegrass from 2.5 to 40 plants m-2 reduced the dry weight of seedlings by about seventyfold”
Claim · model-written summary
Increasing ryegrass density from 40 to 160 plants m-2 had little further effect on seedlings.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Established Ryegrass and Invading Grass Seedlings”
e0“Increasing ryegrass density from 40 to 160 plants m-2 had little further effect”
Claim · model-written summary
Festuca rubra was least affected by root competition.
- Taxon
- F. rubra
Festuca rubrae0 - Outcome
- least affected by root competitione0
- Direction
- least affectede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Established Ryegrass and Invading Grass Seedlings”
e0“F. rubra was least affected by root competition”
Claim · model-written summary
Poa annua was most affected by root competition.
Poa annuaOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Established Ryegrass and Invading Grass Seedlings”
e0“P. annua most affected”
Claim · model-written summary
N fertilizer alleviated root competition effects on seedlings.
- Treatment
- N fertilizer (400 kg N ha-' y-1)e0
- Outcome
- effects of root competitione0
- Direction
- alleviatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Established Ryegrass and Invading Grass Seedlings”
e0“Application of N fertilizer (400 kg N ha-' y-1) alleviated the effects of root competition”
Claim · model-written summary
N fertilizer increased ryegrass yield approximately threefold at the highest densities.
- Treatment
- N fertilizer (400 kg N ha-' y-1)e1
- Outcome
- yield of ryegrasse0
- Direction
- increasede0
- Value
- approximately threefolde0
- Qualifier
- at the highest densitiese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“it also increased the yield of ryegrass approximately threefold at the highest densities”
e1“Application of N fertilizer (400 kg N ha-' y-1)”
Claim · model-written summary
P and K fertilizer had little effect on ryegrass yield.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Applications of P and K fertilizer had little effect on the yield of either ryegrass or intersown seedlings at any density”
Claim · model-written summary
P and K fertilizer had little effect on intersown seedling yield.
- Taxon
- Grass Seedlingst0
- Treatment
- P and K fertilizere0
- Outcome
- intersown seedlingse0
- Direction
- little effecte0
Not reportedComparator
Verbatim
e0“Applications of P and K fertilizer had little effect on the yield of either ryegrass or intersown seedlings at any density”
t0“Invading Grass Seedlings”
Claim · model-written summary
Shoot competition with ryegrass had little effect on seedlings across densities and fertilizer applications.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Shoot competition with ryegrass had little effect on seedlings, regardless of ryegrass density or fertilizer application”
t0“Invading Grass Seedlings”
Claim · model-written summary
Established ryegrass mainly competed with invading seedlings below ground, probably for nitrogen.
- Taxon
- Grass Seedlingst0
- Outcome
- competed with invading seedlings below-grounde0
- Qualifier
- probably for nitrogene0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“established ryegrass plants mainly competed with invading seedlings below-ground, probably for nitrogen”
t0“Invading Grass Seedlings”
The same questions in other papers
phosphorus · yield · LoliumResults differ
3 papers in the same direction as this paper · 14 in the opposite direction
- positive
- positive
- positive
14 papers more in this group
See all 18 papers →potassium · yield · LoliumPositive and negative results
1 paper in the same direction as this paper · 9 in the opposite direction
- positive
- positive
- positive
7 papers more in this group
See all 11 papers →fertilization · yield · LoliumPositive and negative results
37 papers in the same direction as this paper · 9 in the opposite direction · 3 reporting no difference from an alternative
- no effect
- no effect
- no effect
46 papers more in this group
See all 50 papers →nitrogen · yield · LoliumPositive and negative results
41 papers in the same direction as this paper · 10 in the opposite direction · 2 reporting no difference from an alternative
- no effect
- negative
- no effect
50 papers more in this group
See all 54 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.