Abstract
Abstract The influence of N in slurry or in mineral fertilizers on herbage yield and nitrogen fixation by white clover grown in mixed swards was investigated. Two levels of N in cattle slurry were compared with a range of mineral N fertilization. The percentage of N derived from symbiosis (% Nsym) was measured by the 15 N‐isotope dilution method. The measurements were made in spring 1987 in two 4‐year‐old field trials, and included two out of five harvests. The % N sym was approximately 90% without N fertilization. It decreased in response to both mineral N and N in slurry but did not fall below 63%. The sum of two harvests revealed that 51·2 kg N ha −1 were fixed in the absence of N fertilization. With 75 kg mineral N ha −1 or 50 m 3 cattle slurry ha −1 , the yield of fixed N decreased to 17·2 and 24·9 kg ha −1 , respectively. When compared on the basis of the fertilizer effect on dry matter yield and N concentration of perennial ryegrass, the decrease in yield of N fixed due to treatment with cattle slurry was less than that due to mineral N fertilizer. This was owing to the smaller extent of the depression in the proportion of white clover in the sward when the same amount of N was applied in cattle slurry, as compared with mineral fertilizer, although % N sym responded similarly to both types of N fertilization.
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Claims 9
Claim · model-written summary
Without nitrogen fertilization, white clover symbiotic nitrogen percentage was approximately 90%.
- Taxon
- white clover
Trifolium repenst0 - Outcome
- % N syme0
- Value
- 90%e0
- Qualifier
- without N fertilizatione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The % N sym was approximately 90% without N fertilization.”
t0“white clover”
Claim · model-written summary
Mineral nitrogen decreased symbiotic nitrogen percentage, which remained at least 63%.
- Taxon
- white cloverTrifolium repenst0
- Treatment
- mineral Ne0
- Outcome
- % N syme1
- Direction
- decreasede0
- Qualifier
- did not fall below 63%e0
- Comparator
- without N fertilizatione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It decreased in response to both mineral N and N in slurry but did not fall below 63%.”
e1“The % N sym was approximately 90% without N fertilization.”
t0“white clover”
Claim · model-written summary
Slurry nitrogen decreased symbiotic nitrogen percentage, which remained at least 63%.
- Taxon
- white cloverTrifolium repenst0
- Treatment
- N in slurrye0
- Outcome
- % N syme1
- Direction
- decreasede0
- Qualifier
- did not fall below 63%e0
- Comparator
- without N fertilizatione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It decreased in response to both mineral N and N in slurry but did not fall below 63%.”
e1“The % N sym was approximately 90% without N fertilization.”
t0“white clover”
Claim · model-written summary
White clover fixed 51·2 kg N ha −1 across two harvests without nitrogen fertilization.
- Taxon
- white cloverTrifolium repenst0
- Outcome
- fixede0
- Value
- 51·2 kg N ha −1e0
- Qualifier
- in the absence of N fertilizatione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The sum of two harvests revealed that 51·2 kg N ha −1 were fixed in the absence of N fertilization.”
t0“white clover”
Claim · model-written summary
Applying 75 kg mineral N ha −1 decreased fixed nitrogen yield to 17·2 kg ha −1.
- Taxon
- white cloverTrifolium repenst0
- Treatment
- 75 kg mineral N ha −1e0
- Outcome
- yield of fixed Ne0
- Direction
- decreasede0
- Value
- 17·2e0
- Qualifier
- kg ha −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With 75 kg mineral N ha −1 or 50 m 3 cattle slurry ha −1 , the yield of fixed N decreased to 17·2 and 24·9 kg ha −1 , respectively.”
t0“white clover”
Claim · model-written summary
Applying 50 m 3 cattle slurry ha −1 decreased fixed nitrogen yield to 24·9 kg ha −1.
- Taxon
- white cloverTrifolium repenst0
- Treatment
- 50 m 3 cattle slurry ha −1e0
- Outcome
- yield of fixed Ne0
- Direction
- decreasede0
- Value
- 24·9 kg ha −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With 75 kg mineral N ha −1 or 50 m 3 cattle slurry ha −1 , the yield of fixed N decreased to 17·2 and 24·9 kg ha −1 , respectively.”
t0“white clover”
Claim · model-written summary
Slurry caused a smaller decrease in fixed nitrogen yield than mineral fertilizer when compared by their effects on ryegrass dry matter yield and nitrogen concentration.
- Taxon
- white cloverTrifolium repenst0
- Treatment
- cattle slurrye0
- Outcome
- yield of N fixede0
- Direction
- decreasee0
- Qualifier
- the fertilizer effect on dry matter yield and N concentration of perennial ryegrasse0
- Comparator
- mineral N fertilizere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When compared on the basis of the fertilizer effect on dry matter yield and N concentration of perennial ryegrass, the decrease in yield of N fixed due to treatment with cattle slurry was less than that due to mineral N fertilizer.”
t0“white clover”
Claim · model-written summary
Slurry depressed the white clover proportion less than mineral fertilizer at equal nitrogen application.
- Taxon
- white cloverTrifolium repense0
- Treatment
- cattle slurrye0
- Outcome
- proportion of white clovere0
- Direction
- depressione0
- Qualifier
- the same amount of Ne0
- Comparator
- mineral fertilizere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the smaller extent of the depression in the proportion of white clover in the sward when the same amount of N was applied in cattle slurry, as compared with mineral fertilizer”
Claim · model-written summary
Symbiotic nitrogen percentage responded similarly to slurry and mineral nitrogen fertilization.
- Taxon
- white cloverTrifolium repenst1
- Treatment
- cattle slurryt0
- Outcome
- % N syme0
- Direction
- similarlye0
- Comparator
- mineral fertilizerst0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“although % N sym responded similarly to both types of N fertilization.”
t0“nitrogen in cattle slurry and mineral fertilizers”
t1“white clover”
The same questions in other papers
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- no effect
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See all 7 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
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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.