Abstract
The effect of 4 or 5 forms of nitrogenous fertilizer on the yield and botanical composition of a perennial ryegrass/white clover sward was examined in 3 different years. The uptake of N by the grass was also estimated. Ammonium nitrate (as Nitro‐Chalk), ammonium sulphate and urea gave similar yield increases, although in one year, when high rainfall followed the application of fertilizer, urea was slightly inferior. Gas liquor gave variable responses in the 3 years. Nitroform, a urea‐formaldehyde, was generally less effective than the other forms of fertilizer. The uptake of N from Nitro‐Chalk, sulphate of ammonia and urea did not vary greatly from year to year although the uptake of soil N by the untreated control did. Response to N in the yield of dry‐matter varied from year to year. This variation was due partly to differences in the amount of clover present and partly to differences in the extent to which N taken up by the grass was used for the synthesis of dry‐matter. The white clover content of the sward was not greatly reduced in spring by the application of the fertilizer, and there were no consistent differences between the effects on clover of the forms of the fertilizer. A reduction was apparent in the summer but not in the autumn. It may be necessary to increase replication above the level of 3 to 6 which is frequently employed in field experiments if more precise quantitative estimates of response and of the relative efficiency of various forms of nitrogenous fertilizer are required.
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Claims 13
Claim · model-written summary
Ammonium nitrate, ammonium sulphate and urea produced similar yield increases in the sward.
- Taxon
- PERENNIAL RYEGRASS / WHITE CLOVER SWARDt0
- Treatment
- Ammonium nitrate (as Nitro‐Chalk), ammonium sulphate and ureae0
- Outcome
- yielde0
- Direction
- increasese0
Not reportedComparator
Verbatim
e0“Ammonium nitrate (as Nitro‐Chalk), ammonium sulphate and urea gave similar yield increases”
t0“PERENNIAL RYEGRASS / WHITE CLOVER SWARD”
Claim · model-written summary
Urea was slightly inferior for yield in one year with high rainfall after fertilization.
- Taxon
- perennial ryegrass/white clover swardt0
- Treatment
- ureae0
- Outcome
- inferiore0
- Direction
- inferiore0
- Qualifier
- high rainfall followed the application of fertilizere0
Not reportedComparator
Verbatim
e0“in one year, when high rainfall followed the application of fertilizer, urea was slightly inferior”
t0“PERENNIAL RYEGRASS / WHITE CLOVER SWARD”
Claim · model-written summary
Gas liquor produced variable responses over three years.
Not reportedComparatorDirection
Verbatim
e0“Gas liquor gave variable responses in the 3 years”
t0“PERENNIAL RYEGRASS / WHITE CLOVER SWARD”
Claim · model-written summary
Nitroform was generally less effective than the other fertilizer forms.
Verbatim
e0“Nitroform, a urea‐formaldehyde, was generally less effective than the other forms of fertilizer”
t0“PERENNIAL RYEGRASS / WHITE CLOVER SWARD”
Claim · model-written summary
Grass nitrogen uptake from three fertilizer forms varied little across years.
Verbatim
e0“The uptake of N from Nitro‐Chalk, sulphate of ammonia and urea did not vary greatly from year to year”
t0“PERENNIAL RYEGRASS / WHITE CLOVER SWARD”
Claim · model-written summary
Soil nitrogen uptake by the untreated control varied between years.
Not reportedDirection
Verbatim
e0“the uptake of soil N by the untreated control did”
t0“PERENNIAL RYEGRASS / WHITE CLOVER SWARD”
Claim · model-written summary
Dry matter yield response to nitrogen varied by year.
Not reportedDirection
Verbatim
e0“Response to N in the yield of dry‐matter varied from year to year”
t0“PERENNIAL RYEGRASS / WHITE CLOVER SWARD”
Claim · model-written summary
Yearly variation in dry matter yield response was partly attributed to clover amount and conversion of absorbed nitrogen to dry matter.
Verbatim
e0“This variation was due partly to differences in the amount of clover present and partly to differences in the extent to which N taken up by the grass was used for the synthesis of dry‐matter”
t0“PERENNIAL RYEGRASS / WHITE CLOVER SWARD”
Claim · model-written summary
Fertilizer application did not greatly reduce spring white clover content.
- Taxon
- white clover
Trifolium repense0 - Treatment
- application of the fertilizere0
- Outcome
- white clover contente0
- Direction
- not greatly reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The white clover content of the sward was not greatly reduced in spring by the application of the fertilizer”
Claim · model-written summary
Fertilizer forms had no consistent difference in their effects on clover.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Treatment
- forms of the fertilizere0
- Outcome
- effects on clovere0
- Direction
- no consistent differencese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there were no consistent differences between the effects on clover of the forms of the fertilizer”
t0“WHITE CLOVER”
Claim · model-written summary
Clover content was reduced in summer after fertilizer application.
- Taxon
- white cloverTrifolium repense1
- Treatment
- application of the fertilizere1
- Outcome
- white clover contente1
- Direction
- reductione0
- Qualifier
- summere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A reduction was apparent in the summer but not in the autumn”
e1“white clover content of the sward was not greatly reduced in spring by the application of the fertilizer”
Claim · model-written summary
Clover content showed no reduction in autumn after fertilizer application.
- Taxon
- white cloverTrifolium repense1
- Treatment
- application of the fertilizere1
- Outcome
- white clover contente1
- Direction
- not in the autumne0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A reduction was apparent in the summer but not in the autumn”
e1“white clover content of the sward was not greatly reduced in spring by the application of the fertilizer”
Claim · model-written summary
More than three to six replications may be needed for precise quantitative fertilizer comparisons.
Verbatim
e0“It may be necessary to increase replication above the level of 3 to 6 which is frequently employed in field experiments if more precise quantitative estimates of response and of the relative efficiency of various forms of nitrogenous fertilizer are required”
t0“PERENNIAL RYEGRASS / WHITE CLOVER SWARD”
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See all 6 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.