Abstract
SUMMARY A series of twenty-one nitrogen fertilizer rates ranging from 0 to 800 lb nitrogen/acre (897 kg/ha)/annum was applied on a pure S. 23 perennial ryegrass sward and on an S. 23 ryegrass sward containing S. 100 white clover. Total yields of herbage dry matter and crude protein from both swards at all the nitrogen rates were determined each year by cutting the herbage five times at approximately the same stage of growth on each occasion. Four-parameter growth curves relating herbage yield to nitrogen rate were fitted to the data, and are presented for the first 3 years of the experiment. On the pure-grass sward the response of dry-matter yield to nitrogen rate was almost linear between the 0 and 300 lb nitrogen/acre (336 kg/ha) rates, then it decreased steadily, becoming non-significant about the 500 lb/acre (560 kg/ha) rate. In contrast the response of crude-protein yield was virtually linear from the 0 to the 600–700 lb nitrogen/acre (673–785 kg/ha) rates. The inclusion of white clover in the sward increased the yields of dry matter and crude protein at the low nitrogen rates, but decreased the responses, with the result that the yields and responses of the grass + clover sward were not significantly different from those of the pure-grass sward at nitrogen rates above about 300 lb/ acre (336 kg/ha). In terms of profitability at present fertilizer prices the optimum nitrogen rate for dry-matter production on both swards was estimated to be 400–450 lb/ acre (448–504 kg/ha), whereas that for crude-protein production was greater than 600 lb/acre (673 kg/ha). The value of clover in a sward receiving nitrogen fertilizer is discussed.
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Claims 9
Claim · model-written summary
Pure-grass dry-matter yield response was nearly linear from 0 to 300 lb nitrogen/acre.
- Taxon
- perennial ryegrass
Lolium perennet0 - Treatment
- nitrogen ratee0
- Outcome
- dry-matter yielde0
- Direction
- almost lineare0
- Qualifier
- between the 0 and 300 lb nitrogen/acre (336 kg/ha) ratese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On the pure-grass sward the response of dry-matter yield to nitrogen rate was almost linear between the 0 and 300 lb nitrogen/acre (336 kg/ha) rates”
t0“perennial ryegrass”
Claim · model-written summary
Pure-grass dry-matter response decreased steadily above 300 lb nitrogen/acre and became nonsignificant near 500 lb/acre.
- Taxon
- perennial ryegrassLolium perennet0
- Treatment
- nitrogen ratee1
- Outcome
- dry-matter yielde1
- Direction
- decreased steadilye0
- Qualifier
- about the 500 lb/acre (560 kg/ha) ratee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“then it decreased steadily, becoming non-significant about the 500 lb/acre (560 kg/ha) rate”
e1“response of dry-matter yield to nitrogen rate”
t0“perennial ryegrass”
Claim · model-written summary
Crude-protein yield response was virtually linear through 600–700 lb nitrogen/acre.
- Taxon
- perennial ryegrassLolium perennet0
- Treatment
- nitrogen/acree0
- Outcome
- crude-protein yielde0
- Direction
- virtually lineare0
- Qualifier
- from the 0 to the 600–700 lb nitrogen/acre (673–785 kg/ha) ratese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of crude-protein yield was virtually linear from the 0 to the 600–700 lb nitrogen/acre (673–785 kg/ha) rates”
t0“perennial ryegrass”
Claim · model-written summary
White clover increased dry matter yield at low nitrogen rates.
- Taxon
- perennial ryegrassLolium perennet0
- Treatment
- inclusion of white clovere0
- Interactor
- white clover
Trifolium repense0other - Outcome
- yields of dry mattere0
- Direction
- increasede0
- Qualifier
- at the low nitrogen ratese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The inclusion of white clover in the sward increased the yields of dry matter and crude protein at the low nitrogen rates”
t0“perennial ryegrass”
Claim · model-written summary
White clover increased crude protein yield at low nitrogen rates.
- Taxon
- perennial ryegrassLolium perennet0
- Treatment
- inclusion of white clovere0
- Interactor
- white cloverTrifolium repense0other
- Outcome
- crude proteine0
- Direction
- increasede0
- Qualifier
- at the low nitrogen ratese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The inclusion of white clover in the sward increased the yields of dry matter and crude protein at the low nitrogen rates”
t0“perennial ryegrass”
Claim · model-written summary
White clover decreased yield responses to nitrogen.
- Taxon
- perennial ryegrassLolium perennet0
- Treatment
- inclusion of white clovere1
- Interactor
- white cloverTrifolium repense1other
- Outcome
- responsese0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but decreased the responses”
e1“The inclusion of white clover in the sward”
t0“perennial ryegrass”
Claim · model-written summary
Above about 300 lb nitrogen/acre, clover-grass and pure-grass sward yields and responses did not differ significantly.
- Taxon
- perennial ryegrassLolium perennet0
- Outcome
- yields and responsese0
- Direction
- not significantly differente0
- Qualifier
- at nitrogen rates above about 300 lb/ acre (336 kg/ha)e0
- Comparator
- pure-grass swarde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the yields and responses of the grass + clover sward were not significantly different from those of the pure-grass sward at nitrogen rates above about 300 lb/ acre (336 kg/ha)”
t0“perennial ryegrass”
Claim · model-written summary
Profit-maximizing nitrogen for dry-matter production was estimated at 400–450 lb/acre for both swards.
- Taxon
- perennial ryegrassLolium perennet0
- Outcome
- optimum nitrogen rate for dry-matter productione0
- Value
- 400–450 lb/ acre (448–504 kg/ha)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the optimum nitrogen rate for dry-matter production on both swards was estimated to be 400–450 lb/ acre (448–504 kg/ha)”
t0“perennial ryegrass”
Claim · model-written summary
Profit-maximizing nitrogen for crude-protein production was estimated above 600 lb/acre.
- Taxon
- perennial ryegrassLolium perennet0
- Outcome
- crude-protein productione0
- Direction
- greater thane0
- Value
- 600 lb/acre (673 kg/ha)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“that for crude-protein production was greater than 600 lb/acre (673 kg/ha)”
e1“the optimum nitrogen rate”
t0“perennial ryegrass”
The same questions in other papers
Trifolium repens · yield · Lolium perenne (perennial ryegrass)Positive and negative results
2 papers in the same direction as this paper · 2 in the opposite direction · 1 reporting no difference from an alternative
- no effect
- negative
- no effect
2 papers more in this group
See all 6 papers →Trifolium repens · quality: protein · Lolium perenne (perennial ryegrass)Results agree
1 paper in the same direction as this paper
- positive
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.