Abstract
This study compared the response of harvests taken in May, June, August and September-October in terms of crop responses (yield, N uptake, and concentrations of crude protein and nitrate) to N fertilizer and residual soil nitrate and ammonium. Three trials were conducted in south coastal British Columbia in 1990–1992 to evaluate the response of an established sward of orchardgrass (Dactylis glomerata L.) to a range of N fertilizer rates. Both yields and daily crop growth rates were highest in cut 1, lowest in cut 4 and intermediate in cuts 2 and 3. For all four cuts, 95 and 90% of maximum yield was attained at about 136 and 82 kg ha -1 of applied N, respectively. Crop N supply from non-fertilizer sources ranged from 36 to 90 kg N ha -1 , of which about 52% was attributed to nitrate present in the soil prior to growth and about 48% was N released from the soil, translocated from roots or deposited from the atmosphere. At 95% of maximum yield, crude protein concentrations ranged from 147 g kg -1 in the higher yielding cut 1 to 189 g kg -1 in cuts 2 and 4, while at 90% of maximum yield concentrations were 10 g kg -1 lower in each cut. Plant nitrate concentrations were close to levels that are toxic to cattle for the 95% target yield, but relatively safe at the 90% yield. The crop removed about 50 kg ha -1 more N when fertilized for 95% of maximum yield than for 90%, which translates to over 300 kg ha -1 more crude protein. High relative yield leaves behind more soil nitrate after harvest. The results suggest that the first cut should be managed for 95% of maximum yield with about 130 kg N ha -1 . Cuts 2 and 3 should be managed for 90% of maximum yield, to avoid high plant nitrate concentrations, with 100–110 kg N ha -1 . Cut 4 should be given no more than 50 kg N ha -1 for less than 90% of maximum yield because of the risk of residual soil nitrates. This study shows for the first time the benefits and disadvantages of applying N at different rates for each harvest over the growing season. Key words: Plant nitrate, nitrogen use efficiency, nitrogen recovery, Dactylis glomerata, relative yield, maximum economic yield
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Claims 16
Claim · model-written summary
Orchardgrass yield and daily growth rate were highest in cut 1 and lowest in cut 4.
- Taxon
- orchardgrass (Dactylis glomerata L.)
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Dactylis glomeratae1 - Outcome
- yields and daily crop growth ratese0
- Direction
- highest in cut 1, lowest in cut 4e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Both yields and daily crop growth rates were highest in cut 1, lowest in cut 4 and intermediate in cuts 2 and 3”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
About 136 kg ha -1 applied N reached 95% of maximum yield across four cuts.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Treatment
- 136e0
- Outcome
- 95e0
- Direction
- attainede0
- Value
- 136e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For all four cuts, 95 and 90% of maximum yield was attained at about 136 and 82 kg ha -1 of applied N, respectively”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
About 82 kg ha -1 applied N reached 90% of maximum yield across four cuts.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Treatment
- 82 kg ha -1 of applied Ne0
- Outcome
- 90% of maximum yielde0
- Direction
- attainede0
- Value
- 82 kg ha -1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For all four cuts, 95 and 90% of maximum yield was attained at about 136 and 82 kg ha -1 of applied N, respectively”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
Nonfertilizer sources supplied 36 to 90 kg N ha -1 to the crop.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Outcome
- Crop N supply from non-fertilizer sourcese0
- Value
- 36 to 90 kg N ha -1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Crop N supply from non-fertilizer sources ranged from 36 to 90 kg N ha -1”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
About 52% of nonfertilizer nitrogen supply came from soil nitrate present before growth.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae2
- Outcome
- Crop N supply from non-fertilizer sourcese1
- Value
- 52%e0
- Qualifier
- nitrate present in the soil prior to growthe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“about 52% was attributed to nitrate present in the soil prior to growth”
e1“Crop N supply from non-fertilizer sources”
e2“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
About 48% of nonfertilizer nitrogen supply came from soil release, root translocation, or atmospheric deposition.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae2
- Outcome
- Crop N supply from non-fertilizer sourcese1
- Value
- 48%e0
- Qualifier
- N released from the soil, translocated from roots or deposited from the atmospheree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“about 48% was N released from the soil, translocated from roots or deposited from the atmosphere”
e1“Crop N supply from non-fertilizer sources”
e2“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
At the 95% yield target, crude protein was 147 g kg -1 in cut 1.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Outcome
- crude protein concentrationse0
- Value
- 147 g kg -1e0
- Qualifier
- cut 1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 95% of maximum yield, crude protein concentrations ranged from 147 g kg -1 in the higher yielding cut 1 to 189 g kg -1 in cuts 2 and 4”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
At the 95% yield target, crude protein was 189 g kg -1 in cuts 2 and 4.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Outcome
- crude protein concentrationse0
- Value
- 189 g kg -1e0
- Qualifier
- cuts 2 and 4e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 95% of maximum yield, crude protein concentrations ranged from 147 g kg -1 in the higher yielding cut 1 to 189 g kg -1 in cuts 2 and 4”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
Crude protein concentrations at 90% of maximum yield were 10 g kg -1 lower in each cut than at 95%.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae2
- Outcome
- crude protein concentrationse1
- Direction
- lowere0
- Value
- 10 g kg -1e0
- Comparator
- 90% of maximum yielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at 90% of maximum yield concentrations were 10 g kg -1 lower in each cut”
e1“crude protein concentrations”
e2“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
Plant nitrate approached cattle-toxic levels at 95% target yield but was relatively safe at 90%.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Outcome
- Plant nitrate concentrationse0
- Direction
- close to levels that are toxic to cattlee0
- Comparator
- 90% yielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant nitrate concentrations were close to levels that are toxic to cattle for the 95% target yield, but relatively safe at the 90% yield”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
Fertilizing for 95% rather than 90% maximum yield increased nitrogen removal by about 50 kg ha -1.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Treatment
- fertilized for 95% of maximum yielde0
- Outcome
- Ne0
- Direction
- moree0
- Value
- 50 kg ha -1e0
- Comparator
- 90%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The crop removed about 50 kg ha -1 more N when fertilized for 95% of maximum yield than for 90%”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
The greater nitrogen removal at the 95% yield target corresponded to over 300 kg ha -1 additional crude protein.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Outcome
- crude proteine0
- Direction
- moree0
- Value
- over 300 kg ha -1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“which translates to over 300 kg ha -1 more crude protein”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
Higher relative yield left more soil nitrate after harvest.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Outcome
- soil nitrate after harveste0
- Direction
- moree0
- Comparator
- High relative yielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High relative yield leaves behind more soil nitrate after harvest”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
The authors recommend about 130 kg N ha -1 for cut 1 to reach 95% of maximum yield.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Treatment
- about 130 kg N ha -1e0
- Outcome
- first cut should be managed for 95% of maximum yielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the first cut should be managed for 95% of maximum yield with about 130 kg N ha -1”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
The authors recommend 100–110 kg N ha -1 for cuts 2 and 3 to target 90% of maximum yield and avoid high plant nitrate.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Treatment
- 100–110 kg N ha -1e0
- Outcome
- Cuts 2 and 3 should be managed for 90% of maximum yielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cuts 2 and 3 should be managed for 90% of maximum yield, to avoid high plant nitrate concentrations, with 100–110 kg N ha -1”
e1“orchardgrass (Dactylis glomerata L.)”
Claim · model-written summary
The authors recommend no more than 50 kg N ha -1 for cut 4 because of residual nitrate risk.
- Taxon
- orchardgrass (Dactylis glomerata L.)Dactylis glomeratae1
- Treatment
- no more than 50 kg N ha -1e0
- Outcome
- Cut 4 should be given no more than 50 kg N ha -1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cut 4 should be given no more than 50 kg N ha -1 for less than 90% of maximum yield because of the risk of residual soil nitrates”
e1“orchardgrass (Dactylis glomerata L.)”
The same questions in other papers
fertilization · nutrient: content · Dactylis glomerata (cocksfoot)Positive and negative results
9 papers in the same direction as this paper · 2 in the opposite direction
- negative
- no effect
- positive
8 papers more in this group
See all 12 papers →nitrogen · yield · Dactylis glomerata (cocksfoot)Positive and negative results
14 papers in the same direction as this paper · 2 in the opposite direction · 1 reporting no difference from an alternative
- no effect
- no effect
- no effect
14 papers more in this group
See all 18 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.