Abstract
Abstract Knowledge of fertility requirements or nitrogen‐use efficiency of amaranth ( Amaranthus spp.) cultivars is limited. The objectives of this research were to determine the response of grain amaranth to applied N, P, and K, and to determine the effect of cultivar and fertilizer N on nitrogen‐use efficiency. Two field experiments were conducted. In the first, five rates of N, P, and K were applied in a central composite design with the cultivar Plainsman grown in five environments. In a second experiment, six amaranth cultivars, Amont, K266, K283, Plainsman, K432 and D136, were grown in three environments with five N rates (0, 45, 90, 135, and 180 kg N ha −1 ). There was no response to P and K applications when initial soil tests were above 68 kg P ha −1 , and 172 kg K ha −1 , respectively, but grain amaranth responded linearly to applied P at one location with initial soil P tests of 11 kg ha −1 . Grain yield ranged from 794 to 1980 kg ha −1 and responded to N in most environments. Forage yield ranged from 6.1 to 16.6 Mg ha −1 and was increased at higher N rates. At all locations, lodging increased with application of N. Fertilizer N increased pre‐flowering N accumulation but not post‐flowering N accumulation. Nitrogen‐use efficiency (NUE) ratio of grain yield to total soil N supply ranged from 3.48 to 7.91 kg kg −1 across cultivars and environments. Nitrogen‐use efficiency decreased with increased soil N mainly because of decreasing N‐uptake efficiency (ratio of total plant N to total soil N). Grain amaranth is relatively inefficient in N‐use primarily because of its low harvest index (HI = 9–15%) and N harvest index (NHI = 12–26%). This suggests that selection for higher HI and NHI could be effective in improving grain yield and nitrogenuse efficiency of grain amaranth.
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Claims 15
Claim · model-written summary
Grain amaranth showed no yield response to P and K applications when soil tests were high.
- Taxon
- grain amaranth
Amaranthus hypochondriacuse0 - Treatment
- P and K applicationse1
- Outcome
- responsee1
- Direction
- no responsee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e1“There was no response to P and K applications”
Claim · model-written summary
Grain amaranth responded linearly to applied P at one location with low initial soil P.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Treatment
- applied Pe2
- Outcome
- respondede2
- Direction
- responded linearlye2
- Setting
- at one locatione2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e2“grain amaranth responded linearly to applied P at one location”
Claim · model-written summary
Grain yield of grain amaranth ranged from 794 to 1980 kg/ha across environments.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Outcome
- Grain yielde3
- Value
- 794 to 1980 kg ha −1e3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e3“Grain yield ranged from 794 to 1980 kg ha −1 and responded to N in most environments”
Claim · model-written summary
Grain yield of grain amaranth responded to N in most environments.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Treatment
- Ne3
- Outcome
- Grain yielde3
- Direction
- respondede3
- Setting
- most environmentse3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e3“Grain yield ranged from 794 to 1980 kg ha −1 and responded to N in most environments”
Claim · model-written summary
Forage yield of grain amaranth ranged from 6.1 to 16.6 Mg/ha.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Outcome
- Forage yielde4
- Value
- 6.1 to 16.6 Mg ha −1e4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e4“Forage yield ranged from 6.1 to 16.6 Mg ha −1 and was increased at higher N rates”
Claim · model-written summary
Forage yield of grain amaranth increased at higher N rates.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Treatment
- higher N ratese4
- Outcome
- Forage yielde4
- Direction
- was increasede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e4“Forage yield ranged from 6.1 to 16.6 Mg ha −1 and was increased at higher N rates”
Claim · model-written summary
Lodging of grain amaranth increased with N application at all locations.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Treatment
- application of Ne5
- Outcome
- lodginge5
- Direction
- increasede5
- Setting
- At all locationse5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e5“At all locations, lodging increased with application of N”
Claim · model-written summary
Fertilizer N increased pre-flowering N accumulation in grain amaranth.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Treatment
- Fertilizer Ne6
- Outcome
- N accumulatione6
- Direction
- increasede6
- Qualifier
- pre‐floweringe6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e6“Fertilizer N increased pre‐flowering N accumulation but not post‐flowering N accumulation”
Claim · model-written summary
Fertilizer N did not increase post-flowering N accumulation in grain amaranth.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Treatment
- Fertilizer Ne6
- Outcome
- N accumulatione6
- Direction
- but note6
- Qualifier
- post‐floweringe6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e6“Fertilizer N increased pre‐flowering N accumulation but not post‐flowering N accumulation”
Claim · model-written summary
Nitrogen-use efficiency of grain amaranth ranged from 3.48 to 7.91 kg/kg across cultivars and environments.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Outcome
- ratio of grain yield to total soil N supplye7
- Value
- 3.48 to 7.91 kg kg −1e7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e7“Nitrogen‐use efficiency (NUE) ratio of grain yield to total soil N supply ranged from 3.48 to 7.91 kg kg −1 across cultivars and environments”
Claim · model-written summary
Nitrogen-use efficiency of grain amaranth decreased with increased soil N, mainly because of decreasing N-uptake efficiency.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Treatment
- increased soil Ne2
- Outcome
- efficiencye2
- Direction
- decreasede2
- Qualifier
- mainly because of decreasinge2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e2“Nitrogen‐use efficiency decreased with increased soil N mainly because of decreasing N‐uptake efficiency”
Claim · model-written summary
Grain amaranth had a harvest index of 9–15%.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Outcome
- harvest indexe1
- Value
- 9–15%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e1“Grain amaranth is relatively inefficient in N‐use primarily because of its low harvest index (HI = 9–15%) and N harvest index (NHI = 12–26%)”
Claim · model-written summary
Grain amaranth had an N harvest index of 12–26%.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Outcome
- N harvest indexe1
- Value
- 12–26%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e1“Grain amaranth is relatively inefficient in N‐use primarily because of its low harvest index (HI = 9–15%) and N harvest index (NHI = 12–26%)”
Claim · model-written summary
Grain amaranth is relatively inefficient in N use, primarily because of its low harvest index.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Outcome
- relatively inefficiente1
- Qualifier
- low harvest indexe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e1“Grain amaranth is relatively inefficient in N‐use primarily because of its low harvest index (HI = 9–15%) and N harvest index (NHI = 12–26%)”
Claim · model-written summary
Selection for higher harvest index and N harvest index could improve grain yield and nitrogen-use efficiency of grain amaranth.
- Taxon
- grain amaranthAmaranthus hypochondriacuse0
- Treatment
- selection for higher HI and NHIe1
- Outcome
- grain yield and nitrogenuse efficiencye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the response of grain amaranth to applied N, P, and K”
e1“This suggests that selection for higher HI and NHI could be effective in improving grain yield and nitrogenuse efficiency of grain amaranth”
The same questions in other papers
nitrogen · growth · Amaranthus hypochondriacus (grain amaranth)Positive and negative results
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nitrogen · yield · Amaranthus hypochondriacus (grain amaranth)Results agree
5 papers in the same direction as this paper
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2 papers more in this group
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.