Abstract
The objective of this study was to assess the agronomic and nutritional responses of the elephant grass cultivar Carajas when subjected to fertilization with protected and conventional urea. A randomized block design with 4×2+1 factorial arrangement was adopted. The treatments consisted of four doses (100, 200, 400, and 800 kg N ha-1), two nitrogen sources (conventional and protected urea), and one additional treatment without fertilization. The experiment was carried out from October 2015 to March 2016, in a semi-arid region with a dystrophic yellow latosol type soil. The application of conventional urea was done with each of the multiple cuts performed per year, whereas the protected urea was applied in a single dose. Total senescence rate (TSR), leaf and stem elongation, height, tiller density, total forage biomass, green leaf and stem biomass, and dry matter all increased with increasing N doses. However, the phyllochron, live material/dead material ratio, and agronomic efficiency all decreased with N increasing dose. Plants fertilized with protected urea presented greater TSR and phyllochron. Mineral matter content was higher in plants fertilized with conventional urea. Neutral detergent fiber content was maximized at a dose of 437.63 kg N ha-1. The protected urea resulted in a higher value of leaf/stem ratio at the 400 kg N ha-1 dose, whereas ether extract and crude protein at the 800 kg N ha-1. With application of conventional urea, the highest crude protein value occurred at a dose of 100 kg N ha-1. The morphogenesis, structure, production, and chemical composition of elephant grass ‘Carajas’ were all positively influenced when nitrogen doses were increased, with the recommended optimal dose for use being 400 kg N ha-1 for both sources. The use of protected urea is recommended because of its slow release and need for only a single application.
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Claims 13
Claim · model-written summary
Increasing nitrogen dose increased total senescence rate, leaf and stem elongation, and height.
- Taxon
- elephant grass
.jpg?width=60)
Cenchrus purpureust0 - Treatment
- increasing N dosese0
- Outcome
- Total senescence rate (TSR), leaf and stem elongation, heighte0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Total senescence rate (TSR), leaf and stem elongation, height, tiller density, total forage biomass, green leaf and stem biomass, and dry matter all increased with increasing N doses.”
t0“elephant grass”
Claim · model-written summary
Increasing nitrogen dose increased tiller density and forage biomass.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- increasing N dosese0
- Outcome
- tiller density, total forage biomass, green leaf and stem biomasse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total senescence rate (TSR), leaf and stem elongation, height, tiller density, total forage biomass, green leaf and stem biomass, and dry matter all increased with increasing N doses.”
t0“elephant grass”
Claim · model-written summary
Increasing nitrogen dose increased dry matter.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- increasing N dosese0
- Outcome
- dry mattere0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dry matter all increased with increasing N doses.”
t0“elephant grass”
Claim · model-written summary
Increasing nitrogen dose decreased phyllochron, live-to-dead material ratio, and agronomic efficiency.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- N increasing dosee0
- Outcome
- phyllochron, live material/dead material ratio, and agronomic efficiencye0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the phyllochron, live material/dead material ratio, and agronomic efficiency all decreased with N increasing dose.”
t0“elephant grass”
Claim · model-written summary
Protected urea gave a greater total senescence rate than conventional urea.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- protected ureae0
- Outcome
- TSRe0
- Direction
- greatere0
- Comparator
- conventional ureae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants fertilized with protected urea presented greater TSR and phyllochron.”
t0“elephant grass”
e1“protected and conventional urea”
Claim · model-written summary
Protected urea gave a greater phyllochron than conventional urea.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- protected ureae0
- Outcome
- phyllochrone0
- Direction
- greatere0
- Comparator
- conventional ureae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants fertilized with protected urea presented greater TSR and phyllochron.”
t0“elephant grass”
e1“protected and conventional urea”
Claim · model-written summary
Neutral detergent fiber content peaked at 437.63 kg N ha-1.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- a dose of 437.63 kg N ha-1e0
- Outcome
- Neutral detergent fiber contente0
- Direction
- maximizede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Neutral detergent fiber content was maximized at a dose of 437.63 kg N ha-1.”
t0“elephant grass”
Claim · model-written summary
Protected urea produced a higher leaf/stem ratio at 400 kg N ha-1.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- protected ureae0
- Outcome
- leaf/stem ratioe0
- Direction
- highere0
- Qualifier
- 400 kg N ha-1 dosee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The protected urea resulted in a higher value of leaf/stem ratio at the 400 kg N ha-1 dose”
t0“elephant grass”
Claim · model-written summary
Protected urea gave a higher ether extract at 800 kg N ha-1.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- protected ureae0
- Outcome
- ether extracte0
- Direction
- highere0
- Qualifier
- 800 kg N ha-1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The protected urea resulted in a higher value of leaf/stem ratio at the 400 kg N ha-1 dose, whereas ether extract and crude protein at the 800 kg N ha-1.”
t0“elephant grass”
Claim · model-written summary
Protected urea gave a higher crude protein at 800 kg N ha-1.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- protected ureae0
- Outcome
- crude proteine0
- Direction
- highere0
- Qualifier
- 800 kg N ha-1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The protected urea resulted in a higher value of leaf/stem ratio at the 400 kg N ha-1 dose, whereas ether extract and crude protein at the 800 kg N ha-1.”
t0“elephant grass”
Claim · model-written summary
With conventional urea, crude protein was highest at 100 kg N ha-1.
- Taxon
- elephant grassCenchrus purpureust0
- Treatment
- conventional ureae0
- Outcome
- crude protein valuee0
- Direction
- higheste0
- Qualifier
- 100 kg N ha-1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With application of conventional urea, the highest crude protein value occurred at a dose of 100 kg N ha-1.”
t0“elephant grass”
Claim · model-written summary
The authors recommend 400 kg N ha-1 for either urea source.
- Taxon
- elephant grassCenchrus purpureust0
- Outcome
- recommended optimal dose for use being 400 kg N ha-1 for both sourcese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with the recommended optimal dose for use being 400 kg N ha-1 for both sources.”
t0“elephant grass”
Claim · model-written summary
The authors recommend protected urea for its slow release and single application.
- Taxon
- elephant grassCenchrus purpureust0
- Outcome
- use of protected urea is recommendede0
- Qualifier
- slow release and need for only a single applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The use of protected urea is recommended because of its slow release and need for only a single application.”
t0“elephant grass”
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See all 7 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.