Abstract
In Brazilian agriculture, urea is the most commonly used nitrogen (N) source, in spite of having the disadvantage of losing considerable amounts of N by ammonia-N volatilization. The objectives of this study were to evaluate: N lossby ammonia volatilization from: [urea coated with copper sulfate and boric acid], [urea coated with zeolite], [urea+ammonium sulfate], [urea coated with copper sulfate and boric acid+ammonium sulfate], [common urea] and [ammonium nitrate]; and the effect of these N source son the maize yield in terms of amount and quality. The treatments were applied to the surface of a soil under no-tillage maize, in two growing seasons. The first season (2009/2010) was after a maize crop (maize straw left on the soil surface) and the second cycle (2012/2011) after a soybean crop. Due to the weather conditions during the experiments, the volatilization of ammonia-N was highest in the first four days after application of the N sources. Of all urea sources, under volatilization-favorable conditions, the loss of ammonia from urea coated with copper sulfate and boric acid was lowest, while under high rainfall, the losses from the different urea sources was similar, i.e., an adequate rainfall was favorablet o reduce volatilization. The ammonia volatilization losses were greatest in the first four days after application. Maize grain yield differed due to N application and in the treatments, but this was only observed with cultivation of maize crop residues in 2009/2010. The combination of ammonium+urea coated with copper sulfate and boric acid optimized grain yield compared to the other urea treatments. The crude protein concentration in maize was not influenced by the technologies of urea coating.
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Claims 6
Claim · model-written summary
Ammonia nitrogen volatilization was greatest in the first four days after fertilizer application.
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the volatilization of ammonia-N was highest in the first four days after application of the N sources.”
t0“maize”
Claim · model-written summary
Copper sulfate and boric acid coated urea had the lowest ammonia loss among urea sources under favorable volatilization conditions.
- Treatment
- urea coated with copper sulfate and boric acide0
- Outcome
- loss of ammoniae0
- Direction
- loweste0
- Qualifier
- volatilization-favorable conditionse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“under volatilization-favorable conditions, the loss of ammonia from urea coated with copper sulfate and boric acid was lowest”
t0“maize”
Claim · model-written summary
Under high rainfall, ammonia losses from the urea sources were similar.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“under high rainfall, the losses from the different urea sources was similar”
t0“maize”
Claim · model-written summary
Nitrogen application affected maize grain yield only in the 2009/2010 maize residue season.
- Treatment
- N applicatione0
- Outcome
- grain yielde0
- Direction
- differede0
- Qualifier
- maize crop residues in 2009/2010e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Maize grain yield differed due to N application and in the treatments, but this was only observed with cultivation of maize crop residues in 2009/2010.”
Claim · model-written summary
The ammonium plus coated urea combination optimized grain yield relative to other urea treatments.
- Treatment
- ammonium+urea coated with copper sulfate and boric acide0
- Outcome
- grain yielde0
- Direction
- optimizede0
- Comparator
- other urea treatmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The combination of ammonium+urea coated with copper sulfate and boric acid optimized grain yield compared to the other urea treatments.”
t0“maize”
Claim · model-written summary
Urea coating technologies did not influence maize crude protein concentration.
- Treatment
- technologies of urea coatinge0
- Outcome
- crude protein concentratione0
- Direction
- not influencede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The crude protein concentration in maize was not influenced by the technologies of urea coating.”
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