Abstract
Nitrogen (N) is one of the most yield limiting nutrients in lowland rice production. Improving N use efficiency is essential to reduce cost of crop production and environmental pollution. A greenhouse experiment was conducted with the objective to compare conventional and polymer coated urea for lowland rice production. Grain yield, straw yield, panicle density, maximum root length, and root dry weight were significantly increased in a quadratic fashion with the increase of N rate from 0 to 400 mg kg−1 soil. Nitrogen source X N rate interactions for most of these traits were not significant, indicating that lowland rice responded similarly to change in N rates of two N sources. Based on regression equations, maximum grain yield was obtained with the application of 258 mg N kg−1 soil and maximum straw yield was obtained with the addition of 309 mg N kg−1 soil. Nitrogen use efficiency (grain yield per unit of N applied) was maximum for polymer coated urea compared to conventional urea. Root length and root dry weight improved at an adequate N rate, indicating importance of N fertilization in the absorption of water and nutrients and consequently yield. Polymer coated urea had higher soil exchangeable calcium (Ca) and magnesium (Mg), Ca saturation, Mg saturation, base saturation, and effective cation exchange capacity compared to conventional urea. There was a highly significant decrease in soil exchangeable potassium (K) with increasing N rates at harvest of rice plants.
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Claims 10
Claim · model-written summary
Grain yield, straw yield and panicle density increased with N rate from 0 to 400 mg kg−1 soil, in a quadratic fashion.
Verbatim
t0“Lowland Rice”
e0“Grain yield, straw yield, panicle density, maximum root length, and root dry weight were significantly increased in a quadratic fashion with the increase of N rate from 0 to 400 mg kg−1 soil”
e1“A greenhouse experiment was conducted with the objective to compare conventional and polymer coated urea for lowland rice production”
Claim · model-written summary
Maximum root length and root dry weight increased with N rate from 0 to 400 mg kg−1 soil, in a quadratic fashion.
Verbatim
t0“Lowland Rice”
e0“Grain yield, straw yield, panicle density, maximum root length, and root dry weight were significantly increased in a quadratic fashion with the increase of N rate from 0 to 400 mg kg−1 soil”
e1“A greenhouse experiment was conducted with the objective to compare conventional and polymer coated urea for lowland rice production”
Claim · model-written summary
Based on regression equations, maximum grain yield was obtained at 258 mg N kg−1 soil.
Verbatim
t0“Lowland Rice”
e2“Based on regression equations, maximum grain yield was obtained with the application of 258 mg N kg−1 soil and maximum straw yield was obtained with the addition of 309 mg N kg−1 soil”
Claim · model-written summary
Based on regression equations, maximum straw yield was obtained at 309 mg N kg−1 soil.
Verbatim
t0“Lowland Rice”
e2“Based on regression equations, maximum grain yield was obtained with the application of 258 mg N kg−1 soil and maximum straw yield was obtained with the addition of 309 mg N kg−1 soil”
Claim · model-written summary
Nitrogen use efficiency was maximum for polymer coated urea compared with conventional urea.
Verbatim
t0“Lowland Rice”
e3“Nitrogen use efficiency (grain yield per unit of N applied) was maximum for polymer coated urea compared to conventional urea”
Claim · model-written summary
Polymer coated urea increased soil exchangeable calcium and magnesium compared with conventional urea.
Verbatim
t0“Lowland Rice”
e4“Polymer coated urea had higher soil exchangeable calcium (Ca) and magnesium (Mg), Ca saturation, Mg saturation, base saturation, and effective cation exchange capacity compared to conventional urea”
Claim · model-written summary
Polymer coated urea increased Ca saturation, Mg saturation and base saturation compared with conventional urea.
Verbatim
t0“Lowland Rice”
e4“Polymer coated urea had higher soil exchangeable calcium (Ca) and magnesium (Mg), Ca saturation, Mg saturation, base saturation, and effective cation exchange capacity compared to conventional urea”
Claim · model-written summary
Polymer coated urea increased effective cation exchange capacity compared with conventional urea.
Verbatim
t0“Lowland Rice”
e4“Polymer coated urea had higher soil exchangeable calcium (Ca) and magnesium (Mg), Ca saturation, Mg saturation, base saturation, and effective cation exchange capacity compared to conventional urea”
Claim · model-written summary
Soil exchangeable potassium decreased significantly with increasing N rate at harvest of rice plants.
- Taxon
- rice plants
Oryza sativae5 - Treatment
- increasing N ratese5
- Outcome
- soil exchangeable potassium (K)e5
- Direction
- decreasee5
- Qualifier
- highly significante5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“There was a highly significant decrease in soil exchangeable potassium (K) with increasing N rates at harvest of rice plants”
Claim · model-written summary
Nitrogen source by N rate interactions were not significant for most traits, so lowland rice responded similarly to the change in N rates of the two sources.
Verbatim
e6“Nitrogen source X N rate interactions for most of these traits were not significant, indicating that lowland rice responded similarly to change in N rates of two N sources”
The same questions in other papers
nitrogen · nutrient: efficiency · Oryza sativa (rice)Positive and negative results
216 papers in the same direction as this paper · 41 in the opposite direction · 4 reporting no difference from an alternative
- positive
- negative
- negative
258 papers more in this group
See all 262 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.