Abstract
Excessive agricultural nitrogen application can lead to low nitrogen use efficiency, but the use of drip irrigation with plastic film mulching has been shown to improve crop yield, quality, and nitrogen use efficiency. Field experiments were conducted in 2020 and 2021 at the Special Potato Experimental Station, China Agricultural University, in Rizhao City, Shandong Province, China. The aim was to investigate the effects of different soil wetted percentages and nitrogen (N) application rates on soil nitrate-N (NO 3 -N) distribution and the growth of sweet potatoes ( Ipomoea batatas L . ). Three irrigation levels (no irrigation, P0; soil wetted percentage 30 %, P1; and soil wetted percentage 60 %, P2) and three N-application rates (90 kg hm −2 , N1; 180 kg hm −2 , N2; and 270 kg hm −2 , N3) were designed. Various parameters such as soil water and nitrate-N content, dry matter, tuber grade, yield, quality, and nitrogen use efficiency were measured. The results showed that the soil water content was lower in the treatment with N-application rate of 180 kg hm −2 compared to the treatments with N-application rates of 90 kg hm −2 and 270 kg hm −2 . Increasing nitrogen application rates led to an increase in soil nitrogen content and residue at a depth of 0–40 cm. The soil nitrate-N residue in the treatment with N-application rate of 180 kg hm −2 was significantly lower than that in the treatment with N-application rate of 270 kg hm −2 treatment. Sweet potato growth, tuber dry matter, number and weight of large and medium tubers, and yield initially increased and then decreased with increasing nitrogen application rates. In the soil wetted percentage of 60 % treatment, the tuber yield increased in the treatment with N-application rate of 180 kg hm −2 compared to the treatments with N-application rates of 90 kg hm −2 and 270 kg hm −2 . A moderate nitrogen application rate improved tuber quality, including the contents of crude protein, starch, and soluble sugar. Nitrogen use efficiency, sweet potato nitrogen uptake amount, and nitrogen use efficiency initially increased and then decreased with increasing nitrogen application rates in soil wetted percentage of 60 % treatment. Irrigation increased nitrogen uptake efficiency and nitrogen use efficiency. In the treatment with N-application rate of 180 kg hm −2 , nitrogen use efficiency in the soil wetted percentages of 30 % and 60 % treatments were higher than that in the treatment without irrigation. In conclusion, the optimal combination of 180 kg/hm 2 and soil wetted percentage of 60 % was found to be suitable for sweet potato cultivation in the study area, considering factors such as soil nitrate-N residue, sweet potato yield and quality, and nitrogen use efficiency. • Soil nitrate nitrogen residue in 180 kg hm −2 N treatment was much less than in 270 kg hm −2 N. • Irrigation increased nitrogen uptake efficiency and nitrogen use efficiency. • Moderate nitrate application rate improved tuber quality. • The application of 180 kg hm −2 N and soil wetted percentage 60 % was suitable for sweet potato.
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Claims 10
Claim · model-written summary
The 180 kg hm −2 nitrogen treatment had lower soil water content than the 90 and 270 kg hm −2 treatments.
- Taxon
- sweet potato
_Flower.jpg?width=60)
Ipomoea batatast0 - Treatment
- N-application rate of 180 kg hm −2e0
- Outcome
- soil water contente0
- Direction
- lowere0
- Comparator
- N-application rates of 90 kg hm −2 and 270 kg hm −2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Flower.jpg?width=500)
Verbatim
e0“The results showed that the soil water content was lower in the treatment with N-application rate of 180 kg hm −2 compared to the treatments with N-application rates of 90 kg hm −2 and 270 kg hm −2 .”
t0“sweet potato”
Claim · model-written summary
Increasing nitrogen application increased soil nitrogen content and residue at 0–40 cm.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- Increasing nitrogen application ratese0
- Outcome
- soil nitrogen content and residuee0
- Direction
- increasee0
- Qualifier
- 0–40 cme0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing nitrogen application rates led to an increase in soil nitrogen content and residue at a depth of 0–40 cm.”
t0“sweet potato”
Claim · model-written summary
The 180 kg hm −2 treatment had significantly lower soil nitrate-N residue than the 270 kg hm −2 treatment.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- N-application rate of 180 kg hm −2e0
- Outcome
- soil nitrate-N residuee0
- Direction
- lowere0
- Comparator
- N-application rate of 270 kg hm −2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The soil nitrate-N residue in the treatment with N-application rate of 180 kg hm −2 was significantly lower than that in the treatment with N-application rate of 270 kg hm −2 treatment.”
t0“sweet potato”
Claim · model-written summary
Sweet potato growth, tuber dry matter, large and medium tuber number and weight, and yield rose and then fell as nitrogen rates increased.
- Taxon
- Sweet potatoIpomoea batatase0
- Treatment
- increasing nitrogen application ratese0
- Outcome
- growth, tuber dry matter, number and weight of large and medium tubers, and yielde0
- Direction
- initially increased and then decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sweet potato growth, tuber dry matter, number and weight of large and medium tubers, and yield initially increased and then decreased with increasing nitrogen application rates.”
Claim · model-written summary
At 60 % soil wetting, tuber yield was higher with 180 kg hm −2 nitrogen than with 90 or 270 kg hm −2.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- N-application rate of 180 kg hm −2e0
- Outcome
- tuber yielde0
- Direction
- increasede0
- Qualifier
- soil wetted percentage of 60 %e0
- Comparator
- N-application rates of 90 kg hm −2 and 270 kg hm −2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the soil wetted percentage of 60 % treatment, the tuber yield increased in the treatment with N-application rate of 180 kg hm −2 compared to the treatments with N-application rates of 90 kg hm −2 and 270 kg hm −2 .”
t0“sweet potato”
Claim · model-written summary
Moderate nitrogen improved tuber crude protein, starch, and soluble sugar content.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- moderate nitrogen application ratee0
- Outcome
- contents of crude protein, starch, and soluble sugare0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A moderate nitrogen application rate improved tuber quality, including the contents of crude protein, starch, and soluble sugar.”
t0“sweet potato”
Claim · model-written summary
Under 60 % soil wetting, nitrogen use efficiency and uptake rose and then fell as nitrogen rates increased.
- Taxon
- sweet potatoIpomoea batatase0
- Treatment
- increasing nitrogen application ratese0
- Outcome
- Nitrogen use efficiency, sweet potato nitrogen uptake amounte0
- Direction
- initially increased and then decreasede0
- Qualifier
- soil wetted percentage of 60 %e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen use efficiency, sweet potato nitrogen uptake amount, and nitrogen use efficiency initially increased and then decreased with increasing nitrogen application rates in soil wetted percentage of 60 % treatment.”
Claim · model-written summary
Irrigation increased nitrogen uptake efficiency and nitrogen use efficiency.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- Irrigatione0
- Outcome
- nitrogen uptake efficiency and nitrogen use efficiencye0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Irrigation increased nitrogen uptake efficiency and nitrogen use efficiency. In the treatment”
t0“sweet potato”
Claim · model-written summary
At 180 kg hm −2 nitrogen, 30 % and 60 % soil wetting had higher nitrogen use efficiency than no irrigation.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- soil wetted percentages of 30 % and 60 % treatmentse0
- Outcome
- nitrogen use efficiencye0
- Direction
- highere0
- Qualifier
- N-application rate of 180 kg hm −2e0
- Comparator
- treatment without irrigatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the treatment with N-application rate of 180 kg hm −2 , nitrogen use efficiency in the soil wetted percentages of 30 % and 60 % treatments were higher than that in the treatment without irrigation.”
t0“sweet potato”
Claim · model-written summary
The authors identify 180 kg/hm 2 nitrogen with 60 % soil wetting as suitable for local sweet potato cultivation.
- Taxon
- sweet potatoIpomoea batatase0
- Outcome
- 180 kg/hm 2 and soil wetted percentage of 60 %e0
- Setting
- study areae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the optimal combination of 180 kg/hm 2 and soil wetted percentage of 60 % was found to be suitable for sweet potato cultivation in the study area”
The same questions in other papers
nitrogen · yield · Ipomoea batatas (sweet potato)Results differ
30 papers in the same direction as this paper · 4 in the opposite direction
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31 papers more in this group
See all 35 papers →nitrogen · physiology: osmolytes · Ipomoea batatas (sweet potato)Positive and negative results
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