Abstract
Applying nitrogen fertilization is an important way to improve the yield and quality of autumn tea (Camellia sinensis L.), but the effects of nitrogen application rate and nitrogen form still remain unclear. Field experiments were conducted in a drip-irrigated tea garden in Rizhao City, China in 2020 and 2021. The effects of nitrogen application levels (N: 0 kg·hm−2, CK; N: 45 kg·hm−2, U1; 75 kg·hm−2, U2; and 105 kg·hm−2, U3) and nitrogen application forms (ammonium bicarbonate, AB; ammonium bicarbonate + urea, UAB; and urea, U) on soil moisture, as well as nitrogen spatiotemporal change, and autumn tea yield and quality, were studied. Results showed that applying ammonium bicarbonate or urea through a drip irrigation system can significantly increase the tea plant evapotranspiration and the autumn tea yield and quality (including free amino acids and tea polyphenols). With the same nitrogen application, the urea fertilization treatment had the higher ammonium nitrogen content within the 0–60 cm soil layer. The application form of nitrogen fertilizer had a significant impact on the yield of autumn tea, and the yield increasing ability was U > UAB > AB. The partial factor productivity of applied nitrogen under the AB treatment was the lowest. The yield-increasing effect of nitrogen fertilizer can be observed only 16–18 days after topdressing through the drip irrigation system. In 2020 and 2021, the yield of autumn tea under the U3 treatment increased by 40.6% and 23.0%, respectively, compared with the CK treatment. In conclusion, the topdressing with urea 105 kg·hm−2 with drip irrigation for tea plants in autumn is recommended. This recommendation will provide a theoretical basis for efficient irrigation and yield increase in tea gardens.
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Claims 11
Claim · model-written summary
Drip-applied ammonium bicarbonate increased tea plant evapotranspiration.
- Taxon
- tea plante0
- Treatment
- ammonium bicarbonatee0
- Outcome
- tea plant evapotranspiratione0
- Direction
- increasee0
Not reportedComparator
Verbatim
e0“applying ammonium bicarbonate or urea through a drip irrigation system can significantly increase the tea plant evapotranspiration and the autumn tea yield and quality (including free amino acids and tea polyphenols)”
Claim · model-written summary
Drip-applied urea increased tea plant evapotranspiration.
Not reportedComparator
Verbatim
e0“applying ammonium bicarbonate or urea through a drip irrigation system can significantly increase the tea plant evapotranspiration and the autumn tea yield and quality (including free amino acids and tea polyphenols)”
Claim · model-written summary
Drip-applied ammonium bicarbonate increased autumn tea yield and quality.
- Taxon
- tea plante0
- Treatment
- ammonium bicarbonatee0
- Outcome
- autumn tea yield and quality (including free amino acids and tea polyphenols)e0
- Direction
- increasee0
Not reportedComparator
Verbatim
e0“applying ammonium bicarbonate or urea through a drip irrigation system can significantly increase the tea plant evapotranspiration and the autumn tea yield and quality (including free amino acids and tea polyphenols)”
Claim · model-written summary
Drip-applied urea increased autumn tea yield and quality.
- Taxon
- tea plante0
- Treatment
- ureae0
- Outcome
- autumn tea yield and quality (including free amino acids and tea polyphenols)e0
- Direction
- increasee0
Not reportedComparator
Verbatim
e0“applying ammonium bicarbonate or urea through a drip irrigation system can significantly increase the tea plant evapotranspiration and the autumn tea yield and quality (including free amino acids and tea polyphenols)”
Claim · model-written summary
Urea yielded higher ammonium nitrogen content in the 0–60 cm soil layer at equal nitrogen application.
- Treatment
- urea fertilization treatmente0
- Outcome
- ammonium nitrogen contente0
- Direction
- highere0
- Qualifier
- 0–60 cm soil layere0
- Comparator
- same nitrogen applicatione0
Not reportedTaxon
Verbatim
e0“With the same nitrogen application, the urea fertilization treatment had the higher ammonium nitrogen content within the 0–60 cm soil layer.”
Claim · model-written summary
Autumn tea yield response to nitrogen form ranked U above UAB above AB.
Verbatim
e0“The application form of nitrogen fertilizer had a significant impact on the yield of autumn tea, and the yield increasing ability was U > UAB > AB.”
Claim · model-written summary
AB had the lowest partial factor productivity of applied nitrogen.
Verbatim
e0“The partial factor productivity of applied nitrogen under the AB treatment was the lowest.”
Claim · model-written summary
A yield increase from nitrogen fertilizer appeared 16–18 days after drip topdressing.
Not reportedTaxon
Verbatim
e0“The yield-increasing effect of nitrogen fertilizer can be observed only 16–18 days after topdressing through the drip irrigation system.”
Claim · model-written summary
U3 raised autumn tea yield by 40.6% versus CK in 2020.
Verbatim
e0“In 2020 and 2021, the yield of autumn tea under the U3 treatment increased by 40.6% and 23.0%, respectively, compared with the CK treatment.”
Claim · model-written summary
U3 raised autumn tea yield by 23.0% versus CK in 2021.
Verbatim
e0“In 2020 and 2021, the yield of autumn tea under the U3 treatment increased by 40.6% and 23.0%, respectively, compared with the CK treatment.”
Claim · model-written summary
The authors recommend autumn drip topdressing with urea at 105 kg·hm−2 for tea plants.
Verbatim
e0“the topdressing with urea 105 kg·hm−2 with drip irrigation for tea plants in autumn is recommended”
The same questions in other papers
nitrogen · physiology: water · Camellia sinensis (black tea)Positive and negative results
1 in the opposite direction
- no effect
nitrogen · quality: phytochemicals · Camellia sinensis (black tea)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- positive
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.