Abstract
The cultivation of drip-irrigated rice has resulted in lower yields. However, the decrease in rice yield under drip irrigation and its relationship with the existing water and N regime have not been fully explained. Research and development of optimized water and N-management techniques are crucial for increasing rice yield under drip irrigation. In this study, two irrigation treatments were set: conventional drip irrigation (DIO) and drip irrigation with water stress (DIS). Each irrigation treatment contained four N rates: urea N 240 kg ha−1 (LN), urea N 300 kg ha−1 (MN), urea N 360 kg ha−1 (HN), and ammonium sulfate N 300 kg ha−1 (AN). The soil’s ammonium and nitrate contents were measured on the 2nd and 28th days after N application at panicle initiation stage. At anthesis, the aboveground and root biomass of rice were measured. In heading and maturity stage the N content of aboveground was measured and the yield, yield components, and NPFP were assessed at maturity stage. The results showed the following: (1) On the second day after N application, the contents of soil NO3−-N and NH4+-N in the 0–10 cm soil layer were highest for both the DIO and DIS. On the 28th day after N application, the soil NO3−-N content was highest at the 20–40 cm depth, while the soil NH4+-N content was still highest at the 0–10 cm depth. (2) The aboveground and root biomass in DIO treatment were significantly higher than in DIS. Furthermore, the root biomass at the 0–10 cm depth was significantly greater than at the 10–50 cm depth for both the DIO and DIS treatments. In the DIO treatment, the root biomass at the 10–50 cm depth was significantly higher with the HN and AN treatments compared to MN. However, in the DIS treatment, the root biomass at the 10–50 cm depth did not show significant differences between the MN, HN, and AN. (3) N accumulation in rice was significantly higher for the DIO treatment compared to the DIS treatment. Under the same irrigation treatment, the N accumulation in rice was highest in the AN and lowest in the LN. The PrNTA and PrNTC in DIS were significantly higher than in DIO, while the PoNAA and PoNAC were significantly lower in DIS. (4) The number of panicles, spikelets per panicle, seed-setting rate, 1000-grain weight, and grain yield were significantly lower in DIS. Under the DIS, these parameters were not significantly different among the MN, HN, and AN. In the DIO, the seed-setting rate, 1000-grain weight, and yield were not significantly different between the HN and AN, but were significantly higher than in the MN and LN. (5) NPFP was significantly higher in the DIO compared to the DIS. Among the different N rates, NPFP was highest with the AN treatment and lowest with the LN. In summary, under drip irrigation, there was a mismatch between soil mineral N and the distribution of rice roots, leading to reduced N accumulation and utilization in rice, ultimately impacting yield formation. Increasing N application and soil ammonium nutrition can improve rice yield under drip irrigation. However, optimizing N fertilizer management may not increase rice yield further when irrigation is further limited.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 20
Claim · model-written summary
Soil nitrate and ammonium were highest at 0–10 cm two days after application.
- Taxon
- rice
Oryza sativat0 - Outcome
- contents of soil NO3−-N and NH4+-Ne0
- Direction
- higheste0
- Qualifier
- 0–10 cm soil layere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“On the second day after N application, the contents of soil NO3−-N and NH4+-N in the 0–10 cm soil layer were highest for both the DIO and DIS.”
Claim · model-written summary
After 28 days soil nitrate peaked at 20–40 cm.
- Taxon
- riceOryza sativat0
- Outcome
- soil NO3−-N contente0
- Direction
- higheste0
- Qualifier
- 20–40 cm depthe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“On the 28th day after N application, the soil NO3−-N content was highest at the 20–40 cm depth”
Claim · model-written summary
After 28 days soil ammonium remained highest at 0–10 cm.
- Taxon
- riceOryza sativat0
- Outcome
- soil NH4+-N contente0
- Direction
- higheste0
- Qualifier
- 0–10 cm depthe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“while the soil NH4+-N content was still highest at the 0–10 cm depth”
Claim · model-written summary
DIO increased aboveground and root biomass compared with DIS.
- Taxon
- riceOryza sativat0
- Treatment
- DIO treatmente0
- Outcome
- aboveground and root biomasse0
- Direction
- highere0
- Comparator
- DISe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“The aboveground and root biomass in DIO treatment were significantly higher than in DIS.”
Claim · model-written summary
Root biomass at 0–10 cm exceeded 10–50 cm in both irrigation regimes.
- Taxon
- riceOryza sativat0
- Outcome
- root biomasse0
- Direction
- greatere0
- Qualifier
- both the DIO and DIS treatmentse0
- Comparator
- 10–50 cm depthe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“root biomass at the 0–10 cm depth was significantly greater than at the 10–50 cm depth for both the DIO and DIS treatments”
Claim · model-written summary
Under DIO, HN and AN increased deeper root biomass versus MN.
- Taxon
- riceOryza sativat0
- Treatment
- HN and AN treatmentse0
- Outcome
- root biomass at the 10–50 cm depthe0
- Direction
- highere0
- Qualifier
- DIO treatmente0
- Comparator
- MNe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“In the DIO treatment, the root biomass at the 10–50 cm depth was significantly higher with the HN and AN treatments compared to MN.”
Claim · model-written summary
Under DIS, deeper root biomass did not differ significantly among MN, HN and AN.
- Taxon
- riceOryza sativat0
- Treatment
- MN, HN, and ANe0
- Outcome
- root biomass at the 10–50 cm depthe0
- Direction
- did not show significant differencese0
- Comparator
- MN, HN, and ANe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“in the DIS treatment, the root biomass at the 10–50 cm depth did not show significant differences between the MN, HN, and AN”
Claim · model-written summary
DIO increased rice N accumulation relative to DIS.
- Taxon
- riceOryza sativat0
- Treatment
- DIO treatmente0
- Outcome
- N accumulation in ricee0
- Direction
- highere0
- Comparator
- DIS treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“N accumulation in rice was significantly higher for the DIO treatment compared to the DIS treatment”
Claim · model-written summary
AN had the highest rice N accumulation.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“the N accumulation in rice was highest in the AN and lowest in the LN”
Claim · model-written summary
LN had the lowest rice N accumulation.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“the N accumulation in rice was highest in the AN and lowest in the LN”
Claim · model-written summary
DIS increased PrNTA and PrNTC relative to DIO.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“The PrNTA and PrNTC in DIS were significantly higher than in DIO”
Claim · model-written summary
DIS reduced PoNAA and PoNAC relative to DIO.
- Taxon
- riceOryza sativat0
- Treatment
- DISe0
- Outcome
- PoNAA and PoNACe0
- Direction
- lowere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“while the PoNAA and PoNAC were significantly lower in DIS”
Claim · model-written summary
DIS reduced panicle number, spikelets per panicle and seed-setting rate.
- Taxon
- riceOryza sativat0
- Treatment
- DISe0
- Outcome
- number of panicles, spikelets per panicle, seed-setting ratee0
- Direction
- lowere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“The number of panicles, spikelets per panicle, seed-setting rate, 1000-grain weight, and grain yield were significantly lower in DIS.”
Claim · model-written summary
DIS reduced 1000-grain weight and grain yield.
- Taxon
- riceOryza sativat0
- Treatment
- DISe0
- Outcome
- 1000-grain weight, and grain yielde0
- Direction
- lowere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“1000-grain weight, and grain yield were significantly lower in DIS”
Claim · model-written summary
Under DIS, yield parameters did not differ significantly among MN, HN and AN.
- Taxon
- riceOryza sativat0
- Treatment
- MN, HN, and ANe0
- Outcome
- these parameterse0
- Direction
- not significantly differente0
- Comparator
- MN, HN, and ANe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“Under the DIS, these parameters were not significantly different among the MN, HN, and AN.”
Claim · model-written summary
Under DIO, HN and AN produced similar seed set, grain weight and yield.
- Taxon
- riceOryza sativat0
- Treatment
- HNe0
- Outcome
- seed-setting rate, 1000-grain weight, and yielde0
- Direction
- not significantly differente0
- Comparator
- ANe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“In the DIO, the seed-setting rate, 1000-grain weight, and yield were not significantly different between the HN and AN”
Claim · model-written summary
Under DIO, HN and AN exceeded MN and LN for seed set, grain weight and yield.
- Taxon
- riceOryza sativat0
- Direction
- highere0
- Comparator
- MN and LNe0
Not reportedTreatmentOutcome
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“but were significantly higher than in the MN and LN”
Claim · model-written summary
DIO increased NPFP relative to DIS.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“NPFP was significantly higher in the DIO compared to the DIS”
Claim · model-written summary
AN had the highest NPFP and LN the lowest.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“NPFP was highest with the AN treatment and lowest with the LN”
Claim · model-written summary
Increasing nitrogen and ammonium nutrition can improve drip-irrigated rice yield, though limited irrigation may constrain further gains.
- Taxon
- riceOryza sativat0
- Outcome
- rice yielde0
- Qualifier
- when irrigation is further limitede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice”
e0“Increasing N application and soil ammonium nutrition can improve rice yield under drip irrigation. However, optimizing N fertilizer management may not increase rice yield further when irrigation is further limited.”
The same questions in other papers
irrigation · nutrient: content · Oryza sativa (rice)Positive and negative results
118 papers in the same direction as this paper · 24 in the opposite direction · 1 reporting no difference from an alternative
- negative
- negative
- negative
140 papers more in this group
See all 144 papers →irrigation · growth · Oryza sativa (rice)Positive and negative results
221 papers in the same direction as this paper · 62 in the opposite direction · 7 reporting no difference from an alternative
- negative
- negative
- negative
287 papers more in this group
See all 291 papers →drought · yield · Oryza sativa (rice)Positive and negative results
248 papers in the same direction as this paper · 76 in the opposite direction
- positive
- positive
- positive
321 papers more in this group
See all 325 papers →irrigation · yield · Oryza sativa (rice)Positive and negative results
264 papers in the same direction as this paper · 906 in the opposite direction
- positive
- positive
- positive
1,167 papers more in this group
See all 1,171 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.