Abstract
Controlled release urea (CRU) has been widely adopted to increase nitrogen (N) use efficiency and maize production, but the impacts can range widely depending on water availability in the soil. In an experiment using Zhengdan 958 (a popular summer maize hybrid), three levels of water treatments (adequate water condition [W3], which maintained soil moisture at about 75% ± 5% of the soil's field capacity; mild water stress [W2], which maintained moisture content at 55% ± 5% of field capacity; and severe water stress [W1], which had a moisture content of 35% ± 5% of field capacity) and four levels of controlled release urea fertilizer (N0, N1, N2 and N3 were 0, 105, 210 and 315 kg N ha-1, respectively) were compared in a rainout shelter system with soil. The results revealed that CRU had significant effects on maize yields and N use efficiencies under different water conditions. The mean yields increased with increasing water levels and showed significant differences. Under W1, the accumulation of dry matter and N were limited, and N internal efficiency (NIE) and the apparent recovery efficiency of applied N (REN) decreased with N increases; yields of N1, N2, and N3 were similar. Under W2, the dry matter and N accumulation, as well as the yield, showed an increasing trend with an increase in N application, and the NIE and REN of N3 showed no difference from N2. Under W3, yields of N2 and N3 were similar and they were significantly higher than that of N1, but the agronomic N use efficiency (ANUE), REN, and the physiological NUE (PNUE) of N2 were 54.2, 34.9, and 14.4% higher, respectively, than those of N3. N application beyond the optimal N rate did not consistently increase maize yield, and caused a decrease in N use efficiencies. Highest overall dry matter, N accumulation, and yields were observed with N3 under W2, and those showed no differences with N2 and N3 under W3. Under this experimental condition, the CRU of 210 kg ha-1 was optimized when soil moisture content was 75% ± 5% of field capacity, but an N rate of 315 kg ha-1 was superior when soil moisture content during the entire growing season was maintained at 55% ± 5% of field capacity.
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 15
Claim · model-written summary
Maize mean yields increased with water availability and differed significantly.
Zea maysNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“The mean yields increased with increasing water levels and showed significant differences.”
Claim · model-written summary
Under severe water stress, dry matter and nitrogen accumulation were limited.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“Under W1, the accumulation of dry matter and N were limited”
Claim · model-written summary
Under W1, NIE and REN decreased as nitrogen application increased.
- Treatment
- N increasese0
- Outcome
- N internal efficiency (NIE) and the apparent recovery efficiency of applied N (REN)e0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“N internal efficiency (NIE) and the apparent recovery efficiency of applied N (REN) decreased with N increases”
Claim · model-written summary
Under W1, yields at N1, N2, and N3 were similar.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“yields of N1, N2, and N3 were similar”
Claim · model-written summary
Under W2, dry matter accumulation, nitrogen accumulation, and yield increased with nitrogen application.
- Treatment
- N applicatione0
- Outcome
- dry matter and N accumulation, as well as the yielde0
- Direction
- increasing trende0
- Setting
- W2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“Under W2, the dry matter and N accumulation, as well as the yield, showed an increasing trend with an increase in N application”
Claim · model-written summary
Under W2, NIE and REN at N3 did not differ from N2.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“the NIE and REN of N3 showed no difference from N2”
Claim · model-written summary
Under W3, yields at N2 and N3 were similar.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“Under W3, yields of N2 and N3 were similar”
Claim · model-written summary
Under W3, N2 and N3 yields significantly exceeded N1 yield.
Not reportedTreatment
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“they were significantly higher than that of N1”
Claim · model-written summary
At W3, agronomic nitrogen use efficiency at N2 was 54.2% higher than at N3.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“the agronomic N use efficiency (ANUE), REN, and the physiological NUE (PNUE) of N2 were 54.2, 34.9, and 14.4% higher, respectively, than those of N3”
Claim · model-written summary
At W3, REN at N2 was 34.9% higher than at N3.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“REN, and the physiological NUE (PNUE) of N2 were 54.2, 34.9, and 14.4% higher, respectively, than those of N3”
Claim · model-written summary
At W3, physiological NUE at N2 was 14.4% higher than at N3.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“the physiological NUE (PNUE) of N2 were 54.2, 34.9, and 14.4% higher, respectively, than those of N3”
Claim · model-written summary
Nitrogen application beyond the optimum did not consistently raise yield and decreased nitrogen use efficiencies.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“N application beyond the optimal N rate did not consistently increase maize yield, and caused a decrease in N use efficiencies.”
Claim · model-written summary
N3 under W2 produced the highest overall dry matter, nitrogen accumulation, and yields.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“Highest overall dry matter, N accumulation, and yields were observed with N3 under W2”
Claim · model-written summary
The authors identified 210 kg ha-1 CRU at 75% ± 5% field capacity as optimal.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“the CRU of 210 kg ha-1 was optimized when soil moisture content was 75% ± 5% of field capacity”
Claim · model-written summary
The authors considered 315 kg ha-1 superior at 55% ± 5% field capacity.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“maize”
e0“an N rate of 315 kg ha-1 was superior when soil moisture content during the entire growing season was maintained at 55% ± 5% of field capacity”
The same questions in other papers
irrigation · yield · Zea mays (maize)Positive and negative results
790 papers in the same direction as this paper · 209 in the opposite direction · 16 reporting no difference from an alternative
- positive
- negative
- no effect
1,012 papers more in this group
See all 1,016 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.