Abstract
Optimizing crop productivity while mitigating pollution requires a system-wide understanding of nitrogen (N) fertilizer fate and its loss pathways. However, regional variability in N fate and its linkage to yield response in China’s wheat systems remains poorly quantified. We collected 4077 observations to analyze the effects of N fertilizer management, climate, and soil properties on wheat yield, N fate, and reactive nitrogen (Nr) losses using meta-analysis and machine learning. At the national scale, wheat yield increased by 65.40% with N fertilization, with applied N partitioned into 41.56% uptake, 29.66% residual, and 38.81% losses. The Nr losses comprised NH 3 (9.35%), N 2 O (0.73%), NO (0.38%), leaching (7.38%), and runoff (4.68%). At the regional scale, N uptake exhibited an increasing trend from north to south, whereas N residual and N loss gradually decreased. NH 3 volatilization accounted for 91.76% of total N loss in northern China (NC). In central China (CC), NH 3 constituted 53.45% of the losses, with N leaching accounting for 41.38%. By contrast, southern China (SC) showed a more even distribution of losses across pathways. N application rate was the key determinant of N fate, whereas pH, mean annual precipitation, mean annual temperature, and bulk density had the greatest influence on Nr losses. Nationally, N uptake was the dominant driver of yield response, accounting for 54.06% of the variation. Regionally, uptake remained the key factor in CC (37.83%), whereas NC (27.33% uptake; 16.09% loss) and SC (15.20% uptake; 12.37% loss) showed substantial sensitivity to N loss. N residual had minimal impact in most regions but was significant in CC (11.66%). Enhancing nitrogen uptake is the top priority in increasing wheat yield across different regions of China, while the role of fertilizer N loss and residual regionally varied. Accordingly, N management should prioritize loss reduction in NC and SC, and residual management in CC. • Applied N partitions as 41.56% plant uptake, 29.66% soil residual, and 38.81% environmental loss in China’s wheat systems. • N uptake increases from north to south, while soil residual and environmental loss progressively decrease along this gradient. • Northern China loss dominates as NH 3 , Central features NH 3 and N leaching, and Southern shows balanced loss. • N rate governs overall fate, while regional climate and soil properties control specific loss pathways. • Regional nitrogen efficiency disparities directly affect yield stability, forming the basis for tailored management.
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Claims 20
Claim · model-written summary
Nitrogen fertilization increased wheat yield by 65.40%.
- Taxon
- wheat
Triticum aestivume0 - Treatment
- N fertilizatione0
- Outcome
- wheat yielde0
- Direction
- increasede0
- Value
- 65.40%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“wheat yield increased by 65.40% with N fertilization”
Claim · model-written summary
Applied nitrogen partitioned into 41.56% uptake.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- uptakee0
- Value
- 41.56%e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“applied N partitioned into 41.56% uptake, 29.66% residual, and 38.81% losses”
t0“wheat systems”
Claim · model-written summary
Applied nitrogen partitioned into 29.66% residual.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- residuale0
- Value
- 29.66%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“applied N partitioned into 41.56% uptake, 29.66% residual, and 38.81% losses”
t0“wheat systems”
Claim · model-written summary
Applied nitrogen partitioned into 38.81% losses.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- lossese0
- Value
- 38.81%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“applied N partitioned into 41.56% uptake, 29.66% residual, and 38.81% losses”
t0“wheat systems”
Claim · model-written summary
Reactive nitrogen losses included 9.35% ammonia.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- NH 3e0
- Value
- 9.35%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The Nr losses comprised NH 3 (9.35%), N 2 O (0.73%), NO (0.38%), leaching (7.38%), and runoff (4.68%)”
t0“wheat systems”
Claim · model-written summary
Reactive nitrogen losses included 0.73% nitrous oxide.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- N 2 Oe0
- Value
- 0.73%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The Nr losses comprised NH 3 (9.35%), N 2 O (0.73%), NO (0.38%), leaching (7.38%), and runoff (4.68%)”
t0“wheat systems”
Claim · model-written summary
Reactive nitrogen losses included 0.38% nitric oxide.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- NOe0
- Value
- 0.38%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The Nr losses comprised NH 3 (9.35%), N 2 O (0.73%), NO (0.38%), leaching (7.38%), and runoff (4.68%)”
t0“wheat systems”
Claim · model-written summary
Reactive nitrogen losses included 7.38% leaching.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- leachinge0
- Value
- 7.38%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The Nr losses comprised NH 3 (9.35%), N 2 O (0.73%), NO (0.38%), leaching (7.38%), and runoff (4.68%)”
t0“wheat systems”
Claim · model-written summary
Reactive nitrogen losses included 4.68% runoff.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- runoffe0
- Value
- 4.68%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The Nr losses comprised NH 3 (9.35%), N 2 O (0.73%), NO (0.38%), leaching (7.38%), and runoff (4.68%)”
t0“wheat systems”
Claim · model-written summary
Nitrogen uptake increased from north to south.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- N uptakee0
- Direction
- increasing trende0
- Setting
- north to southe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N uptake exhibited an increasing trend from north to south”
t0“wheat systems”
Claim · model-written summary
Residual nitrogen decreased from north to south.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- N residuale0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N residual and N loss gradually decreased”
t0“wheat systems”
Claim · model-written summary
Nitrogen loss decreased from north to south.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- N losse0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N residual and N loss gradually decreased”
t0“wheat systems”
Claim · model-written summary
Ammonia volatilization accounted for 91.76% of total nitrogen loss in northern China.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- NH 3 volatilizatione0
- Value
- 91.76%e0
- Setting
- northern Chinae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NH 3 volatilization accounted for 91.76% of total N loss in northern China (NC)”
t0“wheat systems”
Claim · model-written summary
In central China, ammonia made up 53.45% of losses.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- NH 3e0
- Value
- 53.45%e0
- Setting
- central Chinae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In central China (CC), NH 3 constituted 53.45% of the losses, with N leaching accounting for 41.38%”
t0“wheat systems”
Claim · model-written summary
In central China, nitrogen leaching made up 41.38% of losses.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- N leachinge0
- Value
- 41.38%e0
- Setting
- central Chinae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In central China (CC), NH 3 constituted 53.45% of the losses, with N leaching accounting for 41.38%”
t0“wheat systems”
Claim · model-written summary
Southern China had a more even distribution of nitrogen loss pathways.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- more even distribution of lossese0
- Setting
- southern Chinae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“southern China (SC) showed a more even distribution of losses across pathways”
t0“wheat systems”
Claim · model-written summary
Nitrogen application rate was the principal determinant of nitrogen fate.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- N application ratee0
- Outcome
- N fatee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N application rate was the key determinant of N fate”
t0“wheat systems”
Claim · model-written summary
Nitrogen uptake explained 54.06% of national yield response variation.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- N uptakee0
- Outcome
- yield responsee0
- Value
- 54.06%e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N uptake was the dominant driver of yield response, accounting for 54.06% of the variation”
t0“wheat systems”
Claim · model-written summary
Regional nitrogen uptake and loss contributions to yield response varied.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- uptakee0
- Outcome
- sensitivity to N losse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“uptake remained the key factor in CC (37.83%), whereas NC (27.33% uptake; 16.09% loss) and SC (15.20% uptake; 12.37% loss) showed substantial sensitivity to N loss”
t0“wheat systems”
Claim · model-written summary
The authors recommend reducing nitrogen loss in northern and southern China and managing residual nitrogen in central China.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- loss reduction in NC and SC, and residual management in CCe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N management should prioritize loss reduction in NC and SC, and residual management in CC”
t0“wheat systems”
The same questions in other papers
fertilization · yield · Triticum aestivum (wheat)Positive and negative results
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