Abstract
We assessed long-term yield trajectories in rice-rice (RR) and rice-wheat (RW) in South Asia, using multi-decadal records from 11 RR and 28 RW experiments under Control, NPK, and NPK+farmyard manure (FYM). Trends were classified as positive or declining using site-level regressions (slope ≠ 0, P ≤ 0.05). In RR, positive system productivity trends occurred at 10% (Control) vs. 46% (NPK) and 60% (NPK+FYM), while declines fell from 40% to 9-10%. In RW, corresponding shares of positive trends were 10%, 18%, and 44% for Control, NPK, and NPK+FYM, respectively, with declines dropping from 30% to 11% and 9%. Meta-analysis of crop yields showed consistent patterns: under NPK+FYM, pooled correlations were positive for RR (kharif rice: r = 0.41, P = 0.001; rabi rice= 0.28, P = 0.004), and RW (rice: 0.27, P = 0.011; wheat r = 0.18; P = 0.002), whereas NPK effects were weaker – positive for RW-wheat (0.15, p = 0.048) and RR-rice (rabi; r = 0.29, P = 0.007) but near zero for RR-rice (kharif) and RW-rice. Residual coefficient of variation (residual CV) fell from about 20-30% (Control) to 15-18% (fertilized). Agronomic efficiency of fertilizer-N (AEN) and the sustainability yield index (SYI) were higher under NPK and NPK+FYM than under control, and NPK+FYM kept AEN similar to NPK while reducing the number of sites with low AEN and low SYI. Practical priorities include combining organic resources with balanced NPK; retaining crop residues where possible, reducing puddling where it harms wheat, and routinely tracking AEN, SYI, and trend/stability indicators alongside mean yield.
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Claims 19
Claim · model-written summary
In rice-rice systems, positive system productivity trends occurred at 46% of sites under NPK, compared with 10% under Control.
- Taxon
- rice
Oryza sativat0 - Treatment
- NPKe1
- Outcome
- positive system productivity trendse1
- Direction
- higherinferrede1
- Value
- 46%e1
- Qualifier
- 10% (Control)e1
- Comparator
- Controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e1“In RR, positive system productivity trends occurred at 10% (Control) vs. 46% (NPK) and 60% (NPK+FYM), while declines fell from 40% to 9-10%”
Claim · model-written summary
In rice-rice systems, positive system productivity trends occurred at 60% of sites under NPK+FYM, compared with 10% under Control.
- Taxon
- riceOryza sativat0
- Treatment
- NPK+FYMe1
- Outcome
- positive system productivity trendse1
- Direction
- higherinferrede1
- Value
- 60%e1
- Qualifier
- 10% (Control)e1
- Comparator
- Controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e1“In RR, positive system productivity trends occurred at 10% (Control) vs. 46% (NPK) and 60% (NPK+FYM), while declines fell from 40% to 9-10%”
Claim · model-written summary
In rice-rice systems, declines in system productivity fell from 40% to 9-10% of sites.
- Taxon
- riceOryza sativat0
- Outcome
- declinese1
- Direction
- felle1
- Value
- 40% to 9-10%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e1“In RR, positive system productivity trends occurred at 10% (Control) vs. 46% (NPK) and 60% (NPK+FYM), while declines fell from 40% to 9-10%”
Claim · model-written summary
Under NPK+FYM, pooled correlations were positive for kharif rice in rice-rice systems (r = 0.41, P = 0.001).
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e2“under NPK+FYM, pooled correlations were positive for RR (kharif rice: r = 0.41, P = 0.001; rabi rice= 0.28, P = 0.004), and RW (rice: 0.27, P = 0.011; wheat r = 0.18; P = 0.002)”
Claim · model-written summary
Under NPK+FYM, pooled correlations were positive for rabi rice in rice-rice systems (r = 0.28, P = 0.004).
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e2“under NPK+FYM, pooled correlations were positive for RR (kharif rice: r = 0.41, P = 0.001; rabi rice= 0.28, P = 0.004), and RW (rice: 0.27, P = 0.011; wheat r = 0.18; P = 0.002)”
Claim · model-written summary
Under NPK+FYM, pooled correlations were positive for rice in rice-wheat systems (r = 0.27, P = 0.011).
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e2“under NPK+FYM, pooled correlations were positive for RR (kharif rice: r = 0.41, P = 0.001; rabi rice= 0.28, P = 0.004), and RW (rice: 0.27, P = 0.011; wheat r = 0.18; P = 0.002)”
Claim · model-written summary
Under NPK+FYM, pooled correlations were positive for wheat in rice-wheat systems (r = 0.18, P = 0.002).
- Taxon
- wheat
Triticum aestivume2 - Treatment
- NPK+FYMe2
- Outcome
- pooled correlationse2
- Direction
- positivee2
- Value
- r = 0.18e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e2“under NPK+FYM, pooled correlations were positive for RR (kharif rice: r = 0.41, P = 0.001; rabi rice= 0.28, P = 0.004), and RW (rice: 0.27, P = 0.011; wheat r = 0.18; P = 0.002)”
Claim · model-written summary
Under NPK, pooled correlations were positive for wheat in rice-wheat systems (r = 0.15, p = 0.048), a weaker effect than under NPK+FYM.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e0“NPK effects were weaker”
e4“positive for RW-wheat (0.15, p = 0.048) and RR-rice (rabi; r = 0.29, P = 0.007)”
e2“under NPK+FYM, pooled correlations were positive for RR (kharif rice: r = 0.41, P = 0.001; rabi rice= 0.28, P = 0.004), and RW (rice: 0.27, P = 0.011; wheat r = 0.18; P = 0.002)”
Claim · model-written summary
Under NPK, pooled correlations were positive for rabi rice in rice-rice systems (r = 0.29, P = 0.007).
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e0“NPK effects were weaker”
e4“positive for RW-wheat (0.15, p = 0.048) and RR-rice (rabi; r = 0.29, P = 0.007)”
e2“under NPK+FYM, pooled correlations were positive for RR (kharif rice: r = 0.41, P = 0.001; rabi rice= 0.28, P = 0.004), and RW (rice: 0.27, P = 0.011; wheat r = 0.18; P = 0.002)”
Claim · model-written summary
Under NPK, pooled correlations were near zero for kharif rice in rice-rice systems.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e0“NPK effects were weaker”
e5“but near zero for RR-rice (kharif) and RW-rice”
e2“under NPK+FYM, pooled correlations were positive for RR (kharif rice: r = 0.41, P = 0.001; rabi rice= 0.28, P = 0.004), and RW (rice: 0.27, P = 0.011; wheat r = 0.18; P = 0.002)”
Claim · model-written summary
Under NPK, pooled correlations were near zero for rice in rice-wheat systems.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e0“NPK effects were weaker”
e5“but near zero for RR-rice (kharif) and RW-rice”
e2“under NPK+FYM, pooled correlations were positive for RR (kharif rice: r = 0.41, P = 0.001; rabi rice= 0.28, P = 0.004), and RW (rice: 0.27, P = 0.011; wheat r = 0.18; P = 0.002)”
Claim · model-written summary
Residual coefficient of variation fell from 20-30% under Control to 15-18% under fertilized treatments in rice systems.
- Taxon
- riceOryza sativat0
- Treatment
- fertilizede6
- Outcome
- residual coefficient of variatione6
- Direction
- felle6
- Value
- 15-18%e6
- Comparator
- Controle6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e6“Residual coefficient of variation (residual CV) fell from about 20-30% (Control) to 15-18% (fertilized)”
Claim · model-written summary
Agronomic efficiency of fertilizer-N and the sustainability yield index were higher under NPK and NPK+FYM than under control in rice-based systems.
- Taxon
- riceOryza sativat0
- Treatment
- NPK and NPK+FYMe7
- Outcome
- Agronomic efficiency of fertilizer-N (AEN) and the sustainability yield index (SYI)e7
- Direction
- highere7
- Comparator
- controle7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e7“Agronomic efficiency of fertilizer-N (AEN) and the sustainability yield index (SYI) were higher under NPK and NPK+FYM than under control”
Claim · model-written summary
NPK+FYM kept agronomic efficiency of fertilizer-N similar to NPK.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e4“NPK+FYM kept AEN similar to NPK while reducing the number of sites with low AEN and low SYI”
Claim · model-written summary
NPK+FYM reduced the number of sites with low agronomic efficiency of fertilizer-N and low sustainability yield index.
- Taxon
- riceOryza sativat0
- Treatment
- NPK+FYMe4
- Outcome
- number of sites with low AEN and low SYIe4
- Direction
- reducinge4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e4“NPK+FYM kept AEN similar to NPK while reducing the number of sites with low AEN and low SYI”
Claim · model-written summary
Combining organic resources with balanced NPK is a practical priority for rice-based systems.
- Taxon
- riceOryza sativat0
- Outcome
- combining organic resources with balanced NPKe4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e4“Practical priorities include combining organic resources with balanced NPK”
Claim · model-written summary
Routinely tracking AEN, SYI, and trend/stability indicators alongside mean yield is a practical priority.
- Taxon
- riceOryza sativat0
- Outcome
- routinely tracking AEN, SYI, and trend/stability indicators alongside mean yielde5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e5“routinely tracking AEN, SYI, and trend/stability indicators alongside mean yield”
Claim · model-written summary
Retaining crop residues where possible is a practical priority.
- Taxon
- riceOryza sativat0
- Outcome
- retaining crop residues where possiblee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e6“retaining crop residues where possible, reducing puddling where it harms wheat”
Claim · model-written summary
Reducing puddling where it harms wheat is a practical priority.
- Taxon
- wheatTriticum aestivume6
- Outcome
- reducing puddling where it harms wheate6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice-rice and rice-wheat systems in South Asian”
e6“retaining crop residues where possible, reducing puddling where it harms wheat”
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