Abstract
Abstract. An easy‐to‐use simulation model was developed with the aim of improving fertilizer practice when crop residues are incorporated instead of removed. It was tested against data from a well‐monitored N fertilizer experiment in which three successive brassica crops were grown followed by barley. Experimental findings included: (a) that fertilizer‐N greatly increased yield of 3 crops without increasing residual soil mineral‐N at harvest unless supply exceeded crop demand; (b) that, by contrast, fertilizer‐N increased both yield of and residual soil mineral‐N left by the remaining crop throughout the range of applications; and (c) that at each harvest the apparent disappearance of fertilizer‐N by immobilization and other processes was almost proportional to fertilizer‐N. These phenomena were simulated by the model. Overall the model gave estimates of soil mineral‐N, plant weight and % N in the crop for each crop that were either in close agreement with or linearly related to the measured values. Deviations from this pattern are shown to result almost entirely from experimental error. In addition the model gave simulations of the time course of soil mineral‐N and soil water that were in good agreement with measurement. Simulations with the model indicate that appreciable benefits from residue incorporation of crops will only be obtained when fertilizer‐N is also applied, unless plant masses at harvest are small.
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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 10
Claim · model-written summary
Fertilizer nitrogen greatly increased yield of three crops without increasing residual soil mineral nitrogen unless supply exceeded demand.
- Treatment
- fertilizer‐Ne0
- Outcome
- yield of 3 cropse0
- Direction
- increasede0
- Qualifier
- unless supply exceeded crop demande0
BrassicaNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fertilizer‐N greatly increased yield of 3 crops without increasing residual soil mineral‐N at harvest unless supply exceeded crop demand”
e1“three successive brassica crops were grown followed by barley”
Claim · model-written summary
Fertilizer nitrogen did not increase residual soil mineral nitrogen at harvest for three crops unless supply exceeded demand.
- Treatment
- fertilizer‐Ne0
- Outcome
- residual soil mineral‐N at harveste0
- Direction
- without increasinge0
- Qualifier
- unless supply exceeded crop demande0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fertilizer‐N greatly increased yield of 3 crops without increasing residual soil mineral‐N at harvest unless supply exceeded crop demand”
e1“three successive brassica crops were grown followed by barley”
Claim · model-written summary
Fertilizer nitrogen increased yield of the remaining crop across the application range.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaree1 - Treatment
- fertilizer‐Ne0
- Outcome
- yielde0
- Direction
- increasede0
- Qualifier
- throughout the range of applicationse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“fertilizer‐N increased both yield of and residual soil mineral‐N left by the remaining crop throughout the range of applications”
e1“three successive brassica crops were grown followed by barley”
Claim · model-written summary
Fertilizer nitrogen increased residual soil mineral nitrogen left by barley throughout the application range.
- Taxon
- barleyHordeum vulgaree1
- Treatment
- fertilizer‐Ne0
- Outcome
- residual soil mineral‐N left by the remaining crope0
- Direction
- increasede0
- Qualifier
- throughout the range of applicationse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fertilizer‐N increased both yield of and residual soil mineral‐N left by the remaining crop throughout the range of applications”
e1“three successive brassica crops were grown followed by barley”
Claim · model-written summary
At each harvest apparent fertilizer nitrogen disappearance was almost proportional to fertilizer nitrogen.
- Treatment
- fertilizer‐Ne0
- Outcome
- apparent disappearance of fertilizer‐Ne0
- Qualifier
- almost proportional to fertilizer‐Ne0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at each harvest the apparent disappearance of fertilizer‐N by immobilization and other processes was almost proportional to fertilizer‐N”
e1“three successive brassica crops were grown followed by barley”
Claim · model-written summary
The model simulated the reported yield and nitrogen dynamics.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These phenomena were simulated by the model.”
e1“three successive brassica crops were grown followed by barley”
Claim · model-written summary
Model estimates of soil mineral nitrogen, plant weight and crop nitrogen percentage closely agreed with or were linearly related to measured values.
- Outcome
- soil mineral‐N, plant weight and % N in the crope0
- Direction
- in close agreement with or linearly relatede0
- Comparator
- measured valuese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the model gave estimates of soil mineral‐N, plant weight and % N in the crop for each crop that were either in close agreement with or linearly related to the measured values”
e1“three successive brassica crops were grown followed by barley”
Claim · model-written summary
Deviations in model agreement resulted almost entirely from experimental error.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Deviations from this pattern are shown to result almost entirely from experimental error.”
e1“three successive brassica crops were grown followed by barley”
Claim · model-written summary
Simulated soil mineral nitrogen and soil water time courses agreed well with measurements.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the model gave simulations of the time course of soil mineral‐N and soil water that were in good agreement with measurement”
e1“three successive brassica crops were grown followed by barley”
Claim · model-written summary
Simulations indicated appreciable residue incorporation benefits only with fertilizer nitrogen, unless plant mass at harvest was small.
- Treatment
- fertilizer‐Ne0
- Outcome
- appreciable benefits from residue incorporation of cropse0
- Qualifier
- unless plant masses at harvest are smalle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“appreciable benefits from residue incorporation of crops will only be obtained when fertilizer‐N is also applied, unless plant masses at harvest are small”
e1“three successive brassica crops were grown followed by barley”
The same questions in other papers
fertilization · yield · Hordeum vulgare (barley)Positive and negative results
472 papers in the same direction as this paper · 66 in the opposite direction · 11 reporting no difference from an alternative
- no effect
- negative
- negative
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See all 550 papers →fertilization · yield · BrassicaResults agree
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- positive
- positive
- positive
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See all 7 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.