Abstract
This study investigated the effects of predicted changes in rainfall distribution in marginal (=325 mm annual rainfall) parts of the south-west Australian wheatbelt and options for management and adaptation of the wheat crop. Field experiments with rain-out shelters and irrigation were conducted in 2008 and 2009 to investigate the interactions of rainfall distribution, row spacing, genotype and timing of nitrogen application on growth, water use and grain yield of spring wheat. Water storage before seeding showed potential to maintain or increase yields despite lower in-season rainfall. Widening row spacing reduced biomass and slowed water use but did not increase grain yield, because of increased soil evaporation and water left in the soil at crop maturity. The Agricultural Production Systems Simulator (APSIM) wheat model was used to investigate the effects of recent and projected climate change on yield in relation to row spacing, phenology and nitrogen. Two climate-change scenarios were applied to historical climatic data to create two plausible future climates (‘optimistic’ and ‘pessimistic’) for the year 2030. None of the strategies tested increased wheat yield under the predicted climate scenarios. Simulated yields at wider row spacings were consistently lower due to insufficient biomass, increased soil evaporation and the inability of the crop to use all of the available water before maturity. Simulated yields of short-season genotypes were always greater than yields of longer season genotypes. Nitrogen regimes had little effect in this study. This study points to several genotypic traits that could improve the performance of wheat grown at wider row spacings. These include early vigour to reduce soil evaporation and increase competition with weeds, greater tillering/biomass to reduce limitation by sink size, and a vigorous root system with appropriate lateral spread and growth to depth to access available soil water.
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Claims 8
Claim · model-written summary
Water storage before seeding could maintain or increase yield under reduced seasonal rainfall.
- Taxon
- wheat
Triticum aestivumt0 - Treatment
- Water storage before seedinge0
- Outcome
- yieldse0
- Direction
- increasee0
- Comparator
- lower in-season rainfalle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“wheat”
e0“Water storage before seeding showed potential to maintain or increase yields despite lower in-season rainfall.”
Claim · model-written summary
Wider row spacing reduced biomass.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Widening row spacinge0
- Outcome
- biomasse0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“wheat”
e0“Widening row spacing reduced biomass and slowed water use but did not increase grain yield, because of increased soil evaporation and water left in the soil at crop maturity.”
Claim · model-written summary
Wider row spacing slowed water use.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Widening row spacinge0
- Outcome
- water usee0
- Direction
- slowede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“wheat”
e0“Widening row spacing reduced biomass and slowed water use but did not increase grain yield, because of increased soil evaporation and water left in the soil at crop maturity.”
Claim · model-written summary
Wider row spacing did not increase grain yield.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Widening row spacinge0
- Outcome
- grain yielde0
- Direction
- did not increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“wheat”
e0“Widening row spacing reduced biomass and slowed water use but did not increase grain yield, because of increased soil evaporation and water left in the soil at crop maturity.”
Claim · model-written summary
No tested adaptation increased projected wheat yield.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- strategies testede0
- Outcome
- wheat yielde0
- Direction
- increasede0
- Qualifier
- predicted climate scenariose0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“wheat”
e0“None of the strategies tested increased wheat yield under the predicted climate scenarios.”
Claim · model-written summary
Simulated yield at wider row spacing was consistently lower.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- wider row spacingse0
- Outcome
- yieldse0
- Direction
- lowere0
- Qualifier
- insufficient biomass, increased soil evaporation and the inability of the crop to use all of the available water before maturitye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“wheat”
e0“Simulated yields at wider row spacings were consistently lower due to insufficient biomass, increased soil evaporation and the inability of the crop to use all of the available water before maturity.”
Claim · model-written summary
Short-season genotypes had greater simulated yield than longer-season genotypes.
- Taxon
- wheatTriticum aestivumt0
- Material
- short-season genotypese0
- Outcome
- yieldse0
- Direction
- greatere0
- Comparator
- longer season genotypese0
Not reportedTreatment
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“wheat”
e0“Simulated yields of short-season genotypes were always greater than yields of longer season genotypes.”
Claim · model-written summary
Nitrogen regimes had little effect in the study.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Nitrogen regimese0
- Outcome
- little effecte0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“wheat”
e0“Nitrogen regimes had little effect in this study.”
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See all 498 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.