scholarly journals Contribution of climate models and APSIM phenological parameters to uncertainties in spring wheat simulations: Application of SUFI‐2 algorithm in northeast Australia

Author(s):  
Brian Collins ◽  
Ullah Najeeb ◽  
Qunying Luo ◽  
Daniel K. Y. Tan
Keyword(s):  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Budong Qian ◽  
Qi Jing ◽  
Alex J. Cannon ◽  
Ward Smith ◽  
Brian Grant ◽  
...  

AbstractRepresentative subsets of global climate models (GCMs) are often used in climate change impact studies to account for uncertainty in ensemble climate projections. However, the effectiveness of such subsets has seldom been assessed for the estimations of either the mean or the spread of the full ensembles. We assessed two different approaches that were employed to select 5 GCMs from a 20-member ensemble of GCMs from the CMIP5 ensemble for projecting canola and spring wheat yields across Canada under RCP 4.5 and 8.5 emission scenarios in the periods 2040–2069 and 2070–2099, based on crop simulation models. Averages and spreads of the simulated crop yields using the 5-GCM subsets selected by T&P and KKZ approaches were compared with the full 20-GCM ensemble. Our results showed that the 5-GCM subsets selected by the two approaches could produce full-ensemble means with a relative absolute error of 2.9–4.7% for canola and 1.5–2.2% for spring wheat, and covers 61.8–91.1% and 66.1–80.8% of the full-ensemble spread for canola and spring wheat, respectively. Our results also demonstrated that both approaches were very likely to outperform a subset of randomly selected 5 GCMs in terms of a smaller error and a larger range.


2021 ◽  
Author(s):  
Brian Collins ◽  
Ullah Najeeb ◽  
Qunying Luo ◽  
Daniel K.Y. Tan

AbstractWe used SUFI-2 for the first time to calibrate the phenology module of the APSIM-wheat model for 10 spring wheat cultivars cultivated in northeast Australia (south-eastern Queensland). Calibration resulted in an average RMSE of 5.5 d for developmental stages from stem elongation up to flowering. Projections from 33 climate models under the representative concentration pathway 8.5 were used for simulations at 17 sites. Using adapted sowing times, we simulated significantly shorter crop cycles and grain yield improvements for the period 2036-2065 relative to 1990-2019 for three selected cultivars (Hartog, Scout and Gregory). Photoperiod and vernalisation sensitivities were shown to be the largest and smallest contributors to total uncertainties in the simulated flowering day and grain yield. Uncertainties in climate models had a relatively minor contribution to the total uncertainties in the simulated values of target traits. This contribution significantly increased when climate change impact on the target traits was estimated.


2020 ◽  
Vol 12 (14) ◽  
pp. 2206
Author(s):  
Astrid Vannoppen ◽  
Anne Gobin ◽  
Lola Kotova ◽  
Sara Top ◽  
Lesley De Cruz ◽  
...  

Wheat yield variability will increase in the future due to the projected increase in extreme weather events and long-term climate change effects. Currently, regional agricultural statistics are used to monitor wheat yield. Remotely sensed vegetation indices have a higher spatio-temporal resolution and could give more insight into crop yield. In this paper, we (i) evaluate the possibility to use Normalized Difference Vegetation Index (NDVI) time series to estimate wheat yield in Latvia and (ii) determine which weather variables impact wheat yield changes using both ALARO-0 and REMO Regional Climate Models (RCM) output. The integral from NDVI series (aNDVI) for winter and spring wheat fields is used as a predictor to model regional wheat yield from 2014 to 2018. A correlation analysis between weather variables, wheat yield and aNDVI was used to elucidate which weather variables impact wheat yield changes in Latvia. Our results indicate that high temperatures in June for spring wheat and in July for winter wheat had a negative correlation with yield. A linear regression yield model explained 71% of the variability with a residual standard error of 0.55 Mg/ha. When RCM data were added as predictor variables to the wheat yield empirical model a random forest approach resulted in better results compared to a linear regression approach, the explained variance increased up to 97% and the residual standard error decreased to 0.17 Mg/ha. We conclude that NDVI time series and RCM output enabled regional crop yield and weather impact monitoring at higher spatio-temporal resolutions than regional statistics.


2014 ◽  
Vol 1 (3) ◽  
pp. 57-61
Author(s):  
E. Kopylov

Aim. To study the specifi cities of complex inoculation of spring wheat roots with the bacteria of Azospirillum genus and Chaetomium cochliodes Palliser 3250, and the isolation of bacteria of Azospirillum genus, capable of fi xing atmospheric nitrogen, from the rhizospheric soil, washed-off roots and histoshere. Materials and meth- ods. The phenotypic features of the selected bacteria were identifi ed according to Bergi key. The molecular the polymerase chain reaction and genetic analysis was used for the identifi cation the bacteria. Results. It has been demonstrated that during the introduction into the root system of spring wheat the strain of A. brasilensе 102 actively colonizes rhizospheric soil, root surface and is capable of penetrating into the inner plant tissues. Conclusions. The soil ascomucete of C. cochliodes 3250 promotes better settling down of Azospirillum cells in spring wheat root zone, especially in plant histosphere which induces the increase in the content of chlorophyll a and b in the leaves and yield of the crop.


2008 ◽  
Vol 63 (4) ◽  
Author(s):  
Barbara Gąsiorowska ◽  
Artur Makarewicz

Author(s):  
I.I. Seregina ◽  
◽  
I.G. Makarskaya

Abstract:In model experiments in soil culture, the effect of different methods of treatment with sodium selenite on the photosynthetic activity of spring wheat variety Zlata was studied under extreme growing conditions. Under drought conditions, the inhibition of the growth of the photosynthetic surface of spring wheat plants was revealed. Under conditions of excessive water supply, a sharp decrease in the area of the assimilating surface of wheat plants was observed. The positive effect of sodium selenite solution on the photosynthetic activity of spring wheat plants was established with insufficient and excessive water supply to wheat plants.


Author(s):  
A. G. Abramov ◽  
◽  
I.N. Abramova

The article presents the results of the influence of the magnitude of heterosis on the main elements of the formation of yield (grain size and productivity of the main spike) of spring wheat in the Irkutsk region. The following were used as maternal varieties: Irgina, Krasnoyarskaya 83, Tulun 15, Tselinnaya 60, Altayskaya 92, Niva 2 and a variety from Mongolia Orkhon 85, as testers - Skala, Angara 86, Tulunskaya 12 The best indicators of hypothetical heterosis were manifested by the number of grains in ear in combinations Krasnoyarskaya 83 × Angara 86, Krasnoyarskaya 83 × Skala, Altai 92 × Skala (81.6 ... 85.7%). In terms of grain weight from the main spike, the best results of hypothetical heterosis were noted in hybrid combinations Krasnoyarskaya 83 × Angara 86, Orkhon 85 × Angara 86, Ni-va × Angara 86, Altai 92 × Angara 86 (100.0 ... 130.7%) ... Krasnoyarskaya 83 × Angara 86, Altai 92 × Angara 86, Or-khon × Angara 86 are recognized as the best hybrid combinations that can give the greatest yield of transgressive forms of elite plants.


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