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Phenology algorithms in crop growth models have inevitable systematic errors and uncertainties. In this study, the phenology simulation algorithms in APSIM classical (APSIM 7.9) and APSIM next generation (APSIM-NG) were compared for spring barley models at high latitudes. Phenological data of twelve spring barley varieties were used for the 2014–2018 cropping seasons from northern Sweden and Finland. A factorial-based calibration approach provided within APSIM-NG was performed to calibrate both models. The models have different mechanisms to simulate days to anthesis. The calibration was performed separately for days to anthesis and physiological maturity, and evaluations for the calibrations were done with independent datasets. The calibration performance for both growth stages of APSIM-NG was better compared to APSIM 7.9. However, in the evaluation, APSIM-NG showed an inclination to overestimate days to physiological maturity. The differences between the models are possibly due to slower thermal time accumulation mechanism, with higher cardinal temperatures in APSIM-NG. For a robust phenology prediction at high latitudes with APSIM-NG, more research on the conception of thermal time computation and implementation is suggested.
Uttam Kumar; Julien Morel; Göran Bergkvist; Taru Palosuo; Anne-Maj Gustavsson; Allan Peake; Hamish Brown; Mukhtar Ahmed; David Parsons. Comparative Analysis of Phenology Algorithms of the Spring Barley Model in APSIM 7.9 and APSIM Next Generation: A Case Study for High Latitudes. Plants 2021, 10, 443 .
AMA StyleUttam Kumar, Julien Morel, Göran Bergkvist, Taru Palosuo, Anne-Maj Gustavsson, Allan Peake, Hamish Brown, Mukhtar Ahmed, David Parsons. Comparative Analysis of Phenology Algorithms of the Spring Barley Model in APSIM 7.9 and APSIM Next Generation: A Case Study for High Latitudes. Plants. 2021; 10 (3):443.
Chicago/Turabian StyleUttam Kumar; Julien Morel; Göran Bergkvist; Taru Palosuo; Anne-Maj Gustavsson; Allan Peake; Hamish Brown; Mukhtar Ahmed; David Parsons. 2021. "Comparative Analysis of Phenology Algorithms of the Spring Barley Model in APSIM 7.9 and APSIM Next Generation: A Case Study for High Latitudes." Plants 10, no. 3: 443.
APSIM Next Generation was used to simulate the phenological development and biomass production of silage maize for high latitudes (i.e., >55°). Weather and soil data were carefully specified, as they are important drivers of the development and growth of the crop. Phenology related parameters were calibrated using a factorial experiment of simulations and the minimization of the root mean square error of observed and predicted phenological scaling. Results showed that the model performed well in simulating the phenology of the maize, but largely underestimated the production of biomass. Several factors could explain the discrepancy between observations and predictions of above-ground dry matter yield, such as the current formalization of APSIM for simulating the amount of radiation absorbed by the crop at high latitudes, as the amount of diffuse light and intercepted light increases with latitude. Another factor that can affect the accuracy of the predicted biomass is the increased duration of the day length observed at high latitudes. Indeed, APSIM does not yet formalize the effects of extreme day length on the balance between photorespiration and photosynthesis on the final balance of biomass production. More field measurements are required to better understand the drivers of the underestimation of biomass production, with a particular focus on the light interception efficiency and the radiation use efficiency.
Julien Morel; David Parsons; Magnus A. Halling; Uttam Kumar; Allan Peake; Göran Bergkvist; Hamish Brown; Mårten Hetta. Challenges for Simulating Growth and Phenology of Silage Maize in a Nordic Climate with APSIM. Agronomy 2020, 10, 645 .
AMA StyleJulien Morel, David Parsons, Magnus A. Halling, Uttam Kumar, Allan Peake, Göran Bergkvist, Hamish Brown, Mårten Hetta. Challenges for Simulating Growth and Phenology of Silage Maize in a Nordic Climate with APSIM. Agronomy. 2020; 10 (5):645.
Chicago/Turabian StyleJulien Morel; David Parsons; Magnus A. Halling; Uttam Kumar; Allan Peake; Göran Bergkvist; Hamish Brown; Mårten Hetta. 2020. "Challenges for Simulating Growth and Phenology of Silage Maize in a Nordic Climate with APSIM." Agronomy 10, no. 5: 645.
Severe lodging of irrigated spring-wheat in sub-tropical Australia has previously caused yield loss of between 1.7 and 4.6 t ha–1 (20–60% of potential yield). In response, agronomic management options were assessed for their ability to reduce lodging and increase grain yield, namely plant growth regulators (PGRs), timing of nitrogen (N) application, row spacing and sowing date, in combination with long and short duration cultivars across 15 irrigated environments from 2012 to 2016. Our study identified significant interaction between genotype, environment and agronomic management (G × E × M) for grain yield and lodging, although some combinations of agronomic techniques were broadly applicable across cultivars. PGR application improved grain yield of most cultivars in well-irrigated fields that had more than 120 kg ha–1 N (mineral N + fertiliser N) at sowing, with yield gains of up to 0.5 t ha–1 observed in both lodged and non-lodged fields. However, PGRs had little effect on grain yield when soil + fertiliser N at sowing was less than 80 kg ha–1 N. In-crop N application (compared to sowing N application) often improved grain yield of short duration, lodging resistant cultivars, but reduced the yield of long-duration, lodging susceptible cultivars in some environments. Narrow row spacing of 19 cm had the highest grain yield across cultivars in low lodging environments. At a severely lodged environment, narrow rows were the highest yielding for five out of six cultivars when PGRs were used, but was the highest yielding for only half of the tested cultivars when PGRs were not used. Cultivar × sowing date interaction for grain yield was also associated with the occurrence of lodging. Neither early nor late sowing had a consistent yield benefit across a range of cultivars, as lodging severity varied between sowing date depending on the timing of storm-induced lodging events. Lodging resistant long-duration cultivars had more stable grain yield across environments and increased grain yield in response to early sowing. Further research is needed to determine the optimum management strategy for new cultivars, because farmers do not always choose the most lodging resistant cultivars for reasons of cultivar disease resistance, grain quality and seed availability.
Allan S. Peake; Kerry L. Bell; R.A. Fischer; Matt Gardner; Bianca Das; Nick Poole; Michael Mumford. Cultivar × Management Interaction to Reduce Lodging and Improve Grain Yield of Irrigated Spring Wheat: Optimising Plant Growth Regulator Use, N Application Timing, Row Spacing and Sowing Date. Frontiers in Plant Science 2020, 11, 1 .
AMA StyleAllan S. Peake, Kerry L. Bell, R.A. Fischer, Matt Gardner, Bianca Das, Nick Poole, Michael Mumford. Cultivar × Management Interaction to Reduce Lodging and Improve Grain Yield of Irrigated Spring Wheat: Optimising Plant Growth Regulator Use, N Application Timing, Row Spacing and Sowing Date. Frontiers in Plant Science. 2020; 11 ():1.
Chicago/Turabian StyleAllan S. Peake; Kerry L. Bell; R.A. Fischer; Matt Gardner; Bianca Das; Nick Poole; Michael Mumford. 2020. "Cultivar × Management Interaction to Reduce Lodging and Improve Grain Yield of Irrigated Spring Wheat: Optimising Plant Growth Regulator Use, N Application Timing, Row Spacing and Sowing Date." Frontiers in Plant Science 11, no. : 1.
Short duration spring wheat cultivars are currently preferred for irrigated wheat production in subtropical Australia due to their high levels of lodging resistance. A study was conducted to determine whether recently developed lodging-resistant long duration cultivars could achieve increased grain yield compared to short duration cultivars in irrigated sub-tropical environments. A key aspect of the study methodology required the use of different sowing dates for each maturity group to ensure anthesis was synchronised and thus occurred during the same climatic conditions. Growth of representative cultivars in each experiment was simulated using the APSIM model to characterise each environment for the presence of water or nitrogen stress. Results of the study indicated that the long duration cultivars had an increased grain yield of 0.67 t ha−1 (9.6%) on average across the 14 agro-climatic environments compared to the short duration cultivars. The response varied between agro-climatic environments, with long duration cultivars significantly higher yielding in 70% (or ten) of the environments, no significant difference observed in three environments, and a significantly lower yield associated with long duration cultivars in one environment. The yield advantage of the long duration cultivars was greater in environments where moderate water stress was experienced, with yield differences of up to 1.5 t ha−1 observed in the most water-stressed environments. The yield advantage was less apparent in environments where low levels of water stress were experienced, and in two environments where lodging was more severe among the long duration cultivars. The relatively small difference in duration between the long and short duration cultivars in this study may not have fully exploited the potential benefits of longer duration cultivars. The results suggest that genetic improvement programs should continue to develop longer season germplasm that conveys an adaptive advantage to irrigated sub-tropical environments such as Australia, India and Mexico that experience short-term water deficits, and in which deficit irrigation is often the most profitable strategy for farmers. Additional research is necessary to determine whether ultra-long duration cultivars could further raise yield potential in sub-tropical environments if lodging could be avoided, through either genetic improvement or improved access to plant growth regulators.
A.S. Peake; Bianca Das; K.L. Bell; M. Gardner; N. Poole. Effect of variable crop duration on grain yield of irrigated spring-wheat when flowering is synchronised. Field Crops Research 2018, 228, 183 -194.
AMA StyleA.S. Peake, Bianca Das, K.L. Bell, M. Gardner, N. Poole. Effect of variable crop duration on grain yield of irrigated spring-wheat when flowering is synchronised. Field Crops Research. 2018; 228 ():183-194.
Chicago/Turabian StyleA.S. Peake; Bianca Das; K.L. Bell; M. Gardner; N. Poole. 2018. "Effect of variable crop duration on grain yield of irrigated spring-wheat when flowering is synchronised." Field Crops Research 228, no. : 183-194.
Uncertainty exists as to the optimum whole-farm irrigation strategy for wheat growing in subtropical Australia under water-limited conditions. While deficit irrigation has been shown to have greater economic water productivity (EWP) in such circumstances in other regions, there are limitations to the cost/revenue function approach traditionally used to evaluate EWP, including inapplicability across environments. These limitations can however be overcome with the use of a validated cropping systems model. The APSIM farming systems model was therefore used to determine whether growing larger areas of deficit irrigated wheat is more profitable than full irrigation of a smaller area in sub-tropical Australia, under water limited conditions. Optimal irrigation strategies were not only profitable but also those considered risk-efficient, i.e. closest to a 1:2 ‘line of indifference’ that identifies the two unit increase in risk (measured as standard deviation) acceptable to farmers in return for a unit increase in profit. The value of stored soil water was assessed by simulating rainfed crop production on unirrigated land, and/or assigning an economic value to stored soil water remaining at the end of the season. The results demonstrated that deficit irrigation of larger areas of wheat was generally more profitable and risk-efficient than smaller areas of full irrigation. When precipitation or stored soil water at sowing was increased, the most risk-efficient strategies were those that spread water across a larger area at a reduced frequency of irrigation. However in a low rainfall environment when water was expensive and soil water had the same economic value as irrigation water, fully irrigating a smaller area was the most profitable and risk-efficient option. The importance of evaluating farm-management strategies using EWP (i.e. incorporating gross margins) instead of crop water productivity (grain yield per unit of water use) was evident, as re-ranking of farm-management strategies occurred between these alternative methods of calculating whole-farm WP. Accounting for the intrinsic value of stored soil water and precipitation was fundamental to understanding the benefit of deficit irrigation strategies in water limited situations, as the larger crop area sown in conjunction with deficit irrigation strategies accessed much larger absolute volumes of soil water and precipitation. Future evaluations of deficit irrigation strategies should account for such considerations.
A.S. Peake; P.S. Carberry; S.R. Raine; V. Gett; R.J. Smith. An alternative approach to whole-farm deficit irrigation analysis: Evaluating the risk-efficiency of wheat irrigation strategies in sub-tropical Australia. Agricultural Water Management 2016, 169, 61 -76.
AMA StyleA.S. Peake, P.S. Carberry, S.R. Raine, V. Gett, R.J. Smith. An alternative approach to whole-farm deficit irrigation analysis: Evaluating the risk-efficiency of wheat irrigation strategies in sub-tropical Australia. Agricultural Water Management. 2016; 169 ():61-76.
Chicago/Turabian StyleA.S. Peake; P.S. Carberry; S.R. Raine; V. Gett; R.J. Smith. 2016. "An alternative approach to whole-farm deficit irrigation analysis: Evaluating the risk-efficiency of wheat irrigation strategies in sub-tropical Australia." Agricultural Water Management 169, no. : 61-76.
In-crop nitrogen (N) application is used widely in rainfed winter wheat production to reduce lodging risk; however, uncertainty exists as to its ability to reduce lodging risk in subtropical irrigated wheat production without simultaneously reducing yield potential. The objective of this study was therefore to determine whether in-crop N application reduces lodging risk without reducing yield of irrigated spring wheat in a subtropical environment. Irrigated small-plot experiments were conducted to compare the effect of alternative N timing on lodging and yield in two cultivars. Variable N regimes were imposed during the vegetative growth phase, after which additional N was applied to ensure that total season N application was uniform across N-timing treatments. Treatments with low N at sowing had significantly less lodging and were the highest yielding, exhibiting yield increases of up to 0.8 t ha–1 compared to treatments with high N at sowing. Increased leaf area index, biomass and tiller count at the end of the vegetative growth phase were correlated with increased lodging in both cultivars, although the strength of the correlation varied with cultivar and season. We conclude that canopy-management techniques can be used to simultaneously increase yield and decrease lodging in irrigated spring wheat in the subtropics, but require different implementation from techniques used in temperate regions of Australia.
A. S. Peake; K. L. Bell; P. S. Carberry; N. Poole; S. R. Raine. Vegetative nitrogen stress decreases lodging risk and increases yield of irrigated spring wheat in the subtropics. Crop and Pasture Science 2016, 67, 907 -920.
AMA StyleA. S. Peake, K. L. Bell, P. S. Carberry, N. Poole, S. R. Raine. Vegetative nitrogen stress decreases lodging risk and increases yield of irrigated spring wheat in the subtropics. Crop and Pasture Science. 2016; 67 (9):907-920.
Chicago/Turabian StyleA. S. Peake; K. L. Bell; P. S. Carberry; N. Poole; S. R. Raine. 2016. "Vegetative nitrogen stress decreases lodging risk and increases yield of irrigated spring wheat in the subtropics." Crop and Pasture Science 67, no. 9: 907-920.
Approximately 15% of global wheat production (40% of the wheat produced by developing countries) occurs in irrigated, low-rainfall regions of the subtropics. Irrigated wheat is uncommon in sub-tropical Australia because cotton is more profitable, but high grain prices in 2008 triggered a record area of irrigated wheat production. Unfortunately, widespread lodging occurred and yields were lower than expected, although the losses directly attributable to lodging were unknown. Crop models have not been previously validated for calculating potential yield and yield gaps of mechanised, lodging-susceptible production systems. This study aimed to determine potential yield, farmer-realised yield, and water use requirements of lodging-prone irrigated wheat in sub-tropical Australia, using field monitoring and the APSIM simulation model. Yield data were obtained in 2008 and 2009 from 16 commercial irrigated wheat fields and multiple treatments from four irrigated experiments, and used to assess APSIM's ability to predict grain yield of irrigated wheat. APSIM predicted biomass production satisfactorily in 2008 but substantially over-predicted grain yield of lodged fields. The mean difference (yield gap) between APSIM-estimated potential yield and farmer-realised yield was 1.0 t ha−1 in non-lodged fields, and 2.7 t ha−1 in lodged fields. The average effect of lodging was therefore a decrease of 1.7 t ha−1; the difference between the yield gap calculated for lodged and non-lodged fields. Yield gaps in lodged fields were highly correlated with soil N content at sowing, with most of the lodged fields having more than 300 kg ha−1 of soil N at sowing to a depth of 90 cm. In 2009, management of commercial fields aimed to avoid lodging by using the canopy management technique of in-season N application. APSIM generally under-predicted biomass production and yield in these fields, suggesting that the N uptake parameters in APSIM may require adjustment. Observed yields from fields of a quick-maturing cultivar that experienced little lodging were simulated accurately when N was assumed to be non-limiting. The simulation study found that the potential yield of irrigated spring wheat in sub-tropical Australia is currently between 8 and 9 t ha−1, and average growing season evapotranspiration of such crops was approximately 500–550 mm. Potential yield of furrow-irrigated fields with one or two-metre wide beds were 16% and 8% lower, due to the area occupied by the 60 cm wide unsown furrows between irrigation beds. This study demonstrated the value of using validated simulation models for estimating potential yield and yield gap analysis. Yield gap analysis also enabled the identification of agronomic characteristics (high levels of soil residual N) which probably contributed to lodging. Further investigation is required to determine whether alternative varieties or the canopy management technique of in-season N application can increase the potential yield...
A.S. Peake; N.I. Huth; P.S. Carberry; S.R. Raine; R.J. Smith. Quantifying potential yield and lodging-related yield gaps for irrigated spring wheat in sub-tropical Australia. Field Crops Research 2014, 158, 1 -14.
AMA StyleA.S. Peake, N.I. Huth, P.S. Carberry, S.R. Raine, R.J. Smith. Quantifying potential yield and lodging-related yield gaps for irrigated spring wheat in sub-tropical Australia. Field Crops Research. 2014; 158 ():1-14.
Chicago/Turabian StyleA.S. Peake; N.I. Huth; P.S. Carberry; S.R. Raine; R.J. Smith. 2014. "Quantifying potential yield and lodging-related yield gaps for irrigated spring wheat in sub-tropical Australia." Field Crops Research 158, no. : 1-14.
Allan S. Peake; Neil I. Huth; Alison M. Kelly; Kerry L. Bell. Variation in water extraction with maize plant density and its impact on model application. Field Crops Research 2013, 146, 31 -37.
AMA StyleAllan S. Peake, Neil I. Huth, Alison M. Kelly, Kerry L. Bell. Variation in water extraction with maize plant density and its impact on model application. Field Crops Research. 2013; 146 ():31-37.
Chicago/Turabian StyleAllan S. Peake; Neil I. Huth; Alison M. Kelly; Kerry L. Bell. 2013. "Variation in water extraction with maize plant density and its impact on model application." Field Crops Research 146, no. : 31-37.
Wheat (Triticum aestivum L.) lines containing the 1BL/1RS chromosome translocation yield up to 20% more than established wheat cultivars in some Queensland environments. However, 1BL/1RS germplasm possesses a quality defect known as ‘sticky dough’, which is incompatible with the high-speed dough-mixing processes used for bread production in Australia. Therefore, we investigated whether the 1BL/1RS translocation conveyed a yield advantage to locally adapted germplasm across a wide range of environments that was sufficient to justify attempting to overcome the ‘sticky dough’ defect either through plant breeding or by altering the mixing processes. Three sets of recombinant inbred lines (RILs) that segregated for the presence or absence of the 1BL/1RS translocation were developed from crosses between 1BL/1RS germplasm (Seri and Genaro) and established local cultivars (Hartog and Banks), and grown in 11 environments representing six sites across southern Queensland and northern New South Wales and two years. The effect of the 1BL/1RS translocation on grain yield depended on environment and genetic background. In semi-dwarf genotypes of the Hartog/Seri and Hartog/Genaro crosses, the 1BL/1RS RILs had lower grain yield than the 1B RILs in the three lowest yielding environments. This effect was associated with changes in grain number per unit area, suggesting that the negative yield effect of the translocation is expressed before, or at, anthesis. In the higher yielding environments, the 1BL/1RS translocation conveyed a yield advantage in semi-dwarf genotypes of the Banks/Seri cross, but had no consistent effect on yield in semi-dwarf genotypes of the Hartog/Seri and Hartog/Genaro crosses. The 1BL/1RS translocation was also associated with decreased yield in the double-dwarf genotypes of the Hartog/Seri cross across all environments. We conclude that the 1BL/1RS translocation is not useful for local breeding programs, as it decreased yield among the more advanced, semi-dwarf germplasm in low-yielding environments that potentially represent up to 85% of the target population of environments, and had no consistent positive effect on yield in this germplasm in higher yielding environments.
Allan S. Peake; Arthur Gilmour; Mark Cooper. The 1BL/1RS translocation decreases grain yield of spring wheat germplasm in low yield environments of north-eastern Australia. Crop and Pasture Science 2011, 62, 276 .
AMA StyleAllan S. Peake, Arthur Gilmour, Mark Cooper. The 1BL/1RS translocation decreases grain yield of spring wheat germplasm in low yield environments of north-eastern Australia. Crop and Pasture Science. 2011; 62 (4):276.
Chicago/Turabian StyleAllan S. Peake; Arthur Gilmour; Mark Cooper. 2011. "The 1BL/1RS translocation decreases grain yield of spring wheat germplasm in low yield environments of north-eastern Australia." Crop and Pasture Science 62, no. 4: 276.
Optimum plant population and irrigation strategies for maize grown in the Dalby district of the Darling Downs in Queensland, Australia, were investigated using the APSIM crop simulation model. After testing the model against three seasons of experimental data, simulation experiments using different irrigation strategies were conducted across a range of plant populations ranging from 20 000 to 80 000 plants/ha, on two soil types with plant available water capacities (PAWC) of 146 mm and 220 mm. All soil type × plant population × irrigation strategy scenarios were simulated using the historical climate record for Dalby from 1889 to 2004, in order to obtain long-term average yield and gross margins (LGM) for each scenario. Soil water was reset to two-thirds of PAWC at sowing in each year. Plant populations required to achieve maximum LGMs ranged from 50 000 to 80 000 plants/ha across the range of scenarios, and were higher than currently recommended by district agronomists for partially irrigated maize. The use of higher plant populations increased season-to-season variability in grain yield and gross margins and may not be a suitable strategy for growers who do not want to increase their risk of crop failure. Partially irrigated maize achieved substantially higher gross margins in years where a positive Southern Oscillation Index phase was recorded in August, and the use of higher plant populations in such years also increased long-term profitability, but also increased the risk of crop failure. Economic gains were achieved by varying the timing and amount of irrigation within a limited available irrigation volume, with a single 100 mm irrigation giving greater LGMs than two 50 mm irrigation events on both soil types, when the irrigation events were scheduled to fill a soil water deficit equal to the effective irrigation volume. However, under full irrigation the use of smaller irrigation volumes increased LGMs on the 146 mm PAWC soil, demonstrating the importance of timely irrigation scheduling on low PAWC soils.
A. S. Peake; M. J. Robertson; R. J. Bidstrup. Optimising maize plant population and irrigation strategies on the Darling Downs using the APSIM crop simulation model. Australian Journal of Experimental Agriculture 2008, 48, 313 -325.
AMA StyleA. S. Peake, M. J. Robertson, R. J. Bidstrup. Optimising maize plant population and irrigation strategies on the Darling Downs using the APSIM crop simulation model. Australian Journal of Experimental Agriculture. 2008; 48 (3):313-325.
Chicago/Turabian StyleA. S. Peake; M. J. Robertson; R. J. Bidstrup. 2008. "Optimising maize plant population and irrigation strategies on the Darling Downs using the APSIM crop simulation model." Australian Journal of Experimental Agriculture 48, no. 3: 313-325.