The spatial response of water-limited wheat yield to historical climate change across Western Australia since 1900

Chao Chen1, Andrew L. Fletcher1, Noboru Ota1, Roger A. Lawes1, Yvette M. Oliver1

1 CSIRO Agriculture and Food, PMB 5 Wembley, WA 6913, https://www.csiro.au/, chao.chen@csiro.au

Abstract

Climate change has affected crop yield potential in major rain-fed crop growing regions in Australia, including Western Australia (WA). Understanding changes in potential crop production due to past climate change can help guide the adaptation of cropping systems to future climate change. However, the spatial response of water-limited yield potential to historical climate change across the wheatbelt of WA is unclear. This research used APSIM (Agricultural Production Systems sIMulator) to simulate and map the spatial-temporal changes in water-limited wheat yield potential on ~5 km × ~5 km climate grids for 117 years (1900-2016) across WA. Observed decreases in rainfall resulted in a shift in the regional pattern of wheat yield potential towards the southwest by 70 km. Future climate change is likely to continue to impact water-limited wheat yield and its spatial pattern in WA. Cropping systems will need to continually evolve to cope with a changing climate, requiring improvements in every aspect of agronomy and genetics.

Design and performance of unique field chamber and CO2 control system for the investigation of biological impacts on wheats grown under fluctuating CO2

Mahabubur Mollah1, Glenn Fitzgerald2

1 Agriculture Victoria Research, DJPR – Horsham, Vic, 3400, Email: Mahabubur.Mollah@ecodev.vic.gov.au

2 Agriculture Victoria Research, DJPR – Horsham, Vic, 3400

Abstract

The CO2 concentration [CO2] in the atmosphere is increasing, affecting plant growth and development. Free Air CO2 Enrichment (FACE) technology is used for the study of plant development under elevated CO2. However, criticism of the FACE technology is that it underestimates plant and crop responses to elevated [CO2] because rapidly fluctuating [CO2] within the FACE rings may force stomata to close more often and for longer periods than would occur under non-FACE conditions. Therefore, data from FACE rings cannot be used as validation for plant and crop responses in crop modelling. This report focuses on the engineering of chamber design to test constant vs. variable changes in [CO2] levels on crops. Three chambers were built, and a non-replicated study was conducted during the 2015 and 2016 seasons to assess the methodology and chamber design. The chambers were set up to test the impacts of constant ambient [CO2], elevated [CO2] and variable [CO2] on wheat biomass, yield and water use efficiency. The chamber design and control system performed as expected keeping 1 min average CO2 concentration within 1.8 µmol/mol (insignificant variation) to the set point of 610 µmol/mol for elevated CO2 treatments (fluctuating and constant).

Use of seasonal forecasts for guiding early season decisions in Australian cotton systems

Chris Nunn 1*, Jaclyn N. Brown 2, Peter McIntosh 3, Kavina Dayal 2, Michael P. Bange 1

1CSIRO Agriculture and Food, The Australian Cotton Research Institute, Locked Bag 59, Narrabri, New South Wales, 2390, Australia.

2CSIRO Agriculture and Food, Private Bag 12, Hobart, Tasmania, 7001, Australia.

3CSIRO Oceans and Atmosphere, Retired.

*Corresponding author (christopher.nunn@csiro.au).

Abstract:

Australian cotton production is characterised as a high-value, quality product, earning in excess of $2.5B in exports annually. High year-to-year variability in rainfall and temperature influence productivity which could be managed more effectively with appropriate foresight. Seasonal climate forecasts have the potential to equip growers with upcoming season knowledge to mitigate risk but also to implement less risk averse behaviour in good years. Here we outline the key decision points where a seasonal climate forecast of temperature and rainfall could provide actionable insights. We further test the skill and reliability of Australia’s current seasonal climate forecast system to provide this information at four key locations: Moree, Griffith, Dalby and Emerald compared to the SILO record of weather from 1981-2017. Model predictions were assessed in terms of correctness and also how emphatic the prediction was. In many cases the range of predictions offered across the POAMA ensembles is so large that variation in the median is overshadowed, leading to a flattened response across years. This offers little advantage over the current approaches that use climatology as a guide to the future. Advances in climate modelling need to address both the predictive skill and the broad prediction envelope to offer useful advances in this field.

 

Frost Response in Lentil. Part 2 – Detecting early frost damage using proximal sensing

Eileen Perry1,2, Audrey Delahunty3, James Nuttall4, Alex Clancy4, Ashley Wallace4

1 Agriculture Victoria, 1-7 Taylor Street, Epsom, VIC 3498; eileen.perry@ecodev.vic.gov.au

2 The University of Melbourne, Parkville, VIC, 3000, Australia

3 Agriculture Victoria, Cnr Eleventh St & Koorlong Ave, Irymple, VIC 3498

4 Agriculture Victoria, 110 Natimuk Road, Horsham, VIC 3400

Abstract:

Frost can have negative impacts on both yield and quality of lentil, and currently there is a gap in methods to provide growers with tools to identify, monitor and assess the degree of damage due to frost. To evaluate the potential for spatial, non-destructive detection of frost damage, a trial was established in lentil (cv. Jumbo 2) using active frost treatments over a range of growth stages and intensities. Proximal sensing was used to monitor the crop to determine whether non-destructive methods can detect frost damage, and if post-processing can separate frost effects from natural crop senescence. The results show that in addition to the proximal measurements detecting natural senescence occurring during the period from flowering to pod fill, it also detected a decrease in canopy chlorophyll associated with cold exposure, beyond a threshold cold sum value (5 – 31 ˚C.hr). SFR_G from active fluorometer measurements was fit to cold sums, resulting in R2 values of 0.84 six days following frost application at flowering, and 0.72 eight days following frost at pod filling. NDVI from canopy reflectance measurements was related to cold sums across pooled measurement dates with an R2 value of 0.81. The reflectance index PRI increased with increasing cold exposure, indicating changes in photosynthetic efficiency with increasing frost damage. These initial results agree with previous research on detection of frost damage in wheat.

Evaporative protection in wheat

James Nuttall1, Audrey Delahunty2, Garry O’Leary1, Frank Henry3, Ashley Wallace1

1 Agriculture Victoria, 110 Natimuk Road, Horsham, Victoria, 3400, james.nuttall@ecodev.vic.gov.au

2 Agriculture Victoria, Cnr Eleventh Street & Koorlong Avenue, Irymple, Victoria 3498

3 Agriculture Victoria, 915 Mt Napier Road, Hamilton, Victoria 3300

Abstract:

In semi-arid cropping regions where rainfall is variable, stored soil water is important for reducing the impact of dry periods.  Water lost, in-season due to evaporation represents a lost opportunity for building yield potential.  We tested the value of protecting a wheat crop from inter-row evaporation on growth and water use efficiency.  Protecting the inter-row area using PVC cover significantly increased yield by up to 50%. This demonstrates the benefit of water conservation and/or concentration of water shed to the crop row in a decile 2 year.  The alternative inter-row cover options of a spray-on polymer or 5 t/ha of stubble as a mat did not provide the same benefit as using PVC cover, where yields were equivalent to when there was no cover.  Given the promising results for the PVC cover, testing other inter-row control measures including alternative polymer formulations, stubble load and arrangement or canopy designs to limit evaporative losses of soil water, in-season is of value.

Head rice yield in response to water deficit during reproductive stage and aerobic conditions

  1. Myint1, J. H. Mitchell1, P. J. Snell2 and S. Fukai1

1 The University of Queensland, School of Agriculture and Food Sciences, Brisbane 4072, Qld, Australia, ohnmar.myint@uq.net.au

 2 Yanco Agricultural Institute, NSW Department of Primary Industries, Yanco, NSW, 2703, Australia

Abstract:

Head rice yield (HRY) is an important criterion to determine milling quality of rice. Traditionally rice is grown under flooded condition however with water scarcity aerobic production has been considered a water saving option. The impacts of an aerobic system or one, which suffers mild water deficit at reproductive stage on HRY has not been determined. A series of experiments were sown across two years to investigate the stability and G×E interaction on HRY of 20 diverse rice genotypes grown under well-watered aerobic conditions (WW) as well as various water deficit (WD). Genotype and G×E were highly significant in all environments. Based on HRY, cluster analysis grouped environments into EG1: poor (48.9%), EG2: favourable (64.3%) and EG3: average (57.6%). Of 6 genotype groups, medium maturity genotypes groups: GG3 and GG5 including Lemont, Jefferson, Amaroo, Sherpa and Calrose had good adaptability under WD at grain filling as well as flowering time. IR 64 (GG1) had poor adaptability across environments and is considered as a susceptible genotype. Genotypes with low amylose achieved high HRY under aerobic condition where there is no water shortage but no relationship with grain yield in any environmental group. The stable and consistent genotypes with high HRY under aerobic and WD conditions will be beneficial for farmers and rice industry in Australia and still needs improving.

Manipulation of sowing time and variety to manage abiotic stress risk and maximise yield in lentil and faba bean

Lachlan Lake1, Mariano Cossani1, Amanda Pearce1, Victor O Sadras1

1 South Australian Research and Development Institute, Hartley Grove, Urrbrae, SA, 5064, lachlan.lake@sa.gov.au  

Abstract:

Lentil and faba bean production is constrained by extreme temperatures and drought. Crop species, variety and sowing time are three important management options for limiting the impact of these stresses. We measured phenology and relative grain yield in 10 lentil and 10 faba bean varieties over three seasons (2016 – 2018) and three regions in southern Australia; Hart and Roseworthy in the mid north, Minnipa on the Eyre Peninsula and Bool Lagoon and Conmurra in the South East. Within each location we used six times of sowing, spaced two weeks apart beginning mid-April. For both crops across locations, time to flowering and pod set declined linearly with sowing date. Similarly and across locations and sowing times, flowering was advanced at 3 d d-1 in faba bean and 5 d d-1 in lentil. Yield trends varied with species and location, but delaying sowing generally reduced yield. For every ten days delay in sowing past April 20th, faba bean lost 7% and lentil 5% of maximum yield; for the conditions in these trials sowing before the middle of may was the best strategy. This data set will be used to model risk and to guide management decisions.

Agronomic advice in a variable climate; chess, poker or the pokies?

Peter Hayman1, Barry Mudge2, Mark Stanley3, Graeme Anderson4 and Dale Grey 4

1 SARDI Climate Applications, GPO Box 397, Adelaide, SA, 5001 Peter.Hayman@sa.gov.au

2 Mudge Consulting, The Oaks, Port Germein, SA.

3 Regional Connections, Port Lincoln, SA

4 Biosecurity and Agriculture Services Branch, Agriculture Victoria

Abstract

The variable and erratic climate is an ongoing challenge for grain farming in Australia. Awareness of some of the drivers of climate variability such as El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) is increasing, but communicating and applying probabilistic seasonal climate forecasts to decision making continues to be difficult.

This short paper is a reflection based on 1) an overview of agronomic written advice provided in GRDC updates, fact sheets and Ground Cover articles and 2) workshops on climate risk held in July and November 2018 with 20 early to mid-career agronomists from the southern grains region. We found that most agronomic advice is like chess where there is always an optimum move determined by skill. Climate risk is acknowledged, but it is often treated more like the pokies (random chance) than poker where decision outcomes are due to skill and chance. There are many reasons that probabilistic seasonal climate forecasts are hard to use, one of them might be because we provide advice for chess not poker.

Quantifying the effects of chilling temperatures during the reproductive stages on yield of chickpea

Muhuddin Rajin Anwar1,2,*, Yash Chauhan3, Mark Richards1, Rosy Raman1, Maheswaran Rohan1, David J. Luckett2, Neroli Graham4, Kristy Hobson4

1NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, PMB Wagga Wagga, NSW 2650, Australia

2Graham Centre for Agricultural Innovation (an alliance between NSW Department of Primary Industries and Charles Sturt University) Wagga Wagga, NSW 2650, Australia

3Department of Agriculture and Fisheries (DAF); Centre for Plant Science at the University of Queensland, Australia

4NSW Department of Primary Industries, 4 Marsden Park Rd, Tamworth, NSW 2340, Australia

*Corresponding author, Email: muhuddin.anwar@dpi.nsw.gov.au

Abstract:

Cold temperatures at critical reproductive stages impacts chickpea yield, limiting its adaptation under diverse agro-climatic regions. Crop growth models provide an opportunity to predict yield performance under diverse climates and identify varieties for target environments. We examined the efficacy of the Agricultural Production Systems Simulator (APSIM) to simulate observed chickpea grain yields, and quantify the impact of low temperature stress on yield. It is difficult to easily define temperature stress, as low temperatures along with the duration of stress are likely to have a considerable effect on pod set and yield. Therefore, we developed seven chilling day-degrees indices to assess the effects of chilling temperatures in chickpeas. There was no significant correlation between chilling indices and observed grain yield suggesting that the current model does not predict the effect of chilling temperatures on yield. This is likely due to a combination of multiple abiotic stresses including frosts and other low temperatures. Using a Regression tree model, we assessed yield responses to chilling indices across 75 trials. Our analysis showed that the most severe chilling index (minimum threshold temperature <10oC) may have contributed to most of the variation in yield variability across the 75 locations. Consequently, this study identifies cool temperature damage as a valuable parameter for improving the chickpea yield prediction ability of the APSIM model.

 

Host

The Australian Society of Agronomy is the professional body for agronomists in Australia. It has approximately 500 active members drawn from government, universities, research organisations and the private sector.

Photo Credits

David Marland Photography david_marland@hotmail.com Graham Centre for Agricultural Innovation, Charles Sturt University

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