OPTIMISING IRRIGATED GRAINS

Maize

This research programme aims to improve the productivity of irrigated crops including grain maize. The research investment by the Grains Research Development Corporation (GRDC) ‘Development and validation of soil amelioration and agronomic practices to realise the genetic potential of grain crops grown under a high yield potential, irrigated environment in the northern and southern regions’ aims to maximise the profitability of irrigated farming systems in the Murray and Murrumbidgee region, South East South Australia and Tasmania. 
 
The research project which is led by FAR Australia in collaboration with the Irrigated Cropping Council (ICC) is part of a wider set of investments being made by GRDC in irrigated cropping systems. The research starting with maize this spring aims to develop and evaluate the effectiveness of novel soil management technologies and crop specific agronomic management practices on system profitability. Other crops include faba beans, chickpeas, durum wheat, canola and barley.

 

Two local trial sites have been established under ICC management
  1. Griffith – Two trials have been established looking at Potassium Use Efficiency(PUE)
  2. Kerang – Five trials have been established looking at Nitrogen Use Efficiency, K(Potassium)
  • Most of the sites were sown 30th October and N treatments applied on 1st November. They were then irrigated up 4th November.
 
Nutrition
The research team are focusing on maize establishment nutrition which has been identified to be a priority by the Maize Association of Australia (MAA) group. The proposed trials on nitrogen application rates will explore levels of applied N up to 500kg N/ha under flood and overhead irrigation systems as well N timing, in particular looking at the influence of in crop nitrogen on crop performance. Trials will be assessed to determine nitrogen use efficiency (NUE), dry matter production (DM), harvest index and grain yield. With interest in pushing the productivity boundaries and achieving 20t/ha grain yields under irrigation, the trials should enable us to determine if this can be achieved in both a sustainable and profitable way. All trials will be analysed in terms of economics (in the context of grain prices, water costs, irrigation cost and inputs) in addition to assessing whether they have reached their full potential. 
 
Crop establishment – plant population and row spacing
Research this spring will also be taking a look at crop establishment in particular plant population and row spacing. Under lateral irrigation in NE Victoria it is planned to look at the interaction between plant population and the subsequent nutrition for the crop, again looking at key benchmark parameters such as NUE, harvest DM and grain yield. In further work at Kerang and Boort, Victoria the plan is to use specialist research seeding equipment in order to investigate the interaction between plant population and row width. With interest in narrower 20 inch row spacing used on some farms in the US the idea is to compare this row spacing to the more traditional 30 inch spacing at differing hybrid populations. Again the idea being that results are not only evaluated in terms of yield but also profitability.
 
Stay Green Effects
Stay green effects in maize germplasm has been a topic of conversation for a number of years. With a much greater range of fungicides now entering the market place the research team plan to examine whether experimental new generation fungicides have any influence on green leaf retention in Australian maize crops under irrigation. The work which is purely experimental at this stage will look at whether irrigation allows these newer fungicides to express greater green leaf retention and disease control than older more established standards.

2019 Results

Twelve irrigated grain maize trials were established at five locations in northern Victoria and southern NSW in 2019 The primary focus of the research was to examine nutrition, looking specifically at the influence of higher levels of nitrogen (N) input on harvest dry matter, grain yield, harvest index and nitrogen offtake. Read the interim results...

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