Grains Research and Development

 

Achievable yields for irrigated grains in the northern region

Researcher's Name:
Mr. Allan Peake
Organisation:
CSIRO Ecosystem Sciences P.O. Box 102 Toowoomba QLD 4350 Australia
Email:
Phone:
(07) 4688 1137
Fax:
(07) 4688 1193
Project Code:
CSA00017
Contract Start:
30/11/2008
Contract End:
29/6/2012

Summary

Recent high grain prices have led to increased grain production in irrigation areas normally sown to cotton. Farmers are adapting to grains production and are inquiring about the best agronomic practices to use. This project aims to establish improved agronomic practices, and publish achievable yield and water use benchmarks, for irrigated wheat and sorghum production specific to each irrigated valley in the northern region. Specific project outputs will be published regionally-specific agronomic recommendations on how best to maximise yield for irrigated wheat and sorghum production, along with published yield and water use benchmarks. Project outcomes will be improved knowledge of irrigated grains production potential for irrigation enterprises, and improved industry understanding of the best agronomic practices to use on individual farms.

Rationale

Irrigated cropping regions of northern Australia are beginning to include
cereal crops in their rotations more regularly given recent fluctuations in
grain prices. Irrigators need to know the likely yields and water use
requirement of cereal crops so they can compare the profitability of
different crops, and also require better agronomic recommendations as to
how best to produce cereals in irrigated paddocks.

Expected Outcome

Lodging in irrigated wheat can be reduced through better varietal choice,
using dryland plant populations and delaying the application of nitrogen.
Varieties respond differently to some of the agronomic strategies being
tested, so growers are advised to trial new varieties and agronomy on a
small scale to ensure they are suited to the local growing conditions and
farm management.

Both irrigated wheat and sorghum can achieve very high yields, but
achieving these yields does require a large amount of irrigation water in a
dry season.

Expected Outputs

Irrigated cropping regions of northern Australia are beginning to include
cereal crops in their rotations more regularly given recent fluctuations in
grain prices. Irrigators need to know the likely yields and water use
requirement of cereal crops so they can compare the profitability of
different crops, and also require better agronomic recommendations as to
how best to produce cereals in irrigated paddocks.

Pathway to Adoption

Better agronomic management options are leading to better irrigated
wheat production in the Northern region. This was demonstrated by
growers at Brookstead in 2011 producing what is believed to be a QLD
record 'verified' wheat yield at 8.2 t/ha, after attending a project
communication event and trialling the new agronomic techniques on-farm.

Irrigated wheat has been shown to have yield potential of around 8 t/ha
across the Northern Region, while irrigated sorghum can yield 10-12 t/ha.
These yields require 5-600 mm of water-use by the crop whether the water
is received as rain, irrigation or stored soil water. These water use
estimates don't include losses of irrigation water during storage or delivery
to the paddock.

Research

Benchmarks for yield and water use have been published for irrigated wheat and sorghum. Quick maturing wheat varieties such as Kennedy have a maximum yield of 8-9 t/ha in the northern region, and use around 500-550 mm of water at this yield level, although the benchmark figures do vary a little between locations and years. Fully irrigated sorghum grown in the Northern region has a potential yield of 10-12 t/ha and will use from 500 mm up to 750 mm of water in extreme environments through evapotranspiration. These water use benchmarks do not account for any drainage, runoff or evaporation losses during storage or distribution which vary between farms, seasons and location. Research was also conducted into the wheat disorder known as 'lodging' and agronomic methods used to control it. Delayed nitrogen application, reduced seeding rates, quicker maturing varieties and plant growth regulators were all found to reduce lodging risk. Longreach Crusader and Kennedy were the two most consistently high yielding APH varieties across our experiments. While Longreach Crusader experienced significantly less lodging than Kennedy under high N rates, Kennedy achieved significantly greater protein levels than Crusader at the location where protein analysis was conducted. Varieties responded differently to some of the agronomic strategies being tested, so growers are advised to first trial new varieties and agronomy on a small scale to ensure they are suited to the local growing conditions and farm management. When growing sorghum on limited water, growers were recommended to irrigate a larger area with a smaller amount of water (1 ML/ha), to take advantage of in-season rainfall. This recommendation maximises long term gross margins if irrigated sorghum is grown each year, but may not produce maximum gross margins in all individual years, especially in extremely dry years, when growing a smaller fully irrigated area may be more profitable.

Publications

Communication papers Peake A.S. and Poole N (2012). ?Controlling lodging in high-N paddocks using canopy management techniques? In J Sykes (Ed) Irrigated Wheat Best Practice Guidelines In Cotton Farming Systems, GRDC, ACT. Poole N (2012). ?Disease Management' In J Sykes (Ed) Irrigated Wheat Best Practice Guidelines In Cotton Farming Systems, GRDC, ACT. Peake A.S., Poole N. (2011) Delayed nitrogen application reduces wheat-lodging risk. Farming Ahead, 331, April 2011. Peake A.S. (2011) Delayed nitrogen tactic for lessening lodging risk. Ground Cover, 91, March-April 2011 Peake A.S. (2010) Improving Irrigated Wheat Yields in Central QLD. In Cropping Central, Issue 46 March 2010, Newsletter for the Central QLD Sustainable Farming Systems Project, DEEDI. Public presentations with an accompanying paper: Peake A.S., Bell K., Poole N. and Lawrence, J. (2012 - In Press) Nitrogen stress during tillering decreases lodging risk and increases yield of irrigated bread-wheat (Triticum aestivum) in north-eastern Australia. In "Capturing Opportunities and Overcoming Obstacles in Australian Agronomy?, Proceedings of the 16th ASA Conference, 14-18 October 2012, Armidale, Australia. Peake A.S., Rebetzke G., Chapman S., Dreccer F., McIntrye L., Hundt A., and Bell, K.(2012). Agronomy for high yielding cereal environments: varieties, agronomic strategies and case studies. In GRDC Northern Region Grains Research Updates, Goondiwindi, 6-7 March, 2012.

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