Plan now for summer double crops

Author: Kelly Becker | Date: 21 Oct 2014

Image of Kelly Becker, GRDC Northern Panellist

With summer fast approaching, northern grain growers thinking of double cropping their country should be preparing now and addressing questions of soil nutrition, water availability and weed pressure.

First and foremost is crop selection and checking for any potential issues from residual herbicides which may have been used earlier in the season.

In thinking about herbicides, grain growers will also need to factor in which weeds are likely to be present over summer so that they can utilise a crop which will allow for the right chemistry groups to be used as part of their herbicide rotations.

For example, mungbean growers can use Group A chemistry in crop for grass weed control, whereas sorghum growers tackling the same grass weeds can use Group K residual herbicides.

This approach will allow growers to keep on top of weed pressures while minimising the risk of resistance developing in the weed population.

It is also worth giving spray rigs a once-over to make sure you are getting the best bang for your buck out of the chemistry applied – if the spray rig is not set up properly there is a much smaller margin for error when spraying in spring and summer compared to the more forgiving conditions in winter.

It is vital that growers check the level of plant available water storage capacity (PAWC) in their soils so they can choose a suitable crop type.  This ensures they are not just ‘taking a punt’ on crop establishment.

Soil testing is also encouraged so that you can make an informed decision about the appropriate amounts and types of fertiliser to be applied. Applying nitrogen as close as possible to when the plant needs it will also help maximise its uptake and minimise wastage.

New trial work co-funded by the Grains Research and Development Corporation (GRDC) is highlighting the importance of pre-season soil testing to quantify profile mineral N reserves. The research is being conducted by Queensland Alliance for Agriculture and Food Innovation (QAAFI) Principal Research Fellow Dr Mike Bell who is examining the effect of N fertiliser application time – pre-planting, at planting and in crop/side dressing – and product type (urea alone or in varying formulations).

It is hoped the data obtained will enable growers to more accurately adjust their fertiliser N rates to fit their circumstances.

Central Queensland growers wanting further advice about nutrition can attend the GRDC-supported More Profit from Crop Nutrition workshops to be delivered by Chris Dowling from the Back Paddock Company to be held in Clermont on Tuesday, November 4; Rolleston on Wednesday, November 5; and Banana on Thursday, November 6.

More information about the workshops is available from Department of Agriculture, Fisheries and Forestry (DAFF) extension agronomist and workshop convener Jo Weier on 0427 231 701 or

Fact sheets are on spray rig maintenance and herbicide modes of action are available from


Caption: GRDC Northern Panellist Kelly Becker, of Theodore, says summer croppers should plan now for weed pressures and nutrition needs.

Contact Details

For Interviews

Kelly Becker, GRDC Northern Panellist, Theodore
07 4997 4007, 0409 974 007


Michael Thomson, Senior Consultant, Cox Inall Communications
07 4927 0805, 0408 819 666

Region North