January 2005: Cotton is the cropping mainstay of the Emerald Irrigation Area, however other summer crops are also earning a place for their rotational and soil conditioning benefits.

One such crop is corn and while always having a presence in the 20,000 ha area as an opportunity crop, it is now being recognised as a valuable management tool in cotton growers' crop rotations.

In the 2003/04 season over 1500ha of corn was planted, compared to 8500ha of cotton.

While good prices for the corn crops made growing maize an economically viable option, many growers are convinced that the benefits of the crop extend beyond yield and dollar terms.

One such grower is Emerald farmer Ian Burnett who planted gritting corn last year.

The corn's rotational benefits with his cotton crop are also a major factor in his choice to grow corn.

"Cotton after corn seems to do the job a lot better than other crops," he said.

Last season, the Burnetts planted a gritting variety, Hycorn 345 which they believe offers the best mix of yield and grit quality in their area.

The crop was planted under irrigation and the resulting performance of yield and good quality grain was very pleasing for the Burnetts.

Planted on rain moisture on January 23, 2004, the Burnetts aimed at a planting rate of 65,000 seeds/ha.

The crop received a total of seven waterings before being harvested on July 7.

Given the favourable yield and grain quality, combined with the rotational benefits of corn, Ian said the family will be planting corn into its summer rotation again next season.

Among these rotational benefits are the break from a cotton monoculture and the ability of corn to make for more friable soil for the following crop.

One of the reasons for these benefits can be attributed to the fact that a physiologically mature corn plant stops using soil nutrients and moisture, giving a longer break between cropping and acting as a short fallow period, with any rain or moisture received following maturity being stored in the soil profile.

An additional boon for cotton growers is that while heliothis caterpillar effect corn, the grub is not considered a major pest and as such the need for spraying is reduced.

This has a two-fold effect, firstly less insecticide is used, cutting down input costs and secondly, from an IPM perspective it encourages populations of beneficial insects in the cropping area in much the same way as retaining wheat stubble between cotton rows does.

So while cotton remains a valuable keystone to the corn cropping landscape, corn is making its mark as a summer crop option to enhance another major crop.