Crop rotation was key in 2017 season

07 Feb, 2018 04:00 AM
Liebe Group research and deveopment  co-ordinator Alana Hartley speaking with local growers at the Practice for Profit site.
Liebe Group research and deveopment co-ordinator Alana Hartley speaking with local growers at the Practice for Profit site.

WA growers are often asking how far they can push their cropping system and when is it going to affect their financial returns?

In 2011, the Liebe Group set out to understand this by establishing a crop sequencing trial, Practice for Profit, at the Mills’ family property, just east of Dalwallinu.

For the seventh consecutive season at this site, the trial design drills down into the economic affects of multiple variables – high cost and low cost inputs and crop rotation.

The trial design includes a continuous wheat, wheat-canola, wheat-fallow and wheat-field pea rotation.

High and low inputs are adjusted seasonally to reflect grower standard practice (GSP).

The purpose of these high and low inputs has been to mimic maximum yield potential versus grain production at the lowest possible production costs, regardless of seasonal conditions.

The site was sown on May 10 into a dry soil profile.

With a late break to the season in 2017 and only 128 millimetres of growing season rainfall, emergence was not observed until early July.

It was noticeable early after emergence that the low input treatments, regardless of crop rotation, had lower plant counts and more weeds.

While this can have a significant affect on final yield, due to seasonal conditions, there was no significant difference between those treatments with high or low inputs on yield, protein, hectolitre weight or screenings.

This indicated that inputs did not necessarily compromise production in 2017.

What about the rotations?

It is commonly understood that it is good GSP to include diversity in your rotation for weed management, disease management and other economic reasons – but rotations can also have other benefits.

During the 2017 season, crop rotation was the standout influence on yield and quality at this trial site.

The standout rotation was wheat on chemical fallow.

The additional stored soil moisture from the previous year contributed to an extra 0.32 tonnes a hectare compared to the continuous wheat treatment.

It also resulted in lower screenings as there was adequate moisture to support grain-fill.

Wheat following canola was the poorest performing treatment across the site, only yielding 0.86t/ha, as large canola crops and residual atrazine from 2016 resulted in poor establishment and some crop damage.

So, where should money be spent and what are the returns?

On face value, the best performing treatment was the high input wheat on chemical fallow at an average gross margin (GM) of $348/ha, followed by the low input wheat on chemical fallow at $302/ha.

The wooden spoon award for poorest performing GM was both the wheat high and low following a canola crop at only $98/ha and $68/ha respectively but, that isn’t the whole story.

GM is only a basic economic measure of income minus expenses from that single season.

Analysing the past seven years of data assesses the farm business profit margin (PM) and tells a different story.

Consider this, if the highest performing crops were off a chemical fallow, what about the investment of inputs in the previous year to maintain that chemical fallow?

Has there been consideration of the lost income from not having a crop on that paddock that was treated as a chemical fallow?

The investment in previous years needs to be considered when analysing the economic performance of the current season’s crop.

In 2017, the wheat on chemical fallow had a negative PM as a result of the additional costs and loss of income from the previous year.

Both the continuous wheat and the wheat on canola stubble continued to provide a positive PM despite the less than ideal seasonal conditions.

After seven consecutive years running this trial, it appears that rotation is the biggest influence to the economic performance of the cropping programs however inputs at rates and costs that meet nutritional demands, manage pests and disease effectively, without breaking the budget will contribute to the overall success of the cropping rotation.

The full report from this project will be published in the Liebe Group Annual Research and Development Book.

The Liebe Group would like to thank the Mills family for hosting the site and Wheatbelt NRM for funding the trial in 2017.



Screen name *
Email address *
Remember me?
Comment *


light grey arrow
I love big tractors
light grey arrow
Do you have any plans to visit Esperance area?
light grey arrow
This inquiry is justified as WA Court of Appeal Chief Judge McClure backed Marsh's claim for