Fallow Management and the Economic Costs

The Grower Network members within the low rainfall zones are looking for more analysis on fallow systems in the rotations. They would like to understand what is the correlation between water and soil nutrition and fallows and what soils fallow

Fallow treatments were used in the CSIRO lead project - CSA00056 – Developing farming systems for the LRZ of WA. The project team reported a 0.62t/ha yield increase in wheat after fallow when compared to the continuous wheat rotation at Merredin. At Hyden the team reported a 0.45t/ha increase in wheat yield in the fallow-wheat-fallow-wheat rotation when compared to the continuous wheat rotation. The protein of the following wheat crop has also been seen to increase post a fallow rotation in these trials.

While these results are significant within this trial, the economics of including fallow in the rotation have not been measured along with the yield and protein. There is however clear data showing an increase in the partial gross margins when comparing break crops and wheat rotations against continuous wheat rotations and the analysis is conducted over multiple paddocks and multiple years. Similar results have also been found in a 2013 COGGO funded CFIG project with Bass barley following a fallow rotation having the highest gross margins in this trial.

This investment will incorporate the different versions of fallow treatments that Grower Network members have identified, with the economics (positive and negative) of incorporating fallow in the farming system rotation.

Growers have raised this issue to ensure than they are fully informed regarding the benefits and constraints of introducing fallows into their systems, the economics of different fallow systems and the risks that may be managed when introducing fallows into the farming system rotation.