Impacts of a Crop Sequence

Majority of farmers realise that they should be including broad leaf species into their cropping rotations to help manage in crop weeds and diseases. However in the years between 1999 and 2009 the percentage of legume pulse crops and canola declined significantly in central western farming systems.

The main reasons for this decision were late starts to the growing season, drought and risk aversion. The common misconception has been that broad leaf crops are far riskier and not as profitable as a cereal crop. With this in mind the project aims to outline the benefits of break crops on the longer term financial performance of the following wheat crops.

The project commenced in the year of 2011 and will be looking to conclude in 2014 with this blog article looking at the results from years 2011 and 2012.

2011-2012 summary

  • Crop sequence experimentation undertaken in Central West NSW in 2011 and 2012, has demonstrated that crop sequences which include a brassica or legume break crops can be as profitable as, and in many instances more profitable than, continuous wheat.
  • Growing pulses for hay was found to provide high quality feed as good as from cereals but hay from canola was less nutritious. However, canola hay provided an alternative option in cases where a possible crop failure is likely due to adverse weather.
  • Growing pulses for hay was found to be profitable across a range of season types, achieves excellent grass weed control and provides greater N inputs and higher carry-over of soil water than when the same crop is grown for grain.
  • Measurements of on-farm amounts of shoot N fixed per hectare in farmer-sown crops in 2011 varied from 13 to 42 Kg N/ha with field peas fixing the most N, and also yielding better than lupins and chickpeas
  • Canola was consistently the most profitable break crop option at Junee. However, the rotational benefits of canola were usually restricted to just the first subsequent wheat crop whereas additional wheat yields can occur for 2 years after a legume.
  • Growing pulses for brown manure loses money in the year they are grown, but achieves excellent grass weed control, high N inputs, residual carry-over of soil water, provides more ground cover, and requires less labor than when grown for hay or grain.

benefits of crop sequencing 

From a systems perspective the  break crops out performed consecutive wheat crops due to the reduction in root diseases and nitrogen inputs.  The break crop also provided an effective means of storing soil moisture as well as minimising in crop weed pressures.

Tim Paschke Waikerie SA

When your thinking about utilising break crops on farm start to think about what the cropping rotation needs. The things to keep in mind when making this decision should be factors such as weed and diseases pressures as well as the nitrogen status of your soils.