To determine the impact that grazing of crops in winter had on subsequent grain yield and quality, production factors such as weeds, disease and nutrition, and livestock carrying capacity.

These on-farm trials once again demonstrate that it is possible to graze crops in winter and maintain grain yield.  However, the frequency that yield penalties occurred (when grazing crops) increased when compared to the same set of trials in 2011.  Yield penalties (i.e. greater than 5% yield reduction) occurred in seven out of eleven (64%) trials in 2012 compared to two out of seven (29%) trials in 2011.  There are three possible reasons for this increase.  Firstly, growing season rainfall was significantly less in 2012 with most sites receiving only decile 1 or 2 rainfall.  Moisture stress may reduce the ability of crops to recover from grazing.  Secondly, a number of the 2012 trial sites were located in the low rainfall zone where the short seasons are less suited to crop grazing.  And finally, the timing and intensity of grazing may have increased the frequency of yield penalties experienced.  Four out of the eleven crops were grazed later than recommended and seven out of eleven crops were grazed heavily.  It is quite likely these three factors interact, and that a dry year or location exacerbates the negative impacts of late and/or heavy grazing.

The average amount of grazing value provided by crops was significantly less in 2012 compared to 2011 (214 vs 307 DSE grazing days per hectare).  This was mainly due to the late start and the cold and very dry July experienced in 2012.  The amount of grazing value provided by the crop is important when considering the economic implications of crop grazing.  In a year such as 2012, when grain prices were high, a small yield penalty caused by crop grazing can have a large impact on grain income per hectare.  At the current relatively low livestock prices, a lot of grazing value is needed to make up for any grain yield penalty.