Detailed estimates of time taken in the different systems was also impossible, but estimates were instead made using time calculations from the BCG systems trial. For harvest, these were:
Yield < 1.5 t/ha, Time (hrs/ha) = 0.030 x Yield (t/ha) + 0.066, and
Yield >= 1.5 t/ha, Time (hrs/ha) = 0.084 x Yield (t/ha) + 0.016.
Note that these times also allow for grain tank capacity and unloading.
On the whole, yearly machine hours tended to be driven by sowing and harvest times. Till farmers did not till excessively, and tended to use herbicides for fallow weed control. At Culgoa and Donald, sowing was slightly slower (with the machinery assumptions used) and No Till yields higher, leading to higher total machine hours (Table 30). At Minyip No Till, more work associated with the chickpea crop (rolling, spraying) increased hours above the Till cereal crop in 2007, and in 2008 hours were higher due to higher yields. The Patchewollock Till farmers hours were boosted in 2006 by sowing sorghum and tillage, but sowing using no till and 2007 and 2008 spent similar time to the No Till paddock. The Yaapeet Till paddock required much more time, a combination of tillage and haymaking, and lower yields (except 2008) in the No Till paddock.
Table 30. Yearly machine hours for focus paddocks, 2006-2008.
- Crop and non-crop years have been weighted to give an average across two years of the fallow-crop rotation.
- Culgoa is an exception to this, as the crop years both followed preceding cereal crops.