Question
How long does the earthworks last? Do I need to come back to the field and redo the earthworks?
Answer
Usually, the first time we landform a field it will be good for 5-8 years. Deeper fills can settle and deeper cuts can expand. So for fields with deeper cuts and fills it’s more like 5 years and for shallower it can be 8 years.
There maybe some settlement and expansion over time particularly in fill areas of the field. Our experience is that it's often a good idea to 're-trim' or regrade the field after 5 years but the earthworks required are much smaller than the original earthworks.
You can still use the original machine control file if you wish. However, farmers often re-survey and recalculate the earthworks and create a new machine control file.
The re-survey can also be used for the drainage analysis to check if the re-trim is required.
A new feature we'll have in OSDv2.6+ where you can exaggerate the cut and fill areas using Tools > Cut/Fill > Exaggerate Cut/Fill to reduce the problem of settlement and expansion of the fill.
When we redo a field, it is very quick because the earthworks volumes are much smaller as we are only touching it up. After that it should be good for more than 10 yrs.
