Inversion ploughing: Effects of long-term deep burial on weed seed reserves

• From the view point of weed management, inversion ploughing has a role in the control of grass weeds with short-term seed dormancy. • However, when managing broadleaf weeds with long-term seed dormancy, one must be aware of the risk of prolonging their seedbank life. This could be a problem in herbicide resistance management after resistance has occurred. BACKGROUND Inversion ploughing or deep burial of weed seed using a mouldboard plough is a very effective method of decreasing seedling emergence. This is consistent with the results of many ecological studies which showed that weed seedling emergence is inversely related to the depth of seed burial and that maximum emergence is from shallow depths of around 1 cm for the majority of species. Small-seeded weeds can only emerge from shallow depths while large-seeded ones can germinate from greater depths if conditions are suitable, but rarely do they emerge from 15 cm or more. Therefore, the use of a mouldboard plough with a skimmer attached, that fully inverts the soil to bury weed seeds from on or near the surface to a depth of 15 cm or more, would result in a dramatic reduction of seedling emergence for the majority of weed species. However, data on the effects of inversion ploughing on