NOTES ON THE USE OF POLYTHENE BELOW GROUND TO SEPARATE THE ROOTS OF HERBAGE SPECIES

A method is described by which the root systems of herbage species may be separated under field conditions, using a double layer of 500-gauge black polythene. The effect of such a treatment was examined in field trials; tests on the permeability of this material in laboratory and field were also made. Visual, manual and mechanical examinations of the polythene after 2, 3 and 4 years in the soil are reported. From the results obtained it is concluded that polythene used in this manner is not detrimental to either herbage yield or quality, and that it can be expected to remain a satisfactory barrier below ground for at least 4 years. However, the introduction of polythene placed parallel to drilled perennial ryegrass and white clover did reduce total root weight by 20%, with a concomitant loss in yield; this loss was mainly associated with the grass component.