The present invention provides a ground engaging film roller 30.2 having a generally horizontal axis of rotation and an outer circumference for engaging ground, the roller having opposed outer ends (30.21) of a larger circumference than the circumference of portions (30.22) located between the opposed ends. The present invention also provides a film deployment system having a ground engaging film roller as described above, which is rotationally mounted to a frame (30.18), the ground engaging film roller (30.2) receiving film from above and to a front location of the roller, and passing between a film locating roller (30.3) and the ground engaging roller (30.2), the ground engaging roller (30.2) shaping the ground it engages by forming a channel in ground at the opposed ends (30.21) of the roller (30.2) for the film to be located as it leaves engagement with the ground engaging roller (30.2). The present invention also provides an agricultural or horticultural implement (10, 30) for performing an agricultural or horticultural process, the implement (10,30) including whipper arrangement (50) at a location forward of where the process will be performed. The agricultural or horticultural implement (10,30) can be such that to the rear of where the process is performed there can located film deployment system (30) as described above.La présente invention concerne un rouleau de film en prise avec le sol (30.2) ayant un axe de rotation généralement horizontal et une circonférence externe pour venir en prise avec le sol, le rouleau ayant des extrémités externes opposées (30.21) ayant une circonférence plus grande que la circonférence de parties (30.22) situées entre les extrémités opposées. La présente invention concerne également un système de déploiement de film ayant un rouleau de film en prise avec le sol tel que décrit ci-dessus, qui est monté rotatif sur un cadre (30.18), le rouleau de film en prise avec le sol (30.2) recevant le film par le dessus et vers un emplaceme
