Trial of biodegradable mulch materials (Kent 2012)

notPlanned

Plot size 12 m x 12 m (0.014 ha), 16 trees per plot. All the trees were assessed in each plot. Trees at 2m x 2m spacing, with a 1m buffer zone on the border of each plot (i.e. 2m between each plot, and 6m between nearest trees in neighbouring plots in total). There were 4 replicates of each mulch treatment. The treatments are: 1. Isoplant wood fibre boards (1.2 x 1.2 m) 2. Hardboard/MDF wood fibre boards (1.0 x 1.0 m) 3. Resin-free Coir mat, plant fibre mat (1.0 x 1.0 m) 4. Resin-free Coir mat with photodegradable membrane (Greenfix, 1.2 x 1.2 m) 5. Biodegradable starch-based mat (Mater-Bi, 1.0 x 1.0 m) 6. Standard black plastic mulch mat (1.0 x 1.0 m) 7. Standard black plastic mulch mat (1.2 x 1.2 m) 8. Reusable rubber mat (1.0 x 1.0 m EPDM sheet) 9. Spot weed using herbicides (1.0 x 1.0m) 10. No weeding control Basal Treatments: Site was fenced against browsing mammals. Any established vegetation was killed with a pre plant spray of glyphosate in September, at least 7 days prior to cultivation. The site was sown with Lolium perenne (rye grass) after cultivation in September / October, to establish a grass sward across the experimental area. Planting stock was graded to be of a uniform size (no more than 50mm variation in height, 1mm variation in rcd). Plants were protected by vole guards. Mulches were fixed through grass sward, as per manufacturers recommendations. Assessments: Immediately after planting, and at the end of each year, survival, height and diameter at 5cm above ground level (marked with white paint at time of assessment) of all trees was assessed. To allow comparison between individual trees, assessment took place at the same start point in each plot, and each tree was measured in the same order in each plot for each assessment. A record of any damage caused to the trees by the mulch material was made. At 6 monthly intervals the effectiveness of the mulch material was assessed visually with an estimate of % weed cover penetration of each mulch mat over the plot as a whole. Soil moisture measurement throughout growing season used in situ theta probes buried beneath the mulches before installation.