Reductions in suspended sediment loss for the buffer strips with different vegetation
Table 5 presents the estimates of suspended sediment loss for each individual year and the entire monitoring period. Annual losses from the control treatment ranged between 8.5 kg ha-1 (±10.1 kg ha-1) in 2018-2019 to 111.8 (±154.9 kg ha-1) in 2019-2020. In comparison, the corresponding losses from the replicate plots with grass buffer strips were 3.3 kg ha-1 (±4.2 kg ha-1) in 2018-2019 to 40.9 kg ha-1 (±21.4 kg ha-1) in 2017-2018 and from those with willow buffer strips 6.4 kg ha-1 (±6.1 kg ha-1) in 2018-2019 to 42.8 kg ha-1 (±31.2 kg ha-1) in 2019-2020. Sediment losses from those plots served by deciduous woodland buffer strips ranged between 6.8 kg ha-1 (±6.1 kg ha-1) in 2018-2019 and 26.6 kg ha-1(±6.8 kg ha-1) in 2017-2018.
Relative to the experimental control, suspended sediment loss (Table 6) was reduced by the grass buffer strips by between 0% (2017-2018) and 94% (2019-2020), compared with 0% (2017-2018) to 89% (2019-2020) for the willow buffer strips and 0% (2017-2018) to 76% (2019-2020) for the woodland buffer strips. For the entire monitoring period (2017-2020), reductions in total monitored suspended sediment loss were in the descending order: deciduous willow buffer strips (44%) > deciduous woodland buffer strips (30%) > grass buffer strips (29%).