The effects of wood chips and slash usage on soil loss and soil nutrients of skid trails

This study investigated the sheet erosion that occurs as a result of log skidding operations using a farm tractor on skid trails and the use of wood chips and slash in order to minimize the soil loss. The spreading of them on the skid trails were also investigated for the nutrient status of the soil. A total of four blocks (sample fields) were formed in four defined skid trails in the study area and three runoff plots were established in each block. One of the runoff plots was left empty as a control (CNT). Wood chips (C) was placed in the second plot and slash (S) in the third. A total of 108 water samples were taken from the sample fields, 36 from each of the control, wood chips and slash plots. Subsequently, the total amount of suspended sediment was measured in the laboratory. In addition to, water samples were also taken to the study area to determine the amounts of cations and anions in the surface waters. A total of 84 water samples were collected from the sample fields, 28 from each of the control, chip and slash runoff plots. They were taken from sample fields using ion chromatography (IC) instrument to analyse the amount of some plant nutrients in the laboratory. As a result, the average amount of suspended sediment transported in the CNT was found as 2.58 g m-2, in the C as 1.61 g m-2 and in the S as 2.13 g m-2. Therefore, the amount of soil loss in the control plots was about 1.2 times higher than in the slash plots and 1.6 times higher than in the wood chips plots. In this study, variance analysis results showed a statistically significant difference between the suspended sediment amount carried from the plots (p<0.05). The average amounts of cations and anions for each plot were compared, except for Lithium and Bromide. It was found that between chip plots is between 1.11 and 4.5 times higher than control plots and between slash plots is between 1.08 and 3.46 times. According to the results of variance analysis on plant nutrients; a statistically significant difference (p<0.05) was found between the amounts of Magnesium and Fluoride in the surface waters of the parcels. However, there was no statistically significant difference in the other (p>0.05). This study demonstrated that wood chip and slash can be used to reduce the sheet erosion that occurs in skid trails after log extraction. This study has shown that forest soil is repaired and chemical deterioration is reduced by laying wood chip and slash on the skid trails after extraction is finished.