Impacts of different slash disposals on soil and water erosion of high-intensity management Eucalyptus grandis × urophylla plantation

Background The slash disposal- burning forest- in high-intensity management Eucalyptus grandis × urophylla plantation has accelerated soil degradation. Statement of the problem Slash disposals is a contributing factor, but its specific role in the correlation between rainfall-runoff and soil erosion remains elusive. Objectives his study investigated the characteristics of rainfall-runoff and soil erosion resistance in different methods of slash disposals in plantation. Methods Three methods of slash disposal, namely burning forest (BF), moving away (MA), and spreading evenly (SE), were established. A field simulation experiment of rainfall was conducted, and path analysis was used. Results The findings revealed that the water holding, infiltrating properties and the time the rainfall-runoff generated of SE were increased by approximately 10∼20%, 100%, and 80%, respectively, compared with BF and MA. Water loss, soil loss and nutrient loss were significantly reduced by 62.23% and 61.56%, 69.06% and 49.55%, and 58.8% and 65.42% in SE and BF compared to MA. Path analysis suggested that different from BF and MA, the correlation between soil water properties and rainfall-runoff factors in SE was weakened, simultaneously considering the result that SE had the lower proportions of silt for sediment component (75.31%), it stabilized the soil structure. Conclusions and prospect Consequently, SE mitigated the erosion force by reducing rainfall-runoff and enhancing the anti-erosion of soil through improved water properties, making it a viable slash disposal. This work provides a detailed description of the soil erosion characteristics of plantation, including water, soil, and nutrient losses caused by rainfall-runoff, as well as the soil anti-erosion due to different slash disposals. These findings offer valuable insights for the management of high-intensity Eucalyptus grandis × urophylla plantations.