Abstract:

[Objective] The Dengta Basin in Heyuan, Guangdong, has extensive tea plantation areas and faces severe soil erosion problems. This study aims to investigate the soil erosion characteristics of mountainous tea plantations in this region under different slope management practices. [Methods] This study employed intermittent artificial rainfall simulation experiments (15° slope, 70 mm·h⁻¹ rainfall intensity) and established three slope treatments—bare soil, rice (Oryza sativa L.) straw mulch, and early-stage planting (Vicia dasycarpa Ten.)—for observation. [Results] Straw mulch significantly reduced runoff and sediment loss; its total runoff (33.3 L) was 10.4% less than that of bare soil and the early-stage planting treatment (both 37.2 L), and its total eroded sediment (20.4 g) was only 21.1% of that from bare soil (96.6 g) and 12.5% of that from the early-stage planting treatment (164 g). Erosion was most severe in the early planting treatment, with total sediment loads 1.69 times and 8.02 times those of bare soil and straw mulch, respectively, and sediment yield ranging from 2.42 to 6.91 g·m⁻²·min⁻¹—far higher than those of bare soil and straw mulch. The dynamics of sediment yield differed markedly among the three treatments: the sediment yield of bare soil initially rose rapidly before stabilizing with slight fluctuations, the erosion rate under straw mulch showed an overall downward trend and stabilized in the later stages; although the erosion rate during the early planting stage decreased over time, it remained at the highest level throughout. The cumulative runoff and sediment volumes for all three slope treatments exhibited a good linear relationship with time (R²>0.99), while the sediment loss during specific time periods showed significant linear and quadratic relationships with runoff and rainfall, respectively (R²>0.78). [Conclusion] Straw mulching can effectively reduce soil and water loss in tea plantations in this region, whereas during the early stages of planting, significant surface disturbance and low vegetation cover actually exacerbate erosion. The findings of this study provide a scientific basis for soil and water conservation efforts in tea plantations in the Dengta Basin.

Key words: artificial rainfall, intermittent, soil erosion, Dengta Basin, tea plantations

摘要：

【目的】广东河源灯塔盆地茶园面积广，水土流失问题突出，本文探究该区域山地茶园不同坡面处理的水土流失特征。【方法】通过间歇性人工模拟降雨试验（坡度15°、雨强70 mm·h⁻¹），设置裸土、水稻（Oryza sativa L.）秸秆覆盖和种植初期（苕子，Vicia dasycarpa Ten.）等3种坡面处理进行观测。【结果】秸秆覆盖减流减沙效果显著，其总径流量（33.3 L）较裸土与种植初期（均为37.2 L）少10.4%，总侵蚀泥沙量（20.4 g）仅为裸土（96.6 g）的21.1%、种植初期（164 g）的12.5%。种植初期处理侵蚀最为严重，总泥沙量分别为裸土和秸秆覆盖的1.69倍和8.02倍，产沙率达2.42－6.91 g·m⁻²·min⁻¹，远高于裸土与秸秆覆盖。3种处理产沙动态过程差异明显，裸土产沙率呈先快速上升、后平稳波动的特征，秸秆覆盖产沙率整体呈下降趋势且后期稳定，种植初期产沙率虽随时间下降但始终处于最高水平。3种坡面处理的累积径流量与泥沙量均与时间呈良好线性关系（R²>0.99），时段侵蚀泥沙量与径流量、降雨量分别呈显著线性与二次函数关系（R²>0.78）。【结论】秸秆覆盖可有效减少该区域茶园水土流失，而植物种植初期因地表扰动大、植被覆盖度低，反而加剧侵蚀。研究结果可为灯塔盆地茶园水土保持工作提供科学依据。

关键词: 人工降雨, 间歇性, 土壤侵蚀, 灯塔盆地, 茶园