【摘要】 在 8～ 15°的红壤坡地上 ,对水土流失作了 14年的定位观察。结果表明 :水土流失与土壤坡度和植被覆盖度密切相关。红壤坡地一经开发利用 ,径流量就成倍地减少 ;而侵蚀量在开始的头 2年成倍增加 ,第 3年后趋于稳定。土壤侵蚀量与坡度呈极显著的对数正相关 ,坡度每增加 1°,土壤侵蚀量递增约 12 0 t/ (km2·a) ;土壤侵蚀量与植被覆盖度呈显著的负指数相关 ,当植被覆盖度 >6 0 %时 ,土壤侵蚀量在 2 0 0 t/ (km2 · a)以下 ;土壤侵蚀量与耕种方式密切相关 ,等高耕种的侵蚀量仅为顺坡耕种的 1/ 6。应用土壤肥力平衡观点 ,提出了 Q2 红色粘土母质发育的红壤侵蚀允许指标为 <30 0 t/ (km2· a) ,为红壤坡地水土流失的防治和农业可持续发展提供了理论依据更多还原

【Abstract】 Observation and study on water and soil loss of plots or sloping land with slope gradients of 8~15° in hilly red soil in a location test during 1987~2000 was conducted, the results showed that rate of water and soil loss were greatly related to the land exploitation. Soil erosion rates of the slops significantly increased in the first two years after exploitation,it tended to stability after 3 years. The soil erosion rate was negatively related to vegetative coverage on the sloping land of red earth, and it was below 200 t/(km 2·a) when vegetative coverage was more than 60%. The soil erosion rate were positively related to the slope gradient of the land, and it increased 120 t/(km 2·a) with slope gradient increased 1°. The soil erosion rates were closely related to the cropping patterns. Contour cultivation could reduce soil erosion rate by a factor of six compared with straight cultivation. Permissible soil erosion index for the soils derived from quaternary red clay was 300 t/(km 2·a) according to the view of soil fertility balance.更多还原