【摘要】 选择5种坡地利用方式,分别是裸地、农耕地(玉米)、荒草地、巨桉林地Ⅰ与巨桉林地Ⅱ,建立人工径流小区,对2006年6~11月各小区产流产沙及养分流失进行对比研究。结果表明:(1)5种坡地利用方式产流产沙差异显著(P<0.05),径流深依次是裸地(250.9 mm)>农耕地(232.9 mm)>荒草地(175.4 mm)>巨桉林地Ⅰ(170.5 mm)>巨桉林地Ⅱ(141.3 mm);产沙量大小依次为:农耕地(313.63 t/km2)>裸地(176.80 t/km2)>荒草地(94.45 t/km2)>巨桉林地Ⅰ(90.58 t/km2)>巨桉林地Ⅱ(36.37 t/km2)。(2)5种坡地利用方式养分流失差异显著(P<0.05),其流失量大小顺序均为钾素>磷素>氮素。其中,氮素与磷素流失以水溶态为主,平均为96.16%与69.45%;钾素以颗粒态(与泥沙结合态)为主,平均为74.93%。(3)不同坡地产流产沙主要影响因素不同,裸地与农耕地受降雨影响较大,而荒草地与巨桉林地受人为干扰因素较大。(4)调整农事活动、改善经营措施与减少人为干扰对防止坡地产流产沙以及养分流失具有重要作用。更多还原

【Abstract】 Based on the observation on runoff plots,the properties of runoff and sediment and nutrient loss on the different plots(bare land,farmland,wide grassland,Eucalyptus grandis forestland Ⅰ(with disturbs) and Eucalyptus grandis forestland Ⅱ(without disturbs) were observed from June to November in 2006.The results are listed as follows:(1) The runoff depth and sediment yield had remarkable difference among the patterns(P<0.05).The order of runoff depth and sediment yield loss were bare land(250.9 mm)>farmland(232.9 mm) >wide grassland(175.4 mm) >Eucalyptus grandis forestlandⅠ(170.5 mm) >Eucalyptus grandis forestland Ⅱ(141.3 mm) and farmland(313.63 t/km2)>bare land(176.80 t/km2) >wide grassland(94.45 t/km2)>forestland Ⅰ(90.58 t/km2)>Eucalyptus grandis forestland Ⅱ(36.37 t/km2) respectively.(2)The nutrient loss yields had remarkable difference among the patterns(P<0.05).The order of nutrient loss was K>P>N.96.16 % of total phosphorus(P) and 69.45 % total nitrogen(N) were dissolved in runoff,while 74.93 % potassium(K) was transported as particulate form by runoff.(3) Different slops were affected by every factor in different degree.Bare land and farmland were affected more by rainfall,while wide grassland and Eucalyptus grandis forestland were affected more by human activities.(4) It was significant to soil and water conservation of slope land through adjusting farming and improving management and reducing disturbs of human.更多还原