植被覆盖和施肥对不同坡长坡地总磷流失的影响

发布时间：2018-10-29 14:14

【摘要】：为了研究坡地总磷流失特征,探究植被覆盖和施肥对不同坡长坡地总磷流失的影响,以浙江省丘陵区坡面菜地红壤为研究对象,通过室内人工模拟降雨试验,在固定雨强120mm/h、固定坡度20°、每场降雨试验的产流历时设计为30min的条件下,选定不同坡长(1,2,3,4,5m)、不同植被覆盖度(0,15%,30%,45%,60%,75%,90%)和不同施肥处理空白(CK)、无机复合肥(CF)、有机肥(OF)下进行模拟降雨试验。结果表明:(1)在不同施肥处理、坡长条件下,随着植被覆盖度的增加,单位投影面积总磷流失模数逐渐减少,其中1m坡长下的减少趋势不明显,5m坡长下的减少趋势最明显;不同坡长条件下随着植被覆盖度的增加,单位投影面积总磷流失模数均在90%覆盖度时达到最小,裸地时最大。(2)在不同施肥处理、相同植被覆盖度条件下,等长度增加坡长,总磷流失量的增量非等量增加,且在2~3m处最小,3~4m处最大,说明该试验条件下的临界坡长为4m,最佳坡耕地坡长为3m。(3)在不同施肥处理、坡长条件下,侵蚀相磷素流失量占总磷输出量的比值为30.24%~94.61%,除1m坡长下存在部分比值小于50%以外,其他均高于50%,说明坡地磷流失主要以侵蚀泥沙携带流失为主。(4)不施肥条件下侵蚀相磷素流失量占总磷输出量的比值高于施肥条件下的,且相比施用无机肥,施用有机肥条件下侵蚀相磷素流失量占总磷输出量的比值较高。
[Abstract]:In order to study the characteristics of total phosphorus loss in sloping land and the effect of vegetation cover and fertilization on total phosphorus loss in slope land of different slope length, the red soil of vegetable field in hilly area of Zhejiang Province was taken as the research object, and the experiment of simulated rainfall was carried out in laboratory. At a fixed rainfall intensity of 120 mm / h, a fixed slope of 20 掳, the runoff duration of each rainfall test was designed as 30min, different slope lengths (1 ~ 2 ~ 2 ~ 3 ~ 3 ~ 4 ~ 5 m) and different vegetation coverage (0 ~ 15 ~ 15 ~ 30 ~ 45 ~ 45 ~ 60 ~ 75m) were selected. 90%) and different fertilization treatments with blank (CK), inorganic compound fertilizer (CF), organic fertilizer (OF) were used to simulate rainfall. The results showed that: (1) under the condition of different fertilization and slope length, with the increase of vegetation coverage, the loss modulus of total phosphorus per unit projected area gradually decreased, and the decreasing trend was not obvious under the length of 1m slope. The decreasing trend of 5 m slope is the most obvious. Under different slope length conditions, with the increase of vegetation coverage, the modulus of total phosphorus loss per unit projected area reached the minimum at 90% coverage, and the maximum at bare land. (2) under different fertilization treatments, the loss modulus of total phosphorus per unit projection area was the same under the same vegetation coverage. The increment of total phosphorus loss increased with the increase of equal length of slope, and it was the smallest at 2m and the largest at 3m, which indicated that the critical slope length was 4m, and the optimum slope length was 3m. (3) under different fertilization treatments, the slope length was 3 m. The ratio of phosphorus loss to total phosphorus output in erosive phase was 30.24m 94.61.The ratio of P loss under 1m slope was less than 50%, and the rest was higher than 50%. The results showed that the loss of phosphorus in slope land was mainly carried by erosion and sediment. (4) the ratio of phosphorus loss to total phosphorus output in erosion phase was higher than that in fertilizer application condition, and compared with inorganic fertilizer application. Under the condition of organic fertilizer application, the ratio of phosphorus loss to total phosphorus output in erosive phase was higher.
【作者单位】：浙江大学土水资源与环境研究所浙江省农业资源与环境重点实验室浙江大学环境与资源学院;
【基金】：国家自然科学基金项目(41471221)
【分类号】：S157

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