Combined influences of wheat-seedling cover and antecedent soil moisture on sheet erosion in small-flumes
Combined influences of wheat-seedling cover and antecedent soil moisture on sheet erosion in small-flumes
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DOI：
10.1016/j.still.2015.02.006
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发表时间：
2015-08
影响因子：
6.5
通讯作者：
Jianye Li;Fengbao Zhang;Shiwen Wang;Mingyi Yang
中科院分区：
文献类型：
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作者：
Jianye Li;Fengbao Zhang;Shiwen Wang;Mingyi Yang
评估和预测土壤侵蚀需要了解前期土壤水分和植被覆盖的影响，以及它们对土壤侵蚀过程的综合影响。过去的研究通常集中在植被覆盖或前期土壤水分。尽管这些参数在野外条件下可能是相关的，但关于它们对土壤侵蚀过程的同步组合效应的研究很少。我们进行了土壤侵蚀的实验室模拟暴雨（强度77 ± 4.5 mm h−1;持续时间60 min）在轻壤质土壤在不同水平的小麦幼苗覆盖和前期土壤水分，这两个都是由不同的水喷雾应用（30，40，50，60或70 mm）在40- 44天的生长期。探讨麦苗覆盖与前期土壤水分的联合作用对土壤侵蚀的影响。麦苗覆盖度和前期土壤含水量随施水量的增加而增加，分别从9.7%增加到37.2%和从8.4%增加到12.2%。径流的最短时间观察到的中间值的覆盖和前期水分（60毫米水位）。入渗率和总入渗量一般随施水量的增加而下降。40、50和60 mm水分处理间的径流量和土壤流失量差异不显著（P> 0.05），但在70 mm水分处理下径流量和土壤流失量急剧增加。在70 mm水位下，总径流量和总土壤流失量分别比其他水位高15%~ 37%和15%~ 45%。前期土壤含水量是影响降雨入渗、径流和土壤流失的主要因素。在这项研究中，相对较低的小麦幼苗覆盖的影响被掩盖的前期土壤水分在小水槽尺度。因此，在进行土壤侵蚀评价和预测时，应综合考虑植被覆盖度和前期土壤含水量对土壤侵蚀的影响。
Assessing and predicting soil erosion requires knowledge of the influences of antecedent soil moisture and vegetation cover as well as of their combined effects on soil erosion processes. Past research typically focused on either vegetation cover or antecedent soil moisture. Even though these parameters are likely related under field conditions, studies on their synchronous combined effect on soil erosion processes are scarce. We conducted laboratory experiments on soil erosion using simulated rainstorms (intensity 77 ± 4.5 mm h−1; 60 min duration) on a light loamy soil under different levels of wheat-seedling cover and antecedent soil moisture that were both produced by different sprayed applications of water (30, 40, 50, 60 or 70 mm) during a 40- to 44-day growing period. The objective was to explore the effect of the combined effects of wheat-seedling cover and antecedent soil moisture on soil erosion. Wheat-seedling cover and antecedent soil moisture increased with applied water levels from 9.7% to 37.2% and from 8.4% to 12.2%, respectively. The shortest time to runoff was observed for intermediate values of cover and antecedent moisture (60-mm water level). Infiltration rates and total infiltration generally decreased with increases in water applications. Runoff rate and soil loss were not significantly different (P> 0.05) among the 40-, 50- and 60-mm water treatments, but abruptly increased under the 70-mm treatment. At the 70-mm level, the total runoff volume and total soil loss were, respectively, between 15% and 37% and between 15% and 45% higher than those at the other water levels were. Antecedent soil moisture was the predominant factor affecting infiltration, runoff and soil loss during the rainstorms. In this study, the effects of the relatively low wheat-seedling covers were obscured by those of the antecedent soil moisture at the small-flume scale. This suggests that the effects of vegetation cover and antecedent soil moisture on soil erosion should be considered together when assessing and predicting soil erosion.