| 黄土高原不同退耕年限刺槐林地土壤侵蚀阻力 |
| |
| 引用本文： | 孙龙,张光辉,王兵,栾莉莉.黄土高原不同退耕年限刺槐林地土壤侵蚀阻力[J].农业工程学报,2017,33(10):191-197. |
| |
| 作者姓名： | 孙龙 张光辉 王兵 栾莉莉 |
| |
| 作者单位： | 1. 中国科学院水利部水土保持研究所/黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌 712100;中国科学院生态环境研究中心/城市与区域生态国家重点实验室,北京 100085;2. 中国科学院水利部水土保持研究所/黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌 712100;北京师范大学地理学与遥感科学学院,北京 100875;3. 西北农林科技大学水土保持研究所/黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌,712100;4. 北京师范大学地理学与遥感科学学院,北京,100875 |
| |
| 基金项目： | 中国科学院"百人计划"、国家自然科学基金（41530858,41271287） |
| |
| 摘 要： | 为了明确黄土高原植被恢复后不断蓄积的枯落物对土壤分离过程的影响,论文选取10、15、20、30、40a退耕年限刺槐林样地及对照样地,采集180个土壤样品用于土壤分离试验,在6组侵蚀动力条件下进行变坡水槽冲刷试验,结果表明:随着退耕年限的增大,刺槐林土壤结构趋于稳定且疏松多孔,40年刺槐林地与对照样地相比:容重降低12.9%、总孔隙度增加10.1%、毛管孔隙度增加62.4%,土壤有机质含量增加97.9%、水稳性团聚体增加112.3%.土壤分离能力均值随着林龄呈指数函数递减(R2=0.82、P<0.05).在退耕0~40年范围内,在0~15 a内土壤分离能力下降迅速,对照、10 a刺槐林地、15年刺槐林地之间的土壤分离能力差异显著(P<0.05),退耕15 a以后土壤分离能力趋于稳定.40 a林龄刺槐林细沟可蚀性比对照的细沟可蚀性降低86.3%,临界剪切力提高10.1%.土壤临界剪切力变化范围在4.15~4.78 Pa之间.细沟可蚀性的变化趋势与土壤分离能力变化趋势相似,相比临界剪切力的变化,细沟可蚀性的变化更能反映土壤分离能力的变化情况.
|
| 关 键 词： | 侵蚀 试验 土壤 黄土高原 退耕还林 土壤分离能力 细沟可蚀性 临界剪切力 |
| 收稿时间： | 2016/9/5 0:00:00 |
| 修稿时间： | 2017/4/5 0:00:00 |
Soil erosion resistance of black locust land with different ages of returning farmland on Loess Plateau |
| |
| Sun Long,Zhang Guanghui,Wang Bing and Luan Lili.Soil erosion resistance of black locust land with different ages of returning farmland on Loess Plateau[J].Transactions of the Chinese Society of Agricultural Engineering,2017,33(10):191-197. |
| |
| Authors: | Sun Long Zhang Guanghui Wang Bing and Luan Lili |
| |
| Institution: | 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China; 2. State Key Laboratory of Urban and Regional Ecology, Research Center for Eco?Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China;,1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China; 3. School of Geography, Beijing Normal University, Beijing 100875, China;,4. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China; and 3. School of Geography, Beijing Normal University, Beijing 100875, China; |
| |
| Abstract: | Plant litter has been accumulated greatly along with vegetation restoration on the Loess Plateau. Besides covering soil surface, plant litter can be incorporated into topsoil under natural circumstances by soil splash, sediment deposition, and soil-dwelling animal activities. The distribution (covering soil surface or incorporated into surface soil) and the decomposition of plant litter can modify soil physical properties (including soil detachment capacity and soil erosion resistance) which are closely related to soil detachment process by overland flow. This study was conducted to investigate the effect of vegetation restoration on soil detachment process for black locust (Robinia pseudoacacia L.) stand with different ages of returning farmland on the Loess Plateau. The experiments were performed in the Zhifanggou small watershed (36°46''28"-36°46''42"N, 109°13''46"-109°16''03"E) in August, 2015. After a complete watershed survey, altogether 6 sampling sites were selected, including 1 corn (Zea mays L.) field and 5 black locust stands of 10, 15, 20, 30, and 40 years. Soil samples were collected from the top 5 cm soil layer using a circular steel ring with 10.0 cm diameter and 5.0 cm depth. Soil detachment was measured in a 4.0 m long, 0.35 m wide flume. Prior to the test of soil detachment capacity, soil samples were saturated in a container for 8 h and drained for 12 h. Then the soil samples were inserted into a hole (0.5 m away from the outlet of flume) on the flume bed and were scoured by flowing water under designed flow shear stress. A total of 180 soil samples were collected from different aged black locust stands and scoured under 6 flow shear stresses. In this study, 6 combinations of flow rates and slopes were applied to obtain 6 different flow shear stresses (5.4-17.4Pa) with similar intervals. Rill erodibility is defined as the increase in soil detachment capacity per unit increase in flow shear stress. Critical shear stress is a threshold parameter defined as the value above which a rapid increase in soil detachment capacity per unit increase in shear stress occurs. When the measured detachment capacity was plotted against the flow shear stress, rill erodibility and critical shear stress could be determined from the slope of the fitted straight line and its intercept on the X axis. The results showed that the density of plant litter in 0-5 cm surface soil was 0.065, 0.175, 0.316, 0.289 and 0.171 kg/m2 for 10, 15, 20, 30, and 40-year-old black locust stands, respectively, with the mean value of 0.20 kg/m2. The 40-year-old black locust stands had more capillary porosities, soil organic matter, and water stable aggregates, and smaller soil bulk density. Soil detachment capacity decreased by 49.8%, 73.9%, 85.0%, 86.0%, and 87.0% for 10, 15, 20, 30, and 40-year-old black locust stands, respectively, compared to the control. The soil detachment capacity decreased significantly over time as an exponential function (R2=0.97, P=0.006). The control (corn field) had the biggest rill erodibility (0.29 s/m), and the 40-year-old black locust stand had the smallest rill erodibility (0.04 s/m). Compared to the control, the rill erodibility for 40-year-old black locust stand was reduced by 86.3%. The black locust stand with 20 years had the biggest critical shear stress (4.78 Pa), and the control had the smallest critical shear stress (4.15 Pa). The critical shear stress increased by 10.1% for 40-year-old black locust stand compared to the control. The critical shear stress increased significantly with litter density as a linear function (R2=0.67, P=0.046). Rill erodibility was better than critical shear stress in the respect of reflecting the variation of soil detachment. The soil-plant litter system has a larger erosion resistance to flowing water than the control. Importantly, the soil-root system may have a larger structural stability and erosion resistance to flowing water than soil-plant litter system. |
| |
| Keywords: | erosion experiment soils Loess Plateau farmland afforestation soil detachment capacity rill erodibility critical shear stress |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《农业工程学报》浏览原始摘要信息 |
| 点击此处可从《农业工程学报》下载免费的PDF全文 |
|
