| 三峡库区典型退耕还林模式土壤养分流失控制 |
| 摘要点击 2573 全文点击 1342 投稿时间：2015-02-07 修订日期：2015-07-06 |
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| 中文关键词 三峡库区 退耕还林 径流 泥沙 土壤养分 流失 |
| 英文关键词 Three Gorges Reservoir Area returning farmland to forest runoff sediment soil nutrient loss |
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| 中文摘要 |
| 选择三峡库区典型退耕还林模式,包括园地(茶园)及林地(板栗)与原有坡耕地对照,观测并分析其土壤养分(氮磷)输出途径及数量情况,以评估实施退耕还林工程对流域土壤养分输出的影响. 结果表明: 1 退耕后土壤养分氮磷年流失量(包括随泥沙和地表径流流失的量)减少;总氮(TN)年输出量从大到小依次为坡耕地(2444.27 g·hm-2) >茶园地(998.70 g·hm-2) >板栗林地(532.61 g·hm-2);总磷(TP)为坡耕地(1690.48 g·hm-2)>茶园地(488.06 g·hm-2)>板栗林地(129.00 g·hm-2);与坡耕地比较,退耕还林模式(园地、林地)总氮、总磷年输出载荷分别减少了68.68%和81.75%. 2 茶园地、板栗林地与坡耕地相比,土壤养分速效态氮流失量明显减少,硝态氮(NO3--N)输出总量依次为坡耕地(113.79 g·hm-2)>茶园地(73.75 g·hm-2)>板栗林地(56.06 g·hm-2);铵态氮(NH4+-N)养分输出次序为茶园最大(69.34 g·hm-2),坡耕地次之(52.45 g·hm-2),板栗林地最小(47.23 g·hm-2). 3 硝态氮、铵态氮主要通过地表径流输出,所占总量比例分别为91.4%和92.2%;总氮和总磷主要通过泥沙输出,所占总量比例分别为86.6%和98.4%. 通过退耕还林等措施,该地区地表径流以及土壤侵蚀输出明显减少,土壤养分流失得到有效控制. |
| 英文摘要 |
| Annual soil nutrient loss characteristics on typical reforestation patterns in watershed along the Three Gorges Reservoir Area were studied based on runoff plot experiment.Runoff and sediment nutrition content from May to October 2014 of typical reforestation patterns including garden plot (tea garden), forest land (Chinese chestnut) and the original slope farmland were determined and then analyzed.The results showed that: 1 After the Returning Farmland to Forest Project the quantity of annual soil nutrient (nitrogen and phosphorus, the sum of them in sediment and runoff) loss decreased.The output of total nitrogen (TN) was in the order of slope farmland (2444.27 g·hm-2)>tea garden (998.70 g·hm-2)>Chinese chestnut forest (532.61 g·hm-2), and for total phosphorus (TP) loss was slope farmland (1690.48 g·hm-2)>tea garden (488.06 g·hm-2)>Chinese chestnut forest (129.00 g·hm-2).Compared with slope farmland, the load of TN and TP output of reforestation patterns decreased 68.68% and 81.75%, respectively.2 Compared with slope farmland, available nitrogen loss decreased in reforestation patterns.Total nitrate nitrogen (NO3--N) loss ranked in the order of slope farmland (113.79 g·hm-2)>tea garden (73.75 g·hm-2)>Chinese chestnut forest (56.06 g·hm-2).The largest amount of ammonium nitrogen (NH4+-N) was found in tea garden (69.34 g·hm-2), then in farmland (52.45 g·hm-2), and the least in Chinese chestnut forest (47.23 g·hm-2).3 The main route of NO3--N and NH4+-N loss was both through runoff, the quantity of NO3--N and NH4+-N output in which accounted for 91.4% and 92.2% of the total, respectively.The quantity of TN and TP in sediment accounted for 86.6% and 98.4% of the total.TN and TP loss showed an extremely significant correlation with sediments, which showed that sediment output was the main approach of TN and TP loss. |
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