【作者】 李娜；

【导师】 韩海荣； 尹澄清；

【作者基本信息】 北京林业大学 ， 生态学， 2004， 硕士

【摘要】 本文以江淮地区典型农业流域—六叉河流域为例，在流域尺度上系统的研究了氮、磷养分随壤中流在时间和空间的上迁移动态。研究以作物生长期内不同施肥状况下旱地和水稻田壤中流中氮、磷的迁移动态为入手点，然后结合流域地形特征，以旱地和水田为依托，对流域内有代表性的两种景观结构：旱地—水塘空间梯度系列和旱地—水稻田—水塘系列下的养分在壤中流中的迁移动态进行了研究，通过对田—塘景观梯度内氮、磷养分连续7天动态迁移变化的原位监测，来探索该类景观结构下养分迁移的动态变化规律。研究结果发现： (1) 六叉河流域在气候条件的影响下，雨量丰沛，地下水位较高，壤中流流量非常丰富且贴近地表。降雨频次和雨量决定壤中流的水量变化，降雨分布与流量变化具有高度的一致性和同步反应性，流域壤中流流量过程的主要影响因子是年降雨量及其年内分布规律。水稻田与旱地相比，壤中流要更加丰富，且受降雨影响没有旱地强烈。不同土壤深度下的壤中流流量的时空动态趋势很相近，说明壤中流流量的变化与土地类型及其特征有关。 (2) 不同氮、磷肥处理及降雨(高频暴雨、高频小雨和无雨)情况下，旱地与水田壤中流中磷、氮在水平空间与土壤垂直差异流动的量，都不与肥料多少呈正相关，且绝大多数处理间的差异不显著。影响农田壤中流养分迁移的主要因素是降雨强度和时间，旱地与水田相比壤中流养分浓度受降雨影响要更强烈。另外，较高的壤中流中氮、磷浓度值说明土壤养分借助壤中流进入相邻收纳水体，可能是除了地表径流传输外的的另一个很重要的方式。 (3) 旱地—水田—水塘系统中，土地类型与地形以及降雨共同影响着壤中流流量和养分在壤中流的迁移变化，这一过程是一个受多因素影响的复杂过程，但总体上土地类型的影响作用要更为明显。旱地-水田-水塘系统，在时间和空间共同作用下的壤中流氮、磷浓度，空间上的变化差异要比时间上的更为明显。7天内的累积壤中流中氮、磷含量的最高值出现在水稻田的外排水处，而非海拔较低的大唤塘。说明了多水塘系统对污染物的截留功能及水稻田对污染物截留和输出的双重性。 (4) 旱地—水塘系统中，油菜和西红柿样地具有较高的壤中流流量和较高的的氮磷、磷累积含量，且受降雨影响的动态变化也比较活跃，进一步验证了，农业的施肥耕种以及降雨对壤中流中氮、磷污染物含量的影响巨大。更多还原

【Abstract】 The experiment was conducted on a typical agricultural watehshed-Liu chahe watershed and studied systemically the dynamic change of nutrient in the subsurface with different time and space. The work was begun with the study the dynamic change of nutrient in the farmland and rice field during the plant growth. Then according to the geography character of the watershed as well as rely on the farmland and rice field, much work was conducted on the system of farmland-rice field -pond and farmland-pond to study on the dynamic change of nutriment in different time and different space in the various landscape. The results showed as following(1) with much precipitation and high groundwater level, Liu chahe watershed has a rich subsurface flow whose volume was consistent with precipitation and respond rapidly to the contribution of rainfall.(2) Different treatment and various rainfall hadn’t remarkable influence to the phosphorus and nitrogen concentration in time and space in farmland and rice field. This means with long farming, the content of nitrogen and phosphorus in the soil has been saturated. The high concentration of phosphors and nitrogen in subsurface flow in Liu chahe watershed indicated that the subsurface flow may make great contribution to the none point source pollution.(3) In the various landscape, farmland-rice field-pond, both the type of the land and the precipitation are the factors influenced the dynamic change of subsurface flow. But generally the type of the land has the more influence. The plot with the highest cumulative content of nitrogen and phosphorus was in the outside of the rice field which means the restrain role of pond and the double-role of rice field.(4) The high content of nitrogen and phosphorus as well as the more dynamic change of subsurface flow in tomato field and vegetable field indicted that the practice of fertilizer has a strong influence to the content of phosphorus and nitrogen in subsurface flow.更多还原