【作者】 张怀志；

【导师】 张维理；

【作者基本信息】 中国农业科学院 ， 农业面源污染， 2005， 博士后

【摘要】 本研究在分析已有研究方法的基础上，结合上海水源保护区沟渠纵横，河网密布，作物种植类型较多，轮作模式多样等特点，利用区域尺度多点位成组样本试验、渗漏池试验和径流池试验等方法，通过对采集水样中NO₃—N、NH₄—N、TN和水溶性TP测试分析，并综合考虑降雨过程、施肥、作物类型、种植模式等影响因子，研究了水源保护区内的农田氮磷运移规律，同时对该区域的农田氮磷流失监测评价方法进行了探讨。本研究表明用区域尺度多点位成组样本的方法，可以了解作物类型、生长季节对氮磷流失影响。此研究方法与径流试验和渗漏试验方法相结合，可以较为准确量化点位条件下的氮磷流失潜力。集约化菜地农田总氮和水溶性总磷流失系数分别为7.32％和0.27％，而大田作物稻麦轮作模式的氮磷流失系数分别为0.442％和0.12％，即集约化菜地的氮磷流失系数是稻麦轮作的15倍和2倍；本研究的另一个试验证明，集约化菜田田面水的TN和水溶性TP的浓度同样高于大田作物。两个试验结论证明集约化菜田的氮磷流失潜力要大于大田作物田块；本研究渗漏试验表明，农田氮渗漏流失系数不超过2％，水溶性总磷流失系数不超过0.3％。试验表明总氮和水溶性总磷流失与降雨季节相关。点位特征试验表明，降雨量相对集中季节总氮和水溶性总磷浓度高于降雨相对分散季节，如田面水水溶性总磷，前个降雨条件导致的流失浓度是后者的2～5倍，河水约为2倍；径流试验也有类似结论，不过不排除施肥量和施肥时期对流失的影响。初步获得了水源保护区农田径流系数和渗漏系数，证明了NO₃—N是氮流失的主要形态。试验表明水源保护区单季作物径流系数从10.15～49.39％，西岑、朱家角和马桥三个点位径流系数分别为15.1％、30.6％和22.4％，本研究还表明小麦生长季节径流系数要小于水稻生长季节。塌菜、卷心菜和大麦三季作物的渗漏系数分别为55.1％、54.6％和56.6％，三者差异不大，这也表明水源保护区约有一半以上的降雨通过渗漏途径进入地下水，其携带的氮磷是造成地下水水质变化的重要原因。径流试验中NO₃—N占总流失氮量的24～53％，渗漏试验NO₃—N占总流失氮量的23～70.5％，两个试验都表明NO₃—N流失量在总氮中比例要远高于NH₄—N在总氮中的比例。更多还原

【Abstract】 In this paper the loss pattern of nitrogen and phosphorus from the fields in the riverhead protect region of Huangpu upriver are studied based on the planting patterns, high-density water distributing and other related local status by collecting and analyzing the content of NO₃-N, NH₄-N, total nitrogen and soluble total phosphorus of the water samples. Effecting factors such as raining process, fertilization, crop types are all considered. Determining and evaluating methods of the loss pattem of nitrogen and phosphorus from field are also discussed in the paper.It is showed that multi-points group samples in regional area can be used to reveal the effect of crop types and its growing seasons on the nitrogen and phosphorus loss. The loss potential of nitrogen and phosphorus can be quantified by this method when it’s studied combining with runoff and infiltration experiments.The loss rates of total nitrogen and total soluble phosphorus from the vegetable fields are respectively 7.32 and 0.27. They are 15 and 2 times of that from the rice-wheat rotation fields which are 0.442 and 0.12 respectively. And the concentrations of total nitrogen and total soluble phosphorus in the top-water of the vegetable fields are also higher than that of crop fields. The infiltration experiment shows that the infiltrating loss rates of nitrogen and the soluble phosphorus are less than 2% and 0.3% respectively.The study also shows that the losses of nitrogen and the soluble phosphorus are related to the growing seasons. In high-rainfall seasons the concentrations of nitrogen and the soluble phosphorus are much higher in both the top-water of the fields and river water compared with low-rainfall seasons, which is 2-5 times and 2 times respectively for the soluble phosphorus. Same conclusion on the losses of nitrogen and phosphorus can be gained with the runoff experiment while it is maybe affected by fertilization.The research gets the runoff and infiltrating loss rate from fields of riverhead protect region of Huangpu upriver. And nitrate is the main loss form of nitrogen. The study also shows that the rtmoff loss rate of single crop is 10.15-49.39%, which is 15.1%, 30.6% and 22.4% in the Xicen, Zhujiajiao and Maqiao respectively. And the runoff loss rate of wheat is higher than that of rice. The infiltration rates of Chinese flat cabbage, cabbage and barley are 55.1%, 54.6% and 56.6% respectively which there are not great difference among them. This indicates that about half of rainfall loss from infiltrating to groundwater. And the nitrogen and phosphorus in this part of water are one of the leading causes to groundwater pollution. The loss rates of nitrate in the runoff and infiltration experiments are 24～53% and 23～70.5% respectively, which is all higher than the loss of NH₄-N.更多还原