红壤坡地氮溶质分层输出特征试验研究  

Experimental research on characteristics of nitrogen output from different layers in red soil slopes

作　　者：莫明浩 谢颂华 张杰 涂安国 

机构地区：[1]江西省水土保持科学研究院,江西南昌330029 [2]江西省土壤侵蚀与防治重点实验室,江西南昌330029

出　　处：《水利学报》2016年第7期924-933,共10页Journal of Hydraulic Engineering

基　　金：水利部公益性行业科研专项项目(201401051);国家自然科学基金项目(41461060;41501300);江西省水利科技项目(KT201310;KT201420;KT201213)

摘　　要：南方红壤丘陵地区降水集中且多暴雨,土层薄,易被冲刷侵蚀,坡地农林开发中以径流为载体传输的氮素面源污染对水环境造成威胁。本文利用大型土壤渗漏装置,在施肥前、施肥后、施肥后一年3个不同时期3场自然降雨事件下,对植草覆盖、干草敷盖和裸露3种处理下红壤坡面氮素随径流垂向分层输出特征进行分析。结果表明：地表径流总氮（TN）输出量各处理排序为裸露〉干草敷盖〉植草覆盖,壤中流和地下径流总氮的输出量干草敷盖〉裸露〉植草覆盖。在暴雨条件下红壤坡面径流中总氮分层输出以地下径流为主（占55.28%~95.30%）,氮素流失不仅体现在地表（占0.12%~42.16%）,更多地还体现在地下的壤中流和地下径流。植生覆盖和枯落物覆盖等水土保持措施有利于可溶性无机氮的下渗。Hilly red soil region of southern China is characterized by thin soil layer susceptible to erosionduring the period of concentrated precipitation and frequent rainstorms. Thus, non-point source pollution ofnitrogen carried by runoff in development of agriculture and forestry on slope land poses a threat to the wa-ter environment. In this paper, vertical layered output characteristics of nitrogen carried by runoff onred-soil slope were analyzed in three treatments,which were Bahia grass planting,hay mulching and bareland respectively, under three natural precipitation events which happened before, after and one year afterspreading fertilizer with the use of Drainage Lysimeter. The results showed that output amounts of TNthrough surface runoff in three treatments decreased gradually from bare land,hay mulching to grass plant-ing,and output amounts of TN through interflow and underground runoff were ranked in descending order,from hay mulching,bare land to grass planting. Under condition of rainstorm,underground runoff was maincarrier for layered output of TN in runoff on red soil slope,accounting for 55.28%~95.30%. Nitrogen losswas not only reflected in surface runoff, accounting for 0.12%~42.16%, more of which was also reflectedin interflow and underground runoff. Soil and water conservation measures such as vegetation covering anddry litter mulching could help dissolved inorganic nitrogen infiltration.

关 键 词：红壤 坡地 氮素输出 地表径流 壤中流 地下径流 

分 类 号：X143[环境科学与工程—环境科学]