摘要： 在我国典型半湿润偏干旱的山西寿阳试验区,通过16年的长期定位试验,研究了不同秸秆还田方式对土壤硝态氮空间分布与累积的影响。结果表明,秸秆还田可以有效提高作物产量,同时会增加土壤氮素盈余,提高硝态氮淋失的风险;各处理土壤剖面硝态氮累积量主要集中于0～200 cm区域,在80 cm土层以下出现了明显的硝态氮累积峰;由于秸秆过腹还田处理氮素盈余最多,所以硝态氮累积量最高,在80～100 cm处和200～220 cm处出现了2个硝态氮累积峰,土壤下层硝态氮累积量明显增高,被淋失的风险增大;秸秆覆盖还田虽然累积量最少,但其在200～300 cm的累积量却占总累积量的25.63%,硝态氮淋失风险最高。

关键词: 秸秆还田, 硝态氮, 累积, 淋失风险, 旱地土壤

Abstract: To investigate the effects of different straw returning modes on spatial distribution and accumulation of nitrate nitrogen in soil，a 16-year long-term fix-location experiment has been conducted in an experimental station in Shouyang，Shanxi Province，which is located in the typical partially drought semi-humid climate zone． The results showed: Straw returning effectively elevated the crop production，and nitrogen surplus was also increased，which raised the risk for nitrogen leaching． The accumulation of nitrate nitrogen primarily occurred at 0 - 200 cm depth in longitudinal section of soil in different straw return treatments，and apparent nitrate nitrogen accumulation peaks appeared at soil depth below 80 cm． The treatment of straw return after livestock digestion brought about the largest amount of nitrogen surplus and therefore showed the highest nitrate nitrogen accumulation，with two nitrate nitrogen accumulation peaks appeared at 80 - 100 cm and 200 - 220 cm depths， respectively; the nitrate nitrogen accumulation in the lower soil layer was raised considerably， resulting in increased risk for nitrogen leaching． Although the lowest accumulation of nitrate nitrogen was seen in the treatment of straw returning by mulch， the accumulation at 200 - 300 cm depth accounted for 25． 63% of the total accumulation， suggesting the highest risk for nitrogen leaching among all treatments

Key words: Straw returning, Nitrate nitrogen, Accumulation, Leaching risk, Dryland soil

中图分类号: 

• S143.1