水氮耦合对菘蓝耗水和土壤水分的影响

水氮耦合是菘蓝节水减氮高效的关键技术，研究水氮耦合对菘蓝耗水量和土壤水分动态变化的影响，为高效水肥管理提供理论指导。于2018和2019年在河西走廊中部张掖市民乐县益民灌溉试验站开展了菘蓝水氮耦合的试验研究。结果表明，菘蓝生长发育期内0～160 cm土层土壤贮水量呈锯齿状降低趋势。增加灌水量时土层土壤贮水量递减；适当增施氮肥可以减小土壤贮水消耗量，过量施氮增加了土壤贮水消耗量，灌水和施氮间存在明显的交互效应。高水低氮（W3N1）处理总耗水量最高，值为442.2～442.8 mm，低水中氮（W1N2）处理总耗水量最低，中水中氮（W2N2）较高水高氮（W3N3）总耗水量降幅达13.7%～14.8%。节水减氮可以降低土壤贮水消耗量、降低菘蓝生育期的耗水量，有利于水和氮在作物-土壤水分系统中良性循环。 

Effects of Water and Nitrogen Coupling on Water Consumption and Soil Moisture of Isatis indigotica

Water and nitrogen coupling is the key technology for efficient water saving and nitrogen reduction of Isatis indigotica.The study on effects of water and nitrogen coupling on water consumption and soil moisture dynamic changes of Isatis indigotica provided theoretical guidance for efficient water and fertilizer management.In 2018 and 2019，an experimental study on water and nitrogen coupling of Isatis indigotica was carried out in Yimin Irrigation Experimental Station，Minle County，Zhangye City，central Hexi Corridor.Results showed that，soil water storage in 0～160 cm soil layer showed a zigzag decreasing trend during growth and development of Isatis indigotica.Soil water storage decreased with increase of irrigation amount.Appropriate increase of nitrogen fertilizer could reduce consumption of soil water storage，excessive nitrogen increased consumption of soil water storage，and there was a significant interaction between irrigation and nitrogen application.Total water consumption of high water and low nitrogen（W3N1）treatment was the highest，with the values of 442.2～442.8 mm.Total water consumption of low water and medium nitrogen（W1N2）treatment was the lowest，and total water consumption in medium water and medium nitrogen（W2N2）and high water and high nitrogen（W3N3）decreased by 13.7%～14.8%.Water saving and nitrogen reduction could reduce consumption of soil water storage and water consumption during growth period of Isatis indigotica，which was conducive to virtuous cycle of water and nitrogen in crop-soil water system.