追施氮肥对盐地碱蓬生长及其改良盐渍土效果研究

Effect of nitrogen topdressing on the growth of Suaeda salsa and the improvement of saline soil

为了研究追施氮肥对盐地碱蓬生长及其对盐渍土改良的影响,通过田间小区试验研究了不同追施氮量(0～450 kg/hm2)对盐地碱蓬生长、离子累积以及盐渍土修复的影响。结果表明,追施氮肥能够提高盐地碱蓬茎秆、籽粒和叶片的生物量;在0～450 kg/hm2范围内,盐地碱蓬的各部分生物量均随着追施氮量呈直线增长的趋势。追施氮肥对盐地碱蓬茎秆、籽粒和叶片中的K+、Na+、Ca2+、Mg2+含量无显著影响,但不同器官不同离子含量之间存在较明显的差异。追施氮肥能够增加盐地碱蓬各部分对K、Na、Ca、Mg的累积;450 kg/hm2施氮量的盐地碱蓬的各离子累积量均较不施氮显著增加。土壤表层的Na+、K+含量随着追施氮量增加而降低。总之,追施氮肥能够促进盐地碱蓬对盐渍土的生物修复,降低土壤中的Na+浓度及其危害。

The effects of topdressing different nitrogen levels on the growth of Suaeda salsa and on the im- provement of saline soil, were conducted in field experiments where growth, accumulative amounts of K＋ , Na＋ , Ca^（2＋） , and Mg^（2＋） of S. salsa, as well as salinity concentrations in soils were assessed. The yields of grain, stem, leaf and biomass increased with N topdressing. At the rate of 450 kg/ha, the biomass of component factors in S. salsa presented a linear growth trend with the amount of N topdressing. With a further increase of nitrogen application, the concentrations of K＋ , Na＋ , Ca^（2＋） , and Mg^（2＋） barely changed. The accumulative amounts of K＋ , Na＋ , Ca^（2＋） , and Mg^（2＋） increased with N topdressing. The concentrations of K＋ and Na＋ in surface soils （0-10 cm） showed decreasing trends with N topdressing. N fertilisation could therefore stimulate S. salsa growth and strengthen the effectiveness of bioremediation of saline soil.