氮肥种类和淹水胁迫对砂姜黑土区玉米苗期生长和养分吸收的影响

采用盆栽土培方法,比较0~14 d持续淹水胁迫条件下,不同形态的氮肥以及施氮、磷和钾肥对砂姜黑土区富钾低肥土壤上种植玉米苗期植株的地上部生物量、氮、磷和钾含量与累积量的影响。结果表明,在玉米3叶1心期(淹水胁迫处理前),施硝酸钾处理地上部的生物量明显高于除施硝酸铵处理以外的其它处理(P0.05)。在3个缺素处理中,不施钾处理地上部的生物量明显低于不施磷处理(P0.05),但与不施氮处理差异不显著。在淹水胁迫过程中,施肥和淹水胁迫的交互作用影响不显著,在淹水胁迫处理7 d时,施不同形态的氮肥以及施氮、磷和钾肥显著影响玉米地上部的生物量和氮累积量(P0.05),并极显著影响磷累积量和钾累积量(P0.01);淹水胁迫也显著降低了此时玉米植株地上部的氮累积量,并极显著降低其钾累积量(P0.01),且当胁迫处理延长至14 d时,淹水胁迫还引起生物量和磷累积量的显著下降(P0.05)。延长淹水胁迫持续时间,对生物量、氮累积量和钾累积量的肥效差异与胁迫的抑制效应分别呈现加大和增强的趋势。比较F值大小可知,在淹水胁迫处理7 d时,氮肥种类是玉米地上部生物量、氮和磷累积量变化的主要诱因;而当胁迫处理延长至14d时,淹水胁迫则上升为主要决定因子。与此不同,胁迫处理开始后,淹水胁迫始终是钾累积量变化的主要决定因子。在淹水胁迫条件下,尿素可能是有利于提高富钾低肥土壤苗期玉米耐淹水胁迫性的氮肥种类。

forms fertilizers on nutrient characters of maize(Zea mays L.)seedlings under water logging stress condition in lime concretion black soil

Effects of different nitrogen forms fertilizer, and with or without phosphorus and potassium supply on nutrient charac-ters of maize ( Zea mays L. ) at seedling stage under 0~14 days of water-logging stress condition were carried out in lime con-cretion black soil by incubation experiment. The result showed that, shoot biomass of maize plants with 3rd leaves under KNO3 treatment were significantly higher than that of under the other fertilizer treatments, except of NH4NO3 treatment (P<0. 05) before water-logging stress. Shoot biomass of maize plants was affected by nitrogen, phosphorus and potassium supply, since shoot biomass of maize plants without potassium supply was significantly lower than that of maize plants without phosphorus sup-ply (P<0. 05), while there were no significant difference existed between non-potassium supply treatment and non-nitrogen supply treatment. No interaction between fertilizers and water-logging stress on growth and nutrition accumulation of maize plants was observed. Fertilization significantly affected shoot biomass, and nitrogen accumulation ( P <0. 05 ) , phosphorus and potassium accumulation (P<0. 01) on the 7th day of water-logging stress incubation. At the same time, water-logging stress greatly reduced shoot nitrogen accumulation (P<0. 05), potassium accumulation (P<0. 01), and shoot biomass and phosphorus accumulation (P<0. 05) on the 14th day of stress incubation. The effects of fertilization on shoot biomass, nitro-gen and potassium accumulation were enhanced with the stress incubation time. Fertilizer was the main factor affecting shoot bi-omass, nitrogen and phosphorus accumulation on the 7th day of stress incubation, which was replaced by water-logging stress on the 14th day of stress incubation. However, the stress was always the main factor leading to the change in potassium accu-mulation. Urea supply rather than the other nitrogen forms fertilizers was helpful to alleviate the reduction in shoot biomass and nitrogen, phosphorus and potassium accumulation.