施氮对胡麻磷素营养状况的影响

为了探讨氮肥运筹在调控胡麻磷素营养方面的潜力,通过2个土培试验,研究了氮肥用量及等量氮肥的施用时期、比例对胡麻磷素积累和磷素利用的影响。结果表明：施氮显著增加了植株体内的磷素积累量;0.1 g N/kg土及0.2 g N/kg土的氮肥全部作为基肥施用,成熟期植株体内的磷素积累量较不施氮肥分别提高了24.83%和34.23%;0.2 g N/kg土的氮肥,100%基肥(F₁)、2/3基肥+1/3现蕾追肥(F₂)、1/2基肥+1/2现蕾追肥(F₃)、1/6基肥+5/6枞形追肥(F₄)、1/6基肥+1/3枞形追肥+1/2现蕾追肥(F₅) 5种施用方式下,F₂、F₃、F₄、F₅的植株体内磷素积累量,较F₁,枞形、现蕾、青果和成熟期分别增加了14.17%~32.60%、9.32%~66.20%、20.47%~36.35%和4.65%~31.04%,且增幅依F₂、F₃、F₄、F₅的顺序增加;基肥追肥结合且基肥比例≤1/2的施氮方式,均有效促进了磷的吸收,F₃、F₄、F₅协助磷素累积的效果依次增加。施氮协同提高了磷素吸收效率及磷肥偏生产力;F₅比F₁、F₂、F₃、F₄,植株干物质积累量和籽粒产量分别提高了7.89%~22.02%和9.59%~26.71%,磷素吸收效率和磷肥偏生产力分别提高了10.58%~31.04%和9.59%~26.71%,磷素干物质生产效率降低了2.42%~7.43%。氮磷的吸收具有协助作用,一定范围内氮肥用量的增加提高了氮磷之间的协助作用;等剂量的氮肥,基肥和追肥结合比全部作为基肥施用可更好地发挥氮磷吸收之间的协助作用;基肥占比小于1/2、现蕾期追肥比例1/2左右,是胡麻较好的促生又促进磷素吸收累积和提高磷肥偏生产力的氮肥运筹方式,但该方式下的磷素干物质生产效率及磷素籽粒生产效率均较低。

Effects of Nitrogen Application on Phosphorus Nutrition of Oil Flax

To explore the potential of nitrogen (N) fertilizer management in regulating phosphorus (P) nutrition of oil flax, two soil culture experiments were used, and the response of P accumulation and utilization of oil flax to N fertilizer amount, application period and ratio was studied. The results showed that N application significantly increased P accumulation in plants. Compared with no N fertilizer, 0.1 g N/kg soil and 0.2 g N/kg soil, all applied as basal fertilizer, increased P accumulation in mature plants by 24.83% and 34.23%, respectively. When N fertilizer of 0.2 g N/kg soil was set in the following five application modes: 100% basal fertilizer (F₁), 2/3 basal fertilizer + 1/3 top dressing in budding period (F₂), 1/2 basal fertilizer + 1/2 top dressing in budding period (F₃), 1/6 basal fertilizer + 5/6 top dressing in fir-shaped period (F₄), 1/6 basal fertilizer + 1/3 top dressing in fir-shaped period + 1/2 top dressing in budding period (F₅), P accumulation in oil flax plants of F₂, F₃, F₄ and F₅ increased by 14.17%-32.60% (fir-shaped period), 9.32%-66.20% (budding period), 20.47%-36.35% (green fruit period) and 4.65%-31.04% (mature period), respectively, compared with that of F₁, and the increasing range was in the order of F₂, F₃, F₄ and F₅. The N application mode of basal fertilizer combined with topdressing, accompanied by basal fertilizer ratio ≤1/2, effectively promoted P absorption, and the synergy effect of F₃, F₄ and F₅ on P accumulation increased sequentially. N application synergistically improved P absorption efficiency and P fertilizer partial factor productivity. Compared with F₁, F₂, F₃ and F₄, F₅ increased plant dry matter accumulation and grain yield by 7.89%-22.02% and 9.59%-26.71%, respectively, and improved P absorption efficiency and P fertilizer partial factor productivity by 10.58%-31.04%, and increased phosphorus absorption efficiency and phosphorus partial productivity by 10.58%-31.04% and 9.59%-26.71%, respectively, reduced P dry matter production efficiency by 2.42%-7.43%. The synergy effect existed in the absorption of N and P, and the greater the N fertilizer amount within a certain range, the greater the effect was. For the same amount of N fertilizer, basal fertilizer combined with topdressing played a better role in assisting P absorption than all N was used as basal fertilizer. N fertilizer of basal application less than 1/2 with top dressing of about 1/2 in budding period is a better N fertilizer management mode, which could not only promote oil flax growth, but also improve P absorption and P fertilizer partial factor productivity. However, this way could result in a lower P use efficiency for both dry matter production and grain yield.