不同灌溉施肥条件对紫花苜蓿株高、产量及肥料利用效率的影响

Effect of different irrigation and fertilization condi⁃ tions on alfalfa plant height,yield and fertilizer utilization efficiency

摘要:

为探讨水肥耦合对科尔沁沙地紫花苜蓿人工草地产量和肥料利用效率的影响,根据联合国粮农组织推荐的 Penman-Monteith 方法,以日为步长计算紫花苜蓿实际需水量(ETc),基于 ETc 设置 4 个灌溉水平:60ET(60%ETc),80ET(80%ETc),100ET(100%ETc),120ET(120%ETc),研究不同灌溉量及施肥量对紫花苜蓿株高、产量及肥料利用效率的影响,为科尔沁沙地紫花苜蓿水肥管理提供依据。结果表明:第 1、2 茬地上生物量和总生物量的最大值均出现在 80ET,显著高于其他灌水处理; 在 120ET 灌水条件下,根冠比达到最大值,与 80ET 灌水处理无显著性差异;相同施肥量不同灌水量下 ,第 2 茬和第 3 茬株高均随着灌水量的增加逐渐增加 ,苜蓿第 3 茬株高最大 ,最大值出现在 900 kg/hm² 施肥处理,与 450 kg/hm² 施肥处理无显著性差异;肥料农学效率的最大值出现在 80ET 灌水和 450 kg/hm² 施肥水平下,显著高于相同灌水处理下的 900 kg/hm² 施肥处理,肥料偏生产力的最大值出现在 80ET 灌水和 225 kg/hm² 施肥水平下,显著高于相同灌水处理下的其他施肥处理。除 900 kg/hm² 施肥处理外,肥料农学效率和肥料贡献率随着灌水量的增加呈先升高后降低的变化趋势。

Abstract:

This research evaluated the effects of water and fertilizer regimes on alfalfa plant height，grass yield and fertilizer utilization efficiency in Horqin sandy land. According to the Penman‐Monteith method recommended by the FAO，the actual water demand (ETc) of alfalfa was calculated on a daily base. To provide the basis for alfalfa wa‐ ter and fertilizer management in Horqin sandy land，the effects of different irrigation amount and fertilization on alfalfa height，yield and fertilizer use efficiency in Horqin sandy land were measured using four irrigation levels：60ET(60% ETc)，80ET(80% ETc)，100ET(100%ETc)，120ET(120%ETc). The results showed that the maximum values of the above ‐ground biomass and total biomass on the first and second c Under the 120ET irrigation conditions，the root/shoot ratio reached the maximum，but was not significantly different from 80ET irrigation treatment. Regardless irrigation and the same fertilization conditions the plant height of the second and third crops increased steadily with the increase of the amount of irrigation. The third crop of alfalfa achieved the highest height with the maximum value in 900 kg/hm² ，but was not significantly different from 450 kg/hm2 fertilization treatment. The maximum values of fertilizer agricultural efficiency under the 80ET irrigation and 450 kg/hm² fertilization conditions ,significantly higher than 900 kg/hm² fertilization treatment under the same irrigation treatment,and the maximum value of fertilizer par‐ tial productivity under the 80ET irrigation and 225 kg/hm² fertilization conditions,significantly higher than other fertil‐ ization treatments under the same irrigation treatment.Except for 900 kg/hm² fertilization treatment,the fertilizer agri‐ cultural efficiency and fertilizer contribution rate increased first and second decrease with the increase of irrigation wa‐ ter volume.Considering the yield and fertilizer utilization efficiency，the optimum irrigation and fertilization amount in Horqin area should be 80ET and 150 kg/hm² .