深松及氮肥深施对超高产春玉米根系生长、产量及氮肥利用效率的影响

Effects of Deep Loosening with Nitrogen Deep Placement on Root Growth,Grain Yield and Nitrogen Use Efficiency of Super High-yield Spring Maize

以内单314为材料,研究深松及氮肥深施对超高产春玉米生育后期根系生长、产量及氮肥利用效率的影响。结果表明,随着散粉后生育进程的推进,玉米单株根重、根系体积逐渐下降,且在同一生育期表现出随土层深度加深呈递减的趋势。0～60 cm土层单株根系表面积自散粉期开始呈先升后降的变化趋势,峰值出现在灌浆期。各处理根系活力随土层深度的增加总体上表现为先升高后下降的变化趋势,随着散粉后生育进程的推进,根系活力的峰值出现下移。深松30 cm根重、根系体积及根表面积明显增加,根系活力显著提高;深松30 cm及氮肥深施15 cm可促使根系下移,明显提高深层根系特别是20～40 cm根系活力及比重。

The effects of deep loosening with nitrogen deep placement on root growth, grain yield and nitrogen use efficiency of spring maizeat later growth stages, grown under super high-yield cultivation mode were introduced. With the growth of the advancement, root weight, root volume gradually began to decline after pollination, and demonstrated decreasing trend with the rise of soil depth in the same growth period. Plant root surface area（0 - 60 cm） appeared single apex after pollination, peak appeared at filling stage. On the whole, root activity increased at first and then de- creased with the rise of soil depth, with growth progress, activity peak appeared decreasing. Deep loosening 30 cm, root weight and root volume and root surface area and root activity significantly increased, and nitrogen fertilizer ap- plied 15 cm, promoted root growing down, and obviously improved the deep root vigor and proportion, especially for the 20 - 40 cm deep soil.