Abstract:

The forage yields and nutritional quality of silage maize KD 8 and grain-forage maize Shaandan 8806 under planting densities of 4.8×10⁴, 5.85×10⁴, 6.9×10⁴, 7.95×10⁴ and 9.0×10⁴ plants ·hm^-2 were studied. The results showed that the dry matter, grain and forage nutritive yields of silage corn differed from different planting densities. Planting density had significant effects on the nutrient contents of different silage corn types. The crude protein (CP), nitrogen-free extract (NFE) and crude ash (CA) contents of plant decreased with planting density increasing. The ether extract (EE) and crude fiber (CF) contents of plant increased with the density increasing. The CP and EE yields in the seeds of silage maize were significantly lower than that in the seeds of grain-forage maize, whereas the CP and EE yields in the straw of silage maize were significantly higher than that in the straw of grain-forage maize. From the point of view of overall forage nutritive yields, the best planting density of silage corn KD 8 is 8.86×10⁴ plants ·hm^-2, and the best planting density of grain-forage maize SD 8806 is 7.77×10⁴ plants ·hm^-2.

Key words: Maize, Density, Silage, Grain-forage, Yield, Nutritional quality

摘要：

为明确不同类型青贮玉米（Zea maysL）生产的最佳群体，设置5个种植密度（4.8×10⁴，5.85×10⁴，6.9×10⁴，7.95×10⁴，9.0×10⁴株·hm^-2），研究其对青贮型玉米科多8号和粮饲兼用型玉米陕单8806饲用产量和营养品质的影响。结果表明：青贮玉米的群体干物质产量、籽粒产量和最佳饲用营养产量的最佳适宜密度不同。籽粒产量的最佳适宜密度较低，群体干物质产量的最佳适宜密度较高，而饲用营养产量的最佳适宜密度则介于二者之间。密度对不同类型青贮玉米的营养含量影响显著，植株粗蛋白（CP）、无氮浸出物（NFE）、粗灰分（CA）的含量随密度增加呈下降趋势，粗脂肪（EE）和粗纤维（CF）的含量随密度增加呈增加趋势。而密度对玉米CP，EE，NFE，CA，CF和GE等产量的影响主要通过其籽粒和秸秆干物质产量的显著差异形成。从不同品种来看，青贮型玉米籽粒中的CP和EE产量显著低于粮饲兼用型玉米，而秸秆的CP和EE产量明显高于粮饲兼用型玉米。从玉米整体饲用营养产量来看，在陕西，青贮型玉米科多8号饲用最佳适宜密度为8.86×10⁴株·hm^-2，粮饲兼用型玉米品种陕单8806饲用最佳适宜密度为7.77×10⁴株·hm^-2。

关键词: 玉米, 密度, 青贮型, 粮饲兼用型, 产量, 营养品质