Abstract:

The effects of mixed sowing silage corn and fodder soybean on silage quality were investigated. The experiment was designed with three planting densities of silage corn (54 000, 62 000, 79 500 plants·hm^-2), with three mixed sowing ratios, which silage corn was mixed with fodder soybean by the number of 1:1, 1:2 and 1:3.The single sowing of silage corn was control. The results showed that when the planting density was at 62 000 and mixed sowing ratios was 1:1, NH₃-N content was the lowest. With the increase of planting density, starch content decreased. When the mixed sowing ratios increased under the same silage corn planting density, crude protein content showed a rising trend. When the planting density was 62 000 plants·hm^-2, mixed sowing ratios was 1:3, crude protein content was the highest. When the planted density was 79 500 plants·hm^-2, and mixed sowing ratios was 1:1, dry matter yield was the highest. Grey relevancy analysis was used to compare fermentation quality and nutritional quality. When the planted density was 79 500 plants·hm^-2 and mixed sowing ratios was 1:1, silage quality was the best, followed by 62 000 plants·hm^-2 planting density with mixed sowing ratios of 1:2.

Key words: Silage corn, Fodder soybean, Mixed sowing ratio, Planting density, Silage quality

摘要：

在3个青贮玉米（Zea mays）种植密度（5.4，6.2，7.95 万株·hm^-2）基础上，分别按株数1∶1，1∶2，1∶3三个比例与秣食豆（Glycine max（L.）Merr）混播，以单播为对照，探究青贮玉米种植密度及与秣食豆混播比例对青贮品质的影响。结果表明：青贮玉米种植密度为6.2万株·hm^-2，混播比例为1∶1时氨态氮含量最低，为5.42%。随青贮玉米种植密度的增加，淀粉含量呈降低趋势；在同一种植密度下，随秣食豆混播比例增加，粗蛋白质含量呈增加趋势，其中6.2 万株·hm^-2混播比例为1∶3时粗蛋白质含量最高，达到8.09%，比同一种植密度单播提高19.67%。种植密度为7.95 万株·hm^-2混播比例为1∶1时干物质含量最高，达到了28.71%。采用灰色关联度法综合比较，种植密度为7.95 万株·hm^-2混播比例为1∶1的处理得分最高，综合青贮品质最佳；其次是种植密度6.2 万株·hm^-2混播比例为1∶2的处理。

关键词: 青贮玉米, 秣食豆, 混播比例, 种植密度, 青贮品质