种植密度对不同夏玉米品种饲用和青贮品质的影响

Effect of Planting Density on Feeding and Silage Quality of Different Summer Maize Hybrids

以登海605(DH605)、京农科728(JNK728)和山农饲玉2号(SY2)为试验材料,设置3个种植密度60000株/hm^(2)、75000株/hm^(2)和90000株/hm^(2)(记作D6、D7.5和D9),研究种植密度对不同夏玉米品种不同收获期及不同器官饲用和青贮品质的影响。研究结果表明,随着种植密度增加,DH605的鲜物质和干物质产量显著提高,D9密度下的鲜物质和干物质较D6分别增加17.32%和23.19%,较D7.5分别增加6.26%和7.13%;JNK728和SY2的鲜物质和干物质产量呈现先增加后降低的趋势。蜡熟期进行收获和青贮,玉米的饲用价值最高,以D7.5密度为例,DH605蜡熟期玉米粗饲料分级指数分别较乳熟期和完熟期增加8.31%和27.80%,JNK728分别增加12.55%和75.52%,SY2分别增加7.13%和58.10%;同时瘤胃降解率最高,各品种趋势一致。果穗青贮的饲用品质较秸秆青贮显著提高。本试验研究结果,DH605的最佳种植密度为90000株/hm^(2),JNK728和SY2的最佳种植密度为75000株/hm^(2),在蜡熟期进行收获和青贮效果最好。

Denghai 605(DH605),Jingnongke728(JNK728),and Shannongsiyu 2(SY2)were used as experimen⁃tal materials,and 3 planting densities:60000,75000 and 90000 plants/ha(D6,D7.5 and D9)were designed to ex⁃plore the effects of planting density on the feeding and silage quality of different summer maize hybrids at different harvest stages and different organs.The results showed that the fresh matter and dry matter yield of DH605 in⁃creased significantly with the increase of planting density,and the fresh and dry matter of D9 were increased than that of D6 by 17.32%and 23.19%and by 6.26%and 7.13%than that of D7.5,respectively;and that of JNK728 and SY2 increased first and then decreased.The maize harvest and silage at the dough stage had the highest feed value and rumen degradation rate,and the trend of each hybrid was the same.With D7.5 as an example,the roughage grading index of DH605 at the dough stage was increased by 8.31%and 27.80%;that of JNK728 increased by 12.55%and 75.52%;that of SY2 increased by 7.13%and 58.10%than that at milking stage and full ripening stage,respectively.The feeding quality of ear silage was significantly higher than that of straw silage.Therefore,the opti⁃mal planting density of DH605 was 90000 plants/ha,and that of JNK728 and SY2 was 75000 plants/ha,and the ef⁃fect of harvesting and silage at the dough stage was the best.