不同收割时间对甜玉米秸秆的营养价值和青贮发酵品质的影响

The nutrient components and ensilage fermentation quality of sweet corn stalks harvested at different times

为获得甜玉米秸秆的合理收割时间,研究了在冬季和夏季甜玉米摘穗后,其秸秆收割时间对营养成分及青贮品质的影响。在甜玉米摘穗后第0,3,6,9和12天收割并进行青贮,测定5个收割时间甜玉米秸秆的营养成分,青贮90d后测定其青贮发酵品质。结果表明,冬季不同收割时间对甜玉米秸秆的粗蛋白、粗脂肪和无氮浸出物含量无显著影响(P>0.05),但摘棒当天秸秆的可溶性碳水化合物(WSC)和粗纤维含量较高并与第9天差异显著(P<0.05),摘穗后第3天收割青贮发酵品质较好且显著优于第12天(P<0.05);夏季不同收割时间对秸秆营养成分影响较大,秸秆干物质含量随收割时间推迟显著增加(P<0.05),摘穗当天秸秆的粗蛋白和粗纤维含量最高,而WSC和无氮浸出物含量最低,摘棒当天青贮发酵品质比其他收割时间稍差(P<0.05)。甜玉米秸秆冬季在摘穗后6d内收割,夏季在摘穗后9d内收割营养价值较高;冬季摘穗后第0～6天,夏季摘穗后第3～9天调制青贮效果最好。

The effect of harvest time on nutrient components and ensilage fermentation quality of sweet corn stalks in winter and summer were investigated.The stalks were harvested and ensiled on the day of ear harvest and the 3rd,6th,9th and 12th day after the harvest of corn ears.In winter the contents of crude protein,ether extract and nitrogen free extract in stalks were not significantly different between harvest times but the contents of water soluble carbohydrates and crude fiber in stalk harvested on the day of ear harvest were significantly greater than those harvested on the 9th day after ear harvest.The best fermentation quality was obtained when stalks were harvested on the 3rd day after the ear harvest.In summer,harvest time significantly influenced the nutrient components of stalks.The dry matter content of stalks rose significantly as the harvest time was delayed.The contents of crude protein and crude fiber in stalks were greatest on the day of ear harvest,but the contents of water soluble carbohydrates and nitrogen free extract were the lowest as was the score for silage quality.Sweet corn stalks had the best nutrient quality when harvested within 6 d after ear harvest in winter and within 9 d in summer,and had the best silage quality when harvested within 6 d in winter and during 3-9 d in summer.