施氮量对全株大麦生产性能及青贮品质的影响

Effects of Nitrogen Application rate on Production Performance and Silage Quality of Whole Plant Barley

为研究施氮量对大麦(Hordeum vulagare L.)生产性能及全株大麦青贮发酵品质和营养价值的影响,本研究以‘内农科饲用大麦2号’为试验材料,采用随机区组试验设计,设置施氮量为135 kg·hm^(-2)(N_(135))、180 kg·hm^(-2)(N_(180))、225 kg·hm^(-2)(N_(225))三个处理,每个处理设置3次重复,于大麦乳熟期后进行生产性能测定并调制青贮饲料,青贮45 d后开封检测青贮品质。结果表明:随着施氮量的增加,大麦全生育期延长,N_(225)处理进入成熟期的时间比N_(135)处理延后了10天;N_(225)处理显著增加大麦的分蘖数和有效穗数;随施氮量增加,刚刈割全株大麦原料的干物质含量显著增加(P<0.05),酸性洗涤纤维的含量显著减少(P<0.05);三个施氮处理对全株大麦青贮饲料pH值、乳酸和氨态氮含量均无显著影响,Kaiser评价均为1级。综合分析,全株大麦青贮原料生产没有必要增加施肥来提升栽培成本。

The experiment was conducted to study the effects of nitrogen application rate on barley production performance,fermentation quality and nutritional value of its whole-plant silage.‘Neinongke’forage barley No.2 was used as the experimental material,and a randomized block design was used to set the nitrogen application rates of 135 kg·hm^(-2)(N_(135)),180 kg·hm^(-2)(N_(180)),and 225 kg·hm^(-2)(N_(225)).The production performance was measured and the silage was prepared after the barley milk ripening period.The silage quality was tested after 45 days since ensiling.The results showed that with the increase of nitrogen application rate,the whole growth period of barley was prolonged,and the time of entering maturity stage of the barley under N_(225)treatment was 10 days later than that under N_(135)treatment.N_(225)treatment significantly increased the number of tillers and the number of effective panicles of barley.With the increase of nitrogen application rate,the dry matter content of fresh-cut whole-plant barley increased significantly(P<0.05),and the content of acid detergent fiber decreased significantly(P<0.05).Three treatments of nitrogen application did not significantly affect the pH value,lactic acid content and ammonia nitrogen content of the whole plant barley silage,and Kaiser rating of the silage was level 1.Based on the comprehensive analysis,the nitrogen fertilizer application rate of 180~225 kg·hm^(-2)was suitable for barley silage production under dry farming conditions.