施氮水平对杂交狼尾草产量、品质和氮素吸收利用的影响

Effects of N Fertilization Levels on Yield,Quality and Nitrogen Uptake and Utilization

在大田种植情况下,研究4种施氮水平对杂交狼尾草产量、粗蛋白含量和氮素生产效率的影响,以及牧草产量、粗蛋白含量与施氮量和各种农艺性状的相关性。结果表明,施氮肥能显著提高杂交狼尾草的分蘖数、株高、产量和粗蛋白含量,N2、N4处理间分蘖数差异不显著,N3、N4处理间株高、干草产量和粗蛋白含量差异不显著。杂交狼尾草鲜草产量、干草产量、粗蛋白含量、分蘖数、株高和施氮量相互间都呈正相关,其中鲜草产量与施氮量、分蘖数和粗蛋白含量呈显著相关,与株高和干草产量呈极显著相关;干草产量与施氮量和分蘖数呈显著相关,与株高呈极显著相关;粗蛋白含量与施氮量也呈显著相关。杂交狼尾草在一定的施氮量范围内,随着施氮量增加,牧草的干物质积累总量、粗蛋白质产量和氮素积累总量也越多,而牧草的氮素干物质生产效率、干物质生产效率、粗蛋白质生产效率、氮素农艺效率和氮素表观回收率都逐渐降低。在施纯氮量为350～1050 kg/hm2时,杂交狼尾草的氮素表观回收率为25.73%～45.12%,氮素回收率只有16.68%～20.35%。

Field experiments were conducted to study the effects of four different N application levels on the yield,the crude protein content and the nitrogen production efficiency of hybrid Pennisetum,and the correlations of the yield and crude protein content with the N application rate and various agronomic traits were also investigated.The results showed that the N application could significantly increase the tiller number,the plant height,the yield and the content of crude protein.However,the tiller number was n...