施氮量对一年生黑麦草生长特性的影响

Effects of different N supply levels on Lolium multiflorum growth and yield

研究了不同施氮水平(0、100、200和300 kg/hm2,分别表示为N0、N100、N200和N300)对扬州地区一年生黑麦草产量、分蘖数、株高等生长特性及经济效益的影响。结果表明:施氮量为100,200和300kg/hm2时,黑麦草鲜草总产量分别比不施氮增产75%,146%和134%。当施氮量达到200 kg/hm2时,鲜草总产量最高为74 504 kg/hm2;施氮和刈割次数对一年生黑麦草高度、分蘖数、茎叶比等均有影响,第1次刈割时以N0株高最小,且4个施氮处理差异显著,第2次刈割时各施氮处理差异不显著。施氮肥可以显著提高一年生黑麦草经济效益,当施氮量为200 kg/hm2时,净增收益最高为8 981.44元/hm2。随施氮量增加,净增收益下降。

The effects of different N supply levels（0,100,200 and 300 kg/hm^2）on annual ryegrass growth characters and yield were determined,The results showed that the yield of annual ryegrass increased 75%、146% and 134% compared to No.The yield of annual ryegrass was highest up to 74 504 kg/hm^2 after two cuts when nitrogen application rate reached to 200 kg·hm-2.Nitrogen supply had a significant influence on heights,tiller numbers,stem/leaf and green yield/dry-matter of annual ryegrass.Economical benefit analysis showed that the profit was optimum when the nitrogen applied at the rate of 200 kg/hm^2,which achieved net profit of 8 981.4 yuan/hm^2,the highest net income up to 1 5618.36 yuan/hm^2.Net income decreased with increasing of nitrogen application.