前茬施氮对皖草2号草产量影响的研究

Effect of last-crop nitrogen fertilizing on the grass yield of Wancao No.2

研究前茬施氮水平和施氮方式与后茬皖草2号草产量及全年草产量的动态关系。结果表明:前茬施氮能增加皖草2号的株高,尤以前茬氮肥分期施用处理最为明显。随前茬氮肥水平的加大,后茬皖草2号的鲜草、干草产量相应提高,其中前茬纯氮肥施用量达225 kg/hm2以上时,后茬皖草2号的鲜草、干草产量达到较高水平。相同施氮水平条件下,前茬氮肥分期施用比一次性基施的鲜草、干草产量高。前茬氮肥施用量的增加与氮肥分期施用均能提高小黑麦Triticale cereale—皖草2号Sorghum bicolor×S.sudanense的全年草产量,且差异达极显著水平,前茬纯氮施用量为300和375 kg/hm2且分期施用时,2茬牧草全年干草总产量均可达到较高水平,且两者之间的差异不显著。

The dynamic relations between the different nitrogen application amounts/ methods and grass yield of next-crop/whole year＇s grass yield of Wancao No. 2 were studied. The results showed that the height increased when nitrogen was used in last-crop, and the height was the highest when nitrogen was used twice. Fresh grass and hay yield of next-crop Wancao No. 2 would increase with the increase of applied nitrogen amounts. The fresh and hay yields of next-crop Wancao No. 2 reached the higher level when N fertilizer were used twice and at the level of more than 225 kg/hm^2. Fresh and hay yields of last-crop Wancao No. 2 under the treatment of twice nitrogen fertilizing were higher than those of once only. The whole year＇s dry grass yield of last-crop pasture was increased When N fertilizer was used twice and with the increase of applied nitrogen amounts, the difference was remarkable. The whole year＇s dry grass yields of last and next-crop pastures were the highest when N fertilizer was used twice and at the level of 300 and 375 kg/hm^2 , but the difference were not significant.