施氮量对新疆滴灌冬小麦根系生长及产量的影响

为探明滴灌冬小麦高产需氮肥规律,利用大田试验研究了N_0(0 kg·hm~(-2))、N_1(90kg·h~(-2))、N_2(180kg·h~(-2))、N_3(270kg·h~(-2))、N_4(360kg·h~(-2))施氮量对新冬18号0~60cm土层根系生长的影响及其与产量和氮肥利用率的关系。结果表明,随着施氮量的增加,拔节至成熟期间0~60cm土层根系干重、根长和根系活力均增加,N_3处理孕穗期小麦0~60cm土层根干重、根长分别较N_0处理增加11.93%、29.0%,增幅基本表现为0~20cm20~40cm40~60cm土层;N_3处理较N_0处理小麦产量增加30.35%,氮肥农学利用效率为6.90kg·kg-1。拔节期前后施适量氮肥可促进0~60cm土层根系生长和活力增强,是氮肥增产的重要原因。本试验条件下最适宜施氮量为180~270kg·h~(-2),可获得产量7 591.49~8 004.85kg·h~(-2),氮肥农学利用效率为6.90~8.06。

Effects of Nitrogen Application on the Growth of Root and Yield of Winter Wheat under Drip Irrigation

To verify the effects of nitrogen application on the growth of root and yield of winter wheat under drip irrigation,five different nitrogen application treatments:N₀(0 kg·hm^-2),N₁(90 kg·hm^-2),N₂(180 kg·hm^-2),N₃(270 kg·hm^-2),and N₄(360 kg·hm^-2) were conducted.In the field experiments,effects of different nitrogen application treatments on root growth in 0-60 cm soil layers and the relationship between the yield and nitrogen use efficiency were studied. The results showed that:with the increase of nitrogen application,the dry weight,length and vitality of root in 0-60 cm layers was increased from jointing to maturity stages; the dry weight and length of root in 0-60 cm layers at booting stage under N₃ treatment were increased by 11.93% and 29.0%,respectively,compared to those under N₀ treatment,with an increase amplitude ranged as 0-20 cm > 20-40 cm > 40-60 cm soil layers; the yield under N₃ treatment was increased by 30.35% and the AEN was 6.90 kg·kg^-1. The appropriate amount of nitrogen fertilizer application promoted root growth and strong vitality in 0-60 cm layers before and after jointing stage,and it was an important factor for production increase. In this experiment,the optimum amount of nitrogen was 180-270 kg·hm^-2,and the yield was 7 591.49-8 004.85 kg·hm^-2,with the AEN of 6.90-8.06.