不同轮作方式下蚕豆节约氮对玉米产量的影响

Effects of Spared Nitrogen by Fababean on the Yield of Successing Corn under Different Rotation System

为了评价在中国西南地区广为采用的蚕豆—玉米轮作种植体系中前茬种植蚕豆所增加的土壤氮的供给量对后茬玉米生长的影响,设计了田间二因素试验,分别在不施氮、N75kg/hm2、N150kg/hm2、N300kg/hm2四个氮水平条件下,比较前茬小麦单作、蚕豆单作和小麦/蚕豆间作处理条件下轮作玉米的产量。数据表明,在不施氮(N0)和75kg/hm2(N1)处理时,与前茬小麦单作相比,前茬单作蚕豆和小麦/蚕豆间作处理显著提高了后茬玉米棒子的产量,前茬蚕豆单作时后茬玉米棒子产量提高了21%和33%,而前茬小麦/蚕豆间作时分别提高了7%和30%,因此在外源氮供应低时蚕豆节约氮对下茬玉米的生物有效性高,从而生物固氮残留提供的氮营养增加;但随施氮量的增加,前作不同种植方式下后作玉米产量间差异不显著,表明随施氮量增加蚕豆节约氮对下茬玉米的生物有效性降低。研究认为在蚕豆-玉米轮作体系中进行氮养分资源管理时,要综合考虑轮作方式和施氮水平,以求得经济和环境效益的统一。

Field experiment has been carried out to investigate the effects of spared nitrogen by fababean on the yield of successing corn （Zea mays L.） in rotation systems,in which crop rotation consisted of wheat-maize,fababean-maize,and wheat/fababean intercrops-maize,and four different nitrogen rates applied as well. The results showed that the fresh cob yield and dry stalk yield increased significantly with nitrogen rate increased. Compared with the wheat-maize rotation,the other two rotation cropping treatments increased the fresh cob weigh yield significantly with 30%-33% when 75 kg/hm^2 nitrogen applied,and for non-nitrogen treatment at 7% and 22%,respectively. However,with nitrogen application increased,there was no significant difference of fresh cob weight among different rotation systems,which suggested that the positive bio-availability of nitrogen for successing corn may counteract by applied fertilizer nitrogen in the rotation system,therefore the cropping patterns and nitrogen applied in the pre-crops should be considered for a fertilization scenario in rotation systems in order to achieve a balance between economical benefits and sound environment.