根系分隔和施氮对蚕豆/玉米间作体系根系分布和形态的影响

为西北1熟制灌区豆科/禾本科间作体系高产高效提供科学依据,于2007年在甘肃省农业科学院武威绿洲农业试验站设计了蚕豆/玉米间作体系的田间根系分隔试验,研究蚕豆/玉米2种作物间根系分隔和施氮对作物根系空间分布、根系形态的影响.采用根系行分隔法进行田间作物间根系分隔,并用根钻法采集根系.蚕豆和玉米根系主要分布分别在0～40 cm浅土层和0～60 cm土层,且间作玉米根系在60～120 cm比根系分隔的多,较深根系分布有利于玉米的后期竞争恢复生长.玉米根系可以占据蚕豆地下部空间,而蚕豆的根却较少到间作玉米的地下部空间.种间互作和施氮增加了玉米和蚕豆在纵向和横向2个尺度上的根重密度、根长密度、根表面积、根系体积.蚕豆玉米间作和施氮扩展了2种作物根系纵向和横向的空间生态位,改变了作物根系形态,从而增加了作物水分和养分吸收的有效空间.

Effects of root barrier between intercropped maize and faba bean and nitrogen (N) application on the spatial distributions and morphology of crops' roots

The aim of the research is to provide a scientific basis for higher-yield and higher-efficiency of legum/cereal intercropping system based on the rhizosphere regulation in Hexi Corridor of Gansu Province.The micro-area root barrier experiment was conducted at Wuwei experimental Satation of Gansu Academy of Agricultural Sciences in 2007,in order to study the effects of root barrier and N application rates on the root spatial distribution and root morphology of intercropped faba bean and maize.The row root separation technique was used and crop roots were sampled by auger.The results showed that the roots of faba bean and maize were mainly distributed in 0-40 cm and 0-60 cm soil layer,respectively.The roots of intercropped maize at 60-120 cm soil layer were more than that of maize with root barrier,and the deeper distribution of roots of intercropped maize was in favor of competition-recovery growth at later growth stage.The roots of intercropped maize could extend the below-ground space of intercropped faba bean,and the less root of intercropped faba bean got to the below-ground space of maize.Both interspecific interactions between intercropped faba bean and maize and N application increased the root bulk density (RBD),root length density(RLD),root surface area(RSA),root volume(RV) of both crops in the vertical and horizontal directions in faba bean/mazie intercropping ecology system.Intercropping and N fertilization expanded the root spatial ecology niche of both crops in vertical and horizontal directions,and changed the root morphology of both cropsp to increase water and nutrient uptake,and resulted in higher productivity.