草业学报Issue(6)：53-63,11.DOI:10.11686/cyxb2014269
外源氮素形态对紫花苜蓿不同生育期根系特性的影响
Effects of exogenous nitrogen forms on root characteristics of alfalfa at different growth stages
摘要
Abstract
This paper reports research on the effect of exogenous nitrogen on the root characteristics of “Gan-nong No.3”Alfalfa at different growth stages.Samples were cultivated for the whole growth period using the sand culture method under the condition of complete nutrient solution.Three exogenous nitrogen forms (ni-trate nitrogen,ammonium nitrogen and nitrate nitrogen)were investigated;with the ammonium nitrogen solu-tion at 1∶1 and the others are three solution levels (CK,105,210 mg/L).Results showed that under different forms of nitrogen treatment,the root biomass,root surface area,root volume,root activity,root nodule num-ber,nodule weight,and nitrogenase activity of alfalfa are significantly higher than that of CK.With increasing nitrogen levels,there were increases in the proportions of alfalfa root biomass,root surface area,root volume, root activity,root nodule number,nodule weight and nitrogenase activity.The effects are in the following or-der:NO3 --N and NH4 +-N mixed culture the highest,followed by NH4 +-N and with NO3 --N the lowest. The impact on root average diameter was not large.The maximum values were reached by NO3 - +NH4 + with a concentration of 210 mg/L.In terms of the whole growth stage,root biomass,root surface area,root activi-ty,root nodule number,nodule weight and nitrogenase activity were significantly different during the seedling, budding and flowering stages.However,differences during seed podding and podding were not significant.关键词
紫花苜蓿/NO3--N/NH4 +-N/生育期/根系特性Key words
Alfalfa (Medicago sativa )/nitrate nitrogen/ammonium nitrogen/growing/root characteristics引用本文复制引用
刘晓静,叶芳,张晓玲..外源氮素形态对紫花苜蓿不同生育期根系特性的影响[J].草业学报,2015,(6):53-63,11.基金项目
国家自然科学基金（31460622），草业生态系统教育部重点实验室（甘肃农业大学）项目（CYZS-2011012）和甘肃省财政厅项目资助。 （）
