摘要 为探讨不同氮素形态对紫花苜蓿根系生长的影响,以牧歌37CR紫花苜蓿品种为材料,采用盆栽方法,研究硝态氮(NO3--N)、铵态氮(NH4+-N)、混合态氮(NO3--N∶NH4+-N=1∶1)3种外源氮素形态的4种质量浓度水平(0、100、200、300 mg/L)处理下紫花苜蓿根系的形态特征。结果表明,与不供氮(CK)处理相比,3种氮素形态处理下紫花苜蓿的根系生物量、根表面积、根体积、根平均直径和根系全氮含量均有显著提高,而根长显著降低;随着氮素施用量的增加,同一氮素形态下的紫花苜蓿根系生物量、根平均直径和根系全氮含量均呈增加趋势,根长表现出降低的趋势。同一氮素质量浓度水平下,氮素形态对紫花苜蓿根系生物量和根表面积的影响表现为混合氮处理下最大,NH4+-N处理下次之,NO3--N处理下最低;混合态氮质量浓度为300 mg/L时,紫花苜蓿的根系生物量和根表面积达到最大值。紫花苜蓿根体积和根长表现为NH4+-N处理下最大,混合氮处理下次之,NO3--N处理下最低;NH4+-N质量浓度为300 mg/L时,紫花苜蓿的根体积达到最大值。根系全氮含量表现为NO3--N处理下最高,当NO3--N质量浓度为300 mg/L时,紫花苜蓿的根系全氮含量达到最大值。各指标之间均有不同程度的相关性,根表面积与根平均直径、根系生物量呈极显著正相关,相关系数分别达到0.773和0.914,与根体积呈显著正相关。 To explore the effects of exogenous nitrogen on the root growth of alfalfa(the variety is Mrigley 37CR),pot experiment was carried out to study the morphological characteristics of alfalfa root system under three exogenous nitrogen forms of NO3--N,NH4+-N and NO3--N∶NH4+-N at 1∶1 with four nitrogen solution levels of 0,100,200,300 mg/L.The results showed that the underground biomass,root surface area,root volume,average diameter of roots and root nitrogen content of alfalfa under three nitrogen forms were significantly higher than CK,but the root length was significantly lower than CK.Under the same nitrogen form treatment,underground biomass,average root diameter and root nitrogen content of alfalfa showed an increase trend with the increase of nitrogen application rate,however,alfalfa root length showed a decrease trend with the increase of nitrogen application rate.Under the same nitrogen level,the effect of nitrogen form on the underground biomass and root surface area of alfalfa was the largest under the mixed nitrogen treatment,followed by the NH4+-N treatment,and the lowest under the NO3--N treatment.When the mixed nitrogen concentration was 300 mg/L,the underground biomass and root surface area of alfalfa reached the maximum.The root volume and root length of alfalfa were the largest under NH4+-N treatment,followed by the mixed nitrogen treatment,the lowest under NO3--N treatment.When the NH4+-N concentration was 300 mg/L,the root volume of alfalfa reached the maximum.The root nitrogen content under NO3--N treatment was the highest,when the NO3--N concentration was 300 mg/L,the root nitrogen content of alfalfa reached the maximum.The indicators were correlated with each other in some different degrees.The root surface area was significantly positively correlated with the average root diameter and root biomass,and the correlation coefficients were 0.773 and 0.914,respectively,and the root volume was significantly positively correlated wit
机构地区 山西农业大学高寒区作物研究所
出处 《山西农业科学》 2021年第4期467-471,共5页 Journal of Shanxi Agricultural Sciences
基金 大同市科技攻关项目(20170880) 山西省农业科学院育种工程项目(17yzgc080) 山西省重点研发计划项目(201703D221012-5)。
