稀土对玉米根际土壤P形态分布及生物有效性的影响  

Effect of Rare Earth Elements on the Distribution of P forms in the Rhizosphere Soil and P Uptake by Maize Plant

作　　者：徐星凯[1] 王子健[2] 

机构地区：[1]中国科学院大气物理研究所LAPC室,北京100029 [2]中国科学院生态环境研究中心,北京100085

出　　处：《农业环境科学学报》2006年第1期148-151,共4页Journal of Agro-Environment Science

基　　金：国家自然科学基金重大项目(29890280);中国科学院引进国外杰出人才项目

摘　　要：以潮土为例,采用混合氯化稀土和氯化镧,利用根袋法进行盆栽试验,探讨了稀土对玉米根际土壤P形态分布的影响,同时结合大田试验,分析了稀土施加后植株P吸收与运移。结果表明,随稀土剂量的增加,玉米根际和非根际土壤有效P含量显著降低,相对而言根际土壤有效P含量高于非根际;当施用剂量增至100mg·kg-1风干土时,根际土壤有效P含量的富集效应显著减弱。镧和混合稀土对此具有相似性。通过有氧培养显示,随混合稀土或镧剂量的增加,玉米根际内外土壤有机P矿化所产生的有效P量呈增加趋势,根际与非根际土壤未见显著差异。稀土对苗期玉米P吸收的影响不明显,但当剂量低于10kg·hm-2时可促进大田玉米对土壤P的吸收以及体内的P向籽实运移。Pot and field trials were made to study the effects of lanthanum （La） and mixtures of rare earths （REs） on the distribution of P forms in the rhizosphere soil, P uptake and its translocation in maize plant. With increasing doses of LaCl3 and mixtures of REs chlorides to the soil （luvisol）, available P concentrations in the rhizosphere and bulk soil showed a significant reduction （P〈0.05）. The available P concentration in the rhizosphere soil was larger than that of the bulk soil （P〈0.05）, but this difference was not significant when the doses of mixtures of REs and La alone increased up to 100 mg· kg^-1 dry soil. Under aerobic conditions, the net mineralization of organic P in the rhizosphere and bulk soil increased with increasing amount of La and mixtures of REs, but no significant differences of the P mineralization in both soil zones were found among treatments. Hence, mixtures of REs and La alone had a similar effect on soil available P concentrations and P mineralization. There were no effects of rare earth（s） on the P uptake by young maize plants; however, at doses less than 10 kg·hm^-2, the addition of rare earths improved P uptake by field-grown maize and P translocation towards the grains.

关 键 词：稀土元素 根际 有效P 有机P矿化 玉米 P素吸收 

分 类 号：S143.7[农业科学—肥料学]