保护地草莓不同追肥时期15N吸收利用特点初探

 利用稳定性同位素¹⁵N 示踪技术, 研究了不同时期追肥的草莓对¹⁵N 的吸收利用和分配规律。结果表明, 花前花后各半量追施氮肥利用率最高(48.57 %) , 花后追肥利用率最低(22.92%) 。不同时期追肥, 氮素在各器官中的分配差异较大, 花前追肥, 营养器官分配率为84193 % , 花前花后各半量追肥时, 营养器官分配率65.34 % , 生殖器官34.66 % , 而花后追肥则生殖器官分配率大大提高(47.04 %) ,¹⁵N 的吸收分配随着生长中心而转移, 生长后期生殖器官对　15N 的竞争力高于营养器官。不同时期追肥, 各器官中¹⁵N对总N 的贡献率均较低。

Studies on the 15N Absorption and Utilization Characteristics of Strawberry in Different N Application Stage

The technique of stable isotope 15 N -labelled urea was used to study the rule of nitrogen absorption,utilization an d distribution of strawberry in different N application stage.The results showed that,the treatment fertilizing N before and after flower at half dose respectiv ely got the highest nitrogen utilization rate,and it was as much as 48 57%;whil e the rate of the treatment fertilizing N after flower was the lowest,it was onl y 22 92%.The rate of N -distribution in various organs existed significant dif ference in different N application stages,the rate of N -distribution in vegeta tive tissues of treatment fertilizing N before flower took up 84 93%,but the ra te of treatment fertilizing N before and after flower was 65 34%;the distri bution rate in reproductive tissues of treatment fertilizing N after flower was 47 04%,it was much higher than the other treatment.The competition ability of reproductive tissues to 15 N at the later growing period wa s higher than vegetative tissues.At every N application stage, 15 N in each organ all attributed little to total nitrogen.