氮锌配施对水稻锌的吸收、累积与分配的影响

Effects of combination use of N and Zn fertilizers on absorption,accumulation and distribution of zinc in rice crop

[目的]研究不同施氮量和供锌水平对水稻锌的吸收、累积与分配的影响,为氮锌肥料配施提高水稻的锌营养提供理论依据。[方法]采用田间试验的方法,研究了2个施氮量（200和300kg·hm^-2）和3个供锌水平（0、25和50kg·hm^-2）处理对水稻（镇稻11号）锌营养的影响。[结果]水稻地上部锌含量和锌累积量均随供锌水平的提高而提高,不同的施氮量对水稻不同生育时期（分蘖期、开花期和成熟期）不同部位（叶、茎鞘、籽粒）锌含量和累积量的变化趋势存在差别。水稻各生育期各器官的锌含量变幅为20.1～50.6mg·kg^-1,除开花期和成熟期茎鞘外,低施氮量下Zn25和Zn50处理的不同生育期各器官的锌含量分别与高施氮量下Zn0和Zn25处理相近;同时,同一器官不同生育期锌含量也存在明显的变化,锌含量最高的器官为茎鞘,且不随生长中心的转移而更替。生育前期（分蘖期和开花期）茎鞘中锌的累积量最高,茎鞘中锌的分配率占全株总累积量的60%以上,生育后期（成熟期）茎鞘和籽粒中锌的积累量最高,均占40%左右。高、低施氮量下,不同供锌水平水稻成熟期锌的总累积量分别平均为504.6和496.7g·hm^-2,生产100kg籽粒吸锌量分别平均为2.30和2.20g,籽粒由再分配获得的锌占籽粒总锌量分别平均为43.2%和46.7%。各器官对锌的净吸收累积量、转移量、对籽粒锌的贡献及锌收获指数均为高氮处理高于低氮处理,且茎鞘大于叶片。[结论]提高氮肥用量有利于促进水稻植株的生长发育,促进水稻植株对锌的吸收、累积与分配,生产上应重视氮肥与锌肥之间的配合施用。

[Objectives]The aim of study was to provide a theoretical basis on zinc（Zn） absorption,accumulation and distribution of rice by combined application of nitrogen（N） and Zn fertilizers.[Methods]Field experiments were designed as three Zn levels（0,25,50kg·hm^-2Zn SO4·7H2O） and two N fertilizer rates（200kg·hm^-2,low N; 300kg·hm^-2,high N）.[Results]Results showed that the concentration and accumulation of Zn in different up-ground organs（leaf,stem,grain） of rice plants were increased with increased Zn application rate,and they were also significantly affected by N supply in different growth stages（tillering,flowering,harvest）.The concentration of Zn in various up-ground organs of rice was between 20.1 to 50.6mg·kg^-1at different growing stages.Zn concentrations in different organs of rice plants supplied with low N rate of Zn25 and Zn50 treatments were equal with those supplied with high N rate of Zn0 and Zn25 treatments,respectively,except Zn concentrations in the stem at flowering and harvest stages.Zn concentration in the same organ changed a lot at different growing stages and the highest Zn concentration was always found in stems.The accumulated Zn in stems was the highest among all organs during early growing period（tillering,flowering）,and the distribution percentage of Zn in stems was more than 60%,higher than those in other organs.In late growing period（harvest）,however,the accumulated Zn in the stems and grains were almost equal（40%）.At harvest,the totally accumulated Zn in rice plants was 504.6 and 496.7g·hm^-2,and the amount of Zn required for the formation of 100kg grain was 2.30 and 2.20g,and Zn in the grains coming from the redistribution of Zn in the rice plants（the transfer） was 43.2% and 46.7% under high N and low N application rates,respectively.The net accumulation and transportation of Zn,the contribution of Zn in plants to grain Zn and Zn harvest index which were higher in the stem than leaf,and also were higher to the high N rates than the low N rates.[Conclusions]High N application enhanced root uptake,root-toshoot translocation and remobilization of Zn,and the combined application of N and Zn fertilizers was necessary in rice production.