影响我国主要麦区小麦籽粒和面粉锌含量的产量构成要素与土壤肥力因素

Yield Components and Soil Factors Affecting Zinc Concentration in Wheat Grain and Flour in Major Wheat Production Regions of China

【目的】明确我国主要麦区小麦籽粒和面粉锌含量差异,研究作物与土壤因素对小麦籽粒和面粉锌含量的影响,为提升我国小麦籽粒锌营养提供依据。【方法】于2020—2021和2021—2022年两个小麦生长季,在我国17个小麦主产省/区采集421份小麦植株和土壤样品,研究小麦籽粒、面粉和麸皮锌含量与小麦产量及产量构成的关系,以及与土壤pH、有机质、硝态氮、铵态氮、有效磷、速效钾、有效态微量元素含量和施肥量的关系。【结果】我国小麦籽粒、面粉和麸皮锌的平均含量分别为28.1、10.8和60.6 mg·kg^(-1),94.8%的籽粒和89.5%的面粉样本的锌含量未达到营养学家推荐含量(40和15 mg·kg^(-1))。麦区间小麦籽粒锌含量存在差异,稻麦区最高,麦玉区和旱作区次之,春麦区最低。稻麦区,较低的土壤pH促进了土壤锌活化,有效锌含量显著高于其他麦区,较低的施磷水平也有利于锌吸收和向地上部转移,小麦籽粒和面粉锌平均含量分别为31.5和12.2 mg·kg^(-1)。麦玉区,土壤肥力较高,产量显著高于其他麦区,导致小麦籽粒与面粉锌含量相对降低,分别为27.1和10.3 mg·kg^(-1)。旱作区,较高的土壤pH影响了土壤锌的有效性和小麦对锌的吸收,籽粒与面粉锌含量较低,分别为26.5和10.1 mg·kg^(-1)。春麦区,土壤有效锌含量显著低于其他麦区,不利于小麦吸收累积锌,籽粒与面粉锌含量最低,分别为24.6和9.4 mg·kg^(-1),且随千粒重增加锌含量显著降低。【结论】提高小麦籽粒与面粉锌含量,不仅需要适宜的土壤pH、较高的有效锌水平及合理的氮磷肥调控,还需优化产量构成要素,协同提升小麦产量和籽粒、面粉锌含量。

【Objective】This study was to clarify differences of zinc(Zn)concentration in wheat grain and flour and the corresponding affecting factors over major wheat production regions,with the purpose to provide the theoretical basis for improving the Zn nutritional quality of wheat grain in China.【Method】During 2020-2021 and 2021-2022 wheat growing seasons,421 wheat and soil samples were collected from major wheat production regions in 17 provinces and autonomous regions of China,to explore the relationship of Zn concentration in wheat grain,flour and bran with wheat yield,yield components and soil properties.【Result】The average Zn concentration of the wheat grain,flour and bran was 28.1,10.8 and 60.6 mg·kg^(-1),respectively,with 94.8%of grain and 89.5%of flour samples could not meet with the recommended Zn concentration of 40 mg·kg^(-1) for grain and 15 mg·kg^(-1) for flour by nutritionists.The highest grain Zn concentration was observed in rice-wheat region(RW),followed by that in wheat-maize regions(MW)and dryland wheat region(DW),and the lowest was in spring-wheat region(SW).In rice-wheat region,the lower pH promoted the activation of soil Zn,and its availability was significantly higher than that in other regions,the lowered phosphorus fertilizer application rate was also conducive to Zn absorption and its translocation from root to the aboveground,and the average Zn concentration in wheat grains and flour was therefore as high as 31.5 and 12.2 mg·kg^(-1),respectively.In wheat-maize region,the soil fertility was higher,so that the yield was significantly greater than that in other wheat regions,resulting in relatively lower Zn concentrations in wheat grains and flour,which were 27.1 and 10.3 mg·kg^(-1),respectively.In dryland wheat region,the higher soil pH limited soil Zn availability and wheat Zn absorption,leading to the grain and flour Zn concentration being relatively lower as 26.5 and 10.1 mg·kg^(-1),respectively.In spring-wheat region,since the soil available Zn concentration was significantly lower than that in other wheat regions,which was not conducive to Zn absorption by wheat and its accumulation in grain,and therefore the Zn concentrations in grain and flour were the lowest as 24.6 and 9.4 mg·kg^(-1),respectively,while Zn concentration decreased significantly with the increase of 1000-grain weight.【Conclusion】Therefore,in order to improve the Zn concentration of wheat grains and flour,it was not only necessary to improve the soil pH,available Zn level and reasonable nitrogen and phosphorus fertilizer application,but also jointly to optimize the yield components to improve the wheat yield and grain and flour Zn concentration.