目的 在大田条件下研究了白花蛇舌草对氮、磷、钾的吸收分配规律。方法 定期取样研究干物质积累规律，采用常规测定方法测定植株氮、磷、钾的量。结果 白花蛇舌草苗期对氮、磷、钾吸收较少，分枝开花期和结果期吸收量快速增加，成熟期氮、磷吸收减少，钾出现"负吸收"。白花蛇舌草植株对氮素吸收最多、钾次之、磷最少，全生育期植株对氮、磷、钾的吸收比率为1.00：0.16：0.54.苗期和分枝开花期氮、磷、钾主要积累在叶和茎中，其中氮素以叶中分配最多，磷和钾则主要分配在茎中；结果期和成熟期氮、磷、钾多分配在花果和茎中，氮和磷花果中最多，钾则茎中最高。结论 白花蛇舌草在苗期对肥料要求不多，可适当少施。分枝开花期和结果期吸收量骤增，要加大施肥用量，结果期对磷肥和钾肥要求较多，应适当补施磷肥和钾肥以满足此期果实生长的需要。

Objective The absorption and distribution of nitrogen(N),phosphorus(P),and potassium(K) of Hedyotis diffusa was studied in field tests.Methods Through regular sampling,dry matter accumulation was studied,the contents of N,P,and K were analyzed by conventional methods.Results The uptake amount of N,P,and K by H.diffusa was lower at seedling stage,but increased rapidly at branching,blossoming,and fruiting stages,and the uptake amount of N and P decreased and K was negatively absorbed at mature stage.The uptake amount of N by H.diffusa was the highest,following was K₂O,while P₂O₅ was the lowest.In the growing season of H.diffusa,the ratio of N,P₂O₅,and K₂O was 1.00:0.14:0.54.N Mainly distributed in leaf at seedling,branching,and blossoming stages,while P₂O₅ and K₂O mainly distributed in stem.The mineral nutrition mostly distributed in stem,flowers,and fruits at fruiting and mature stages,N and P₂O₅ mostly distributed in flowers and fruits,but K₂O mainly accumulated in stem.Conclusion A little fertilizer should be applied at seedling stage,oppositly the use amount of fertilizer should be increased at branching,blossoming,and fruiting stages,particularly P and K at fruiting stage.

河南省科技攻关项目(0524420022)