【摘要】 利用15N示踪技术,研究了施钾量和施钾时期对高产小麦氮素和钾素吸收利用的影响.结果表明:0～20cm土层土壤速效钾含量为118.5mg.kg-1时,一次性基施钾肥未提高植株的氮、钾积累量;速效钾含量为79.0mg.kg-1时,施钾显著提高了植株的氮、钾积累量.采用分期施钾时(1/2基施、1/2拔节期追施),随施钾量增加,小麦吸收的肥料氮和土壤氮量及追施氮肥在土壤中的残留量均增加,肥料氮的损失量降低.分期施钾显著提高了植株的氮、钾积累量、吸收效率和生产效率,当施钾量为135kg.hm-2时,与一次性施钾相比,分期施钾促进了植株对追肥氮和土壤氮的吸收,提高了追施氮肥在土壤中的残留量.结果还表明:施钾提高了小麦的籽粒产量、蛋白质含量和湿面筋含量;分期施钾处理优于一次性施钾处理,以K45+45(45kg.hm-2基施、45kg.hm-2拔节期追施)处理最优.过多施钾使小麦产量和品质趋于降低.更多还原

【Abstract】 The study with 15N tracing techniques showed that basal application of K did not increase the N and K accumulation in wheat plant when the available K content in 0～20 cm soil layer was 118.5 mg·kg-1,but increased the accumulation significantly when the soil available K content was 79.0 mg·kg-1.When the fertilizer K was 1/2 basal-applied and 1/2 top-dressed at elongation stage,the absorbed fertilizer N and soil N by plant as well as the residual N of top-dressed N in soil were increased with increasing K application rate,while the fertilizer N loss decreased.Compared with basal application,the split application of K increased the accumulated amount,uptake efficiency,and productive efficiency of N and K significantly.When the K application rate was 135 kg·hm-2,split application of K promoted the absorption of top-dressed and soil N by plant,and increased the residual N of top-dressed N in soil.The results also showed that K application increased the grain yield and its protein and wet gluten contents.At the same K application rate,split application had better effect than basal application,and treatment K45+45(45 kg·hm-2 as basal and 45 kg·hm-2 top-dressed)showed the best effect.Applying excessive K tended to decrease wheat yield and its quality.更多还原