施钾时期对甘薯产量及钾肥利用率的影响

Effects of potassium application period on the yield and potassium utilization efficiency of sweet potato

为了明确不同时期施用钾肥对甘薯块根产量及钾肥利用率的影响,以济徐23为材料,进行大田试验。研究钾肥施用时期对甘薯块根干物质积累特性、干物质分配、钾肥利用率的影响。结果表明,不同时期施用钾肥均可提高块根产量,基施增产幅度最大,为26.09%,封垄期追施次之,高峰期追施最小。与对照处理相比,施用钾肥提高了块根膨大速率,基施和封垄期追施处理块根膨大前期增幅较大,而高峰期追施钾肥块根膨大后期增幅略高;基施处理显著降低全时期甘薯茎叶鲜重与块根鲜重的比值(T/R值),而封垄期追施处理显著降低生长中后期T/R值;施肥处理均可提高收获期块根干物质分配率,基施钾肥处理达到显著水平。基施钾肥处理钾肥产块根效率、钾肥收获指数、钾肥农学利用率和钾肥偏生产力显著高于其他施钾处理。基施钾肥通过提高钾肥农学利用率、偏生产力和钾肥收获指数,降低T/R值,促进块根膨大,最终获得高产。

Field trial was conducted to study the effect of different potassium application period on the yield and utilization efficiency of sweet potato Jixu No. 23 as experiment material,and the effect of potassium application period on the accumulation characteristic of dry matter,the distribution of dry matter and potassium utilization efficiency. The results showed that all the different potassium application periods increased storage root yield,applying potassium as basal fertilizer sharpest increased the yield by 26. 09%,followed by as top cover fertilizer,and the lowest was as top-growth peak fertilizer. Compared with the control treatment,applying potassium as basal fertilizer significantly increased the velocity of storage root; significantly reduced T / R ratio of the whole growth period,and the potassium as top cover fertilizer reduced T / R ratio of the later growth period;Three fertilizer treatments significantly improved the dry matter allocation rate at the harvest time. The potassium using efficiency,potassium harvest index,agronomic efficiency of potassium fertilizers and partial factor productivity of potassium of basal treatment were significantly higher than those of other potassium application treatments. In conclusion,applying potassium as basal fertilizer significantly increased the potassium using efficiency,potassium harvest index,agronomic efficiency of potassium fertilizers and partial factor productivity,significantly reduced the T / R ratio,increased velocity of storage root,improved the utilization rate of dry matter distribution at the harvest time and ultimately obtained the greatest increase of sweet potato yield.