基于土壤速效钾转移吸收利用系数的烤烟施钾水平研究

Study on the Potassium Application Level of Flue-cured Tobacco Based on Soil Available Potassium Absorption and Utilization Coefficient

为减肥增效,通过研究土壤速效钾吸收利用系数及烤烟钾肥利用率探讨烤烟施钾水平。结果表明,烟株对土壤速效钾的吸收利用系数在旺长期和成熟期分别为0.19和0.26,烤烟旺长期及成熟期南平土壤速效钾有效供应量分别为16.95和23.25kg/hm2,不同施钾水平对烤烟钾肥利用率有显著影响,旺长期钾肥利用率达16.58%~43.6%,成熟期达28.20%~70.79%。为达到目标产量,按16500株/hm2计,最佳施钾量为180.30kg/hm2。综合大田试验结果认为南平烟区施钾量为180.30~236.55kg/hm2较适宜。考虑到烟株生长后期钾肥略显不足,中部叶及上部叶还原糖累积偏低,且烟株仍具有一定吸收钾的能力,氮磷钾配比为1.0∶0.8∶2.1时,特别是雨量充沛的年份,打顶后追施部分钾肥有利于烟叶品质的提高。

In order to decrease the fertilizer application and improve efficiency,the research on the regulation of soil,potash fertilizer and tobacco was studied. The results showed that the absorption and utilization coefficient of soil available potassium in its vigorous stage and mature stage of tobacco were 0.19 and 0.26,respectively. The effective supply of available potassium in Nanping soil in its vigorous stage and mature stage were 16.95 and 23.25 kg/hm 2,respectively. Different potassium levels had significant effects on the utilization rate of potassium fertilizer in flue-cured tobacco. Potash fertilizer utilization rates reached 16.58%-43.6% in their vigorous stage,28.20%-70.79% in their mature stage. To achieve the target yield,the optimal potassium application rate was 180.30-236.55 kg/hm 2 based on 16 500 plants per hectare.Considering that potash fertilizer was slightly insufficient in the later period of tobacco growth,the accumulation of sugar reduction in the middle and upper leaves was low,and tobacco still had a certain ability to absorb potassium. When the ratio of nitrogen,phosphorus and potassium was 1.0 ∶0.8 ∶2.1,topdressing potash fertilizer after topping was beneficial for improving tobacco quality,especially in good rainfall years.