高硼植烟土壤对烤烟生长发育的影响及其钾肥调控措施

目的]探讨高硼植烟土壤对烟株生长发育的影响及钾肥对烤烟高硼毒害的缓解效果,为开展高硼植烟土壤生产优质烟叶提供科学施肥依据.方法]以烤烟品种K326为材料,通过大田试验,比较适宜硼植烟土壤(不施钾肥)及高硼植烟土壤不同施钾量(不施钾肥及分别施钾112.5、330.0和420.0 kg/ha)对烤烟生长发育、生理特性及经济效益的影响.结果]在不施钾肥的情况下,与适宜硼植烟土壤相比,高硼植烟土壤抑制烤烟的生理代谢及生长发育,烟株主要农艺性状指标、净光合速率、SPAD值、过氧化物酶(POD)活性及干物质量均显著降低(P<0.05,下同),主要病害病情指数及烟株丙二醛(MDA)含量显著升高,经济效益显著下降,呈现明显的硼毒害现象.在高硼植烟土壤条件下,与不施钾肥处理相比,各施钾处理的大多数农艺性状指标、净光合速率、SPAD值、POD活性及干物质量显著增加,MDA含量显著降低,硼毒害作用逐渐减轻,经济效益逐渐提高.其中以施钾420.0 kg/ha的经济效益最高,较高硼不施钾处理产量增加20.61%,产值增加57.50%,中上等烟比例提高21.10%(绝对值),均价提高7.17元/kg.结论]高硼植烟土壤会抑制烟株的生理代谢及生长发育,增施钾肥可缓解烤烟受到的硼毒害,进而提高经济效益.其中以增施420.0 kg/ha钾肥的效果较佳.

Effects of high-boron soil planting tobacco on growth of flue-cured tobacco and potassium fertilizer regulation measures

Objective]The aim of this study was to investigate the effects of high boron content in tobacco-planted soil on growth and development of tobacco and mitigation effects of potassium fertilizer on high boron toxicity to provide scientific fertilization basis for producing high quality flue-cured tobacco in high-boron soil.Method]Taking K326,a flue-cured tobacco cultivar,as material,a field experiment was conducted to compare soil with suitable boron content(no potassium application)with different application rates of potassium(no potassium application,potassium fertilizer 112.5 kg/ha,potassium fertilizer 330.0 kg/ha and potassium fertilizer 420.0 kg/ha)in high-boron soil in effects on the growth, physiological characteristics and economic benefit of tobacco.Result]Soil with high boron content significantly inhibited the physiological metabolism and growth of flue-cured tobacco compared with that of suitable boron content soil under no application of potassium. The main agronomic characters ,net photosynthetic rate ,SPAD value ,peroxidase(POD) activity and dry matter content of flue-cured tobacco were significantly reduced(P<0.05,the same below),the disease indexes of main diseases and malondialdehyde(MDA)content of tobacco were increased significantly,the economic bene-fit decreased significantly and the phenomenon of boron toxicity was obvious. Application of potassium fertilizer in high-boron soil could reduce the toxic effect of high-boron soil planting tobacco,which the most of agronomic characters,net photosynthetic rate,SPAD value,POD activity,and dry matter content was significantly increased,economic benefit gradually enhanced and leaf MDA was significantly decreased as compared with those of treatment with no potassium application. Among them,potassium 420.0 kg/ha treatment achieved the highest economic benefit,the yield increased by 20.61%compared with high boron no potassium application treatment,the output value increased by 57.50%,the propor-tion of high-middle quality tobacco increased by 21.10%(absolut value),and the average price increased by 7.17 yuan/kg.Conclusion]High boron soil which plants tobacco inhibites the physiological metabolism and growth of flue-cured tobac-co,and the application of potassium fertilizer can alleviate boron toxicity from flue-cured tobacco,and then increase the economic benefits. The optimum potassium application rates is 420.0 kg/ha.