钾肥追施对植烟红壤供钾能力及烟叶钾含量的影响

Effects of Topdressing Potassium Fertilizer on Potassium Supply of Red Soil and Potassium Content in Tobacco Leaves

为探讨钾肥类型及不同用量追施对植烟红壤钾素供应、烤烟生长以及烟叶含钾量的影响,采用田间小区试验,在钾肥常规施用量和减施50%条件下,设置揭膜上厢肥(120 kg/hm^(2))、包膜硫酸钾(120 kg/hm^(2))、包膜硫酸钾(60 kg/hm^(2))、炭载揭膜上厢肥(60 kg/hm^(2))和炭载硫酸钾(60 kg/hm^(2))5个处理,研究了不同类型钾肥及用量对烤烟农艺性状、干物质量、烟叶含钾量以及土壤水溶性钾、速效钾和缓效钾供应的影响。结果表明:在常规施肥水平下,包膜硫酸钾具有明显的缓释效果,提高烟叶钾含量效果明显;在钾肥减施50%条件下,包膜硫酸钾和炭载揭膜上厢肥均能有效促进烟株生长发育,提高烟株干物质积累,且炭载揭膜上厢肥能有效提高土壤钾素有效性,其烤烟中、下部叶含钾量显著提高19.38%~40.15%、12.94%~32.49%。综上,在减量钾肥追施50%条件下(60 kg/hm^(2)),炭载揭膜上厢肥是钾肥追施最佳方案,可在生产中推广应用。

A field plot experiment was conducted to investigate the effects of different types and application rates of potassium fertilizer on potassium supply in red soil,tobacco growth,and potassium content in tobacco leaves.Considering the conventional and 50%reduced application rates of potassium fertilizer,we designed five treatments:application of fertilizer at 120 kg/hm^(2) during film uncovering and hilling,application of coated potassium sulfate at 120 kg/hm^(2),application of coated potassium sulfate at 60 kg/hm^(2),application of charcoal-loaded fertilizer at 60 kg/hm^(2) during film uncovering and hilling,and application of charcoal-loaded potassium sulfate(60 kg/hm^(2)).The agronomic traits,dry matter accumulation,and potassium content in leaves of tobacco,as well as the watersoluble potassium,available potassium,and slow-release potassium supply in soil,were studied.The results showed that under the conventional application rate,coated potassium sulfate presented significant slow release and increased the potassium content in tobacco leaves.Under 50%reduced application,both coated potassium sulfate and charcoal-loaded fertilizer applied during film uncovering and hilling promoted the growth and development of tobacco plants and increased dry matter accumulation.Moreover,the application of charcoal-loaded fertilizer during film uncovering and hilling effectively improved the potassium availability in soil and increased the potassium content in the middle and lower leaves of tobacco by 19.38%-40.15%and 12.94%-32.49%,respectively.In summary,under the 50%reduced application of potassium fertilizer(60 kg/hm^(2)),the best solution for potassium fertilizer application was charcoal-loaded fertilizer applied during film uncovering and hilling,which can be promoted and applied in production.