连续多年施用硫酸钾肥对烟田土壤及烟株硫素含量的影响

为明确连续施用硫酸钾肥对烟田土壤及烟株硫含量及硫分配的影响，设置并开展了3年的硫酸钾肥定位试验。研究结果表明，根际土的有效硫含量受烤烟生育期及施肥量的影响较小，但根外土有效硫随施肥量的增加而增加，且以旺长期最高。土壤全硫含量受烟草根系及施肥量的影响，根际土中含量显著低于根外土，且两者均随施肥量的增加而显著增加（对照的根际土除外）。硫酸钾肥显著增加了叶部全硫含量及其积累量，并且随施用量的增加而增加；其对茎部的影响次之，对根部影响最小，但施肥量对成熟期各部位全硫分配率的影响较小。连续3年施用含硫量达125．4kg／hm0的肥料后，各叶位的含硫量均达到0．7％及以上。因此，应根据烟田土壤及烟叶硫含量的实际情况，合理规范硫酸钾类肥料在烟草生产中的施用量。

Effects of Successive Fertilization of Potassium Sulfate on Change of Sulfur Content in Soil and Tobacco Plant

In order to evaluate the effect of successive fertilization of potassium sulfate on change of sulfur （S） content in soil and tobacco plant, a 3 year continuous fertilization field experiment was established and analyzed. The results showed that the soil available S content in rhizosphere of tobacco changed little with the growth stages and the fertilizer rates, but it increased with the S fertilizer rates, and decreased with the growth stages in out-rhizosphere, with the highest values at the vigorous growth stage. The total soil S was significantly affected by tobacco root and the S fertilizer rate. The total S content in rhizosphere was obviously lower than that in out-rhizosphere, and both of them increased with the S fertilizer rates except for the rhizosphere soil in CK. The application of potassium sulfate fertilizer significantly increased the total S content and its accumulation in leaves, and they both increased with the S fertilizer rates in general. But it had less effect on stem, and the least on root. Moreover, the S fertilizer rate dad little influence on the distribution of total S in each part of tobacco at maturity stage. After 3 year＇s application of sulfate fertilizer with 125.4 kg/hm2 per year in this study, the total S content at different leaf positions reached at 0.7% or above, which was the critical valve affecting the quality of tobacco leave. In conclusion, the S fertilizer rates in tobacco plantation should be adjusted reasonably according to the soil condition and the S content in tobacco leaves in the future.