烤烟对硫素的田间吸收利用规律研究

 应用³⁵S放射性核素标记技术,研究了烤烟对硫素的田间利用规律。结果表明:（1）烤烟在红壤上对硫酸钾肥中的硫素利用率为13.61%～37.3%. 硫素利用率随施硫量的提高而降低。（2）烤烟从施入的肥料中吸收的硫占烟株全硫量的42%～59%,不同SO₄^2-施用量处理烟株从肥料之外（空气、降水、土壤）吸收的硫量占烟株全硫量的41%～58%. 施硫对提高烟株利用土壤中的硫素具有“激发效应”。（3）烟株吸硫总量随施硫量的提高而增加;施硫水平2～10 kg/千株烟,烟叶含硫量均（S%）<0.7%. （4）红壤中全硫呈均匀分布,烤烟施肥进入土壤中的SO₄^2-离子有向中下层淋溶迁移趋势。

Study on Sulphur (S) Uptake Pattern by Flue-cured Tobacco in the Field

Sulphur absorption pattern by flue-cured tobacco in the field was studied by using ³⁵ S for isotopic tracing. the results showed that: (1) S utilization rate by flue-cured tobacco from K₂SO₄ in the field on red soil is 13.61%～37.3%. S utilization rate by the tobacco reduced as the rate of S applied increased; (2) S being absorbed by tobacco plant from fertilizer is accounted for 42%～59% of the total S content in the whole plant, S absorbed by the tobacco plant from non-fertilizer source (air, rainfall, soil) accounted for 41%～58% of total S in the plant. It has a kind of “stimulation” effect for tobacco plant to absorb S from the soil by applying S; (3) the total S quantity absorbed by tobacco plant is increasing as the quantity of S applied increasing; the level of S applied ranged from 2～10 kg/1000 plants, S content in the tobacco leaf in all treatments are less than 0.7%; (4) Sulphur is uniformly distributed in the red soils, the SO₄^2- applied to the tobacco soils intended to move down to the deeper soil layer.