土壤调理剂施用对植烟酸化土壤pH值和烤烟根系特性的影响

为明确植烟酸化土壤施用调理剂后土壤pH值的动态变化,及其对烤烟根系特性的影响,以云南省保山市昌宁县、腾冲市的植烟酸化土壤为研究对象,采用盆栽试验,研究了石灰、木本泥炭基腐殖酸钾(腐殖酸钾)+水热法矿物钾肥(矿物钾肥)、腐殖酸钾+钙镁磷肥3种土壤调理剂组合,及硫酸钾施用对土壤pH值和烤烟根系特性的影响。结果表明:添加腐殖酸钾+矿物钾肥、腐殖酸钾+钙镁磷肥后60 d内,土壤pH值表现为先下降后逐步回升的趋势;短期内施用石灰对提高土壤pH值的效果最好,但长期来看有复酸风险。施用腐殖酸钾+矿物钾肥、腐殖酸钾+钙镁磷肥可显著(P<0.05)提高根际土壤有机酸含量、烤烟根系活力、根系ATP酶活性与地上部干物质量。在腾冲市供试土壤上,施用腐殖酸钾+矿物钾肥、腐殖酸钾+钙镁磷肥处理的烟株根系生物量较空白对照分别显著(P<0.05)增加46.09%、83.70%。结果表明,腐殖酸钾+矿物钾肥或腐殖酸钾+钙镁磷肥的土壤调理剂组合,能够减缓植烟酸化土壤继续酸化,且有利于烟株的生长发育。

Effects of soil conditioner application on pH value of acidified soil and root characteristics of flue-cured tobacco

To clarify the dynamic variations of soil pH value and the effect on the root characteristics of flue-cured tobacco of soil conditioner application in acidified tobacco-planting soil, a pot experiment was conducted with soils of Changning County and Tengchong City, Baoshan City, Yunnan Province. The used soil conditioners consisted of lime, woody peat-based potassium humate (potassium humate for short)+hydrothermal mineral potassium fertilizer (mineral potassium fertilizer for short), potassium humate+calcium magnesium phosphate fertilizer. Also, potassium sulfate was used as one treatment besides the blank control (CK). The results showed that the soil pH value presented a trend of decreasing first and then gradually increasing after the addition of potassium humate+mineral potassium fertilizer and potassium humate+calcium magnesium phosphate fertilizer within 60 d. Lime application increased soil pH in a short time, yet it tended to become more acid for the long run. The application of potassium humate+mineral potassium fertilizer and potassium humate+calcium magnesium phosphate fertilizer significantly (P<0.05) increased the rhizosphere organic acid content, root activity, root ATPase activity and above-ground biomass of tobacco. In the soil of Tengchong City, compared with CK, root biomass was significantly (P<0.05) increased by 46.09% and 83.70%, respectively, after applying potassium humate+mineral potassium fertilizer and potassium humate+calcium magnesium phosphate fertilizer.In general, the application of potassium humate+mineral potassium fertilizer and potassium humate+calcium magnesium phosphate fertilizer could slow down the acidification of the acidified tobacco-planting soil, which is also beneficial for the growth and development of tobacco plants.