腐殖酸钾不同追施时期对土壤钾素与烤烟含钾量的影响

Effects of Different Topdressing Time of Potassium Humate on Potassium Content of Soil and Flue-cured Tobacco

【目的】探明腐殖酸钾不同追施时期对土壤钾素和烤烟含钾量的影响,为烤烟生产合理施用钾肥提供科学依据。【方法】以云烟85为试验材料,采用田间试验方法,研究常规追钾(CK,在烤烟移栽后30 d一次性施入硫酸钾225 kg/hm^(2)),在烤烟移栽后30 d、50 d和70 d各施1/3硫酸钾基础上,将剩下2/3的硫酸钾以腐殖酸钾(150 kg/hm^(2))形式分别于移栽后30 d(T_(1))、50 d(T_(2))和70 d(T_(3))追施,研究其对土壤钾素和烤烟含钾量的影响。【结果】与常规追钾处理比,腐殖酸钾追施处理烤烟移栽后90 d和120 d土壤速效钾含量分别增加3.43%-44.31%和3.93%-12.61%,移栽后120 d土壤缓效钾含量较移栽后90 d的降幅均<5%,而常规施肥处理降幅达12.55%。烤烟生育期不同部位烟叶含钾量均呈先升后降趋势,均在移栽后60 d达高峰。与常规追钾处理比,移栽后30 d追施腐殖酸钾处理采烤后下部叶含钾量提高27.31%,移栽后50 d追施腐殖酸钾和70 d追施腐殖酸钾处理采烤后各部位烟叶含钾量分别提高14.06%-36.32%和14.06%-17.59%。不同生育期各部位烟叶含钾量与土壤速效钾、缓效钾含量呈显著或极显著相关关系,且烟叶含钾量与前一时期土壤钾素含量的相关性比同一时期更显著。【结论】烤烟移栽后50 d用腐殖酸钾代替2/3硫酸钾追施效果最佳,可满足烟株整个生育期土壤钾素的供应,有效维持土壤钾素平衡和提高成熟期烟叶含钾量,从而改善烟叶品质。

【Objective】The effects of different topdressing time of potassium humate on potassium content of soil and flue-cured tobacco were discussed to provide the scientific basis for rational potassium application in production of flue-cured tobacco.【Method】The effects of CK(applying 225 kg/hm^(2) of potassium sulphate on 30th day after transplanting tobacco seedlings),T_(1)(applying 75 kg/hm^(2) of potassium sulphate and 150 kg/hm^(2) of potassium humate on 30th day after transplanting tobacco seedlings),T_(2)(applying 75 kg/hm^(2) of potassium sulphate and 150 kg/hm^(2) of potassium humate on 50th day after transplanting tobacco seedlings)and T_(3)(applying 75 kg/hm^(2) of potassium sulphate and 150 kg/hm^(2) of potassium humate on 70th day after transplanting tobacco seedlings)on potassium content of soil and flue-cured tobacco(Yunyan 85)were studied by a field experiment.【Result】The soil available potassium content of T_(1),T_(2) and T_(3) on 90th and 120th day after transplanting tobacco seedlings increased by 3.43%-44.31%and 3.93%-12.61%compared with CK respectively.The decrease range in soil slow-release potassium content of T_(1),T_(2) and T_(3) on 120th day after transplant of tobacco seedlings was less than 5%compared with on 90th day after transplant of tobacco seedlings but the decrease range in soil slow-release potassium content of CK reached 12.55%.The potassium content of tobacco leaves at different positions showed a first rising and then decreasing trend during growth period of tobacco and reached the peak on 60th day after transplant of tobacco seedlings.The potassium content in the cured lower tobacco leaves of T_(1) increased by 27.31%compared with CK.The potassium content in the cured tobacco leaves on different positions of T_(2) and T_(3) increased by 14.06%-36.32%and 14.06%-17.59%compared with CK respectively.The potassium content of tobacco leaves on different positions was significantly or very significantly related to soil available potassium and slow-release potassium content during different growth period of tobacco.The correlation between potassium content of tobacco leaves and soil potassium content at previous stage was more significant than at the same stage.【Conclusion】T_(2) with the optimal fertilization effect could meet supply of soil potassium for growth of tobacco plants during the whole growth period of tobacco,effectively maintain balance of soil potassium,increase potassium content of tobacco leaves at maturity stage and improve quality of tobacco leaves.