烤烟油菜轮作及平衡施肥对土壤速效钾和烟叶钾的影响

为研究不同种类油菜与烤烟轮作以及平衡施肥处理对土壤供钾能力的提升效果，通过小区试验，采用双因素裂区设计，测定主因素（冬闲、‘重蓉油1号’、‘德油早1号’和‘GSX-1’）和副因素（常规施肥、减施氮肥和增施磷肥）下作物生长周期内土壤速效钾的变化情况以及烟叶钾含量。结果表明，烤烟油菜轮作可不同程度提高土壤速效钾含量，且在油菜移栽初期（30天）提升效果最显著，是冬闲处理的1.43~2.05倍。随着油菜生育期的推进，轮作对土壤速效钾的提升效果逐渐减弱，不同油菜种类对土壤速效钾提升效果整体表现为‘重蓉油1号’>‘GSX-1’>‘德油早1号’>冬闲。从烤烟移栽初期到收获期，土壤速效钾含量均有所下降，降幅为15.71%~117.80%。除个别处理外，烤烟油菜轮作的土壤速效钾和烟叶钾含量相较冬闲处理有所增加，且以增施磷肥提钾效果最佳。‘重蓉油1号’油菜与烤烟轮作和增施磷肥时土壤速效钾及烟叶钾含量较高，是当地最优的种植模式。

Effects of Tobacco-Rape Rotation and Balanced Fertilization on Soil Available Potassium and Potassium in Tobacco Leaves

The paper aims to study the effects of different kinds of tobacco-rape rotation and balanced fertilization on soil potassium supply capacity. A two-factor split plot experiment was designed, including main factors (winter fallow, ‘Chongrongyou 1’, ‘Deyouzao 1’and ‘GSX-1’) and by-factors (conventional fertilization, nitrogen reduction and phosphorus increase), to analyze the content of soil available potassium and potassium in tobacco leaves. The results showed that tobacco-rape rotation could improve soil available potassium content to different degrees, and the effect was the most significant in the early stage of rape transplanting (30 days), which was 1.43-2.05 times that of winter fallow treatment. With the advance of rape growth period, the effect of rotation on soil available potassium content decreased sharply, and the effect of different rape varieties on soil available potassium was as follows: ‘Chongrongyou 1’> ‘GSX-1’> ‘Deyouzao 1’> winter fallow. From the early stage of transplanting to harvest of tobacco, the content of soil available potassium decreased by 15.71%-117.80%. Except individual treatments, the content of soil available potassium and tobacco leaf potassium in tobacco-rape rotation were higher than those in winter fallow treatment, and the effect of phosphorus increase on potassium increase was the best. In conclusion, the content of soil available potassium and tobacco leaf potassium are relatively high under ‘Chongrongyou 1’- tobacco rotation and phosphorus increase, which is a good local cropping system.